[gnome-shell/wip/exalm/gestures2: 1/10] workspaceAnimation: Split from WindowManager

[Alexander Mikhaylenko <alexm src gnome org>]

commit 7f6a2de65d75c48a6e7cafba2b79f2052941b8b7
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Tue Jul 2 22:28:47 2019 +0500

    workspaceAnimation: Split from WindowManager
    
    It's already too complex, and will get more complex in future, split it
    out. Update the code style.

 js/js-resources.gresource.xml |   1 +
 js/ui/windowManager.js        | 400 +--------------------------------------
 js/ui/workspaceAnimation.js   | 422 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 430 insertions(+), 393 deletions(-)
---
diff --git a/js/js-resources.gresource.xml b/js/js-resources.gresource.xml
index e7c0dda007..a51ff95422 100644
--- a/js/js-resources.gresource.xml
+++ b/js/js-resources.gresource.xml
@@ -111,6 +111,7 @@
     <file>ui/windowManager.js</file>
     <file>ui/windowPreview.js</file>
     <file>ui/workspace.js</file>
+    <file>ui/workspaceAnimation.js</file>
     <file>ui/workspaceSwitcherPopup.js</file>
     <file>ui/workspaceThumbnail.js</file>
     <file>ui/workspacesView.js</file>
diff --git a/js/ui/windowManager.js b/js/ui/windowManager.js
index 1b90c3b7da..8d31e38b5e 100644
--- a/js/ui/windowManager.js
+++ b/js/ui/windowManager.js
@@ -14,9 +14,9 @@ const WindowMenu = imports.ui.windowMenu;
 const PadOsd = imports.ui.padOsd;
 const EdgeDragAction = imports.ui.edgeDragAction;
 const CloseDialog = imports.ui.closeDialog;
-const SwipeTracker = imports.ui.swipeTracker;
 const SwitchMonitor = imports.ui.switchMonitor;
 const IBusManager = imports.misc.ibusManager;
+const WorkspaceAnimation = imports.ui.workspaceAnimation;
 
 const { loadInterfaceXML } = imports.misc.fileUtils;
 
@@ -563,7 +563,6 @@ var WindowManager = class {
         this._resizing = new Set();
         this._resizePending = new Set();
         this._destroying = new Set();
-        this._movingWindow = null;
 
         this._dimmedWindows = [];
 
@@ -573,15 +572,6 @@ var WindowManager = class {
 
         this._isWorkspacePrepended = false;
 
-        this._switchData = null;
-        this._shellwm.connect('kill-switch-workspace', shellwm => {
-            if (this._switchData) {
-                if (this._switchData.inProgress)
-                    this._switchWorkspaceDone(shellwm);
-                else if (!this._switchData.gestureActivated)
-                    this._finishWorkspaceSwitch(this._switchData);
-            }
-        });
         this._shellwm.connect('kill-window-effects', (shellwm, actor) => {
             this._minimizeWindowDone(shellwm, actor);
             this._mapWindowDone(shellwm, actor);
@@ -603,7 +593,6 @@ var WindowManager = class {
         this._shellwm.connect('confirm-display-change', this._confirmDisplayChange.bind(this));
         this._shellwm.connect('create-close-dialog', this._createCloseDialog.bind(this));
         this._shellwm.connect('create-inhibit-shortcuts-dialog', 
this._createInhibitShortcutsDialog.bind(this));
-        global.display.connect('restacked', this._syncStacking.bind(this));
 
         this._workspaceSwitcherPopup = null;
         this._tilePreview = null;
@@ -926,17 +915,10 @@ var WindowManager = class {
         Main.overview.connect('showing', () => {
             for (let i = 0; i < this._dimmedWindows.length; i++)
                 this._undimWindow(this._dimmedWindows[i]);
-
-            if (this._switchData) {
-                if (this._switchData.gestureActivated)
-                    this._switchWorkspaceStop();
-                this._swipeTracker.enabled = false;
-            }
         });
         Main.overview.connect('hiding', () => {
             for (let i = 0; i < this._dimmedWindows.length; i++)
                 this._dimWindow(this._dimmedWindows[i]);
-            this._swipeTracker.enabled = true;
         });
 
         this._windowMenuManager = new WindowMenu.WindowMenuManager();
@@ -947,13 +929,6 @@ var WindowManager = class {
         global.workspace_manager.override_workspace_layout(Meta.DisplayCorner.TOPLEFT,
                                                            false, -1, 1);
 
