bump version to 0.6

This reverts commit dda63d68cde58c7f4a7162b11a2fd614365d36ff.

Makefile

@@ -1,6 +1,6 @@
 .PHONY: *
 
-TSC_SCRIPT_FLAGS = --lib es2020 ./src/extern.d.ts
+TSC_SCRIPT_FLAGS = --lib es2020 ./src/extern/qt.d.ts
 
 config:
 	mkdir -p ./package/contents/config

README.md

@@ -16,19 +16,27 @@ scrolled through horizontally.
 Similar window managers include [PaperWM](https://github.com/paperwm/PaperWM) and
 [Cardboard](https://gitlab.com/cardboardwm/cardboard).
 
+## Dependencies
+Karousel requires the following QML modules:
+- QtQuick 2.15
+- org.kde.kwin 3.0
+- org.kde.notification 1.0
+
 ## Limitations
 - Doesn't support multiple screens
 - Doesn't support windows on all desktops
 - Doesn't support windows on multiple activities
 
 ## Key bindings
+The key bindings can be configured in KDE System Settings among KWin's own keyboard shortcuts.
+Here's the default ones:
 | Shortcut                 | Action                                                                                                                         |
 | ---                      | ---                                                                                                                            |
 | Meta+Space               | Toggle floating                                                                                                                |
 | Meta+A                   | Move focus left                                                                                                                |
-| Meta+D                   | Move focus right                                                                                                               |
-| Meta+W                   | Move focus up                                                                                                                  |
-| Meta+S                   | Move focus down                                                                                                                |
+| Meta+D                   | Move focus right (Clashes with default KDE shortcuts, may require manual remapping)                                            |
+| Meta+W                   | Move focus up (Clashes with default KDE shortcuts, may require manual remapping)                                               |
+| Meta+S                   | Move focus down (Clashes with default KDE shortcuts, may require manual remapping)                                             |
 | Meta+Home                | Move focus to start                                                                                                            |
 | Meta+End                 | Move focus to end                                                                                                              |
 | Meta+Shift+A             | Move window left (Moves window out of and into columns)                                                                        |
@@ -37,14 +45,13 @@ Similar window managers include [PaperWM](https://github.com/paperwm/PaperWM) an
 | Meta+Shift+S             | Move window down                                                                                                               |
 | Meta+Shift+Home          | Move window to start                                                                                                           |
 | Meta+Shift+End           | Move window to end                                                                                                             |
-| Meta+X                   | Expand window (Expands focused window vertically; toggles stacked layout for focused column)                                   |
+| Meta+X                   | Toggle stacked layout for focused column (One window in the column visible, others shaded; not supported on Wayland)           |
 | Meta+Ctrl+Shift+A        | Move column left                                                                                                               |
 | Meta+Ctrl+Shift+D        | Move column right                                                                                                              |
 | Meta+Ctrl+Shift+Home     | Move column to start                                                                                                           |
 | Meta+Ctrl+Shift+End      | Move column to end                                                                                                             |
-| Meta+Ctrl+X              | Expand column (Expands focused column horizontally to fill the screen)                                                         |
-| Meta+Alt++               | Expand fully visible columns (Expands fully visible columns to fill the screen)                                                |
-| Meta+Alt+-               | Shrink visible columns (Shrinks fully and partially visible columns, making them fully visible and filling the screen)         |
+| Meta+Ctrl++              | Increase column width                                                                                                          |
+| Meta+Ctrl+-              | Decrease column width                                                                                                          |
 | Meta+Alt+Return          | Center focused window (Scrolls so that the focused window is centered in the screen)                                           |
 | Meta+Alt+A               | Scroll one column to the left                                                                                                  |
 | Meta+Alt+D               | Scroll one column to the right                                                                                                 |
@@ -52,7 +59,7 @@ Similar window managers include [PaperWM](https://github.com/paperwm/PaperWM) an
 | Meta+Alt+PgDown          | Scroll right                                                                                                                   |
 | Meta+Alt+Home            | Scroll to start                                                                                                                |
 | Meta+Alt+End             | Scroll to end                                                                                                                  |
-| Meta+[N]                 | Move focus to column N                                                                                                         |
+| Meta+[N]                 | Move focus to column N (Clashes with default KDE shortcuts, may require manual remapping)                                      |
 | Meta+Shift+[N]           | Move window to column N (Requires manual remapping according to your keyboard layout, e.g. Meta+Shift+1 -> Meta+!)             |
 | Meta+Ctrl+Shift+[N]      | Move column to position N (Requires manual remapping according to your keyboard layout, e.g. Meta+Ctrl+Shift+1 -> Meta+Ctrl+!) |
 | Meta+Ctrl+Shift+F[N]     | Move column to desktop N                                                                                                       |

generators/docs/keyBindings.ts

@@ -1,4 +1,4 @@
-interface KeyBinding {
+type KeyBinding = {
     name: string;
     description: string;
     comment?: string;
@@ -6,7 +6,7 @@ interface KeyBinding {
     action: string;
 }
 
-interface NumKeyBinding {
+type NumKeyBinding = {
     name: string;
     description: string;
     comment?: string;

package/contents/code/main.qml

@@ -1,5 +1,6 @@
 import QtQuick 2.15
 import org.kde.kwin 3.0
+import org.kde.notification 1.0
 import "./main.js" as Karousel
 
 Item {
@@ -9,11 +10,19 @@ Item {
 
     Component.onCompleted: {
         qmlBase.karouselInstance = Karousel.init();
-        print("script started");
     }
 
     Component.onDestruction: {
         qmlBase.karouselInstance.destroy();
-        print("script stopped");
+    }
+
+    Notification {
+        id: notificationInvalidWindowRules
+        componentName: "plasma_workspace"
+        eventId: "notification"
+        title: "Karousel"
+        text: "Your Window Rules JSON is malformed, please review your Karousel configuration"
+        flags: Notification.Persistent
+        urgency: Notification.HighUrgency
     }
 }

package/contents/ui/config.ui

@@ -11,19 +11,16 @@
         <layout class="QVBoxLayout" name="layout_main">
             <item>
                 <widget class="QTabWidget" name="tabContainer">
-                    <widget class="QWidget" name="tab_general">
+                    <widget class="QWidget" name="tab_parameters">
                         <attribute name="title">
-                            <string>General</string>
+                            <string>Parameters</string>
                         </attribute>
-                        <layout class="QGridLayout" name="layout_tab_general" columnstretch="0,1">
+                        <layout class="QFormLayout">
                             <item row="0" column="0">
                                 <widget class="QLabel" name="label_gapsOuterTop">
                                     <property name="text">
                                         <string>Top margin:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="0" column="1">
@@ -45,9 +42,6 @@
                                     <property name="text">
                                         <string>Bottom margin:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="1" column="1">
@@ -69,9 +63,6 @@
                                     <property name="text">
                                         <string>Left margin:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="2" column="1">
@@ -93,9 +84,6 @@
                                     <property name="text">
                                         <string>Right margin:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="3" column="1">
@@ -117,9 +105,6 @@
                                     <property name="text">
                                         <string>Horizontal gaps between windows:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="4" column="1">
@@ -141,9 +126,6 @@
                                     <property name="text">
                                         <string>Vertical gaps between windows:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="5" column="1">
@@ -165,9 +147,6 @@
                                     <property name="text">
                                         <string>Overscroll amount:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="6" column="1">
@@ -189,9 +168,6 @@
                                     <property name="text">
                                         <string>Manual scroll step size:</string>
                                     </property>
-                                    <property name="alignment">
-                                        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
-                                    </property>
                                 </widget>
                             </item>
                             <item row="7" column="1">
@@ -208,28 +184,164 @@
                                 </widget>
                             </item>
 
-                            <item row="8" column="1">
-                                <widget class="QCheckBox" name="kcfg_stackColumnsByDefault">
+                            <item row="8" column="0">
+                                <widget class="QLabel" name="label_offScreenOpacity">
                                     <property name="text">
-                                        <string>Stack columns by default</string>
+                                        <string>Obscured window opacity:</string>
                                     </property>
                                 </widget>
                             </item>
+                            <item row="8" column="1">
+                                <widget class="QSpinBox" name="kcfg_offScreenOpacity">
+                                    <property name="suffix">
+                                        <string> %</string>
+                                    </property>
+                                    <property name="maximum">
+                                        <number>100</number>
+                                    </property>
+                                    <property name="value">
+                                        <number>0</number>
+                                    </property>
+                                </widget>
+                            </item>
+                        </layout>
+                    </widget>
 
-                            <item row="9" column="0" colspan="2">
-                                <spacer name="bottomSpacer_tab_general">
+                    <widget class="QWidget" name="tab_behavior">
+                        <attribute name="title">
+                            <string>Behavior</string>
+                        </attribute>
+                        <layout class="QVBoxLayout">
+                            <item>
+                                <widget class="QGroupBox">
+                                    <property name="flat">
+                                        <bool>true</bool>
+                                    </property>
+                                    <layout class="QVBoxLayout">
+                                        <item>
+                                            <widget class="QCheckBox" name="kcfg_untileOnDrag">
+                                                <property name="text">
+                                                    <string>Un-tile windows by dragging them</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QCheckBox" name="kcfg_stackColumnsByDefault">
+                                                <property name="text">
+                                                    <string>Stack columns by default</string>
+                                                </property>
+                                                <property name="toolTip">
+                                                    <string>New columns start in stacked mode (one window in the column visible, others shaded). Not supported on Wayland.</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QCheckBox" name="kcfg_resizeNeighborColumn">
+                                                <property name="text">
+                                                    <string>Resize neighbor column on edge resize</string>
+                                                </property>
+                                                <property name="toolTip">
+                                                    <string>When resizing a column by dragging its edge, also inversely resize the column on the other side of the edge</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QCheckBox" name="kcfg_reMaximize">
+                                                <property name="text">
+                                                    <string>Re-maximize tiled windows</string>
+                                                </property>
+                                                <property name="toolTip">
+                                                    <string>Restore maximized and full-screen states of tiled windows on focus</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QCheckBox" name="kcfg_skipSwitcher">
+                                                <property name="text">
+                                                    <string>Tiled windows skip switcher</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                    </layout>
+                                </widget>
+                            </item>
+
+                            <item>
+                                <widget class="QGroupBox">
+                                    <property name="title">
+                                        <string>Scrolling mode</string>
+                                    </property>
+                                    <layout class="QVBoxLayout">
+                                        <item>
+                                            <widget class="QRadioButton" name="kcfg_scrollingLazy">
+                                                <property name="text">
+                                                    <string>Only scroll as necessary</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QRadioButton" name="kcfg_scrollingCentered">
+                                                <property name="text">
+                                                    <string>Center focused column</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QRadioButton" name="kcfg_scrollingGrouped">
+                                                <property name="text">
+                                                    <string>Prevent needlessly obscuring columns</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                    </layout>
+                                </widget>
+                            </item>
+
+                            <item>
+                                <widget class="QGroupBox">
+                                    <property name="title">
+                                        <string>Layering mode</string>
+                                    </property>
+                                    <layout class="QVBoxLayout">
+                                        <item>
+                                            <widget class="QRadioButton" name="kcfg_tiledKeepBelow">
+                                                <property name="text">
+                                                    <string>Keep tiled windows below</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                        <item>
+                                            <widget class="QRadioButton" name="kcfg_floatingKeepAbove">
+                                                <property name="text">
+                                                    <string>Keep floating windows above</string>
+                                                </property>
+                                            </widget>
+                                        </item>
+                                    </layout>
+                                </widget>
+                            </item>
+
+                            <item>
+                                <spacer name="spacer_footer">
                                     <property name="orientation">
                                         <enum>Qt::Vertical</enum>
                                     </property>
+                                    <property name="sizeHint" stdset="0">
+                                        <size>
+                                            <width>0</width>
+                                            <height>0</height>
+                                        </size>
+                                    </property>
                                 </spacer>
                             </item>
                         </layout>
                     </widget>
+
                     <widget class="QWidget" name="tab_windowRules">
                         <attribute name="title">
-                            <string>Window rules</string>
+                            <string>Window Rules</string>
                         </attribute>
-                        <layout class="QVBoxLayout" name="layout_tab_windowRules">
+                        <layout class="QVBoxLayout">
                             <item>
                                 <widget class="QPlainTextEdit" name="kcfg_windowRules">
                                     <property name="tabChangesFocus">

package/metadata.json

@@ -9,7 +9,7 @@
         }],
         "Id": "karousel",
         "ServiceTypes": ["KWin/Script"],
-        "Version": "0.2.1",
+        "Version": "0.6",
         "License": "GPLv3",
         "Website": "https://github.com/peterfajdiga/karousel",
         "BugReportUrl": "https://github.com/peterfajdiga/karousel/issues"

src/Actions.ts

@@ -0,0 +1,329 @@
+namespace Actions {
+    export function init(world: World, config: Config) {
+        return {
+            focusLeft: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const prevColumn = grid.getPrevColumn(column);
+                    if (prevColumn === null) {
+                        return;
+                    }
+                    prevColumn.focus();
+                });
+            },
+
+            focusRight: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const nextColumn = grid.getNextColumn(column);
+                    if (nextColumn === null) {
+                        return;
+                    }
+                    nextColumn.focus();
+                });
+            },
+
+            focusUp: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const prevWindow = column.getPrevWindow(window);
+                    if (prevWindow === null) {
+                        return;
+                    }
+                    prevWindow.focus();
+                });
+            },
+
+            focusDown: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const nextWindow = column.getNextWindow(window);
+                    if (nextWindow === null) {
+                        return;
+                    }
+                    nextWindow.focus();
+                });
+            },
+
+            focusStart: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const firstColumn = grid.getFirstColumn();
+                    if (firstColumn === null) {
+                        return;
+                    }
+                    firstColumn.focus();
+                });
+            },
+
+            focusEnd: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const lastColumn = grid.getLastColumn();
+                    if (lastColumn === null) {
+                        return;
+                    }
+                    lastColumn.focus();
+                });
+            },
+
+            windowMoveLeft: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    if (column.getWindowCount() === 1) {
+                        // move from own column into existing column
+                        const prevColumn = grid.getPrevColumn(column);
+                        if (prevColumn === null) {
+                            return;
+                        }
+                        window.moveToColumn(prevColumn);
+                        grid.desktop.autoAdjustScroll();
+                    } else {
+                        // move from shared column into own column
+                        const newColumn = new Column(grid, grid.getPrevColumn(column));
+                        window.moveToColumn(newColumn);
+                    }
+                });
+            },
+
+            windowMoveRight: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    if (column.getWindowCount() === 1) {
+                        // move from own column into existing column
+                        const nextColumn = grid.getNextColumn(column);
+                        if (nextColumn === null) {
+                            return;
+                        }
+                        window.moveToColumn(nextColumn);
+                        grid.desktop.autoAdjustScroll();
+                    } else {
+                        // move from shared column into own column
+                        const newColumn = new Column(grid, column);
+                        window.moveToColumn(newColumn);
+                    }
+                });
+            },
+
+            windowMoveUp: () => {
+                // TODO (optimization): only arrange moved windows
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    column.moveWindowUp(window);
+                });
+            },
+
+            windowMoveDown: () => {
+                // TODO (optimization): only arrange moved windows
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    column.moveWindowDown(window);
+                });
+            },
+
+            windowMoveStart: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const newColumn = new Column(grid, null);
+                    window.moveToColumn(newColumn);
+                });
+            },
+
+            windowMoveEnd: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const newColumn = new Column(grid, grid.getLastColumn());
+                    window.moveToColumn(newColumn);
+                });
+            },
+
+            windowToggleFloating: () => {
+                const kwinClient = workspace.activeClient;
+                world.do((clientManager, desktopManager) => {
+                    clientManager.toggleFloatingClient(kwinClient);
+                });
+            },
+
+            columnMoveLeft: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    grid.moveColumnLeft(column);
+                });
+            },
+
+            columnMoveRight: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    grid.moveColumnRight(column);
+                });
+            },
+
+            columnMoveStart: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    column.moveAfter(null);
+                });
+            },
+
+            columnMoveEnd: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    column.moveAfter(grid.getLastColumn());
+                });
+            },
+
+            columnToggleStacked: () => {
+                world.doIfTiledFocused(false, (world, desktopManager, window, column, grid) => {
+                    column.toggleStacked();
+                });
+            },
+
+            columnWidthIncrease: () => {
+                world.doIfTiledFocused(false, (world, desktopManager, window, column, grid) => {
+                    grid.increaseColumnWidth(column);
+                });
+            },
+
+            columnWidthDecrease: () => {
+                world.doIfTiledFocused(false, (world, desktopManager, window, column, grid) => {
+                    grid.decreaseColumnWidth(column);
+                });
+            },
+
+            columnsWidthEqualize: () => {
+                world.do((clientManager, desktopManager) => {
+                    desktopManager.getCurrentDesktop().equalizeVisibleColumnsWidths();
+                });
+            },
+
+            gridScrollLeft: () => {
+                gridScroll(world, -config.manualScrollStep);
+            },
+
+            gridScrollRight: () => {
+                gridScroll(world, config.manualScrollStep);
+            },
+
+            gridScrollStart: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const firstColumn = grid.getFirstColumn();
+                    if (firstColumn === null) {
+                        return;
+                    }
+                    grid.desktop.scrollToColumn(firstColumn);
+                });
+            },
+
+            gridScrollEnd: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const lastColumn = grid.getLastColumn();
+                    if (lastColumn === null) {
+                        return;
+                    }
+                    grid.desktop.scrollToColumn(lastColumn);
+                });
+            },
+
+            gridScrollFocused: () => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    grid.desktop.scrollCenterRange(column);
+                })
+            },
+
+            gridScrollLeftColumn: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const column = grid.getLeftmostVisibleColumn(grid.desktop.getCurrentVisibleRange(), true);
+                    if (column === null) {
+                        return;
+                    }
+
+                    const prevColumn = grid.getPrevColumn(column);
+                    if (prevColumn === null) {
+                        return;
+                    }
+
+                    grid.desktop.scrollToColumn(prevColumn);
+                });
+            },
+
+            gridScrollRightColumn: () => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const column = grid.getRightmostVisibleColumn(grid.desktop.getCurrentVisibleRange(), true);
+                    if (column === null) {
+                        return;
+                    }
+
+                    const nextColumn = grid.getNextColumn(column);
+                    if (nextColumn === null) {
+                        return;
+                    }
+
+                    grid.desktop.scrollToColumn(nextColumn);
+                });
+            },
+        };
+    }
+
+    export function initNum(world: World) {
+        return {
+            focusColumn: (columnIndex: number) => {
+                world.do((clientManager, desktopManager) => {
+                    const grid = desktopManager.getCurrentDesktop().grid;
+                    const targetColumn = grid.getColumnAtIndex(columnIndex);
+                    if (targetColumn === null) {
+                        return null;
+                    }
+                    targetColumn.focus();
+                });
+            },
+
+            windowMoveToColumn: (columnIndex: number) => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const targetColumn = grid.getColumnAtIndex(columnIndex);
+                    if (targetColumn === null) {
+                        return null;
+                    }
+                    window.moveToColumn(targetColumn);
+                    grid.desktop.autoAdjustScroll();
+                });
+            },
+
+            columnMoveToColumn: (columnIndex: number) => {
+                world.doIfTiledFocused(true, (world, desktopManager, window, column, grid) => {
+                    const targetColumn = grid.getColumnAtIndex(columnIndex);
+                    if (targetColumn === null || targetColumn === column) {
+                        return null;
+                    }
+                    if (targetColumn.isAfter(column)) {
+                        column.moveAfter(targetColumn);
+                    } else {
+                        column.moveAfter(grid.getPrevColumn(targetColumn));
+                    }
+                });
+            },
+
+            columnMoveToDesktop: (desktopIndex: number) => {
+                world.doIfTiledFocused(true, (clientManager, desktopManager, window, column, oldGrid) => {
+                    const desktopNumber = desktopIndex + 1;
+                    const newGrid = desktopManager.getDesktopInCurrentActivity(desktopNumber).grid;
+                    if (newGrid === null || newGrid === oldGrid) {
+                        return;
+                    }
+                    column.moveToGrid(newGrid, newGrid.getLastColumn());
+                });
+            },
+
+            tailMoveToDesktop: (desktopIndex: number) => {
+                world.doIfTiledFocused(true, (clientManager, desktopManager, window, column, oldGrid) => {
+                    const desktopNumber = desktopIndex + 1;
+                    const newGrid = desktopManager.getDesktopInCurrentActivity(desktopNumber).grid;
+                    if (newGrid === null || newGrid === oldGrid) {
+                        return;
+                    }
+                    oldGrid.evacuateTail(newGrid, column);
+                });
+            },
+        };
+    }
+
+    function gridScroll(world: World, amount: number) {
+        world.do((clientManager, desktopManager) => {
+            const grid = desktopManager.getCurrentDesktop().grid;
+            grid.desktop.adjustScroll(amount, false);
+        });
+    }
+
+    export type Config = {
+        manualScrollStep: number,
+    };
+}

src/ClientAreaOption.ts

@@ -0,0 +1,10 @@
+enum ClientAreaOption {
+    PlacementArea,
+    MovementArea,
+    MaximizeArea,
+    MaximizeFullArea,
+    FullScreenArea,
+    WorkArea,
+    FullArea,
+    ScreenArea,
+}

src/actions.ts

@@ -1,354 +0,0 @@
-function initActions(world: World) {
-    return {
-        focusLeft: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const prevColumn = grid.getPrevColumn(column);
-                if (prevColumn === null) {
-                    return;
-                }
-                prevColumn.focus();
-            });
-        },
-
-        focusRight: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const nextColumn = grid.getNextColumn(column);
-                if (nextColumn === null) {
-                    return;
-                }
-                nextColumn.focus();
-            });
-        },
-
-        focusUp: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const prevWindow = column.getPrevWindow(window);
-                if (prevWindow === null) {
-                    return;
-                }
-                prevWindow.focus();
-            });
-        },
-
-        focusDown: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const nextWindow = column.getNextWindow(window);
-                if (nextWindow === null) {
-                    return;
-                }
-                nextWindow.focus();
-            });
-        },
-
-        focusStart: () => {
-            const grid = world.getCurrentGrid();
-            const firstColumn = grid.getFirstColumn();
-            if (firstColumn === null) {
-                return;
-            }
-            firstColumn.focus();
-            grid.arrange();
-        },
-
-        focusEnd: () => {
-            const grid = world.getCurrentGrid();
-            const lastColumn = grid.getLastColumn();
-            if (lastColumn === null) {
-                return;
-            }
-            lastColumn.focus();
-            grid.arrange();
-        },
-
-        windowMoveLeft: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                if (column.getWindowCount() === 1) {
-                    // move from own column into existing column
-                    const prevColumn = grid.getPrevColumn(column);
-                    if (prevColumn === null) {
-                        return;
-                    }
-                    window.moveToColumn(prevColumn);
-                    grid.autoAdjustScroll();
-                } else {
-                    // move from shared column into own column
-                    const newColumn = new Column(grid, grid.getPrevColumn(column));
-                    window.moveToColumn(newColumn);
-                }
-                grid.arrange();
-            });
-        },
-
-        windowMoveRight: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                if (column.getWindowCount() === 1) {
-                    // move from own column into existing column
-                    const nextColumn = grid.getNextColumn(column);
-                    if (nextColumn === null) {
-                        return;
-                    }
-                    window.moveToColumn(nextColumn);
-                    grid.autoAdjustScroll();
-                } else {
-                    // move from shared column into own column
-                    const newColumn = new Column(grid, column);
-                    window.moveToColumn(newColumn);
-                }
-                grid.arrange();
-            });
-        },
-
-        windowMoveUp: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                column.moveWindowUp(window);
-                grid.arrange(); // TODO (optimization): only arrange moved windows
-            });
-        },
-
-        windowMoveDown: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                column.moveWindowDown(window);
-                grid.arrange(); // TODO (optimization): only arrange moved windows
-            });
-        },
-
-        windowMoveStart: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const newColumn = new Column(grid, null);
-                window.moveToColumn(newColumn);
-                grid.arrange();
-            });
-        },
-
-        windowMoveEnd: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const newColumn = new Column(grid, grid.getLastColumn());
-                window.moveToColumn(newColumn);
-                grid.arrange();
-            });
-        },
-
-        windowExpand: () => {
-            world.doIfTiledFocused(false, (window, column, grid) => {
-                column.toggleStacked();
-                grid.arrange();
-            });
-        },
-
-        windowToggleFloating: () => {
-            const kwinClient = workspace.activeClient;
-            world.toggleFloatingClient(kwinClient);
-        },
-
-        columnMoveLeft: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                grid.moveColumnLeft(column);
-                grid.arrange();
-            });
-        },
-
-        columnMoveRight: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                grid.moveColumnRight(column);
-                grid.arrange();
-            });
-        },
-
-        columnMoveStart: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                column.moveAfter(null);
-                grid.arrange();
-            });
-        },
-
-        columnMoveEnd: () => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                column.moveAfter(grid.getLastColumn());
-                grid.arrange();
-            });
-        },
-
-        columnExpand: () => {
-            world.doIfTiledFocused(false, (window, column, grid) => {
-                column.expand();
-                grid.arrange();
-            });
-        },
-
-        expandVisibleColumns: () => {
-            const grid = world.getCurrentGrid();
-            grid.rescaleVisibleColumns(true, true);
-            grid.arrange();
-        },
-
-        shrinkVisibleColumns: () => {
-            const grid = world.getCurrentGrid();
-            grid.rescaleVisibleColumns(false, false);
-            grid.arrange();
-        },
-
-        gridScrollLeft: () => {
-            gridScroll(world, -world.config.manualScrollStep);
-        },
-
-        gridScrollRight: () => {
-            gridScroll(world, world.config.manualScrollStep);
-        },
-
-        gridScrollStart: () => {
-            const grid = world.getCurrentGrid();
-            const firstColumn = grid.getFirstColumn();
-            if (firstColumn === null) {
-                return;
-            }
-            grid.scrollToColumn(firstColumn);
-            grid.arrange();
-        },
-
-        gridScrollEnd: () => {
-            const grid = world.getCurrentGrid();
-            const lastColumn = grid.getLastColumn();
-            if (lastColumn === null) {
-                return;
-            }
-            grid.scrollToColumn(lastColumn);
-            grid.arrange();
-        },
-
-        gridScrollFocused: () => {
-            const focusedWindow = world.getFocusedWindow();
-            if (focusedWindow === null) {
-                return;
-            }
-            const column = focusedWindow.column;
-            const grid = column.grid;
-            grid.scrollCenterColumn(column);
-            grid.arrange();
-        },
-
-        gridScrollLeftColumn: () => {
-            const grid = world.getCurrentGrid();
-            const column = grid.getLeftmostVisibleColumn(true);
-            if (column === null) {
-                return;
-            }
-
-            const prevColumn = grid.getPrevColumn(column);
-            if (prevColumn === null) {
-                return;
-            }
-
-            grid.scrollToColumn(prevColumn);
-            grid.arrange();
-        },
-
-        gridScrollRightColumn: () => {
-            const grid = world.getCurrentGrid();
-            const column = grid.getRightmostVisibleColumn(true);
-            if (column === null) {
-                return;
-            }
-
-            const nextColumn = grid.getNextColumn(column);
-            if (nextColumn === null) {
-                return;
-            }
-
-            grid.scrollToColumn(nextColumn);
-            grid.arrange();
-        },
-    };
-}
-
-function initNumActions(world: World) {
-    return {
-        focusColumn: (columnIndex: number) => {
-            const grid = world.getCurrentGrid();
-            const targetColumn = grid.getColumnAtIndex(columnIndex);
-            if (targetColumn === null) {
-                return null;
-            }
-            targetColumn.focus();
-        },
-
-        windowMoveToColumn: (columnIndex: number) => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const targetColumn = grid.getColumnAtIndex(columnIndex);
-                if (targetColumn === null) {
-                    return null;
-                }
-                window.moveToColumn(targetColumn);
-                grid.autoAdjustScroll();
-                grid.arrange();
-            });
-        },
-
-        columnMoveToColumn: (columnIndex: number) => {
-            world.doIfTiledFocused(true, (window, column, grid) => {
-                const targetColumn = grid.getColumnAtIndex(columnIndex);
-                if (targetColumn === null || targetColumn === column) {
-                    return null;
-                }
-                if (targetColumn.isAfter(column)) {
-                    column.moveAfter(targetColumn);
-                } else {
-                    column.moveAfter(grid.getPrevColumn(targetColumn));
-                }
-                grid.arrange();
-            });
-        },
-
-        columnMoveToDesktop: (desktopIndex: number) => {
-            world.doIfTiledFocused(true, (window, column, oldGrid) => {
-                const desktopNumber = desktopIndex + 1;
-                const newGrid = world.getGridInCurrentActivity(desktopNumber);
-                if (newGrid === null || newGrid === oldGrid) {
-                    return;
-                }
-                column.moveToGrid(newGrid, newGrid.getLastColumn());
-                oldGrid.arrange();
-                newGrid.arrange();
-            });
-        },
-
-        tailMoveToDesktop: (desktopIndex: number) => {
-            world.doIfTiledFocused(true, (window, column, oldGrid) => {
-                const desktopNumber = desktopIndex + 1;
-                const newGrid = world.getGridInCurrentActivity(desktopNumber);
-                if (newGrid === null || newGrid === oldGrid) {
-                    return;
-                }
-                oldGrid.evacuateTail(newGrid, column);
-                oldGrid.arrange();
-                newGrid.arrange();
-            });
-        },
-    };
-}
-
-function gridScroll(world: World, amount: number) {
-    const scrollAmount = amount;
-    const grid = world.getCurrentGrid();
-    grid.adjustScroll(scrollAmount, false);
-    grid.arrange();
-}
-
-function canTileEver(kwinClient: AbstractClient) {
-    return kwinClient.resizeable;
-}
-
-function canTileNow(kwinClient: AbstractClient) {
-    return canTileEver(kwinClient) && !kwinClient.minimized && kwinClient.desktop > 0 && kwinClient.activities.length === 1;
-}
-
-function makeTileable(kwinClient: AbstractClient) {
-    if (kwinClient.minimized) {
-        kwinClient.minimized = false;
-    }
-    if (kwinClient.desktop <= 0) {
-        kwinClient.desktop = workspace.currentDesktop;
-    }
-    if (kwinClient.activities.length !== 1) {
-        kwinClient.activities = [workspace.currentActivity];
-    }
-}

src/config/config.ts

@@ -7,6 +7,16 @@ type Config = {
     gapsInnerVertical: number,
     overscroll: number,
     manualScrollStep: number,
+    offScreenOpacity: number,
+    untileOnDrag: boolean,
     stackColumnsByDefault: boolean,
+    resizeNeighborColumn: boolean,
+    reMaximize: boolean,
+    skipSwitcher: boolean,
+    scrollingLazy: boolean,
+    scrollingCentered: boolean,
+    scrollingGrouped: boolean,
+    tiledKeepBelow: boolean,
+    floatingKeepAbove: boolean,
     windowRules: string,
-}
+};

src/config/definition.ts

@@ -7,22 +7,45 @@ const defaultWindowRules = `[
         "class": "kcalc",
         "tile": false
     },
+    {
+        "class": "org.kde.kcalc",
+        "tile": false
+    },
     {
         "class": "kfind",
         "tile": true
     },
+    {
+        "class": "org.kde.kfind",
+        "tile": true
+    },
     {
         "class": "kruler",
         "tile": false
     },
     {
-        "class": "zoom",
-        "caption": "Zoom Cloud Meetings",
+        "class": "org.kde.kruler",
+        "tile": false
+    },
+    {
+        "class": "krunner",
+        "tile": false
+    },
+    {
+        "class": "org.kde.krunner",
+        "tile": false
+    },
+    {
+        "class": "yakuake",
+        "tile": false
+    },
+    {
+        "class": "org.kde.yakuake",
         "tile": false
     },
     {
         "class": "zoom",
-        "caption": "zoom",
+        "caption": "Zoom Cloud Meetings|zoom|zoom <2>",
         "tile": false
     },
     {
@@ -81,18 +104,68 @@ const configDef = [
     {
         "name": "overscroll",
         "type": "UInt",
-        "default": 18
+        "default": 0
     },
     {
         "name": "manualScrollStep",
         "type": "UInt",
         "default": 200
     },
+    {
+        "name": "offScreenOpacity",
+        "type": "UInt",
+        "default": 100
+    },
+    {
+        "name": "untileOnDrag",
+        "type": "Bool",
+        "default": true
+    },
     {
         "name": "stackColumnsByDefault",
         "type": "Bool",
         "default": false
     },
+    {
+        "name": "resizeNeighborColumn",
+        "type": "Bool",
+        "default": false
+    },
+    {
+        "name": "reMaximize",
+        "type": "Bool",
+        "default": false
+    },
+    {
+        "name": "skipSwitcher",
+        "type": "Bool",
+        "default": false
+    },
+    {
+        "name": "scrollingLazy",
+        "type": "Bool",
+        "default": true
+    },
+    {
+        "name": "scrollingCentered",
+        "type": "Bool",
+        "default": false
+    },
+    {
+        "name": "scrollingGrouped",
+        "type": "Bool",
+        "default": false
+    },
+    {
+        "name": "tiledKeepBelow",
+        "type": "Bool",
+        "default": true
+    },
+    {
+        "name": "floatingKeepAbove",
+        "type": "Bool",
+        "default": false
+    },
     {
         "name": "windowRules",
         "type": "String",

src/config/loader.ts

@@ -1,4 +1,4 @@
-function loadConfig() {
+function loadConfig(): Config {
     const config: any = {};
     for (const entry of configDef) {
         config[entry.name] = KWin.readConfig(entry.name, entry.default);

src/extern.d.ts

@@ -1,13 +0,0 @@
-declare const qmlBase;
-declare const console;
-declare const KWin;
-declare const Qt;
-declare const workspace;
-declare const options;
-
-type AbstractClient = any;
-type TopLevel = any;
-type X11Client = any;
-type QRect = any;
-type QSignal = any;
-type QQmlTimer = any;

src/extern/global.d.ts

@@ -0,0 +1,6 @@
+declare const qmlBase: QmlObject;
+declare const notificationInvalidWindowRules: Notification;
+
+type Notification = {
+    sendEvent(): void;
+};

src/extern/kwin.d.ts

@@ -0,0 +1,77 @@
+declare const KWin: {
+    // Functions
+    readConfig(key: string, defaultValue: any): any;
+    registerShortcut(name: string, description: string, keySequence: string, callback: () => void): void;
+};
+
+declare const workspace: {
+    // Read-write Properties
+    readonly desktops: number;
+    readonly currentDesktop: number;
+    readonly currentActivity: string;
+
+    // Read-write Properties
+    activeClient: KwinClient;
+
+    // Signals
+    currentDesktopChanged: QSignal<[oldDesktopNumber: number]>
+    clientAdded: QSignal<[KwinClient]>;
+    clientRemoved: QSignal<[KwinClient]>;
+    clientMinimized: QSignal<[KwinClient]>;
+    clientUnminimized: QSignal<[KwinClient]>;
+    clientMaximizeSet: QSignal<[KwinClient, horizontally: boolean, vertically: boolean]>;
+    clientActivated: QSignal<[KwinClient]>;
+    numberDesktopsChanged: QSignal<[oldNumberOfVirtualDesktops: number]>;
+    currentActivityChanged: QSignal<[newActivity: string]>;
+    virtualScreenSizeChanged: QSignal<[void]>;
+
+    // Functions
+    clientArea(option: ClientAreaOption, screenNumber: number, desktopNumber: number);
+    clientList(): KwinClient[];
+};
+
+type Tile = any;
+
+interface KwinClient {
+    // Read-only Properties
+    readonly shadeable: boolean;
+    readonly caption: string;
+    readonly minSize: QmlSize;
+    readonly transient: boolean;
+    readonly transientFor: KwinClient;
+    readonly move: boolean;
+    readonly resize: boolean;
+    readonly resizeable: boolean;
+    readonly screen: number;
+    readonly resourceClass: QByteArray;
+    readonly dock: boolean;
+    readonly normalWindow: boolean;
+    readonly managed: boolean;
+    opacity: number;
+
+    // Read-write Properties
+    fullScreen: boolean;
+    activities: string[]; // empty array means all activities
+    skipSwitcher: boolean;
+    keepAbove: boolean;
+    keepBelow: boolean;
+    shade: boolean;
+    minimized: boolean;
+    frameGeometry: QmlRect;
+    desktop: number; // -1 means all desktops
+    tile: Tile;
+
+    // Signals
+    fullScreenChanged: QSignal<[void]>;
+    desktopChanged: QSignal<[void]>;
+    activitiesChanged: QSignal<[KwinClient]>;
+    captionChanged: QSignal<[void]>;
+    tileChanged: QSignal<[Tile]>;
+    moveResizedChanged: QSignal<[void]>;
+    moveResizeCursorChanged: QSignal<[void]>;
+    clientStartUserMovedResized: QSignal<[void]>;
+    frameGeometryChanged: QSignal<[KwinClient, oldGeometry: QmlRect]>;
+
+    // Functions
+    setMaximize(vertically: boolean, horizontally: boolean): void;
+}

src/extern/qt.d.ts

@@ -0,0 +1,41 @@
+declare const console: {
+    log(...args: any[]);
+    assert(boolean);
+};
+
+declare const Qt: {
+    rect(x: number, y: number, width: number, height: number): QmlRect;
+    createQmlObject(qml: string, parent: QmlObject);
+};
+
+type QmlObject = unknown;
+
+type QByteArray = string;
+
+type QmlRect = {
+    x: number;
+    y: number;
+    width: number;
+    height: number;
+    top: number;
+    bottom: number; // top + height
+    left: number;
+    right: number; // left + width
+};
+
+type QmlSize = {
+    width: number;
+    height: number;
+};
+
+type QSignal<T extends unknown[]> = {
+    connect(handler: (...args: [...T]) => void): void;
+    disconnect(handler: (...args: [...T]) => void): void;
+};
+
+type QmlTimer = {
+    interval: number;
+    triggered: QSignal<[void]>;
+    restart(): void;
+    destroy(): void;
+};

src/keyBindings/definition.ts

@@ -14,18 +14,21 @@ const keyBindings: KeyBinding[] = [
     {
         "name": "focus-right",
         "description": "Move focus right",
+        "comment": "Clashes with default KDE shortcuts, may require manual remapping",
         "defaultKeySequence": "Meta+D",
         "action": "focusRight",
     },
     {
         "name": "focus-up",
         "description": "Move focus up",
+        "comment": "Clashes with default KDE shortcuts, may require manual remapping",
         "defaultKeySequence": "Meta+W",
         "action": "focusUp",
     },
     {
         "name": "focus-down",
         "description": "Move focus down",
+        "comment": "Clashes with default KDE shortcuts, may require manual remapping",
         "defaultKeySequence": "Meta+S",
         "action": "focusDown",
     },
@@ -80,11 +83,11 @@ const keyBindings: KeyBinding[] = [
         "action": "windowMoveEnd",
     },
     {
-        "name": "window-expand",
-        "description": "Expand window",
-        "comment": "Expands focused window vertically; toggles stacked layout for focused column",
+        "name": "column-toggle-stacked",
+        "description": "Toggle stacked layout for focused column",
+        "comment": "One window in the column visible, others shaded; not supported on Wayland",
         "defaultKeySequence": "Meta+X",
-        "action": "windowExpand",
+        "action": "columnToggleStacked",
     },
     {
         "name": "column-move-left",
@@ -111,25 +114,22 @@ const keyBindings: KeyBinding[] = [
         "action": "columnMoveEnd",
     },
     {
-        "name": "column-expand",
-        "description": "Expand column",
-        "comment": "Expands focused column horizontally to fill the screen",
+        "name": "column-width-increase",
+        "description": "Increase column width",
+        "defaultKeySequence": "Meta+Ctrl++",
+        "action": "columnWidthIncrease",
+    },
+    {
+        "name": "column-width-decrease",
+        "description": "Decrease column width",
+        "defaultKeySequence": "Meta+Ctrl+-",
+        "action": "columnWidthDecrease",
+    },
+    {
+        "name": "columns-width-equalize",
+        "description": "Equalize widths of visible columns",
         "defaultKeySequence": "Meta+Ctrl+X",
-        "action": "columnExpand",
-    },
-    {
-        "name": "expand-visible-columns",
-        "description": "Expand fully visible columns",
-        "comment": "Expands fully visible columns to fill the screen",
-        "defaultKeySequence": "Meta+Alt++",
-        "action": "expandVisibleColumns",
-    },
-    {
-        "name": "shrink-visible-columns",
-        "description": "Shrink visible columns",
-        "comment": "Shrinks fully and partially visible columns, making them fully visible and filling the screen",
-        "defaultKeySequence": "Meta+Alt+-",
-        "action": "shrinkVisibleColumns",
+        "action": "columnsWidthEqualize",
     },
     {
         "name": "grid-scroll-focused",
@@ -180,6 +180,7 @@ const numKeyBindings: NumKeyBinding[] = [
     {
         "name": "focus-",
         "description": "Move focus to column ",
+        "comment": "Clashes with default KDE shortcuts, may require manual remapping",
         "defaultModifiers": "Meta",
         "fKeys": false,
         "action": "focusColumn",

src/keyBindings/loader.ts

@@ -1,27 +1,27 @@
-interface KeyBinding {
+type KeyBinding = {
     name: string;
     description: string;
     comment?: string;
     defaultKeySequence: string;
-    action: keyof ReturnType<typeof initActions>;
-}
+    action: keyof ReturnType<typeof Actions.init>;
+};
 