-        let swipeTracker = new SwipeTracker.SwipeTracker(global.stage,
-            Shell.ActionMode.NORMAL, { allowDrag: false, allowScroll: false });
-        swipeTracker.connect('begin', this._switchWorkspaceBegin.bind(this));
-        swipeTracker.connect('update', this._switchWorkspaceUpdate.bind(this));
-        swipeTracker.connect('end', this._switchWorkspaceEnd.bind(this));
-        this._swipeTracker = swipeTracker;
-
         let appSwitchAction = new AppSwitchAction();
         appSwitchAction.connect('activated', this._switchApp.bind(this));
         global.stage.add_action(appSwitchAction);
@@ -985,6 +960,9 @@ var WindowManager = class {
         global.display.connect('in-fullscreen-changed', updateUnfullscreenGesture);
 
         global.stage.add_action(topDragAction);
+
+        this._workspaceAnimation =
+            new WorkspaceAnimation.WorkspaceAnimationController();
     }
 
     async _startX11Services(task, cancellable) {
@@ -1137,8 +1115,7 @@ var WindowManager = class {
     }
 
     _shouldAnimate() {
-        return !(Main.overview.visible ||
-            (this._switchData && this._switchData.gestureActivated));
+        return !(Main.overview.visible || this._workspaceAnimation.gestureActive);
     }
 
     _shouldAnimateActor(actor, types) {
@@ -1638,376 +1615,13 @@ var WindowManager = class {
         return !(this._allowedKeybindings[binding.get_name()] & Main.actionMode);
     }
 
-    _syncStacking() {
-        if (this._switchData == null)
-            return;
-
-        let windows = global.get_window_actors();
-        let lastCurSibling = null;
-        let lastDirSibling = [];
-        for (let i = 0; i < windows.length; i++) {
-            if (windows[i].get_parent() == this._switchData.curGroup) {
-                this._switchData.curGroup.set_child_above_sibling(windows[i], lastCurSibling);
-                lastCurSibling = windows[i];
-            } else {
-                for (let dir of Object.values(Meta.MotionDirection)) {
-                    let info = this._switchData.surroundings[dir];
-                    if (!info || windows[i].get_parent() != info.actor)
-                        continue;
-
-                    let sibling = lastDirSibling[dir];
-                    if (sibling == undefined)
-                        sibling = null;
-
-                    info.actor.set_child_above_sibling(windows[i], sibling);
-                    lastDirSibling[dir] = windows[i];
-                    break;
-                }
-            }
-        }
-    }
-
-    _getPositionForDirection(direction, fromWs, toWs) {
-        let xDest = 0, yDest = 0;
-
-        let oldWsIsFullscreen = fromWs.list_windows().some(w => w.is_fullscreen());
-        let newWsIsFullscreen = toWs.list_windows().some(w => w.is_fullscreen());
-
-        // We have to shift windows up or down by the height of the panel to prevent having a
-        // visible gap between the windows while switching workspaces. Since fullscreen windows
-        // hide the panel, they don't need to be shifted up or down.
-        let shiftHeight = Main.panel.height;
-
-        if (direction == Meta.MotionDirection.UP ||
-            direction == Meta.MotionDirection.UP_LEFT ||
-            direction == Meta.MotionDirection.UP_RIGHT)
-            yDest = -global.screen_height + (oldWsIsFullscreen ? 0 : shiftHeight);
-        else if (direction == Meta.MotionDirection.DOWN ||
-            direction == Meta.MotionDirection.DOWN_LEFT ||
-            direction == Meta.MotionDirection.DOWN_RIGHT)
-            yDest = global.screen_height - (newWsIsFullscreen ? 0 : shiftHeight);
-
-        if (direction == Meta.MotionDirection.LEFT ||
-            direction == Meta.MotionDirection.UP_LEFT ||
-            direction == Meta.MotionDirection.DOWN_LEFT)
-            xDest = -global.screen_width;
-        else if (direction == Meta.MotionDirection.RIGHT ||
-                 direction == Meta.MotionDirection.UP_RIGHT ||
-                 direction == Meta.MotionDirection.DOWN_RIGHT)
-            xDest = global.screen_width;
-
-        return [xDest, yDest];
-    }
-
-    _prepareWorkspaceSwitch(from, to, direction) {
-        if (this._switchData)
-            return;
-
-        let wgroup = global.window_group;
-        let windows = global.get_window_actors();
-        let switchData = {};
-
-        this._switchData = switchData;
-        switchData.curGroup = new Clutter.Actor();
-        switchData.movingWindowBin = new Clutter.Actor();
-        switchData.windows = [];
-        switchData.surroundings = {};
-        switchData.gestureActivated = false;
-        switchData.inProgress = false;
-
-        switchData.container = new Clutter.Actor();
-        switchData.container.add_actor(switchData.curGroup);
-
-        wgroup.add_actor(switchData.movingWindowBin);
-        wgroup.add_actor(switchData.container);
-
-        let workspaceManager = global.workspace_manager;
-        let curWs = workspaceManager.get_workspace_by_index(from);
-
-        for (let dir of Object.values(Meta.MotionDirection)) {
-            let ws = null;
-
-            if (to < 0)
-                ws = curWs.get_neighbor(dir);
-            else if (dir == direction)
-                ws = workspaceManager.get_workspace_by_index(to);
-
-            if (ws == null || ws == curWs) {
-                switchData.surroundings[dir] = null;
-                continue;
-            }
-
-            let [x, y] = this._getPositionForDirection(dir, curWs, ws);
-            let info = {
-                index: ws.index(),
-                actor: new Clutter.Actor(),
-                xDest: x,
-                yDest: y,
-            };
-            switchData.surroundings[dir] = info;
-            switchData.container.add_actor(info.actor);
-            switchData.container.set_child_above_sibling(info.actor, null);
-
-            info.actor.set_position(x, y);
-        }
-
-        wgroup.set_child_above_sibling(switchData.movingWindowBin, null);
-
-        for (let i = 0; i < windows.length; i++) {
-            let actor = windows[i];
-            let window = actor.get_meta_window();
-
-            if (!window.showing_on_its_workspace())
-                continue;
-
-            if (window.is_on_all_workspaces())
-                continue;
-
-            let record = { window: actor,
-                           parent: actor.get_parent() };
-
-            if (this._movingWindow && window == this._movingWindow) {
-                record.parent.remove_child(actor);
-                switchData.movingWindow = record;
-                switchData.windows.push(switchData.movingWindow);
-                switchData.movingWindowBin.add_child(actor);
-            } else if (window.get_workspace().index() == from) {
-                record.parent.remove_child(actor);
-                switchData.windows.push(record);
-                switchData.curGroup.add_child(actor);
-            } else {
-                let visible = false;
-                for (let dir of Object.values(Meta.MotionDirection)) {
-                    let info = switchData.surroundings[dir];
-
-                    if (!info || info.index != window.get_workspace().index())
-                        continue;
-
-                    record.parent.remove_child(actor);
-                    switchData.windows.push(record);
-                    info.actor.add_child(actor);
-                    visible = true;
-                    break;
-                }
-
-                actor.visible = visible;
-            }
-        }
-
-        for (let i = 0; i < switchData.windows.length; i++) {
-            let w = switchData.windows[i];
-
-            w.windowDestroyId = w.window.connect('destroy', () => {
-                switchData.windows.splice(switchData.windows.indexOf(w), 1);
-            });
-        }
-    }
-
-    _finishWorkspaceSwitch(switchData) {
-        this._switchData = null;
-
-        for (let i = 0; i < switchData.windows.length; i++) {
-            let w = switchData.windows[i];
-
-            w.window.disconnect(w.windowDestroyId);
-            w.window.get_parent().remove_child(w.window);
-            w.parent.add_child(w.window);
-
-            if (!w.window.get_meta_window().get_workspace().active)
-                w.window.hide();
-        }
-        switchData.container.destroy();
-        switchData.movingWindowBin.destroy();
-
-        this._movingWindow = null;
-    }
-
     _switchWorkspace(shellwm, from, to, direction) {
         if (!Main.sessionMode.hasWorkspaces || !this._shouldAnimate()) {
             shellwm.completed_switch_workspace();
             return;
         }
 