-interface NumKeyBinding {
+type NumKeyBinding = {
     name: string;
     description: string;
     comment?: string;
     defaultModifiers: string;
     fKeys: boolean;
-    action: keyof ReturnType<typeof initNumActions>;
-}
+    action: keyof ReturnType<typeof Actions.initNum>;
+};
 
 function catchWrap(f: () => void) {
     return () => {
         try {
             f();
         } catch (error: any) {
-            console.log(error);
-            console.log(error.stack);
+            log(error);
+            log(error.stack);
         }
     };
 }
@@ -38,24 +38,27 @@ function registerKeyBinding(name: string, description: string, keySequence: stri
 function registerNumKeyBindings(name: string, description: string, modifiers: string, fKeys: boolean, callback: (i: number) => void) {
     const numPrefix = fKeys ? "F" : "";
     const n = fKeys ? 12 : 9;
-    for (let i = 0; i < n; i++) {
+    for (let i = 0; i < 12; i++) {
         const numKey = String(i + 1);
+        const keySequence = i < n ?
+            modifiers + "+" + numPrefix + numKey :
+            "";
         registerKeyBinding(
             name + numKey,
             description + numKey,
-            modifiers + "+" + numPrefix + numKey,
+            keySequence,
             () => callback(i),
         );
     }
 }
 
-function registerKeyBindings(world: World) {
-    const actions = initActions(world);
+function registerKeyBindings(world: World, config: Config) {
+    const actions = Actions.init(world, config);
     for (const binding of keyBindings) {
         registerKeyBinding(binding.name, binding.description, binding.defaultKeySequence, actions[binding.action]);
     }
 
-    const numActions = initNumActions(world);
+    const numActions = Actions.initNum(world);
     for (const binding of numKeyBindings) {
         registerNumKeyBindings(binding.name, binding.description, binding.defaultModifiers, binding.fKeys, numActions[binding.action]);
     }

src/layout/Column.ts

@@ -1,24 +1,23 @@
 class Column {
     public grid: Grid;
     public gridX: number;
-    public width: number; // TODO: increase column width to contain transients
+    private width: number; // TODO: increase column width to contain transients
     private readonly windows: LinkedList<Window>;
     private stacked: boolean;
     private focusTaker: Window|null;
-    private widthBeforeExpand: number;
+    private static readonly minWidth = 10;
 
     constructor(grid: Grid, prevColumn: Column|null) {
         this.gridX = 0;
         this.width = 0;
         this.windows = new LinkedList();
-        this.stacked = grid.world.config.stackColumnsByDefault;
+        this.stacked = grid.config.stackColumnsByDefault;
         this.focusTaker = null;
-        this.widthBeforeExpand = 0;
         this.grid = grid;
         this.grid.onColumnAdded(this, prevColumn);
     }
 
-    moveToGrid(targetGrid: Grid, prevColumn: Column|null) {
+    public moveToGrid(targetGrid: Grid, prevColumn: Column|null) {
         if (targetGrid === this.grid) {
             this.grid.onColumnMoved(this, prevColumn);
         } else {
@@ -26,60 +25,73 @@ class Column {
             this.grid = targetGrid;
             targetGrid.onColumnAdded(this, prevColumn);
             for (const window of this.windows.iterator()) {
-                window.client.kwinClient.desktop = targetGrid.desktop;
+                window.client.kwinClient.desktop = targetGrid.desktop.desktopNumber;
             }
         }
     }
 
-    moveAfter(prevColumn: Column|null) {
+    public moveAfter(prevColumn: Column|null) {
         if (prevColumn === this) {
             return;
         }
         this.grid.onColumnMoved(this, prevColumn);
     }
 
-    isAfter(other: Column) {
+    public isAfter(other: Column) {
         return this.gridX > other.gridX;
     }
 
-    isBefore(other: Column) {
+    public isBefore(other: Column) {
         return this.gridX < other.gridX;
     }
 
-    moveWindowUp(window: Window) {
+    public moveWindowUp(window: Window) {
         this.windows.moveBack(window);
+        this.grid.desktop.onLayoutChanged();
     }
 
-    moveWindowDown(window: Window) {
+    public moveWindowDown(window: Window) {
         this.windows.moveForward(window);
+        this.grid.desktop.onLayoutChanged();
     }
 
-    getWindowCount() {
+    public getWindowCount() {
         return this.windows.length();
     }
 
-    isEmpty() {
+    public isEmpty() {
         return this.getWindowCount() === 0;
     }
 
-    getPrevWindow(window: Window) {
+    public getPrevWindow(window: Window) {
         return this.windows.getPrev(window);
     }
 
-    getNextWindow(window: Window) {
+    public getNextWindow(window: Window) {
         return this.windows.getNext(window);
     }
 
-    getWidth() {
+    public getWidth() {
         return this.width;
     }
 
-    getMaxWidth() {
-        return this.grid.tilingArea.width;
+    public getMinWidth() {
+        let maxMinWidth = Column.minWidth;
+        for (const window of this.windows.iterator()) {
+            const minWidth = window.client.kwinClient.minSize.width;
+            if (minWidth > maxMinWidth) {
+                maxMinWidth = minWidth;
+            }
+        }
+        return maxMinWidth;
     }
 
-    setWidth(width: number, setPreferred: boolean) {
-        width = Math.min(width, this.getMaxWidth());
+    public getMaxWidth() {
+        return this.grid.desktop.tilingArea.width;
+    }
+
+    public setWidth(width: number, setPreferred: boolean) {
+        width = clamp(width, this.getMinWidth(), this.getMaxWidth());
         const oldWidth = this.width;
         this.width = width;
         if (setPreferred) {
@@ -92,22 +104,34 @@ class Column {
         }
     }
 
-    adjustWidth(widthDelta: number, setPreferred: boolean) {
+    public adjustWidth(widthDelta: number, setPreferred: boolean) {
         this.setWidth(this.width + widthDelta, setPreferred);
     }
 
-    expand() {
-        const maxWidth = this.getMaxWidth();
-        const isAlreadyExpanded = this.width === maxWidth && this.widthBeforeExpand > 0;
-        if (isAlreadyExpanded) {
-            this.setWidth(this.widthBeforeExpand, false);
-        } else {
-            this.widthBeforeExpand = this.width;
-            this.setWidth(maxWidth, false);
+    public updateWidth() {
+        let minErr = Infinity;
+        let closestPreferredWidth = this.width;
+        for (const window of this.windows.iterator()) {
+            const err = Math.abs(window.client.preferredWidth - this.width);
+            if (err < minErr) {
+                minErr = err;
+                closestPreferredWidth = window.client.preferredWidth;
+            }
         }
+        this.setWidth(closestPreferredWidth, false);
     }
 
-    adjustWindowHeight(window: Window, heightDelta: number, top: boolean) {
+    // returns x position of left edge in grid space
+    public getLeft() {
+        return this.gridX;
+    }
+
+    // returns x position of right edge in grid space
+    public getRight() {
+        return this.gridX + this.width;
+    }
+
+    public adjustWindowHeight(window: Window, heightDelta: number, top: boolean) {
         const otherWindow = top ? this.windows.getPrev(window) : this.windows.getNext(window);
         if (otherWindow === null) {
             return;
@@ -115,18 +139,20 @@ class Column {
 
         window.height += heightDelta;
         otherWindow.height -= heightDelta;
+
+        this.grid.desktop.onLayoutChanged();
     }
 
-    resizeWindows() {
+    public resizeWindows() {
         const nWindows = this.windows.length();
         if (nWindows === 0) {
             return;
         }
         if (nWindows === 1) {
-            this.stacked = this.grid.world.config.stackColumnsByDefault;
+            this.stacked = this.grid.config.stackColumnsByDefault;
         }
 
-        let remainingPixels = this.grid.tilingArea.height - (nWindows-1) * this.grid.world.config.gapsInnerVertical;
+        let remainingPixels = this.grid.desktop.tilingArea.height - (nWindows-1) * this.grid.config.gapsInnerVertical;
         let remainingWindows = nWindows;
         for (const window of this.windows.iterator()) {
             const windowHeight = Math.round(remainingPixels / remainingWindows);
@@ -135,16 +161,18 @@ class Column {
             remainingWindows--;
         }
         // TODO: respect min height
+
+        this.grid.desktop.onLayoutChanged();
     }
 
-    getFocusTaker() {
+    public getFocusTaker() {
         if (this.focusTaker === null || !this.windows.contains(this.focusTaker)) {
             return null;
         }
         return this.focusTaker;
     }
 
-    focus() {
+    public focus() {
         const window = this.getFocusTaker() ?? this.windows.getFirst();
         if (window === null) {
             return;
@@ -152,20 +180,27 @@ class Column {
         window.focus();
     }
 
-    arrange(x: number) {
-        if (this.stacked && this.windows.length() >= 2) {
+    public arrange(x: number, visibleRange: Range, forceOpaque: boolean) {
+        if (this.grid.config.offScreenOpacity < 1.0 && !forceOpaque) {
+            const opacity = this.isVisible(visibleRange, true) ? 100 : this.grid.config.offScreenOpacity;
+            for (const window of this.windows.iterator()) {
+                window.client.kwinClient.opacity = opacity;
+            }
+        }
+
+        if (this.stacked && this.windows.length() >= 2 && this.canStack()) {
             this.arrangeStacked(x);
             return;
         }
-        let y = this.grid.tilingArea.y;
+        let y = this.grid.desktop.tilingArea.y;
         for (const window of this.windows.iterator()) {
             window.client.setShade(false);
             window.arrange(x, y, this.width, window.height);
-            y += window.height + this.grid.world.config.gapsInnerVertical;
+            y += window.height + this.grid.config.gapsInnerVertical;
         }
     }
 
-    arrangeStacked(x: number) {
+    public arrangeStacked(x: number) {
         const expandedWindow = this.getFocusTaker();
         let collapsedHeight;
         for (const window of this.windows.iterator()) {
@@ -178,28 +213,48 @@ class Column {
         }
 
         const nCollapsed = this.getWindowCount() - 1;
-        const expandedHeight = this.grid.tilingArea.height - nCollapsed * (collapsedHeight + this.grid.world.config.gapsInnerVertical);
-        let y = this.grid.tilingArea.y;
+        const expandedHeight = this.grid.desktop.tilingArea.height - nCollapsed * (collapsedHeight! + this.grid.config.gapsInnerVertical);
+        let y = this.grid.desktop.tilingArea.y;
         for (const window of this.windows.iterator()) {
             if (window === expandedWindow) {
                 window.arrange(x, y, this.width, expandedHeight);
                 y += expandedHeight;
             } else {
                 window.arrange(x, y, this.width, window.height);
-                y += collapsedHeight;
+                y += collapsedHeight!;
             }
-            y += this.grid.world.config.gapsInnerVertical;
+            y += this.grid.config.gapsInnerVertical;
         }
     }
 
-    toggleStacked() {
+    public toggleStacked() {
         if (this.windows.length() < 2) {
             return;
         }
         this.stacked = !this.stacked;
+        this.grid.desktop.onLayoutChanged();
     }
 
-    onWindowAdded(window: Window) {
+    private canStack() {
+        for (const window of this.windows.iterator()) {
+            if (!window.client.kwinClient.shadeable) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public isVisible(visibleRange: Desktop.Range, fullyVisible: boolean) {
+        if (fullyVisible) {
+            return this.getLeft() >= visibleRange.getLeft() &&
+                this.getRight() <= visibleRange.getRight();
+        } else {
+            return this.getRight() + this.grid.config.gapsInnerHorizontal > visibleRange.getLeft() &&
+                this.getLeft() - this.grid.config.gapsInnerHorizontal < visibleRange.getRight();
+        }
+    }
+
+    public onWindowAdded(window: Window) {
         this.windows.insertEnd(window);
         if (this.width === 0) {
             this.setWidth(window.client.preferredWidth, false);
@@ -211,9 +266,11 @@ class Column {
         if (window.isFocused()) {
             this.onWindowFocused(window);
         }
+
+        this.grid.desktop.onLayoutChanged();
     }
 
-    onWindowRemoved(window: Window, passFocus: boolean) {
+    public onWindowRemoved(window: Window, passFocus: boolean) {
         const lastWindow = this.windows.length() === 1;
         const windowToFocus = this.getPrevWindow(window) ?? this.getNextWindow(window);
 
@@ -232,21 +289,23 @@ class Column {
                 windowToFocus.focus();
             }
         }
+
+        this.grid.desktop.onLayoutChanged();
     }
 
-    onWindowFocused(window: Window) {
+    public onWindowFocused(window: Window) {
         this.grid.onColumnFocused(this);
         this.focusTaker = window;
     }
 
-    restoreToTiled() {
+    public restoreToTiled() {
         const lastFocusedWindow = this.getFocusTaker();
         if (lastFocusedWindow !== null) {
             lastFocusedWindow.restoreToTiled();
         }
     }
 
-    destroy(passFocus: boolean) {
+    private destroy(passFocus: boolean) {
         this.grid.onColumnRemoved(this, passFocus);
     }
 }

src/layout/Desktop.ts

@@ -0,0 +1,232 @@
+class Desktop {
+    public readonly grid: Grid;
+    public readonly desktopNumber: number;
+    private readonly pinManager: PinManager;
+    private readonly config: Desktop.Config;
+    private scrollX: number;
+    private dirty: boolean;
+    private dirtyScroll: boolean;
+    private dirtyPins: boolean;
+    public clientArea: QmlRect;
+    public tilingArea: QmlRect;
+
+    constructor(desktopNumber: number, pinManager: PinManager, config: Desktop.Config, layoutConfig: LayoutConfig) {
+        this.pinManager = pinManager;
+        this.config = config;
+        this.scrollX = 0;
+        this.dirty = true;
+        this.dirtyScroll = true;
+        this.dirtyPins = true;
+        this.desktopNumber = desktopNumber;
+        this.grid = new Grid(this, layoutConfig);
+        this.clientArea = Desktop.getClientArea(desktopNumber);
+        this.tilingArea = Desktop.getTilingArea(this.clientArea, desktopNumber, pinManager, config);
+    }
+
+    private updateArea() {
+        const newClientArea = Desktop.getClientArea(this.desktopNumber);
+        if (newClientArea === this.clientArea && !this.dirtyPins) {
+            return;
+        }
+        this.clientArea = newClientArea;
+        this.tilingArea = Desktop.getTilingArea(newClientArea, this.desktopNumber, this.pinManager, this.config);
+        this.dirty = true;
+        this.dirtyScroll = true;
+        this.dirtyPins = false;
+        this.grid.onScreenSizeChanged();
+        this.autoAdjustScroll();
+    }
+
+    private static getClientArea(desktopNumber: number) {
+        return workspace.clientArea(ClientAreaOption.PlacementArea, 0, desktopNumber);
+    }
+
+    private static getTilingArea(clientArea: QmlRect, desktopNumber: number, pinManager: PinManager, config: Desktop.Config) {
+        const availableSpace = pinManager.getAvailableSpace(desktopNumber, clientArea);
+        const top = availableSpace.top + config.marginTop;
+        const bottom = availableSpace.bottom - config.marginBottom;
+        const left = availableSpace.left + config.marginLeft;
+        const right = availableSpace.right - config.marginRight;
+        return Qt.rect(
+            left,
+            top,
+            right - left,
+            bottom - top,
+        )
+    }
+
+    // calculates a Range that scrolls the contained Range into view
+    public calculateVisibleRange(containedRange: Desktop.Range) {
+        const left = containedRange.getLeft();
+        const right = containedRange.getRight();
+        const initialVisibleRange = this.getCurrentVisibleRange();
+
+        let targetScrollX: number;
+        if (left < initialVisibleRange.getLeft()) {
+            targetScrollX = left;
+        } else if (right > initialVisibleRange.getRight()) {
+            targetScrollX = right - this.tilingArea.width;
+        } else {
+            return this.getVisibleRange(this.clampScrollX(this.scrollX));
+        }
+
+        const overscroll = this.getTargetOverscroll(targetScrollX, left < initialVisibleRange.getLeft());
+        return this.getVisibleRange(this.clampScrollX(targetScrollX + overscroll));
+    }
+
+    private getTargetOverscroll(targetScrollX: number, scrollLeft: boolean) {
+        if (this.config.overscroll === 0) {
+            return 0;
+        }
+        const visibleColumnsWidth = this.grid.getVisibleColumnsWidth(this.getVisibleRange(targetScrollX), true);
+        const remainingSpace = this.tilingArea.width - visibleColumnsWidth;
+        const overscrollX = Math.min(this.config.overscroll, Math.round(remainingSpace / 2));
+        const direction = scrollLeft ? -1 : 1;
+        return overscrollX * direction;
+    }
+
+    public scrollToRange(range: Desktop.Range) {
+        this.setScroll(this.calculateVisibleRange(range).getLeft(), true);
+    }
+
+    public scrollCenterRange(range: Desktop.Range) {
+        const windowCenter = range.getLeft() + range.getWidth() / 2;
+        const screenCenter = this.scrollX + this.tilingArea.width / 2;
+        this.adjustScroll(Math.round(windowCenter - screenCenter), false);
+    }
+
+    public autoAdjustScroll() {
+        const focusedColumn = this.grid.getLastFocusedColumn();
+        if (focusedColumn === null || focusedColumn.grid !== this.grid) {
+            return;
+        }
+
+        this.scrollToColumn(focusedColumn);
+    }
+
+    public scrollToColumn(column: Column) {
+        if (this.dirtyScroll || !column.isVisible(this.getCurrentVisibleRange(), true)) {
+            this.config.scroller.scrollToColumn(this, column);
+        }
+    }
+
+    private getVisibleRange(scrollX: number) {
+        return new Desktop.RangeImpl(scrollX, this.tilingArea.width);
+    }
+
+    public getCurrentVisibleRange() {
+        return this.getVisibleRange(this.scrollX);
+    }
+
+    private clampScrollX(x: number) {
+        return this.config.scroller.clampScrollX(this, x);
+    }
+
+    public setScroll(x: number, force: boolean) {
+        const oldScrollX = this.scrollX;
+        this.scrollX = force ? x : this.clampScrollX(x);
+        if (this.scrollX !== oldScrollX) {
+            this.onLayoutChanged();
+        }
+        this.dirtyScroll = false;
+    }
+
+    public adjustScroll(dx: number, force: boolean) {
+        this.setScroll(this.scrollX + dx, force);
+    }
+
+    public equalizeVisibleColumnsWidths() {
+        const visibleRange = this.getCurrentVisibleRange();
+        const visibleColumns = Array.from(this.grid.getVisibleColumns(visibleRange, true));
+
+        let remainingWidth = this.tilingArea.width - (visibleColumns.length-1) * this.grid.config.gapsInnerHorizontal;
+        let remainingColumns = visibleColumns.length;
+        for (const column of visibleColumns) {
+            const columnWidth = Math.round(remainingWidth / remainingColumns);
+            column.setWidth(columnWidth, true);
+            remainingWidth -= columnWidth;
+            remainingColumns--;
+        }
+
+        const targetVisibleRange = Desktop.RangeImpl.fromRanges(
+            visibleColumns[0],
+            visibleColumns[visibleColumns.length - 1],
+        );
+        this.setScroll(this.calculateVisibleRange(targetVisibleRange).getLeft(), false);
+    }
+
+    public arrange() {
+        // TODO (optimization): only arrange visible windows
+        this.updateArea();
+        if (!this.dirty) {
+            return;
+        }
+        this.grid.arrange(this.tilingArea.x - this.scrollX, this.getCurrentVisibleRange());
+        this.dirty = false;
+    }
+
+    public onLayoutChanged() {
+        this.dirty = true;
+        this.dirtyScroll = true;
+    }
+
+    public onPinsChanged() {
+        this.dirty = true;
+        this.dirtyScroll = true;
+        this.dirtyPins = true;
+    }
+
+    public destroy() {
+        this.grid.destroy();
+    }
+}
+
+namespace Desktop {
+    export type Config = {
+        marginTop: number,
+        marginBottom: number,
+        marginLeft: number,
+        marginRight: number,
+        overscroll: number,
+        scroller: Desktop.Scroller,
+    };
+
+    export type Range = {
+        getLeft(): number;
+        getRight(): number;
+        getWidth(): number;
+    }
+
+    export class RangeImpl {
+        private readonly x: number;
+        private readonly width: number;
+
+        constructor(x: number, width: number) {
+            this.x = x;
+            this.width = width;
+        }
+
+        public getLeft() {
+            return this.x;
+        }
+
+        public getRight() {
+            return this.x + this.width;
+        }
+
+        public getWidth() {
+            return this.width;
+        }
+
+        public static fromRanges(leftRange: Range, rightRange: Range) {
+            const left = leftRange.getLeft();
+            const right = rightRange.getRight();
+            return new RangeImpl(left, right - left);
+        }
+    }
+
+    export type Scroller = {
+        scrollToColumn(desktop: Desktop, column: Column): void;
+        clampScrollX(desktop: Desktop, x: number): number;
+    }
+}

src/layout/Grid.ts

@@ -1,58 +1,37 @@
+import Range = Desktop.Range;
+
 class Grid {
-    public readonly world: World;
+    public readonly desktop: Desktop;
+    public readonly config: LayoutConfig;
     private readonly columns: LinkedList<Column>;
     private lastFocusedColumn: Column|null;
-    private scrollX: number;
     private width: number;
     private userResize: boolean; // is any part of the grid being resized by the user
-    public clientArea: QRect;
-    public tilingArea: QRect;
-    public readonly desktop: number;
     private readonly userResizeFinishedDelayer: Delayer;
 
-    constructor(world: World, desktop: number) {
-        this.world = world;
+    constructor(desktop: Desktop, config: LayoutConfig) {
+        this.desktop = desktop;
+        this.config = config;
         this.columns = new LinkedList();
         this.lastFocusedColumn = null;
-        this.scrollX = 0;
         this.width = 0;
         this.userResize = false;
-        this.desktop = desktop;
-        this.updateArea();
         this.userResizeFinishedDelayer = new Delayer(50, () => {
             // this delay prevents windows' contents from freezing after resizing
-            this.autoAdjustScroll();
-            this.arrange();
+            this.desktop.onLayoutChanged();
+            this.desktop.autoAdjustScroll();
+            this.desktop.arrange();
         });
     }
 
-    updateArea() {
-        const newClientArea = workspace.clientArea(workspace.PlacementArea, 0, this.desktop);
-        if (newClientArea === this.clientArea) {
-            return;
-        }
-
-        this.clientArea = newClientArea;
-        this.tilingArea = Qt.rect(
-            newClientArea.x + this.world.config.gapsOuterLeft,
-            newClientArea.y + this.world.config.gapsOuterTop,
-            newClientArea.width - this.world.config.gapsOuterLeft - this.world.config.gapsOuterRight,
-            newClientArea.height - this.world.config.gapsOuterTop - this.world.config.gapsOuterBottom,
-        )
-        for (const column of this.columns.iterator()) {
-            column.resizeWindows();
-        }
-
-        this.autoAdjustScroll();
-    }
-
-    moveColumnLeft(column: Column) {
+    public moveColumnLeft(column: Column) {
         this.columns.moveBack(column);
         this.columnsSetX(column);
-        this.autoAdjustScroll();
+        this.desktop.onLayoutChanged();
+        this.desktop.autoAdjustScroll();
     }
 
-    moveColumnRight(column: Column) {
+    public moveColumnRight(column: Column) {
         const nextColumn = this.columns.getNext(column);
         if (nextColumn === null) {
             return;
@@ -60,179 +39,212 @@ class Grid {
         this.moveColumnLeft(nextColumn);
     }
 
-    getPrevColumn(column: Column) {
+    public getWidth() {
+        return this.width;
+    }
+
+    public getPrevColumn(column: Column) {
         return this.columns.getPrev(column);
     }
 
-    getNextColumn(column: Column) {
+    public getNextColumn(column: Column) {
         return this.columns.getNext(column);
     }
 
-    getFirstColumn() {
+    public getFirstColumn() {
         return this.columns.getFirst();
     }
 
-    getLastColumn() {
+    public getLastColumn() {
         return this.columns.getLast();
     }
 
-    getColumnAtIndex(i: number) {
+    public getColumnAtIndex(i: number) {
         return this.columns.getItemAtIndex(i);
     }
 
-    getLastFocusedColumn() {
+    public getLastFocusedColumn() {
         if (this.lastFocusedColumn === null || this.lastFocusedColumn.grid !== this) {
             return null;
         }
         return this.lastFocusedColumn;
     }
 
-    getLeftmostVisibleColumn(fullyVisible: boolean) {
+    public getLastFocusedWindow() {
+        const lastFocusedColumn = this.getLastFocusedColumn();
+        if (lastFocusedColumn === null) {
+            return null;
+        }
+        return lastFocusedColumn.getFocusTaker();
+    }
+
+    private columnsSetX(firstMovedColumn: Column|null) {
+        const lastUnmovedColumn = firstMovedColumn === null ? this.columns.getLast() : this.columns.getPrev(firstMovedColumn);
+        let x = lastUnmovedColumn === null ? 0 : lastUnmovedColumn.getRight() + this.config.gapsInnerHorizontal;
+        if (firstMovedColumn !== null) {
+            for (const column of this.columns.iteratorFrom(firstMovedColumn)) {
+                column.gridX = x;
+                x += column.getWidth() + this.config.gapsInnerHorizontal;
+            }
+        }
+        this.width = x - this.config.gapsInnerHorizontal;
+    }
+
+    public getLeftmostVisibleColumn(visibleRange: Desktop.Range, fullyVisible: boolean) {
         for (const column of this.columns.iterator()) {
-            const left = column.gridX - this.scrollX; // in screen space
-            const right = left + column.width; // in screen space
-            const x = fullyVisible ? left : right;
-            if (x >= 0) {
+            if (column.isVisible(visibleRange, fullyVisible)) {
                 return column;
             }
         }
         return null;
     }
 
-    getRightmostVisibleColumn(fullyVisible: boolean) {
+    public getRightmostVisibleColumn(visibleRange: Desktop.Range, fullyVisible: boolean) {
         let last = null;
         for (const column of this.columns.iterator()) {
-            const left = column.gridX - this.scrollX; // in screen space
-            const right = left + column.width; // in screen space
-            const x = fullyVisible ? right : left;
-            if (x <= this.tilingArea.width) {
+            if (column.isVisible(visibleRange, fullyVisible)) {
                 last = column;
-            } else {
+            } else if (last !== null) {
                 break;
             }
         }
         return last;
     }
 
-    rescaleVisibleColumns(fullyVisible: boolean, allowScaleUp: boolean) {
-        const startColumn = this.getLeftmostVisibleColumn(fullyVisible);
-        const endColumn = this.getRightmostVisibleColumn(fullyVisible);
-        if (startColumn === null || endColumn === null) {
-            return;
-        }
-
-        const startX = startColumn.gridX;
-        const endX = endColumn.gridX + endColumn.width;
-        const width = endX - startX;
-        let remainingWidth = this.tilingArea.width - 2 * this.world.config.overscroll;
-        const scaleRatio = remainingWidth / width;
-        if (!allowScaleUp && scaleRatio >= 1.0) {
-            return;
-        }
-
-        for (const column of this.columns.iteratorFrom(startColumn)) {
-            if (column !== endColumn) {
-                const newWidth = Math.round(column.width * scaleRatio);
-                column.setWidth(newWidth, true);
-                remainingWidth -= newWidth + this.world.config.gapsInnerHorizontal;
-            } else {
-                column.setWidth(remainingWidth, true);
-                break;
-            }
-        }
-
-        this.setScroll(startX - this.world.config.overscroll, false);
-    }
-
-    scrollToColumn(column: Column) {
-        const left = column.gridX - this.scrollX; // in screen space
-        const right = left + column.width; // in screen space
-        const remainingSpace = this.tilingArea.width - column.width;
-        const overScrollX = Math.min(this.world.config.overscroll, Math.round(remainingSpace / 2));
-        if (left < 0) {
-            this.adjustScroll(left - overScrollX, false);
-        } else if (right > this.tilingArea.width) {
-            this.adjustScroll(right - this.tilingArea.width + overScrollX, false);
-        } else {
-            this.removeOverscroll();
-        }
-    }
-
-    scrollCenterColumn(column: Column) {
-        const windowCenter = column.gridX + column.width / 2 + this.world.config.gapsInnerHorizontal - this.scrollX; // in screen space
-        const screenCenter = this.tilingArea.x + this.tilingArea.width / 2;
-        this.adjustScroll(Math.round(windowCenter - screenCenter), false);
-    }
-
-    autoAdjustScroll() {
-        const focusedWindow = this.world.getFocusedWindow();
-        if (focusedWindow === null) {
-            this.removeOverscroll();
-            return;
-        }
-
-        const column = focusedWindow.column;
-        if (column.grid !== this) {
-            return;
-        }
-        this.scrollToColumn(column);
-    }
-
-    private setScroll(x: number, force: boolean) {
-        if (!force) {
-            let minScroll = 0;
-            let maxScroll = this.width - this.tilingArea.width;
-            if (maxScroll < 0) {
-                const centerScroll = Math.round(maxScroll / 2);
-                minScroll = centerScroll;
-                maxScroll = centerScroll;
-            }
-            x = clamp(x, minScroll, maxScroll);
-        }
-        this.scrollX = x;
-    }
-
-    adjustScroll(dx: number, force: boolean) {
-        this.setScroll(this.scrollX + dx, force);
-    }
-
-    private removeOverscroll() {
-        this.setScroll(this.scrollX, false);
-    }
-
-    private columnsSetX(firstMovedColumn: Column|null) {
-        const lastUnmovedColumn = firstMovedColumn === null ? this.columns.getLast() : this.columns.getPrev(firstMovedColumn);
-        let x = lastUnmovedColumn === null ? 0 : lastUnmovedColumn.gridX + lastUnmovedColumn.width + this.world.config.gapsInnerHorizontal;
-        if (firstMovedColumn !== null) {
-            for (const column of this.columns.iteratorFrom(firstMovedColumn)) {
-                column.gridX = x;
-                x += column.width + this.world.config.gapsInnerHorizontal;
-            }
-        }
-        this.width = x - this.world.config.gapsInnerHorizontal;
-    }
-
-    arrange() {
-        // TODO (optimization): only arrange visible windows
-        this.updateArea();
-        let x = this.tilingArea.x - this.scrollX;
+    public *getVisibleColumns(visibleRange: Desktop.Range, fullyVisible: boolean) {
         for (const column of this.columns.iterator()) {
-            column.arrange(x);
-            x += column.getWidth() + this.world.config.gapsInnerHorizontal;
+            if (column.isVisible(visibleRange, fullyVisible)) {
+                yield column;
+            }
         }
     }
 
-    onColumnAdded(column: Column, prevColumn: Column|null) {
+    public getVisibleColumnsWidth(visibleRange: Desktop.Range, fullyVisible: boolean) {
+        let width = 0;
+        let nVisible = 0;
+        for (const column of this.getVisibleColumns(visibleRange, fullyVisible)) {
+            width += column.getWidth();
+            nVisible++;
+        }
+
+        if (nVisible > 0) {
+            width += (nVisible-1) * this.config.gapsInnerHorizontal;
+        }
+
+        return width;
+    }
+
+    public increaseColumnWidth(column: Column) {
+        const visibleRange = this.desktop.calculateVisibleRange(column);
+        if(!column.isVisible(visibleRange, true) || column.getWidth() >= column.getMaxWidth()) {
+            return;
+        }
+
+        let leftVisibleColumn = this.getLeftmostVisibleColumn(visibleRange, true);
+        let rightVisibleColumn = this.getRightmostVisibleColumn(visibleRange, true);
+        if (leftVisibleColumn === null || rightVisibleColumn === null) {
+            console.assert(false);
+            return;
+        }
+
+        const leftSpace = leftVisibleColumn.getLeft() - visibleRange.getLeft();
+        const rightSpace = visibleRange.getRight() - rightVisibleColumn.getRight();
+        if (leftSpace + rightSpace > 0) {
+            column.adjustWidth(leftSpace + rightSpace, true);
+        } else {
+            // left and right columns are touching the screen's edges
+            const leftSpace = leftVisibleColumn === column ? Infinity : leftVisibleColumn.getWidth() + this.config.gapsInnerHorizontal;
+            const rightSpace = rightVisibleColumn === column ? Infinity : rightVisibleColumn.getWidth() + this.config.gapsInnerHorizontal;
+            if (leftSpace < rightSpace) {
+                column.adjustWidth(leftSpace, true);
+                leftVisibleColumn = this.getNextColumn(leftVisibleColumn)!;
+            } else {
+                column.adjustWidth(rightSpace, true);
+                rightVisibleColumn = this.getPrevColumn(rightVisibleColumn)!;
+            }
+        }
+
+        this.desktop.scrollCenterRange(Desktop.RangeImpl.fromRanges(leftVisibleColumn, rightVisibleColumn));
+    }
+
+    public decreaseColumnWidth(column: Column) {
+        const visibleRange = this.desktop.calculateVisibleRange(column);
+        if (!column.isVisible(visibleRange, true)) {
+            return;
+        }
+
+        if (this.width <= visibleRange.getWidth()) {
+            column.setWidth(Math.round(column.getWidth() / 2), true);
+            return;
+        }
+
+        const leftVisibleColumn = this.getLeftmostVisibleColumn(visibleRange, true);
+        const rightVisibleColumn = this.getRightmostVisibleColumn(visibleRange, true);
+        if (leftVisibleColumn === null || rightVisibleColumn === null) {
+            console.assert(false);
+            return;
+        }
+
+        let leftOffScreenColumn = this.getPrevColumn(leftVisibleColumn);
+        if (leftOffScreenColumn === column) {
+            leftOffScreenColumn = null;
+        }
+        let rightOffScreenColumn = this.getNextColumn(rightVisibleColumn);
+        if (rightOffScreenColumn === column) {
+            rightOffScreenColumn = null;
+        }
+        if (leftOffScreenColumn === null && rightOffScreenColumn === null) {
+            console.assert(false);
+            return;
+        }
+
+        const leftInvisibleWidth = leftOffScreenColumn === null ? Infinity : visibleRange.getLeft() - leftOffScreenColumn.getLeft();
+        const rightInvisibleWidth = rightOffScreenColumn === null ? Infinity : rightOffScreenColumn.getRight() - visibleRange.getRight();
+
+        const leftSpace = leftVisibleColumn.getLeft() - visibleRange.getLeft();
+        const rightSpace = visibleRange.getRight() - rightVisibleColumn.getRight();
+
+        if (leftInvisibleWidth < rightInvisibleWidth) {
+            const deltaWidth = rightSpace - leftInvisibleWidth;
+            column.adjustWidth(deltaWidth, true);
+            console.assert(leftOffScreenColumn !== null);
+            const newVisibleWidth = rightVisibleColumn.getRight() - leftOffScreenColumn!.getLeft();
+            const leftVisibleColumn = newVisibleWidth <= visibleRange.getWidth() ? leftOffScreenColumn! : this.getNextColumn(leftOffScreenColumn!)!;
+            this.desktop.scrollCenterRange(Desktop.RangeImpl.fromRanges(leftVisibleColumn, rightVisibleColumn));
+        } else {
+            const deltaWidth = leftSpace - rightInvisibleWidth;
+            column.adjustWidth(deltaWidth, true);
+            console.assert(rightOffScreenColumn !== null);
+            const newVisibleWidth = rightOffScreenColumn!.getRight() - leftVisibleColumn.getLeft();
+            const rightVisibleColumn = newVisibleWidth <= visibleRange.getWidth() ? rightOffScreenColumn! : this.getPrevColumn(rightOffScreenColumn!)!;
+            this.desktop.scrollCenterRange(Desktop.RangeImpl.fromRanges(leftVisibleColumn, rightVisibleColumn));
+        }
+    }
+
+    public arrange(x: number, visibleRange: Range) {
+        for (const column of this.columns.iterator()) {
+            column.arrange(x, visibleRange, this.userResize);
+            x += column.getWidth() + this.config.gapsInnerHorizontal;
+        }
+
+        const focusedWindow = this.getLastFocusedWindow();
+        if (focusedWindow !== null) {
+            focusedWindow.client.ensureTransientsVisible(this.desktop.clientArea);
+        }
+    }
+
+    public onColumnAdded(column: Column, prevColumn: Column|null) {
         if (prevColumn === null) {
             this.columns.insertStart(column);
         } else {
             this.columns.insertAfter(column, prevColumn);
         }
         this.columnsSetX(column);
-        this.autoAdjustScroll();
+        this.desktop.onLayoutChanged();
+        this.desktop.autoAdjustScroll();
     }
 
-    onColumnRemoved(column: Column, passFocus: boolean) {
+    public onColumnRemoved(column: Column, passFocus: boolean) {
         const isLastColumn = this.columns.length() === 1;
         const nextColumn = this.getNextColumn(column);
         const columnToFocus = isLastColumn ? null : this.getPrevColumn(column) ?? nextColumn;
@@ -243,60 +255,70 @@ class Grid {
         this.columns.remove(column);
         this.columnsSetX(nextColumn);
 
+        this.desktop.onLayoutChanged();
         if (passFocus && columnToFocus !== null) {
             columnToFocus.focus();
         } else {
-            this.removeOverscroll();
+            this.desktop.autoAdjustScroll();
         }
     }
 
-    onColumnMoved(column: Column, prevColumn: Column|null) {
+    public onColumnMoved(column: Column, prevColumn: Column|null) {
         const movedLeft = prevColumn === null ? true : column.isAfter(prevColumn);
         const firstMovedColumn = movedLeft ? column : this.getNextColumn(column);
         this.columns.move(column, prevColumn);
         this.columnsSetX(firstMovedColumn);
-        this.autoAdjustScroll();
+        this.desktop.onLayoutChanged();
+        this.desktop.autoAdjustScroll();
     }
 
-    onColumnWidthChanged(column: Column, oldWidth: number, width: number) {
+    public onColumnWidthChanged(column: Column, oldWidth: number, width: number) {
         const nextColumn = this.columns.getNext(column);
         this.columnsSetX(nextColumn);
         if (!this.userResize) {
-            this.autoAdjustScroll();
+            this.desktop.autoAdjustScroll();
         }
+        this.desktop.onLayoutChanged();
     }
 
-    onColumnFocused(column: Column) {
+    public onColumnFocused(column: Column) {
         const lastFocusedColumn = this.getLastFocusedColumn();
         if (lastFocusedColumn !== null) {
             lastFocusedColumn.restoreToTiled();
         }
         this.lastFocusedColumn = column;
-        this.scrollToColumn(column);
+        this.desktop.scrollToColumn(column);
     }
 
-    onUserResizeStarted() {
+    public onScreenSizeChanged() {
+        for (const column of this.columns.iterator()) {
+            column.updateWidth();
+            column.resizeWindows();
+        }
+    }
+
+    public onUserResizeStarted() {
         this.userResize = true;
     }
 
-    onUserResizeFinished() {
+    public onUserResizeFinished() {
         this.userResize = false;
         this.userResizeFinishedDelayer.run();
     }
 
-    evacuateTail(targetGrid: Grid, startColumn: Column) {
+    public evacuateTail(targetGrid: Grid, startColumn: Column) {
         for (const column of this.columns.iteratorFrom(startColumn)) {
             column.moveToGrid(targetGrid, targetGrid.getLastColumn());
         }
     }
 
-    evacuate(targetGrid: Grid) {
+    public evacuate(targetGrid: Grid) {
         for (const column of this.columns.iterator()) {
             column.moveToGrid(targetGrid, targetGrid.getLastColumn());
         }
     }
 