-        this._prepareWorkspaceSwitch(from, to, direction);
-        this._switchData.inProgress = true;
-
-        let workspaceManager = global.workspace_manager;
-        let fromWs = workspaceManager.get_workspace_by_index(from);
-        let toWs = workspaceManager.get_workspace_by_index(to);
-
-        let [xDest, yDest] = this._getPositionForDirection(direction, fromWs, toWs);
-
-        /* @direction is the direction that the "camera" moves, so the
-         * screen contents have to move one screen's worth in the
-         * opposite direction.
-         */
-        xDest = -xDest;
-        yDest = -yDest;
-
-        this._switchData.container.ease({
-            x: xDest,
-            y: yDest,
-            duration: WINDOW_ANIMATION_TIME,
-            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
-            onComplete: () => this._switchWorkspaceDone(shellwm),
-        });
-    }
-
-    _switchWorkspaceDone(shellwm) {
-        this._finishWorkspaceSwitch(this._switchData);
-        shellwm.completed_switch_workspace();
-    }
-
-    _directionForProgress(progress) {
-        if (global.workspace_manager.layout_rows === -1) {
-            return progress > 0
-                ? Meta.MotionDirection.DOWN
-                : Meta.MotionDirection.UP;
-        } else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL) {
-            return progress > 0
-                ? Meta.MotionDirection.LEFT
-                : Meta.MotionDirection.RIGHT;
-        } else {
-            return progress > 0
-                ? Meta.MotionDirection.RIGHT
-                : Meta.MotionDirection.LEFT;
-        }
-    }
-
-    _getProgressRange() {
-        if (!this._switchData)
-            return [0, 0];
-
-        let lower = 0;
-        let upper = 0;
-
-        let horiz = global.workspace_manager.layout_rows !== -1;
-        let baseDistance;
-        if (horiz)
-            baseDistance = global.screen_width;
-        else
-            baseDistance = global.screen_height;
-
-        let direction = this._directionForProgress(-1);
-        let info = this._switchData.surroundings[direction];
-        if (info !== null) {
-            let distance = horiz ? info.xDest : info.yDest;
-            lower = -Math.abs(distance) / baseDistance;
-        }
-
-        direction = this._directionForProgress(1);
-        info = this._switchData.surroundings[direction];
-        if (info !== null) {
-            let distance = horiz ? info.xDest : info.yDest;
-            upper = Math.abs(distance) / baseDistance;
-        }
-
-        return [lower, upper];
-    }
-
-    _switchWorkspaceBegin(tracker, monitor) {
-        if (Meta.prefs_get_workspaces_only_on_primary() &&
-            monitor !== Main.layoutManager.primaryIndex)
-            return;
-
-        let workspaceManager = global.workspace_manager;
-        let horiz = workspaceManager.layout_rows !== -1;
-        tracker.orientation = horiz
-            ? Clutter.Orientation.HORIZONTAL
-            : Clutter.Orientation.VERTICAL;
-
-        let activeWorkspace = workspaceManager.get_active_workspace();
-
-        let baseDistance;
-        if (horiz)
-            baseDistance = global.screen_width;
-        else
-            baseDistance = global.screen_height;
-
-        let progress;
-        if (this._switchData && this._switchData.gestureActivated) {
-            this._switchData.container.remove_all_transitions();
-            if (!horiz)
-                progress = -this._switchData.container.y / baseDistance;
-            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
-                progress = this._switchData.container.x / baseDistance;
-            else
-                progress = -this._switchData.container.x / baseDistance;
-        } else {
-            this._prepareWorkspaceSwitch(activeWorkspace.index(), -1);
-            progress = 0;
-        }
-
-        let points = [];
-        let [lower, upper] = this._getProgressRange();
-
-        if (lower !== 0)
-            points.push(lower);
-
-        points.push(0);
-
-        if (upper !== 0)
-            points.push(upper);
-
-        tracker.confirmSwipe(baseDistance, points, progress, 0);
-    }
-
-    _switchWorkspaceUpdate(tracker, progress) {
-        if (!this._switchData)
-            return;
-
-        let direction = this._directionForProgress(progress);
-        let info = this._switchData.surroundings[direction];
-        let xPos = 0;
-        let yPos = 0;
-        if (info) {
-            if (global.workspace_manager.layout_rows === -1)
-                yPos = -Math.round(progress * global.screen_height);
-            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
-                xPos = Math.round(progress * global.screen_width);
-            else
-                xPos = -Math.round(progress * global.screen_width);
-        }
-
-        this._switchData.container.set_position(xPos, yPos);
-    }
-
-    _switchWorkspaceEnd(tracker, duration, endProgress) {
-        if (!this._switchData)
-            return;
-
-        let workspaceManager = global.workspace_manager;
-        let activeWorkspace = workspaceManager.get_active_workspace();
-        let newWs = activeWorkspace;
-        let xDest = 0;
-        let yDest = 0;
-        if (endProgress !== 0) {
-            let direction = this._directionForProgress(endProgress);
-            newWs = activeWorkspace.get_neighbor(direction);
-            xDest = -this._switchData.surroundings[direction].xDest;
-            yDest = -this._switchData.surroundings[direction].yDest;
-        }
-
-        let switchData = this._switchData;
-        switchData.gestureActivated = true;
-
-        this._switchData.container.ease({
-            x: xDest,
-            y: yDest,
-            duration,
-            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
-            onComplete: () => {
-                if (!newWs.active)
-                    this.actionMoveWorkspace(newWs);
-                this._finishWorkspaceSwitch(switchData);
-            },
-        });
-    }
-
-    _switchWorkspaceStop() {
-        this._switchData.container.x = 0;
-        this._switchData.container.y = 0;
-        this._finishWorkspaceSwitch(this._switchData);
+        this._workspaceAnimation.animateSwitch(shellwm, from, to, direction);
     }
 