-    destroy() {
+    public destroy() {
         this.userResizeFinishedDelayer.destroy();
     }
 }

src/layout/LayoutConfig.ts

@@ -0,0 +1,11 @@
+type LayoutConfig = {
+    gapsInnerHorizontal: number,
+    gapsInnerVertical: number,
+    offScreenOpacity: number,
+    stackColumnsByDefault: boolean,
+    resizeNeighborColumn: boolean,
+    reMaximize: boolean,
+    skipSwitcher: boolean,
+    tiledKeepBelow: boolean,
+    maximizedKeepAbove: boolean,
+};

src/layout/ScrollerCentered.ts

@@ -0,0 +1,21 @@
+class ScrollerCentered {
+    public scrollToColumn(desktop: Desktop, column: Column) {
+        desktop.scrollCenterRange(column);
+    }
+
+    public clampScrollX(desktop: Desktop, x: number) {
+        return ScrollerCentered.clampScrollX(desktop, x);
+    }
+
+    public static clampScrollX(desktop: Desktop, x: number) {
+        const firstColumn = desktop.grid.getFirstColumn();
+        if (firstColumn === null) {
+            return 0;
+        }
+        const lastColumn = desktop.grid.getLastColumn()!;
+
+        let minScroll = Math.round((firstColumn.getWidth() - desktop.tilingArea.width) / 2);
+        let maxScroll = Math.round(desktop.grid.getWidth() - (desktop.tilingArea.width + lastColumn.getWidth()) / 2);
+        return clamp(x, minScroll, maxScroll);
+    }
+}

src/layout/ScrollerGrouped.ts

@@ -0,0 +1,87 @@
+class ScrollerGrouped {
+    private readonly layoutConfig: LayoutConfig;
+
+    constructor(layoutConfig: LayoutConfig) {
+        this.layoutConfig = layoutConfig;
+    }
+
+    public scrollToColumn(desktop: Desktop, column: Column) {
+        const columnRange = new ScrollerGrouped.ColumnRange(column);
+        const visibleRange = desktop.getCurrentVisibleRange();
+        columnRange.addNeighbors(visibleRange, this.layoutConfig.gapsInnerHorizontal, true);
+        columnRange.addNeighbors(visibleRange, this.layoutConfig.gapsInnerHorizontal, false);
+        desktop.scrollCenterRange(columnRange);
+    }
+
+    public clampScrollX(desktop: Desktop, x: number) {
+        return ScrollerCentered.clampScrollX(desktop, x);
+    }
+}
+
+namespace ScrollerGrouped {
+    import Range = Desktop.Range;
+
+    export class ColumnRange {
+        private left: Column;
+        private right: Column;
+        private width: number;
+
+        constructor(initialColumn: Column) {
+            this.left = initialColumn;
+            this.right = initialColumn;
+            this.width = initialColumn.getWidth();
+        }
+
+        public addNeighbors(visibleRange: Range, gap: number, requireVisible: boolean) {
+            const grid = this.left.grid;
+
+            let leftColumn: Column|null = this.left;
+            while (true) {
+                leftColumn = grid.getPrevColumn(leftColumn);
+                if (
+                    leftColumn === null ||
+                    requireVisible && !leftColumn.isVisible(visibleRange, true) ||
+                    this.width + gap + leftColumn.getWidth() > visibleRange.getWidth()
+                ) {
+                    break;
+                }
+                this.addLeft(leftColumn, gap);
+            }
+
+            let rightColumn: Column|null = this.right;
+            while (true) {
+                rightColumn = grid.getNextColumn(rightColumn);
+                if (
+                    rightColumn === null ||
+                    requireVisible && !rightColumn.isVisible(visibleRange, true) ||
+                    this.width + gap + rightColumn.getWidth() > visibleRange.getWidth()
+                ) {
+                    break;
+                }
+                this.addRight(rightColumn, gap);
+            }
+        }
+
+        public addLeft(column: Column, gap: number) {
+            this.left = column;
+            this.width += column.getWidth() + gap;
+        }
+
+        public addRight(column: Column, gap: number) {
+            this.right = column;
+            this.width += column.getWidth() + gap;
+        }
+
+        public getLeft() {
+            return this.left.getLeft();
+        }
+
+        public getRight() {
+            return this.right.getRight();
+        }
+
+        public getWidth() {
+            return this.width;
+        }
+    }
+}

src/layout/ScrollerLazy.ts

@@ -0,0 +1,14 @@
+class ScrollerLazy {
+    public scrollToColumn(desktop: Desktop, column: Column) {
+        desktop.scrollToRange(column);
+    }
+
+    public clampScrollX(desktop: Desktop, x: number) {
+        let minScroll = 0;
+        let maxScroll = desktop.grid.getWidth() - desktop.tilingArea.width;
+        if (maxScroll < 0) {
+            return Math.round(maxScroll / 2);
+        }
+        return clamp(x, minScroll, maxScroll);
+    }
+}

src/layout/Window.ts

@@ -2,7 +2,7 @@ class Window {
     public column: Column;
     public readonly client: ClientWrapper;
     public height: number;
-    public readonly focusedState: WindowState;
+    public readonly focusedState: Window.State;
     private skipArrange: boolean;
 
     constructor(client: ClientWrapper, column: Column) {
@@ -18,7 +18,7 @@ class Window {
         column.onWindowAdded(this);
     }
 
-    moveToColumn(targetColumn: Column) {
+    public moveToColumn(targetColumn: Column) {
         if (targetColumn === this.column) {
             return;
         }
@@ -27,21 +27,31 @@ class Window {
         targetColumn.onWindowAdded(this);
     }
 
-    arrange(x: number, y: number, width: number, height: number) {
+    public arrange(x: number, y: number, width: number, height: number) {
         if (this.skipArrange) {
-            // window is being manually resized, prevent fighting with the user
+            // window is maximized, fullscreen, or being manually resized, prevent fighting with the user
             return;
         }
-        this.client.place(x, y, width, height);
-        if (this.isFocused()) {
+
+        let maximized = false;
+        if (this.column.grid.config.reMaximize && this.isFocused()) {
             // do this here rather than in `onFocused` to ensure it happens after placement
             // (otherwise placement may not happen at all)
-            this.client.setMaximize(this.focusedState.maximizedVertically, this.focusedState.maximizedHorizontally);
-            this.client.setFullScreen(this.focusedState.fullScreen);
+            if (this.focusedState.maximizedVertically || this.focusedState.maximizedHorizontally) {
+                this.client.setMaximize(this.focusedState.maximizedVertically, this.focusedState.maximizedHorizontally);
+                maximized = true;
+            }
+            if (this.focusedState.fullScreen) {
+                this.client.setFullScreen(true);
+                maximized = true;
+            }
+        }
+        if (!maximized) {
+            this.client.place(x, y, width, height);
         }
     }
 
-    focus() {
+    public focus() {
         if (this.client.isShaded()) {
             // workaround for KWin deactivating clients when unshading immediately after activation
             this.client.setShade(false);
@@ -49,67 +59,93 @@ class Window {
         this.client.focus();
     }
 
-    isFocused() {
+    public isFocused() {
         return this.client.isFocused();
     }
 
-    onFocused() {
+    public onFocused() {
         this.column.onWindowFocused(this);
     }
 
-    restoreToTiled() {
+    public restoreToTiled() {
         if (this.isFocused()) {
             return;
         }
-        this.client.setMaximize(false, false);
         this.client.setFullScreen(false);
+        this.client.setMaximize(false, false);
+        this.column.grid.desktop.onLayoutChanged();
     }
 
-    onMaximizedChanged(horizontally: boolean, vertically: boolean) {
+    public onMaximizedChanged(horizontally: boolean, vertically: boolean) {
         const maximized = horizontally || vertically;
         this.skipArrange = maximized;
-        this.client.kwinClient.keepBelow = !maximized;
+        if (this.column.grid.config.tiledKeepBelow) {
+            this.client.kwinClient.keepBelow = !maximized;
+        }
+        if (this.column.grid.config.maximizedKeepAbove) {
+            this.client.kwinClient.keepAbove = maximized;
+        }
         if (this.isFocused()) {
             this.focusedState.maximizedHorizontally = horizontally;
             this.focusedState.maximizedVertically = vertically;
         }
+        this.column.grid.desktop.onLayoutChanged();
     }
 
-    onFullScreenChanged(fullScreen: boolean) {
+    public onFullScreenChanged(fullScreen: boolean) {
         this.skipArrange = fullScreen;
-        if (this.isFocused()) {
+        if (this.column.grid.config.tiledKeepBelow) {
             this.client.kwinClient.keepBelow = !fullScreen;
+        }
+        if (this.column.grid.config.maximizedKeepAbove) {
+            this.client.kwinClient.keepAbove = fullScreen;
+        }
+        if (this.isFocused()) {
             this.focusedState.fullScreen = fullScreen;
         }
+        this.column.grid.desktop.onLayoutChanged();
     }
 
-    onUserResize(oldGeometry: QRect) {
+    public onUserResize(oldGeometry: QmlRect, resizeNeighborColumn: boolean) {
         const newGeometry = this.client.kwinClient.frameGeometry;
         const widthDelta = newGeometry.width - oldGeometry.width;
         const heightDelta = newGeometry.height - oldGeometry.height;
         if (widthDelta !== 0) {
             this.column.adjustWidth(widthDelta, true);
-            if (newGeometry.x !== oldGeometry.x) {
-                this.column.grid.adjustScroll(widthDelta, true);
+            let leftEdgeDelta = newGeometry.left - oldGeometry.left;
+            const resizingLeftSide = leftEdgeDelta !== 0;
+            if (resizeNeighborColumn && this.column.grid.config.resizeNeighborColumn) {
+                const neighborColumn = resizingLeftSide ? this.column.grid.getPrevColumn(this.column) : this.column.grid.getNextColumn(this.column);
+                if (neighborColumn !== null) {
+                    const oldNeighborWidth = neighborColumn.getWidth();
+                    neighborColumn.adjustWidth(-widthDelta, true);
+                    if (resizingLeftSide) {
+                        leftEdgeDelta -= neighborColumn.getWidth() - oldNeighborWidth;
+                    }
+                }
             }
+            this.column.grid.desktop.adjustScroll(-leftEdgeDelta, true);
         }
         if (heightDelta !== 0) {
             this.column.adjustWindowHeight(this, heightDelta, newGeometry.y !== oldGeometry.y);
         }
     }
 
-    onProgrammaticResize(oldGeometry: QRect) {
+    public onFrameGeometryChanged() {
         const newGeometry = this.client.kwinClient.frameGeometry;
         this.column.setWidth(newGeometry.width, true);
+        this.column.grid.desktop.onLayoutChanged();
     }
 
-    destroy(passFocus: boolean) {
+    public destroy(passFocus: boolean) {
         this.column.onWindowRemoved(this, passFocus);
     }
 }
 
-type WindowState = {
-    fullScreen: boolean,
-    maximizedHorizontally: boolean,
-    maximizedVertically: boolean,
+namespace Window {
+    export type State = {
+        fullScreen: boolean,
+        maximizedHorizontally: boolean,
+        maximizedVertically: boolean,
+    }
 }

src/main.ts

@@ -1,6 +1,6 @@
 function init() {
     const config = loadConfig();
     const world = new World(config);
-    registerKeyBindings(world);
+    registerKeyBindings(world, config);
     return world;
 }

src/rules/ClientMatcher.ts

@@ -5,8 +5,8 @@ class ClientMatcher {
         this.rules = rules;
     }
 
-    matches(kwinClient: AbstractClient) {
-        const rule = this.rules.get(String(kwinClient.resourceClass));
+    public matches(kwinClient: KwinClient) {
+        const rule = this.rules.get(kwinClient.resourceClass);
         if (rule === undefined) {
             return false;
         }

src/rules/WindowRule.ts

@@ -2,4 +2,4 @@ type WindowRule = {
     class: string,
     caption: string,
     tile: boolean,
-}
+};

src/rules/WindowRuleEnforcer.ts

@@ -3,21 +3,25 @@ class WindowRuleEnforcer {
     private readonly preferTiling: ClientMatcher;
     private readonly followCaption: Set<string>;
 
-    constructor(world: World, windowRules: WindowRule[]) {
-        const [mapFloat, mapTile] = createWindowRuleMaps(windowRules);
+    constructor(windowRules: WindowRule[]) {
+        const [mapFloat, mapTile] = WindowRuleEnforcer.createWindowRuleMaps(windowRules);
         this.preferFloating = new ClientMatcher(mapFloat);
         this.preferTiling = new ClientMatcher(mapTile);
         this.followCaption = new Set([...mapFloat.keys(), ...mapTile.keys()]);
     }
 
-    shouldTile(kwinClient: AbstractClient) {
-        return canTileNow(kwinClient) && (
-            this.preferTiling.matches(kwinClient) ||
-            kwinClient.normalWindow && kwinClient.managed && !this.preferFloating.matches(kwinClient)
+    public shouldTile(kwinClient: KwinClient) {
+        return Clients.canTileNow(kwinClient) && (
+            this.preferTiling.matches(kwinClient) || (
+                kwinClient.normalWindow &&
+                !kwinClient.transient &&
+                kwinClient.managed &&
+                !this.preferFloating.matches(kwinClient)
+            )
         );
     }
 
-    initClientSignalManager(world: World, kwinClient: AbstractClient) {
+    public initClientSignalManager(world: World, kwinClient: KwinClient) {
         if (!this.followCaption.has(kwinClient.resourceClass)) {
             return null;
         }
@@ -26,58 +30,60 @@ class WindowRuleEnforcer {
         const manager = new SignalManager();
         manager.connect(kwinClient.captionChanged, () => {
             const shouldTile = enforcer.shouldTile(kwinClient);
-            if (shouldTile) {
-                world.tileClient(kwinClient);
-            } else {
-                world.untileClient(kwinClient);
-            }
+            world.do((clientManager, desktopManager) => {
+                if (shouldTile) {
+                    clientManager.tileClient(kwinClient);
+                } else {
+                    clientManager.untileClient(kwinClient);
+                }
+            });
         });
         return manager;
     }
-}
 
-function createWindowRuleMaps(windowRules: WindowRule[]) {
-    const mapFloat = new Map<string, string[]>();
-    const mapTile = new Map<string, string[]>();
-    for (const windowRule of windowRules) {
-        const map = windowRule.tile ? mapTile : mapFloat;
-        let captions = map.get(windowRule.class);
-        if (captions === undefined) {
-            captions = [];
-            map.set(windowRule.class, captions);
+    private static createWindowRuleMaps(windowRules: WindowRule[]) {
+        const mapFloat = new Map<string, string[]>();
+        const mapTile = new Map<string, string[]>();
+        for (const windowRule of windowRules) {
+            const map = windowRule.tile ? mapTile : mapFloat;
+            let captions = map.get(windowRule.class);
+            if (captions === undefined) {
+                captions = [];
+                map.set(windowRule.class, captions);
+            }
+            if (windowRule.caption !== undefined) {
+                captions.push(windowRule.caption);
+            }
         }
-        if (windowRule.caption !== undefined) {
-            captions.push(windowRule.caption);
+
+        return [
+            WindowRuleEnforcer.createWindowRuleRegexMap(mapFloat),
+            WindowRuleEnforcer.createWindowRuleRegexMap(mapTile),
+        ];
+    }
+
+    private static createWindowRuleRegexMap(windowRuleMap: Map<string, string[]>) {
+        const regexMap = new Map<string, RegExp>;
+        for (const [k, v] of windowRuleMap) {
+            regexMap.set(k, WindowRuleEnforcer.joinRegexes(v));
         }
+        return regexMap;
     }
 
-    return [
-        createWindowRuleRegexMap(mapFloat),
-        createWindowRuleRegexMap(mapTile),
-    ];
-}
+    private static joinRegexes(regexes: string[]) {
+        if (regexes.length == 0) {
+            return new RegExp("");
+        }
 
-function createWindowRuleRegexMap(windowRuleMap: Map<string, string[]>) {
-    const regexMap = new Map<string, RegExp>;
-    for (const [k, v] of windowRuleMap) {
-        regexMap.set(k, joinRegexes(v));
-    }
-    return regexMap;
-}
+        if (regexes.length == 1) {
+            return new RegExp("^" + regexes[0] + "$");
+        }
 
-function joinRegexes(regexes: string[]) {
-    if (regexes.length == 0) {
-        return new RegExp("");
+        const joinedRegexes = regexes.map(WindowRuleEnforcer.wrapParens).join("|");
+        return new RegExp("^" + joinedRegexes + "$");
     }
 
-    if (regexes.length == 1) {
-        return new RegExp("^" + regexes[0] + "$");
+    private static wrapParens(str: string) {
+        return "(" + str + ")";
     }
-
-    const joinedRegexes = regexes.map(wrapParens).join("|");
-    return new RegExp("^" + joinedRegexes + "$");
-}
-
-function wrapParens(str: string) {
-    return "(" + str + ")";
 }

src/utils/Delayer.ts

@@ -1,5 +1,5 @@
 class Delayer {
-    private readonly timer: QQmlTimer;
+    private readonly timer: QmlTimer;
 
     constructor(delay: number, f: () => void) {
         this.timer = initQmlTimer();
@@ -7,11 +7,11 @@ class Delayer {
         this.timer.triggered.connect(f);
     }
 
-    run() {
+    public run() {
         this.timer.restart();
     }
 
-    destroy() {
+    public destroy() {
         this.timer.destroy();
     }
 }

src/utils/Doer.ts

@@ -5,13 +5,13 @@ class Doer {
         this.nCalls = 0;
     }
 
-    do (f: () => void) {
+    public do (f: () => void) {
         this.nCalls++;
         f();
         this.nCalls--;
     }
 
-    isDoing() {
+    public isDoing() {
         return this.nCalls > 0;
     }
 }

src/utils/LinkedList.ts

@@ -1,7 +1,7 @@
 class LinkedList<T> {
-    private firstNode: LinkedListNode<T>|null;
-    private lastNode: LinkedListNode<T>|null;
-    private readonly itemMap: Map<T, LinkedListNode<T>>;
+    private firstNode: LinkedList.Node<T>|null;
+    private lastNode: LinkedList.Node<T>|null;
+    private readonly itemMap: Map<T, LinkedList.Node<T>>;
 
     constructor() {
         this.firstNode = null;
@@ -17,31 +17,31 @@ class LinkedList<T> {
         return node;
     }
 
-    insertBefore(item: T, nextItem: T) {
+    public insertBefore(item: T, nextItem: T) {
         const nextNode = this.getNode(nextItem);
         this.insert(item, nextNode.prev, nextNode);
     }
 
-    insertAfter(item: T, prevItem: T) {
+    public insertAfter(item: T, prevItem: T) {
         const prevNode = this.getNode(prevItem);
         this.insert(item, prevNode, prevNode.next);
     }
 
-    insertStart(item: T) {
+    public insertStart(item: T) {
         this.insert(item, null, this.firstNode);
     }
 
-    insertEnd(item: T) {
+    public insertEnd(item: T) {
         this.insert(item, this.lastNode, null);
     }
 
-    private insert(item: T, prevNode: LinkedListNode<T>|null, nextNode: LinkedListNode<T>|null) {
-        const node = new LinkedListNode(item);
+    private insert(item: T, prevNode: LinkedList.Node<T>|null, nextNode: LinkedList.Node<T>|null) {
+        const node = new LinkedList.Node(item);
         this.itemMap.set(item, node);
         this.insertNode(node, prevNode, nextNode);
     }
 
-    private insertNode(node: LinkedListNode<T>, prevNode: LinkedListNode<T>|null, nextNode: LinkedListNode<T>|null) {
+    private insertNode(node: LinkedList.Node<T>, prevNode: LinkedList.Node<T>|null, nextNode: LinkedList.Node<T>|null) {
         node.prev = prevNode;
         node.next = nextNode;
         if (nextNode !== null) {
@@ -60,31 +60,31 @@ class LinkedList<T> {
         }
     }
 
-    getPrev(item: T) {
+    public getPrev(item: T) {
         const prevNode = this.getNode(item).prev;
         return prevNode === null ? null : prevNode.item;
     }
 
-    getNext(item: T) {
+    public getNext(item: T) {
         const nextNode = this.getNode(item).next;
         return nextNode === null ? null : nextNode.item;
     }
 
-    getFirst() {
+    public getFirst() {
         if (this.firstNode === null) {
             return null;
         }
         return this.firstNode.item;
     }
 
-    getLast() {
+    public getLast() {
         if (this.lastNode === null) {
             return null;
         }
         return this.lastNode.item;
     }
 
-    getItemAtIndex(index: number) {
+    public getItemAtIndex(index: number) {
         let node = this.firstNode;
         if (node === null) {
             return null;
@@ -98,13 +98,13 @@ class LinkedList<T> {
         return node.item;
     }
 
-    remove(item: T) {
+    public remove(item: T) {
         const node = this.getNode(item);
         this.itemMap.delete(item);
         this.removeNode(node);
     }
 
-    private removeNode(node: LinkedListNode<T>) {
+    private removeNode(node: LinkedList.Node<T>) {
         const prevNode = node.prev;
         const nextNode = node.next;
         if (prevNode !== null) {
@@ -121,11 +121,11 @@ class LinkedList<T> {
         }
     }
 
-    contains(item: T) {
+    public contains(item: T) {
         return this.itemMap.has(item);
     }
 
-    private swap(node0: LinkedListNode<T>, node1: LinkedListNode<T>) {
+    private swap(node0: LinkedList.Node<T>, node1: LinkedList.Node<T>) {
         console.assert(node0.next === node1 && node1.prev === node0);
         const prevNode = node0.prev;
         const nextNode = node1.next;
@@ -150,7 +150,7 @@ class LinkedList<T> {
         }
     }
 
-    move(item: T, prevItem: T|null) {
+    public move(item: T, prevItem: T|null) {
         const node = this.getNode(item);
         this.removeNode(node);
         if (prevItem === null) {
@@ -161,7 +161,7 @@ class LinkedList<T> {
         }
     }
 
-    moveBack(item: T) {
+    public moveBack(item: T) {
         const node = this.getNode(item);
         if (node.prev !== null) {
             console.assert(node !== this.firstNode);
@@ -169,7 +169,7 @@ class LinkedList<T> {
         }
     }
 
-    moveForward(item: T) {
+    public moveForward(item: T) {
         const node = this.getNode(item);
         if (node.next !== null) {
             console.assert(node !== this.lastNode);
@@ -177,32 +177,34 @@ class LinkedList<T> {
         }
     }
 
-    length() {
+    public length() {
         return this.itemMap.size;
     }
 
-    *iterator() {
+    public *iterator() {
         for (let node = this.firstNode; node !== null; node = node.next) {
             yield node.item;
         }
     }
 
-    *iteratorFrom(startItem: T) {
-        for (let node: LinkedListNode<T>|null = this.getNode(startItem); node !== null; node = node.next) {
+    public *iteratorFrom(startItem: T) {
+        for (let node: LinkedList.Node<T>|null = this.getNode(startItem); node !== null; node = node.next) {
             yield node.item;
         }
     }
 }
 
-// TODO (optimization): reuse nodes
-class LinkedListNode<T> {
-    public readonly item: T;
-    public prev: LinkedListNode<T>|null;
-    public next: LinkedListNode<T>|null;
+namespace LinkedList {
+    // TODO (optimization): reuse nodes
+    export class Node<T> {
+        public readonly item: T;
+        public prev: Node<T> | null;
+        public next: Node<T> | null;
 
-    constructor(item: T) {
-        this.item = item;
-        this.prev = null;
-        this.next = null;
+        constructor(item: T) {
+            this.item = item;
+            this.prev = null;
+            this.next = null;
+        }
     }
 }

src/utils/SignalManager.ts

@@ -1,16 +1,16 @@
 class SignalManager {
-    private connections: { signal: QSignal, handler: (...args: any[]) => void }[];
+    private connections: { signal: QSignal<any>, handler: (...args: any) => void }[];
 
     constructor() {
         this.connections = [];
     }
 
-    connect(signal: QSignal, handler: (...args: any[]) => void) {
+    public connect<T extends unknown[]>(signal: QSignal<T>, handler: (...args: [...T]) => void) {
         signal.connect(handler);
         this.connections.push({ signal: signal, handler: handler });
     }
 
-    destroy() {
+    public destroy() {
         for (const connection of this.connections) {
             connection.signal.disconnect(connection.handler);
         }

src/utils/log.ts

@@ -0,0 +1,3 @@
+function log(...args: any[]) {
+    console.log("Karousel:", ...args);
+}

src/utils/math.ts

@@ -8,9 +8,7 @@ function clamp(value: number, min: number, max: number) {
     return value;
 }
 
-function rectEqual(a: QRect, b: QRect) {
-    return a.x === b.x &&
-        a.y === b.y &&
-        a.width === b.width &&
-        a.height === b.height;
+function union<T>(array0: T[], array1: T[]) {
+    const set = new Set([...array0, ...array1]);
+    return [...set];
 }

src/workspace.ts

@@ -1,9 +1,8 @@
 function initWorkspaceSignalHandlers(world: World) {
     const manager = new SignalManager();
 
-    manager.connect(workspace.clientAdded, (kwinClient: AbstractClient) => {
-        console.assert(!world.hasClient(kwinClient));
-        if (canTileEver(kwinClient)) {
+    manager.connect(workspace.clientAdded, (kwinClient: KwinClient) => {
+        if (Clients.canTileEver(kwinClient)) {
             // never open new tileable clients on all desktops or activities
             if (kwinClient.desktop <= 0) {
                 kwinClient.desktop = workspace.currentDesktop;
@@ -12,48 +11,56 @@ function initWorkspaceSignalHandlers(world: World) {
                 kwinClient.activities = [workspace.currentActivity];
             }
         }
-        world.addClient(kwinClient);
-    });
-
-    manager.connect(workspace.clientRemoved, (kwinClient: AbstractClient) => {
-        console.assert(world.hasClient(kwinClient));
-        world.removeClient(kwinClient, true);
-    });
-
-    manager.connect(workspace.clientMinimized, (kwinClient: AbstractClient) => {
-        world.minimizeClient(kwinClient);
-    });
-
-    manager.connect(workspace.clientUnminimized, (kwinClient: AbstractClient) => {
-        world.unminimizeClient(kwinClient);
-    });
-
-    manager.connect(workspace.clientMaximizeSet, (kwinClient: AbstractClient, horizontally: boolean, vertically: boolean) => {
-        world.doIfTiled(kwinClient, false, (window, column, grid) => {
-            window.onMaximizedChanged(horizontally, vertically);
-            grid.arrange();
+        world.do((clientManager, desktopManager) => {
+            clientManager.addClient(kwinClient)
         });
     });
 
-    manager.connect(workspace.clientActivated, (kwinClient: AbstractClient) => {
+    manager.connect(workspace.clientRemoved, (kwinClient: KwinClient) => {
+        world.do((clientManager, desktopManager) => {
+            clientManager.removeClient(kwinClient, true);
+        });
+    });
+
+    manager.connect(workspace.clientMinimized, (kwinClient: KwinClient) => {
+        world.do((clientManager, desktopManager) => {
+            clientManager.minimizeClient(kwinClient);
+        });
+    });
+
+    manager.connect(workspace.clientUnminimized, (kwinClient: KwinClient) => {
+        world.do((clientManager, desktopManager) => {
+            clientManager.unminimizeClient(kwinClient);
+        });
+    });
+
+    manager.connect(workspace.clientMaximizeSet, (kwinClient: KwinClient, horizontally: boolean, vertically: boolean) => {
+        if ((horizontally || vertically) && kwinClient.tile !== null) {
+            kwinClient.tile = null;
+        }
+        world.doIfTiled(kwinClient, false, (world, desktopManager, window, column, grid) => {
+            window.onMaximizedChanged(horizontally, vertically);
+        });
+    });
+
+    manager.connect(workspace.clientActivated, (kwinClient: KwinClient) => {
         if (kwinClient === null) {
             return;
         }
-        world.onClientFocused(kwinClient);
-        world.doIfTiled(kwinClient, true, (window, column, grid) => {
-            window.onFocused();
-            grid.arrange();
+        world.do((clientManager, desktopManager) => {
+            clientManager.onClientFocused(kwinClient);
         });
     });
 
-    manager.connect(workspace.clientFullScreenSet, (kwinClient: X11Client, fullScreen: boolean, user: boolean) => {
-        world.doIfTiled(kwinClient, false, (window, column, grid) => {
-            window.onFullScreenChanged(fullScreen);
-            grid.arrange();
-        });
+    manager.connect(workspace.currentDesktopChanged, () => {
+        world.do(() => {}); // re-arrange desktop
     });
 
-    manager.connect(workspace.numberDesktopsChanged, (oldNumberOfDesktops: number) => {
+    manager.connect(workspace.currentActivityChanged, () => {
+        world.do(() => {}); // re-arrange desktop
+    });
+
+    manager.connect(workspace.numberDesktopsChanged, (oldNumberOfVirtualDesktops: number) => {
         world.updateDesktops();
     });
 

src/world/ClientManager.ts

@@ -0,0 +1,204 @@
+class ClientManager {
+    private readonly world: World;
+    private readonly config: ClientManager.Config;
+    private readonly desktopManager: DesktopManager;
+    private readonly pinManager: PinManager;
+    private readonly clientMap: Map<KwinClient, ClientWrapper>;
+    private lastFocusedClient: KwinClient|null;
+    private readonly windowRuleEnforcer: WindowRuleEnforcer;
+
+    constructor(config: Config, world: World, desktopManager: DesktopManager, pinManager: PinManager) {
+        this.world = world;
+        this.config = { keepAbove: config.floatingKeepAbove };
+        this.desktopManager = desktopManager;
+        this.pinManager = pinManager;
+        this.clientMap = new Map();
+        this.lastFocusedClient = null;
+
+        let parsedWindowRules: WindowRule[] = [];
+        try {
+            parsedWindowRules = JSON.parse(config.windowRules);
+        } catch (error: any) {
+            notificationInvalidWindowRules.sendEvent();
+            log("failed to parse windowRules:", error);
+        }
+        this.windowRuleEnforcer = new WindowRuleEnforcer(parsedWindowRules);
+    }
+
+    public addClient(kwinClient: KwinClient) {
+        console.assert(!this.hasClient(kwinClient));
+
+        let constructState: (client: ClientWrapper) => ClientState.State;
+        if (kwinClient.dock) {
+            constructState = () => new ClientState.Docked(this.world, kwinClient);
+        } else if (this.windowRuleEnforcer.shouldTile(kwinClient)) {
+            const grid = this.desktopManager.getDesktopForClient(kwinClient).grid;
+            constructState = (client: ClientWrapper) => new ClientState.Tiled(this.world, client, grid);
+        } else {
+            constructState = (client: ClientWrapper) => new ClientState.Floating(this.world, client, this.config, false);
+        }
+
+        const client = new ClientWrapper(
+            kwinClient,
+            constructState,
+            this.findTransientFor(kwinClient),
+            this.windowRuleEnforcer.initClientSignalManager(this.world, kwinClient),
+        );
+        this.clientMap.set(kwinClient, client);
+    }
+
+    public removeClient(kwinClient: KwinClient, passFocus: boolean) {
+        console.assert(this.hasClient(kwinClient));
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        client.destroy(passFocus && kwinClient === this.lastFocusedClient);
+        this.clientMap.delete(kwinClient);
+    }
+
+    private findTransientFor(kwinClient: KwinClient) {
+        if (!kwinClient.transient) {
+            return null;
+        }
+
+        const transientFor = this.clientMap.get(kwinClient.transientFor);
+        if (transientFor === undefined) {
+            return null;
+        }
+
+        return transientFor;
+    }
+
+    public minimizeClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        if (client.stateManager.getState() instanceof ClientState.Tiled) {
+            client.stateManager.setState(() => new ClientState.TiledMinimized(), kwinClient === this.lastFocusedClient);
+        }
+    }
+
+    public unminimizeClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        if (client.stateManager.getState() instanceof ClientState.TiledMinimized) {
+            const grid = this.desktopManager.getDesktopForClient(kwinClient).grid;
+            client.stateManager.setState(() => new ClientState.Tiled(this.world, client, grid), false);
+        }
+    }
+
+    public tileClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        if (client.stateManager.getState() instanceof ClientState.Tiled) {
+            return;
+        }
+        const grid = this.desktopManager.getDesktopForClient(kwinClient).grid;
+        client.stateManager.setState(() => new ClientState.Tiled(this.world, client, grid), false);
+    }
+
+    public untileClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        if (client.stateManager.getState() instanceof ClientState.Tiled) {
+            client.stateManager.setState(() => new ClientState.Floating(this.world, client, this.config, true), false);
+        }
+    }
+
+    public pinClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        client.stateManager.setState(() => new ClientState.Pinned(this.world, this.pinManager, this.desktopManager, kwinClient, this.config), false);
+        this.pinManager.addClient(kwinClient);
+        for (const desktop of this.desktopManager.getDesktopsForClient(kwinClient)) {
+            desktop.onPinsChanged();
+        }
+    }
+
+    public unpinClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+        console.assert(client.stateManager.getState() instanceof ClientState.Pinned);
+        client.stateManager.setState(() => new ClientState.Floating(this.world, client, this.config, false), false);
+        this.pinManager.removeClient(kwinClient);
+        for (const desktop of this.desktopManager.getDesktopsForClient(kwinClient)) {
+            desktop.onPinsChanged();
+        }
+    }
+
+    public toggleFloatingClient(kwinClient: KwinClient) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return;
+        }
+
+        const clientState = client.stateManager.getState();
+        if ((clientState instanceof ClientState.Floating || clientState instanceof ClientState.Pinned) && Clients.canTileEver(kwinClient)) {
+            Clients.makeTileable(kwinClient);
+            const grid = this.desktopManager.getDesktopForClient(kwinClient).grid;
+            client.stateManager.setState(() => new ClientState.Tiled(this.world, client, grid), false);
+        } else if (clientState instanceof ClientState.Tiled) {
+            client.stateManager.setState(() => new ClientState.Floating(this.world, client, this.config, true), false);
+        }
+    }
+
+    public hasClient(kwinClient: KwinClient) {
+        return this.clientMap.has(kwinClient);
+    }
+
+    public onClientFocused(kwinClient: KwinClient) {
+        this.lastFocusedClient = kwinClient;
+        const window = this.findTiledWindow(kwinClient, true);
+        if (window !== null) {
+            window.onFocused();
+        }
+    }
+
+    public findTiledWindow(kwinClient: KwinClient, followTransient: boolean) {
+        const client = this.clientMap.get(kwinClient);
+        if (client === undefined) {
+            return null;
+        }
+
+        return this.findTiledWindowOfClient(client, followTransient);
+    }
+
+    private findTiledWindowOfClient(client: ClientWrapper, followTransient: boolean): Window|null {
+        const clientState = client.stateManager.getState();
+        if (clientState instanceof ClientState.Tiled) {
+            return clientState.window;
+        } else if (followTransient && client.transientFor !== null) {
+            return this.findTiledWindowOfClient(client.transientFor, true);
+        } else {
+            return null;
+        }
+    }
+
+    private removeAllClients() {
+        for (const kwinClient of Array.from(this.clientMap.keys())) {
+            this.removeClient(kwinClient, false);
+        }
+    }
+
+    public destroy() {
+        this.removeAllClients();
+    }
+}
+
+namespace ClientManager {
+    export type Config = {
+        keepAbove: boolean,
+    }
+}

src/world/ClientStateDocked.ts

@@ -1,23 +0,0 @@
-class ClientStateDocked {
-    private readonly world: World;
-    private readonly signalManager: SignalManager;
-
-    constructor(world: World, kwinClient: AbstractClient) {
-        this.world = world;
-        this.signalManager = ClientStateDocked.initSignalManager(world, kwinClient);
-        world.onScreenResized();
-    }
-
-    destroy(passFocus: boolean) {
-        this.signalManager.destroy();
-        this.world.onScreenResized();
-    }
-
-    private static initSignalManager(world: World, kwinClient: AbstractClient) {
-        const manager = new SignalManager();
-        manager.connect(kwinClient.frameGeometryChanged, (kwinClient: TopLevel, oldGeometry: QRect) => {
-            world.onScreenResized();
-        });
-        return manager;
-    }
-}

src/world/ClientStateManager.ts

@@ -1,30 +0,0 @@
-class ClientStateManager {
-    private state: ClientState;
-
-    constructor(initialState: ClientState) {
-        this.state = initialState;
-    }
-
-    setState(newState: ClientState, passFocus: boolean) {
-        this.state.destroy(passFocus);
-        this.state = newState;
-    }
-
-    getState() {
-        return this.state;
-    }
-
-    destroy(passFocus: boolean) {
-        this.state.destroy(passFocus);
-    }
-}
-
-type ClientState = ClientStateTiled | ClientStateTiledMinimized | ClientStateFloating | ClientStateDocked;
-
-class ClientStateTiledMinimized {
-    destroy(passFocus: boolean) {}
-}
-
-class ClientStateFloating {
-    destroy(passFocus: boolean) {}
-}

src/world/ClientStateTiled.ts

@@ -1,103 +0,0 @@
-class ClientStateTiled {
-    readonly window: Window;
-    private readonly signalManager: SignalManager;
-
-    constructor(world: World, client: ClientWrapper) {
-        client.prepareForTiling();
-
-        const grid = world.getClientGrid(client.kwinClient);
-        const column = new Column(grid, grid.getLastFocusedColumn() ?? grid.getLastColumn());
-        const window = new Window(client, column);
-        grid.arrange();
-
-        this.window = window;
-        this.signalManager = ClientStateTiled.initSignalManager(world, window);
-    }
-
-    destroy(passFocus: boolean) {
-        this.signalManager.destroy();
-
-        const window = this.window;
-        const grid = window.column.grid;
-        const clientWrapper = window.client;
-        window.destroy(passFocus);
-        grid.arrange();
-
-        clientWrapper.prepareForFloating(grid.clientArea);
-    }
-
-    static initSignalManager(world: World, window: Window) {
-        const client = window.client;
-        const kwinClient = client.kwinClient;
-        const manager = new SignalManager();
-
-        manager.connect(kwinClient.desktopChanged, () => {
-            if (kwinClient.desktop === -1) {
-                // windows on all desktops are not supported
-                world.untileClient(kwinClient);
-                return;
-            }
-            ClientStateTiled.moveWindowToCorrectGrid(world, window);
-        });
-
-        manager.connect(kwinClient.activitiesChanged, (kwinClient: AbstractClient) => {
-            if (kwinClient.activities.length !== 1) {
-                // windows on multiple activities are not supported
-                world.untileClient(kwinClient);
-                return;
-            }
-            ClientStateTiled.moveWindowToCorrectGrid(world, window);
-        })
-
-        let lastResize = false;
-        manager.connect(kwinClient.moveResizedChanged, () => {
-            if (kwinClient.move) {
-                world.untileClient(kwinClient);
-                return;
-            }
-
-            const grid = window.column.grid;
-            const resize = kwinClient.resize;
-            if (!lastResize && resize) {
-                grid.onUserResizeStarted();
-            }
-            if (lastResize && !resize) {
-                grid.onUserResizeFinished();
-            }
-            lastResize = resize;
-        });
-
-        manager.connect(kwinClient.frameGeometryChanged, (kwinClient: TopLevel, oldGeometry: QRect) => {
-            console.assert(!kwinClient.move, "moved clients are removed in kwinClient.moveResizedChanged");
-            const grid = window.column.grid;
-            if (kwinClient.resize) {
-                window.onUserResize(oldGeometry);
-                grid.arrange();
-            } else {
-                const maximized = rectEqual(kwinClient.frameGeometry, grid.clientArea);
-                if (!client.isManipulatingGeometry() && !kwinClient.fullScreen && !maximized) {
-                    window.onProgrammaticResize(oldGeometry);
-                    grid.arrange();
-                }
-            }
-        });
-
-        return manager;
-    }
-
-    static moveWindowToCorrectGrid(world: World, window: Window) {
-        const kwinClient = window.client.kwinClient;
-
-        const oldGrid = window.column.grid;
-        const newGrid = world.getClientGrid(kwinClient);
-        if (oldGrid === newGrid) {
-            // window already on the correct grid
-            return;
-        }
-
-        const newColumn = new Column(newGrid, newGrid.getLastFocusedColumn() ?? newGrid.getLastColumn());
-        window.moveToColumn(newColumn);
-        oldGrid.arrange();
-        newGrid.arrange();
-    }
-}

src/world/ClientWrapper.ts

@@ -1,115 +1,104 @@
 class ClientWrapper {
-    public readonly kwinClient: AbstractClient;
-    public readonly stateManager: ClientStateManager;
+    public readonly kwinClient: KwinClient;
+    public readonly stateManager: ClientState.Manager;
     public transientFor: ClientWrapper | null;
     private readonly transients: ClientWrapper[];
-    private readonly signalManager: SignalManager;
     private readonly rulesSignalManager: SignalManager | null;
     public preferredWidth: number;
     private readonly manipulatingGeometry: Doer;
+    private lastPlacement: QmlRect | null; // workaround for issue #19
 
     constructor(
-        kwinClient: AbstractClient,
-        initialState: ClientState,
+        kwinClient: KwinClient,
+        constructInitialState: (client: ClientWrapper) => ClientState.State,
         transientFor: ClientWrapper | null,
         rulesSignalManager: SignalManager | null,
     ) {
         this.kwinClient = kwinClient;
-        this.stateManager = new ClientStateManager(initialState);
         this.transientFor = transientFor;
         this.transients = [];
         if (transientFor !== null) {
             transientFor.addTransient(this);
         }
-        this.signalManager = ClientWrapper.initSignalManager(this);
         this.rulesSignalManager = rulesSignalManager;
         this.preferredWidth = kwinClient.frameGeometry.width;
         this.manipulatingGeometry = new Doer();
+        this.lastPlacement = null;
+        this.stateManager = new ClientState.Manager(constructInitialState(this));
     }
 
-    place(x: number, y: number, width: number, height: number) {
+    public place(x: number, y: number, width: number, height: number) {
         this.manipulatingGeometry.do(() => {
             if (this.kwinClient.resize) {
                 // window is being manually resized, prevent fighting with the user
                 return;
             }
-            this.kwinClient.frameGeometry = Qt.rect(x, y, width, height);
+            this.lastPlacement = Qt.rect(x, y, width, height);
+            this.kwinClient.frameGeometry = this.lastPlacement;
         });
     }
 