     _showTilePreview(shellwm, window, tileRect, monitorIndex) {
@@ -2209,7 +1823,7 @@ var WindowManager = class {
             // This won't have any effect for "always sticky" windows
             // (like desktop windows or docks)
 
-            this._movingWindow = window;
+            this._workspaceAnimation.movingWindow = window;
             window.change_workspace(workspace);
 
             global.display.clear_mouse_mode();
diff --git a/js/ui/workspaceAnimation.js b/js/ui/workspaceAnimation.js
new file mode 100644
index 0000000000..9d7a98905d
--- /dev/null
+++ b/js/ui/workspaceAnimation.js
@@ -0,0 +1,422 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+/* exported WorkspaceAnimationController */
+
+const { Clutter, Meta, Shell } = imports.gi;
+
+const Main = imports.ui.main;
+const SwipeTracker = imports.ui.swipeTracker;
+
+const WINDOW_ANIMATION_TIME = 250;
+
+var WorkspaceAnimationController = class {
+    constructor() {
+        this._shellwm = global.window_manager;
+        this._movingWindow = null;
+
+        this._switchData = null;
+        this._shellwm.connect('kill-switch-workspace', shellwm => {
+            if (this._switchData) {
+                if (this._switchData.inProgress)
+                    this._switchWorkspaceDone(shellwm);
+                else if (!this._switchData.gestureActivated)
+                    this._finishWorkspaceSwitch(this._switchData);
+            }
+        });
+
+        global.display.connect('restacked', this._syncStacking.bind(this));
+
+        Main.overview.connect('showing', () => {
+            if (this._switchData) {
+                if (this._switchData.gestureActivated)
+                    this._switchWorkspaceStop();
+                this._swipeTracker.enabled = false;
+            }
+        });
+        Main.overview.connect('hiding', () => {
+            this._swipeTracker.enabled = true;
+        });
+
+        const swipeTracker = new SwipeTracker.SwipeTracker(global.stage,
+            Shell.ActionMode.NORMAL, { allowDrag: false, allowScroll: false });
+        swipeTracker.connect('begin', this._switchWorkspaceBegin.bind(this));
+        swipeTracker.connect('update', this._switchWorkspaceUpdate.bind(this));
+        swipeTracker.connect('end', this._switchWorkspaceEnd.bind(this));
+        this._swipeTracker = swipeTracker;
+    }
+
+    _syncStacking() {
+        if (this._switchData === null)
+            return;
+
+        const windows = global.get_window_actors();
+        let lastCurSibling = null;
+        const lastDirSibling = [];
+        for (let i = 0; i < windows.length; i++) {
+            if (windows[i].get_parent() === this._switchData.curGroup) {
+                this._switchData.curGroup.set_child_above_sibling(windows[i], lastCurSibling);
+                lastCurSibling = windows[i];
+            } else {
+                for (const dir of Object.values(Meta.MotionDirection)) {
+                    const info = this._switchData.surroundings[dir];
+                    if (!info || windows[i].get_parent() !== info.actor)
+                        continue;
+
+                    let sibling = lastDirSibling[dir];
+                    if (sibling === undefined)
+                        sibling = null;
+
+                    info.actor.set_child_above_sibling(windows[i], sibling);
+                    lastDirSibling[dir] = windows[i];
+                    break;
+                }
+            }
+        }
+    }
+
+    _getPositionForDirection(direction, fromWs, toWs) {
+        let xDest = 0, yDest = 0;
+
+        const oldWsIsFullscreen = fromWs.list_windows().some(w => w.is_fullscreen());
+        const newWsIsFullscreen = toWs.list_windows().some(w => w.is_fullscreen());
+
+        // We have to shift windows up or down by the height of the panel to prevent having a
+        // visible gap between the windows while switching workspaces. Since fullscreen windows
+        // hide the panel, they don't need to be shifted up or down.
+        const shiftHeight = Main.panel.height;
+
+        if (direction === Meta.MotionDirection.UP ||
+            direction === Meta.MotionDirection.UP_LEFT ||
+            direction === Meta.MotionDirection.UP_RIGHT)
+            yDest = -global.screen_height + (oldWsIsFullscreen ? 0 : shiftHeight);