-    private moveTransient(dx: number, dy: number) {
-        // TODO: prevent moving off the grid
-        if (this.stateManager.getState() instanceof ClientStateFloating) {
-            const frame = this.kwinClient.frameGeometry;
-            this.kwinClient.frameGeometry = Qt.rect(
-                frame.x + dx,
-                frame.y + dy,
-                frame.width,
-                frame.height,
-            );
+    private moveTransient(dx: number, dy: number, desktopNumber: number) {
+        if (this.stateManager.getState() instanceof ClientState.Floating) {
+            if (this.kwinClient.desktop === desktopNumber) {
+                const frame = this.kwinClient.frameGeometry;
+                this.kwinClient.frameGeometry = Qt.rect(
+                    frame.x + dx,
+                    frame.y + dy,
+                    frame.width,
+                    frame.height,
+                );
+            }
 
             for (const transient of this.transients) {
-                transient.moveTransient(dx, dy);
+                transient.moveTransient(dx, dy, desktopNumber);
             }
         }
     }
 
-    focus() {
+    public moveTransients(dx: number, dy: number) {
+        for (const transient of this.transients) {
+            transient.moveTransient(dx, dy, this.kwinClient.desktop);
+        }
+    }
+
+    public focus() {
         workspace.activeClient = this.kwinClient;
     }
 
-    isFocused() {
+    public isFocused() {
         return workspace.activeClient === this.kwinClient;
     }
 
-    setMaximize(horizontally: boolean, vertically: boolean) {
+    public setMaximize(horizontally: boolean, vertically: boolean) {
         this.manipulatingGeometry.do(() => {
             this.kwinClient.setMaximize(vertically, horizontally);
         });
     }
 
-    setFullScreen(fullScreen: boolean) {
+    public setFullScreen(fullScreen: boolean) {
         this.manipulatingGeometry.do(() => {
             this.kwinClient.fullScreen = fullScreen;
         });
     }
 
-    setShade(shade: boolean) {
+    public setShade(shade: boolean) {
         this.manipulatingGeometry.do(() => {
             this.kwinClient.shade = shade;
         });
     }
 
-    isShaded() {
+    public isShaded() {
         return this.kwinClient.shade;
     }
 
-    isManipulatingGeometry() {
+    public isManipulatingGeometry(newGeometry: QmlRect | null) {
+        if (newGeometry !== null && newGeometry === this.lastPlacement) {
+            return true;
+        }
         return this.manipulatingGeometry.isDoing();
     }
 
-    prepareForTiling() {
-        this.kwinClient.keepBelow = true;
-        this.setFullScreen(false);
-        this.setMaximize(false, false);
-    }
-
-    prepareForFloating(screenSize: QRect) {
-        this.kwinClient.keepBelow = false;
-        this.setShade(false);
-        this.setFullScreen(false);
-        this.setMaximize(false, false);
-
-        const clientRect = this.kwinClient.frameGeometry;
-        const width = this.preferredWidth;
-        this.place(
-            clamp(clientRect.x, screenSize.left, screenSize.right - width),
-            clientRect.y,
-            width,
-            Math.min(clientRect.height, Math.round(screenSize.height / 2)),
-        );
-    }
-
     private addTransient(transient: ClientWrapper) {
         this.transients.push(transient);
     }
@@ -119,9 +108,29 @@ class ClientWrapper {
         this.transients.splice(i, 1);
     }
 
-    destroy(passFocus: boolean) {
+    public ensureTransientsVisible(screenSize: QmlRect) {
+        for (const transient of this.transients) {
+            if (transient.stateManager.getState() instanceof ClientState.Floating) {
+                transient.ensureVisible(screenSize);
+                transient.ensureTransientsVisible(screenSize);
+            }
+        }
+    }
+
+    public ensureVisible(screenSize: QmlRect) {
+        if (this.kwinClient.desktop !== workspace.currentDesktop) {
+            return;
+        }
+        const frame = this.kwinClient.frameGeometry;
+        if (frame.left < screenSize.left) {
+            frame.x = screenSize.left;
+        } else if (frame.right > screenSize.right) {
+            frame.x = screenSize.right - frame.width;
+        }
+    }
+
+    public destroy(passFocus: boolean) {
         this.stateManager.destroy(passFocus);
-        this.signalManager.destroy();
         if (this.rulesSignalManager !== null) {
             this.rulesSignalManager.destroy();
         }
@@ -132,23 +141,4 @@ class ClientWrapper {
             transient.transientFor = null;
         }
     }
-
-    static initSignalManager(client: ClientWrapper) {
-        const manager = new SignalManager();
-        manager.connect(client.kwinClient.frameGeometryChanged, (kwinClient: TopLevel, oldGeometry: QRect) => {
-            if (client.stateManager.getState() instanceof ClientStateTiled) {
-                const newGeometry = client.kwinClient.frameGeometry;
-                const oldCenterX = oldGeometry.x + oldGeometry.width/2;
-                const oldCenterY = oldGeometry.y + oldGeometry.height/2;
-                const newCenterX = newGeometry.x + newGeometry.width/2;
-                const newCenterY = newGeometry.y + newGeometry.height/2;
-                const dx = Math.round(newCenterX - oldCenterX);
-                const dy = Math.round(newCenterY - oldCenterY);
-                for (const transient of client.transients) {
-                    transient.moveTransient(dx, dy);
-                }
-            }
-        });
-        return manager;
-    }
 }

src/world/Clients.ts

@@ -0,0 +1,35 @@
+namespace Clients {
+    export function canTileEver(kwinClient: KwinClient) {
+        return kwinClient.resizeable;
+    }
+
+    export function canTileNow(kwinClient: KwinClient) {
+        return canTileEver(kwinClient) && !kwinClient.minimized && kwinClient.desktop > 0 && kwinClient.activities.length === 1;
+    }
+
+    export function makeTileable(kwinClient: KwinClient) {
+        if (kwinClient.minimized) {
+            kwinClient.minimized = false;
+        }
+        if (kwinClient.desktop <= 0) {
+            kwinClient.desktop = workspace.currentDesktop;
+        }
+        if (kwinClient.activities.length !== 1) {
+            kwinClient.activities = [workspace.currentActivity];
+        }
+    }
+
+    export function isMaximizedGeometry(kwinClient: KwinClient) {
+        const maximizeArea = workspace.clientArea(ClientAreaOption.MaximizeArea, kwinClient.screen, kwinClient.desktop);
+        return kwinClient.frameGeometry === maximizeArea;
+    }
+
+    export function isFullScreenGeometry(kwinClient: KwinClient) {
+        const fullScreenArea = workspace.clientArea(ClientAreaOption.FullScreenArea, kwinClient.screen, kwinClient.desktop);
+        return kwinClient.frameGeometry === fullScreenArea;
+    }
+
+    export function isOnVirtualDesktop(kwinClient: KwinClient, desktopNumber: number) {
+        return kwinClient.desktop === desktopNumber || kwinClient.desktop === -1;
+    }
+}

src/world/DesktopManager.ts

@@ -0,0 +1,147 @@
+class DesktopManager {
+    private readonly pinManager: PinManager;
+    private readonly config: Desktop.Config;
+    public readonly layoutConfig: LayoutConfig;
+    private readonly desktopsPerActivity: Map<string, Desktop[]>;
+    private nVirtualDesktops: number;
+
+    constructor(pinManager: PinManager, config: Desktop.Config, layoutConfig: LayoutConfig, currentActivity: string) {
+        this.pinManager = pinManager;
+        this.config = config;
+        this.layoutConfig = layoutConfig;
+        this.desktopsPerActivity = new Map();
+        this.nVirtualDesktops = 0;
+        this.update()
+        this.addActivity(currentActivity);
+    }
+
+    public update() {
+        this.setNVirtualDesktops(workspace.desktops);
+    }
+
+    public getDesktop(activity: string, desktopNumber: number) {
+        const desktopIndex = desktopNumber - 1;
+        if (desktopIndex >= this.nVirtualDesktops || desktopIndex < 0) {
+            throw new Error("invalid desktop number: " + String(desktopNumber));
+        }
+        if (!this.desktopsPerActivity.has(activity)) {
+            this.addActivity(activity);
+        }
+        return this.desktopsPerActivity.get(activity)![desktopIndex];
+    }
+
+    public getCurrentDesktop() {
+        return this.getDesktop(workspace.currentActivity, workspace.currentDesktop);
+    }
+
+    public getDesktopInCurrentActivity(desktopNumber: number) {
+        return this.getDesktop(workspace.currentActivity, desktopNumber);
+    }
+
+    public getDesktopForClient(kwinClient: KwinClient) {
+        console.assert(kwinClient.activities.length === 1 && kwinClient.desktop > 0);
+        return this.getDesktop(kwinClient.activities[0], kwinClient.desktop);
+    }
+
+    private setNVirtualDesktops(nVirtualDesktops: number) {
+        if (nVirtualDesktops > this.nVirtualDesktops) {
+            this.addDesktopsToActivities(nVirtualDesktops - this.nVirtualDesktops);
+        } else if (nVirtualDesktops < this.nVirtualDesktops) {
+            this.removeDesktopsFromActivities(this.nVirtualDesktops - nVirtualDesktops);
+        }
+        this.nVirtualDesktops = nVirtualDesktops;
+    }
+
+    private addDesktopsToActivities(n: number) {
+        for (const desktops of this.desktopsPerActivity.values()) {
+            this.addDesktops(desktops, n);
+        }
+    }
+
+    private addDesktops(desktops: Desktop[], n: number) {
+        const nStart = desktops.length;
+        for (let i = 0; i < n; i++) {
+            const desktopNumber = nStart + i + 1;
+            desktops.push(new Desktop(desktopNumber, this.pinManager, this.config, this.layoutConfig));
+        }
+    }
+
+    private removeDesktopsFromActivities(n: number) {
+        const lastRemainingDesktopIndex = this.nVirtualDesktops - n - 1;
+        for (const desktops of this.desktopsPerActivity.values()) {
+            const targetDesktop = desktops[lastRemainingDesktopIndex];
+            for (let i = 0; i < n; i++) {
+                const removedDesktop = desktops.pop()!;
+                removedDesktop.grid.evacuate(targetDesktop.grid);
+            }
+        }
+    }
+
+    private addActivity(activity: string) {
+        const desktops: Desktop[] = [];
+        this.addDesktops(desktops, this.nVirtualDesktops);
+        this.desktopsPerActivity.set(activity, desktops);
+    }
+
+    private removeActivity(activity: string) {
+        const removedDesktops = this.desktopsPerActivity.get(activity)!;
+        this.desktopsPerActivity.delete(activity);
+        const targetActivityDesktops = this.desktopsPerActivity.values().next().value;
+        for (let i = 0; i < removedDesktops.length; i++) {
+            removedDesktops[i].grid.evacuate(targetActivityDesktops[i]);
+        }
+    }
+
+    public destroy() {
+        for (const desktop of this.desktops()) {
+            desktop.destroy();
+        }
+    }
+
+    public *desktops() {
+        for (const desktops of this.desktopsPerActivity.values()) {
+            for (const desktop of desktops) {
+                yield desktop;
+            }
+        }
+    }
+
+    public *getDesktopsForClient(kwinClient: KwinClient) {
+        const activities = kwinClient.activities.length > 0 ? kwinClient.activities : this.desktopsPerActivity.keys();
+        for (const activity of activities) {
+            if (!this.desktopsPerActivity.has(activity)) {
+                this.addActivity(activity);
+            }
+            const activityDesktops = this.desktopsPerActivity.get(activity)!;
+            if (kwinClient.desktop === -1) {
+                for (const desktop of activityDesktops) {
+                    yield desktop;
+                }
+            } else {
+                const desktopIndex = kwinClient.desktop - 1;
+                yield activityDesktops[desktopIndex];
+            }
+        }
+    }
+
+    // empty array means all
+    public *getDesktops(desktopNumbers: number[], inputActivities: string[]) {
+        const activities = inputActivities.length > 0 ? inputActivities : this.desktopsPerActivity.keys();
+        for (const activity of activities) {
+            if (!this.desktopsPerActivity.has(activity)) {
+                this.addActivity(activity);
+            }
+            const activityDesktops = this.desktopsPerActivity.get(activity)!;
+            if (desktopNumbers.length === 0) {
+                for (const desktop of activityDesktops) {
+                    yield desktop;
+                }
+            } else {
+                for (const desktopNumber of desktopNumbers) {
+                    const desktopIndex = desktopNumber - 1;
+                    yield activityDesktops[desktopIndex];
+                }
+            }
+        }
+    }
+}

src/world/GridManager.ts

@@ -1,81 +0,0 @@
-class GridManager {
-    private readonly world: World;
-    private readonly gridsPerActivity: Map<string, Grid[]>;
-    private nDesktops: number;
-
-    constructor(world: World, currentActivity: string, nDesktops: number) {
-        this.world = world;
-        this.gridsPerActivity = new Map();
-        this.nDesktops = 0;
-        this.setNDesktops(nDesktops);
-        this.addActivity(currentActivity);
-    }
-
-    get(activity: string, desktopNumber: number) {
-        const desktopIndex = desktopNumber - 1;
-        if (desktopIndex >= this.nDesktops || this.nDesktops < 0) {
-            throw new Error("invalid desktop number: " + String(desktopNumber));
-        }
-        if (!this.gridsPerActivity.has(activity)) {
-            this.addActivity(activity);
-        }
-        return this.gridsPerActivity.get(activity)![desktopIndex];
-    }
-
-    setNDesktops(nDesktops: number) {
-        if (nDesktops > this.nDesktops) {
-            this.addDesktopsToActivities(nDesktops - this.nDesktops);
-        } else if (nDesktops < this.nDesktops) {
-            this.removeDesktopsFromActivities(this.nDesktops - nDesktops);
-        }
-        this.nDesktops = nDesktops;
-    }
-
-    private addDesktopsToActivities(n: number) {
-        for (const grids of this.gridsPerActivity.values()) {
-            this.addDesktops(grids, n);
-        }
-    }
-
-    private addDesktops(grids: Grid[], n: number) {
-        const nStart = grids.length;
-        for (let i = 0; i < n; i++) {
-            const desktopNumber = nStart + i + 1;
-            grids.push(new Grid(this.world, desktopNumber));
-        }
-    }
-
-    private removeDesktopsFromActivities(n: number) {
-        const lastRemainingDesktopIndex = this.nDesktops - n - 1;
-        for (const grids of this.gridsPerActivity.values()) {
-            const targetGrid = grids[lastRemainingDesktopIndex];
-            for (let i = 0; i < n; i++) {
-                const removedGrid = grids.pop()!;
-                removedGrid.evacuate(targetGrid);
-            }
-        }
-    }
-
-    addActivity(activity: string) {
-        const grids: Grid[] = [];
-        this.addDesktops(grids, this.nDesktops);
-        this.gridsPerActivity.set(activity, grids);
-    }
-
-    removeActivity(activity: string) {
-        const removedGrids = this.gridsPerActivity.get(activity)!;
-        this.gridsPerActivity.delete(activity);
-        const targetActivityGrids = this.gridsPerActivity.values().next().value;
-        for (let i = 0; i < removedGrids.length; i++) {
-            removedGrids[i].evacuate(targetActivityGrids[i]);
-        }
-    }
-
-    *grids() {
-        for (const grids of this.gridsPerActivity.values()) {
-            for (const grid of grids) {
-                yield grid;
-            }
-        }
-    }
-}

src/world/PinManager.ts

@@ -0,0 +1,86 @@
+class PinManager {
+    private readonly pinnedClients: Set<KwinClient>;
+
+    constructor() {
+        this.pinnedClients = new Set();
+    }
+
+    public addClient(kwinClient: KwinClient) {
+        this.pinnedClients.add(kwinClient);
+    }
+
+    public removeClient(kwinClient: KwinClient) {
+        this.pinnedClients.delete(kwinClient);
+    }
+
+    public getAvailableSpace(desktopNumber: number, screen: QmlRect) {
+        const baseLot = new PinManager.Lot(screen.top, screen.bottom, screen.left, screen.right);
+        let lots = [baseLot];
+        for (const client of this.pinnedClients) {
+            if (!Clients.isOnVirtualDesktop(client, desktopNumber)) {
+                continue;
+            }
+
+            const newLots: PinManager.Lot[] = [];
+            for (const lot of lots) {
+                lot.split(newLots, client.frameGeometry);
+            }
+            lots = newLots;
+        }
+
+        let largestLot = baseLot;
+        let largestArea = 0;
+        for (const lot of lots) {
+            const area = lot.area();
+            if (area > largestArea) {
+                largestArea = area;
+                largestLot = lot;
+            }
+        }
+        return largestLot;
+    }
+}
+
+namespace PinManager {
+    export class Lot {
+        private static readonly minWidth = 200;
+        private static readonly minHeight = 200;
+
+        constructor(
+            public readonly top: number,
+            public readonly bottom: number,
+            public readonly left: number,
+            public readonly right: number,
+        ) {}
+
+        public split(destLots: Lot[], obstacle: QmlRect) {
+            if (!this.contains(obstacle)) {
+                // don't split
+                destLots.push(this);
+                return;
+            }
+
+            if (obstacle.top - this.top >= Lot.minHeight) {
+                destLots.push(new Lot(this.top, obstacle.top, this.left, this.right));
+            }
+            if (this.bottom - obstacle.bottom >= Lot.minHeight) {
+                destLots.push(new Lot(obstacle.bottom, this.bottom, this.left, this.right));
+            }
+            if (obstacle.left - this.left >= Lot.minWidth) {
+                destLots.push(new Lot(this.top, this.bottom, this.left, obstacle.left));
+            }
+            if (this.right - obstacle.right >= Lot.minWidth) {
+                destLots.push(new Lot(this.top, this.bottom, obstacle.right, this.right));
+            }
+        }
+
+        private contains(obstacle: QmlRect) {
+            return obstacle.right > this.left && obstacle.left < this.right &&
+                obstacle.bottom > this.top && obstacle.top < this.bottom;
+        }
+
+        public area() {
+            return (this.bottom - this.top) * (this.right - this.left);
+        }
+    }
+}

src/world/World.ts

@@ -1,226 +1,109 @@
 class World {
-    public readonly config: Config;
-    private readonly gridManager: GridManager;
-    private readonly clientMap: Map<AbstractClient, ClientWrapper>;
-    private lastFocusedClient: AbstractClient|null;
+    public readonly untileOnDrag: boolean;
+    private readonly desktopManager: DesktopManager;
+    public readonly clientManager: ClientManager;
+    private readonly pinManager: PinManager;
     private readonly workspaceSignalManager: SignalManager;
-    private readonly windowRuleEnforcer: WindowRuleEnforcer;
     private readonly screenResizedDelayer: Delayer;
 
     constructor(config: Config) {
-        this.config = config;
-        this.clientMap = new Map();
-        this.lastFocusedClient = null;
+        this.untileOnDrag = config.untileOnDrag;
         this.workspaceSignalManager = initWorkspaceSignalHandlers(this);
 
-        let parsedWindowRules: WindowRule[] = [];
-        try {
-            parsedWindowRules = JSON.parse(config.windowRules);
-        } catch (error: any) {
-            console.log("failed to parse windowRules:", error);
-        }
-        this.windowRuleEnforcer = new WindowRuleEnforcer(this, parsedWindowRules);
-
         this.screenResizedDelayer = new Delayer(1000, () => {
             // this delay ensures that docks get taken into account by `workspace.clientArea`
-            const gridManager = this.gridManager; // workaround for bug in Qt5's JS engine
-            for (const grid of gridManager.grids()) {
-                grid.arrange();
+            const desktopManager = this.desktopManager; // workaround for bug in Qt5's JS engine
+            for (const desktop of desktopManager.desktops()) {
+                desktop.onLayoutChanged();
             }
+            this.update();
         });
 
-        this.gridManager = new GridManager(this, workspace.currentActivity, workspace.desktops);
-        this.addExistingClients();
-    }
+        this.pinManager = new PinManager();
 
-    updateDesktops() {
-        this.gridManager.setNDesktops(workspace.desktops);
+        const layoutConfig = {
+            gapsInnerHorizontal: config.gapsInnerHorizontal,
+            gapsInnerVertical: config.gapsInnerVertical,
+            offScreenOpacity: config.offScreenOpacity / 100.0,
+            stackColumnsByDefault: config.stackColumnsByDefault,
+            resizeNeighborColumn: config.resizeNeighborColumn,
+            reMaximize: config.reMaximize,
+            skipSwitcher: config.skipSwitcher,
+            tiledKeepBelow: config.tiledKeepBelow,
+            maximizedKeepAbove: config.floatingKeepAbove,
+        };
+
+        this.desktopManager = new DesktopManager(
+            this.pinManager,
+            {
+                marginTop: config.gapsOuterTop,
+                marginBottom: config.gapsOuterBottom,
+                marginLeft: config.gapsOuterLeft,
+                marginRight: config.gapsOuterRight,
+                overscroll: config.overscroll,
+                scroller: config.scrollingLazy ? new ScrollerLazy() :
+                    config.scrollingCentered ? new ScrollerCentered() :
+                    config.scrollingGrouped ? new ScrollerGrouped(layoutConfig) :
+                    console.assert(false),
+            },
+            layoutConfig,
+            workspace.currentActivity,
+        );
+        this.clientManager = new ClientManager(config, this, this.desktopManager, this.pinManager);
+        this.addExistingClients();
+        this.update();
     }
 
     private addExistingClients() {
         const kwinClients = workspace.clientList();
         for (let i = 0; i < kwinClients.length; i++) {
             const kwinClient = kwinClients[i];
-            this.addClient(kwinClient);
+            this.clientManager.addClient(kwinClient);
         }
     }
 
-    getGrid(activity: string, desktopNumber: number) {
-        console.assert(desktopNumber > 0 && desktopNumber <= workspace.desktops);
-        return this.gridManager.get(activity, desktopNumber);
+    public updateDesktops() {
+        this.desktopManager.update();
     }
 
-    getGridInCurrentActivity(desktopNumber: number) {
-        return this.getGrid(workspace.currentActivity, desktopNumber);
+    private update() {
+        this.desktopManager.getCurrentDesktop().arrange();
     }
 
-    getCurrentGrid() {
-        return this.getGrid(workspace.currentActivity, workspace.currentDesktop);
+    public do(f: (clientManager: ClientManager, desktopManager: DesktopManager) => void) {
+        f(this.clientManager, this.desktopManager);
+        this.update();
     }
 
-    getClientGrid(kwinClient: AbstractClient) {
-        console.assert(kwinClient.activities.length === 1);
-        return this.getGrid(kwinClient.activities[0], kwinClient.desktop);
-    }
-
-    addClient(kwinClient: AbstractClient) {
-        const client = new ClientWrapper(
-            kwinClient,
-            new ClientStateFloating(),
-            this.findTransientFor(kwinClient),
-            this.windowRuleEnforcer.initClientSignalManager(this, kwinClient),
-        );
-        this.clientMap.set(kwinClient, client);
-
-        if (kwinClient.dock) {
-            client.stateManager.setState(new ClientStateDocked(this, kwinClient), false);
-        } else if (this.windowRuleEnforcer.shouldTile(kwinClient)) {
-            client.stateManager.setState(new ClientStateTiled(this, client), false);
-        }
-    }
-
-    removeClient(kwinClient: AbstractClient, passFocus: boolean) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
+    public doIfTiled(
+        kwinClient: KwinClient,
+        followTransient: boolean,
+        f: (clientManager: ClientManager, desktopManager: DesktopManager, window: Window, column: Column, grid: Grid) => void,
+    ) {
+        const window = this.clientManager.findTiledWindow(kwinClient, followTransient);
+        if (window === null) {
             return;
         }
-        client.destroy(passFocus && kwinClient === this.lastFocusedClient);
-        this.clientMap.delete(kwinClient);
+        const column = window.column;
+        const grid = column.grid;
+        f(this.clientManager, this.desktopManager, window, column, grid);
+        this.update();
     }
 
-    findTransientFor(kwinClient: AbstractClient) {
-        if (!kwinClient.transient) {
-            return null;
-        }
-
-        const transientFor = this.clientMap.get(kwinClient.transientFor);
-        if (transientFor === undefined) {
-            return null;
-        }
-
-        return transientFor;
-    }
-
-    minimizeClient(kwinClient: AbstractClient) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-        if (client.stateManager.getState() instanceof ClientStateTiled) {
-            client.stateManager.setState(new ClientStateTiledMinimized(), kwinClient === this.lastFocusedClient);
-        }
-    }
-
-    unminimizeClient(kwinClient: AbstractClient) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-        if (client.stateManager.getState() instanceof ClientStateTiledMinimized) {
-            client.stateManager.setState(new ClientStateTiled(this, client), false);
-        }
-    }
-
-    tileClient(kwinClient: AbstractClient) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-        if (client.stateManager.getState() instanceof ClientStateTiled) {
-            return;
-        }
-        client.stateManager.setState(new ClientStateTiled(this, client), false);
-    }
-
-    untileClient(kwinClient: AbstractClient) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-        if (client.stateManager.getState() instanceof ClientStateTiled) {
-            client.stateManager.setState(new ClientStateFloating(), false);
-        }
-    }
-
-    toggleFloatingClient(kwinClient: AbstractClient) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-
-        const clientState = client.stateManager.getState();
-        if (clientState instanceof ClientStateFloating && canTileEver(kwinClient)) {
-            makeTileable(kwinClient);
-            client.stateManager.setState(new ClientStateTiled(this, client), false);
-        } else if (clientState instanceof ClientStateTiled) {
-            client.stateManager.setState(new ClientStateFloating(), false);
-        }
-    }
-
-    hasClient(kwinClient: AbstractClient) {
-        return this.clientMap.has(kwinClient);
-    }
-
-    onClientFocused(kwinClient: AbstractClient) {
-        this.lastFocusedClient = kwinClient;
-    }
-
-    private doIfTiledInner(client: ClientWrapper, followTransient: boolean, f: (window: Window, column: Column, grid: Grid) => void) {
-        const clientState = client.stateManager.getState();
-        if (clientState instanceof ClientStateTiled) {
-            const window = clientState.window;
-            const column = window.column;
-            const grid = column.grid;
-            f(window, column, grid);
-        } else if (followTransient && client.transientFor !== null) {
-            this.doIfTiledInner(client.transientFor, true, f);
-        }
-    }
-
-    doIfTiled(kwinClient: AbstractClient, followTransient: boolean, f: (window: Window, column: Column, grid: Grid) => void) {
-        const client = this.clientMap.get(kwinClient);
-        if (client === undefined) {
-            return;
-        }
-        this.doIfTiledInner(client, followTransient, f);
-    }
-
-    doIfTiledFocused(followTransient: boolean, f: (window: Window, column: Column, grid: Grid) => void) {
+    public doIfTiledFocused(
+        followTransient: boolean,
+        f: (clientManager: ClientManager, desktopManager: DesktopManager, window: Window, column: Column, grid: Grid) => void,
+    ) {
         this.doIfTiled(workspace.activeClient, followTransient, f);
     }
 
-    getFocusedWindow() {
-        const activeClient = workspace.activeClient;
-        if (activeClient === null) {
-            return null;
-        }
-        const client = this.clientMap.get(activeClient);
-        if (client === undefined) {
-            return null;
-        }
-        const clientState = client.stateManager.getState();
-        if (clientState instanceof ClientStateTiled) {
-            return clientState.window;
-        } else {
-            return null;
-        }
-    }
-
-    removeAllClients() {
-        for (const kwinClient of Array.from(this.clientMap.keys())) {
-            this.removeClient(kwinClient, false);
-        }
-    }
-
-    destroy() {
+    public destroy() {
         this.workspaceSignalManager.destroy();
-        this.removeAllClients();
-        for (const grid of this.gridManager.grids()) {
-            grid.destroy();
-        }
+        this.clientManager.destroy();
+        this.desktopManager.destroy();
     }
 
-    onScreenResized() {
+    public onScreenResized() {
         this.screenResizedDelayer.run();
     }
 }

src/world/clientState/Docked.ts

@@ -0,0 +1,25 @@
+namespace ClientState {
+    export class Docked implements State {
+        private readonly world: World;
+        private readonly signalManager: SignalManager;
+
+        constructor(world: World, kwinClient: KwinClient) {
+            this.world = world;
+            this.signalManager = Docked.initSignalManager(world, kwinClient);
+            world.onScreenResized();
+        }
+
+        public destroy(passFocus: boolean) {
+            this.signalManager.destroy();
+            this.world.onScreenResized();
+        }
+
+        private static initSignalManager(world: World, kwinClient: KwinClient) {
+            const manager = new SignalManager();
+            manager.connect(kwinClient.frameGeometryChanged, (kwinClient: KwinClient, oldGeometry: QmlRect) => {
+                world.onScreenResized();
+            });
+            return manager;
+        }
+    }
+}

src/world/clientState/Floating.ts

@@ -0,0 +1,62 @@
+namespace ClientState {
+    export class Floating implements State {
+        private readonly client: ClientWrapper;
+        private readonly config: ClientManager.Config;
+        private readonly signalManager: SignalManager;
+
+        constructor(world: World, client: ClientWrapper, config: ClientManager.Config, limitHeight: boolean) {
+            this.client = client;
+            this.config = config;
+            if (config.keepAbove) {
+                client.kwinClient.keepAbove = true;
+            }
+            if (limitHeight && client.kwinClient.tile === null) {
+                Floating.limitHeight(client);
+            }
+            this.signalManager = Floating.initSignalManager(world, client.kwinClient);
+        }
+
+        public destroy(passFocus: boolean) {
+            this.signalManager.destroy();
+            if (this.config.keepAbove) {
+                this.client.kwinClient.keepAbove = false;
+            }
+        }
+
+        private static limitHeight(client: ClientWrapper) {
+            const placementArea = workspace.clientArea(ClientAreaOption.PlacementArea, client.kwinClient.screen, client.kwinClient.desktop);
+            const clientRect = client.kwinClient.frameGeometry;
+            const width = client.preferredWidth;
+            client.place(
+                clientRect.x,
+                clientRect.y,
+                width,
+                Math.min(clientRect.height, Math.round(placementArea.height / 2)),
+            );
+        }
+
+        private static initSignalManager(world: World, kwinClient: KwinClient) {
+            const manager = new SignalManager();
+
+            manager.connect(kwinClient.tileChanged, () => {
+                // on X11, this fires after `frameGeometryChanged`
+                if (kwinClient.tile !== null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.pinClient(kwinClient);
+                    });
+                }
+            });
+            
+            manager.connect(kwinClient.frameGeometryChanged, () => {
+                // on Wayland, this fires after `tileChanged`
+                if (kwinClient.tile !== null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.pinClient(kwinClient);
+                    });
+                }
+            })
+
+            return manager;
+        }
+    }
+}

src/world/clientState/Manager.ts

@@ -0,0 +1,26 @@
+namespace ClientState {
+    export class Manager {
+        private state: State;
+
+        constructor(initialState: State) {
+            this.state = initialState;
+        }
+
+        public setState(constructNewState: () => State, passFocus: boolean) {
+            this.state.destroy(passFocus);
+            this.state = constructNewState();
+        }
+
+        public getState() {
+            return this.state;
+        }
+
+        public destroy(passFocus: boolean) {
+            this.state.destroy(passFocus);
+        }
+    }
+
+    export type State = {
+        destroy(passFocus: boolean): void,
+    };
+}

src/world/clientState/Pinned.ts

@@ -0,0 +1,87 @@
+namespace ClientState {
+    export class Pinned implements State {
+        private readonly kwinClient: KwinClient;
+        private readonly pinManager: PinManager;
+        private readonly desktopManager: DesktopManager;
+        private readonly config: ClientManager.Config;
+        private readonly signalManager: SignalManager;
+
+        constructor(world: World, pinManager: PinManager, desktopManager: DesktopManager, kwinClient: KwinClient, config: ClientManager.Config) {
+            this.kwinClient = kwinClient;
+            this.pinManager = pinManager;
+            this.desktopManager = desktopManager;
+            this.config = config;
+            if (config.keepAbove) {
+                kwinClient.keepAbove = true;
+            }
+            this.signalManager = Pinned.initSignalManager(world, pinManager, kwinClient);
+        }
+
+        public destroy(passFocus: boolean) {
+            this.signalManager.destroy();
+            if (this.config.keepAbove) {
+                this.kwinClient.keepAbove = true;
+            }
+            this.pinManager.removeClient(this.kwinClient);
+            for (const desktop of this.desktopManager.getDesktopsForClient(this.kwinClient)) {
+                desktop.onPinsChanged();
+            }
+        }
+
+        private static initSignalManager(world: World, pinManager: PinManager, kwinClient: KwinClient) {
+            const manager = new SignalManager();
+            let oldDesktopNumber = kwinClient.desktop;
+            let oldActivities = kwinClient.activities;
+
+            manager.connect(kwinClient.tileChanged, () => {
+                if (kwinClient.tile === null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.unpinClient(kwinClient);
+                    });
+                }
+            });
+
+            manager.connect(kwinClient.frameGeometryChanged, (kwinClient: KwinClient, oldGeometry: QmlRect) => {
+                if (kwinClient.tile === null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.unpinClient(kwinClient);
+                    });
+                    return;
+                }
+
+                world.do((clientManager, desktopManager) => {
+                    for (const desktop of desktopManager.getDesktopsForClient(kwinClient)) {
+                        desktop.onPinsChanged();
+                    }
+                })
+            });
+
+            manager.connect(kwinClient.desktopChanged, () => {
+                const changedDesktops = oldDesktopNumber === -1 || kwinClient.desktop === -1 ?
+                    [] :
+                    [oldDesktopNumber, kwinClient.desktop];
+                world.do((clientManager, desktopManager) => {
+                    for (const desktop of desktopManager.getDesktops(changedDesktops, kwinClient.activities)) {
+                        desktop.onPinsChanged();
+                    }
+                });
+                oldDesktopNumber = kwinClient.desktop;
+            });
+
+            manager.connect(kwinClient.activitiesChanged, (kwinClient: KwinClient) => {
+                const desktops = kwinClient.desktop === -1 ? [] : [kwinClient.desktop];
+                const changedActivities = oldActivities.length === 0 || kwinClient.activities.length === 0 ?
+                    [] :
+                    union(oldActivities, kwinClient.activities);
+                world.do((clientManager, desktopManager) => {
+                    for (const desktop of desktopManager.getDesktops(desktops, changedActivities)) {
+                        desktop.onPinsChanged();
+                    }
+                });
+                oldActivities = kwinClient.activities;
+            });
+
+            return manager;
+        }
+    }
+}

src/world/clientState/Tiled.ts

@@ -0,0 +1,182 @@
+namespace ClientState {
+    export class Tiled implements State {
+        public readonly window: Window;
+        private readonly defaultState: Tiled.WindowState;
+        private readonly signalManager: SignalManager;
+
+        constructor(world: World, client: ClientWrapper, grid: Grid) {
+            this.defaultState = { skipSwitcher: client.kwinClient.skipSwitcher };
+            Tiled.prepareClientForTiling(client, grid.config);
+
+            const column = new Column(grid, grid.getLastFocusedColumn() ?? grid.getLastColumn());
+            const window = new Window(client, column);
+
+            this.window = window;
+            this.signalManager = Tiled.initSignalManager(world, window);
+        }
+
+        public destroy(passFocus: boolean) {
+            this.signalManager.destroy();
+
+            const window = this.window;
+            const grid = window.column.grid;
+            const client = window.client;
+            window.destroy(passFocus);
+
+            Tiled.restoreClientAfterTiling(client, grid.config, this.defaultState, grid.desktop.clientArea);
+        }
+
+        private static initSignalManager(world: World, window: Window) {
+            const client = window.client;
+            const kwinClient = client.kwinClient;
+            const manager = new SignalManager();
+
+            manager.connect(kwinClient.desktopChanged, () => {
+                world.do((clientManager, desktopManager) => {
+                    if (kwinClient.desktop === -1) {
+                        // windows on all desktops are not supported
+                        clientManager.untileClient(kwinClient);
+                        return;
+                    }
+                    Tiled.moveWindowToCorrectGrid(desktopManager, window);
+                });
+            });
+
+            manager.connect(kwinClient.activitiesChanged, () => {
+                world.do((clientManager, desktopManager) => {
+                    if (kwinClient.activities.length !== 1) {
+                        // windows on multiple activities are not supported
+                        clientManager.untileClient(kwinClient);
+                        return;
+                    }
+                    Tiled.moveWindowToCorrectGrid(desktopManager, window);
+                });
+            })
+
+            let lastResize = false;
+            manager.connect(kwinClient.moveResizedChanged, () => {
+                world.do((clientManager, desktopManager) => {
+                    if (kwinClient.move) {
+                        if (world.untileOnDrag) {
+                            clientManager.untileClient(kwinClient);
+                        }
+                        return;
+                    }
+
+                    const grid = window.column.grid;
+                    const resize = kwinClient.resize;
+                    if (!lastResize && resize) {
+                        grid.onUserResizeStarted();
+                    }
+                    if (lastResize && !resize) {
+                        grid.onUserResizeFinished();
+                    }
+                    lastResize = resize;
+                });
+            });
+
+            let cursorChangedAfterResizeStart = false;
+            manager.connect(kwinClient.moveResizeCursorChanged, () => {
+                cursorChangedAfterResizeStart = true;
+            });
+            manager.connect(kwinClient.clientStartUserMovedResized, () => {
+                cursorChangedAfterResizeStart = false;
+            });
+
+            manager.connect(kwinClient.frameGeometryChanged, (kwinClient: KwinClient, oldGeometry: QmlRect) => {
+                // on Wayland, this fires after `tileChanged`
+                if (kwinClient.tile !== null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.pinClient(kwinClient);
+                    });
+                    return;
+                }
+
+                const newGeometry = client.kwinClient.frameGeometry;
+                const oldCenterX = oldGeometry.x + oldGeometry.width/2;
+                const oldCenterY = oldGeometry.y + oldGeometry.height/2;
+                const newCenterX = newGeometry.x + newGeometry.width/2;
+                const newCenterY = newGeometry.y + newGeometry.height/2;
+                const dx = Math.round(newCenterX - oldCenterX);
+                const dy = Math.round(newCenterY - oldCenterY);
+                if (dx !== 0 || dy !== 0) {
+                    client.moveTransients(dx, dy);
+                }
+
+                if (kwinClient.resize) {
+                    world.do(() => window.onUserResize(oldGeometry, !cursorChangedAfterResizeStart));
+                } else if (
+                    !client.isManipulatingGeometry(newGeometry) &&
+                    !Clients.isMaximizedGeometry(kwinClient) &&
+                    !Clients.isFullScreenGeometry(kwinClient) // not using `kwinClient.fullScreen` because it may not be set yet at this point
+                ) {
+                    world.do(() => window.onFrameGeometryChanged());
+                }
+            });
+
+            manager.connect(kwinClient.fullScreenChanged, () => {
+                world.do(() => window.onFullScreenChanged(kwinClient.fullScreen));
+            });
+
+            manager.connect(kwinClient.tileChanged, () => {
+                // on X11, this fires after `frameGeometryChanged`
+                if (kwinClient.tile !== null) {
+                    world.do((clientManager, desktopManager) => {
+                        clientManager.pinClient(kwinClient);
+                    });
+                }
+            });
+
+            return manager;
+        }
+
+        private static moveWindowToCorrectGrid(desktopManager: DesktopManager, window: Window) {
+            const kwinClient = window.client.kwinClient;
+
+            const oldGrid = window.column.grid;
+            const newGrid = desktopManager.getDesktopForClient(kwinClient).grid;
+            if (oldGrid === newGrid) {
+                // window already on the correct grid
+                return;
+            }
+
+            const newColumn = new Column(newGrid, newGrid.getLastFocusedColumn() ?? newGrid.getLastColumn());
+            window.moveToColumn(newColumn);
+        }
+
+        private static prepareClientForTiling(client: ClientWrapper, config: LayoutConfig) {
+            if (config.skipSwitcher) {
+                client.kwinClient.skipSwitcher = true;
+            }
+            if (config.tiledKeepBelow) {
+                client.kwinClient.keepBelow = true;
+            }
+            client.setFullScreen(false);
+            if (client.kwinClient.tile !== null) {
+                client.setMaximize(false, true); // disable quick tile mode
+            }
+            client.setMaximize(false, false);
+        }
+
+        private static restoreClientAfterTiling(client: ClientWrapper, config: LayoutConfig, defaultState: Tiled.WindowState, screenSize: QmlRect) {
+            if (config.skipSwitcher) {
+                client.kwinClient.skipSwitcher = defaultState.skipSwitcher;
+            }
+            if (config.tiledKeepBelow) {
+                client.kwinClient.keepBelow = false;
+            }
+            client.setShade(false);
+            client.setFullScreen(false);
+            if (client.kwinClient.tile === null) {
+                client.setMaximize(false, false);
+            }
+            client.ensureVisible(screenSize);
+        }
+    }
+
+    namespace Tiled {
+        export type WindowState = {
+            skipSwitcher: boolean,
+        }
+    }
+}

src/world/clientState/TiledMinimized.ts

@@ -0,0 +1,5 @@
+namespace ClientState {
+    export class TiledMinimized implements State {
+        public destroy(passFocus: boolean) {}
+    }
+}