+        else if (direction === Meta.MotionDirection.DOWN ||
+            direction === Meta.MotionDirection.DOWN_LEFT ||
+            direction === Meta.MotionDirection.DOWN_RIGHT)
+            yDest = global.screen_height - (newWsIsFullscreen ? 0 : shiftHeight);
+
+        if (direction === Meta.MotionDirection.LEFT ||
+            direction === Meta.MotionDirection.UP_LEFT ||
+            direction === Meta.MotionDirection.DOWN_LEFT)
+            xDest = -global.screen_width;
+        else if (direction === Meta.MotionDirection.RIGHT ||
+                 direction === Meta.MotionDirection.UP_RIGHT ||
+                 direction === Meta.MotionDirection.DOWN_RIGHT)
+            xDest = global.screen_width;
+
+        return [xDest, yDest];
+    }
+
+    _prepareWorkspaceSwitch(from, to, direction) {
+        if (this._switchData)
+            return;
+
+        const wgroup = global.window_group;
+        const windows = global.get_window_actors();
+        const switchData = {};
+
+        this._switchData = switchData;
+        switchData.curGroup = new Clutter.Actor();
+        switchData.movingWindowBin = new Clutter.Actor();
+        switchData.windows = [];
+        switchData.surroundings = {};
+        switchData.gestureActivated = false;
+        switchData.inProgress = false;
+
+        switchData.container = new Clutter.Actor();
+        switchData.container.add_child(switchData.curGroup);
+
+        wgroup.add_child(switchData.movingWindowBin);
+        wgroup.add_child(switchData.container);
+
+        const workspaceManager = global.workspace_manager;
+        const curWs = workspaceManager.get_workspace_by_index(from);
+
+        for (const dir of Object.values(Meta.MotionDirection)) {
+            let ws = null;
+
+            if (to < 0)
+                ws = curWs.get_neighbor(dir);
+            else if (dir === direction)
+                ws = workspaceManager.get_workspace_by_index(to);
+
+            if (ws === null || ws === curWs) {
+                switchData.surroundings[dir] = null;
+                continue;
+            }
+
+            const [x, y] = this._getPositionForDirection(dir, curWs, ws);
+            const info = {
+                index: ws.index(),
+                actor: new Clutter.Actor(),
+                xDest: x,
+                yDest: y,
+            };
+            switchData.surroundings[dir] = info;
+            switchData.container.add_child(info.actor);
+            switchData.container.set_child_above_sibling(info.actor, null);
+
+            info.actor.set_position(x, y);
+        }
+
+        wgroup.set_child_above_sibling(switchData.movingWindowBin, null);
+
+        for (const windowActor of windows) {
+            const window = windowActor.get_meta_window();
+
+            if (!window.showing_on_its_workspace())
+                continue;
+
+            if (window.is_on_all_workspaces())
+                continue;
+
+            const record = {
+                windowActor,
+                parent: windowActor.get_parent(),
+            };
+
+            if (this.movingWindow && window === this.movingWindow) {
+                record.parent.remove_child(windowActor);
+                switchData.movingWindow = record;
+                switchData.windows.push(switchData.movingWindow);
+                switchData.movingWindowBin.add_child(windowActor);
+            } else if (window.get_workspace().index() === from) {
+                record.parent.remove_child(windowActor);
+                switchData.windows.push(record);
+                switchData.curGroup.add_child(windowActor);
+            } else {
+                let visible = false;
+                for (const dir of Object.values(Meta.MotionDirection)) {
+                    const info = switchData.surroundings[dir];
+
+                    if (!info || info.index !== window.get_workspace().index())
+                        continue;
+
+                    record.parent.remove_child(windowActor);
+                    switchData.windows.push(record);
+                    info.actor.add_child(windowActor);
+                    visible = true;
+                    break;
+                }
+
+                windowActor.visible = visible;
+            }
+        }
+
+        for (const record of switchData.windows) {
+            record.windowDestroyId = record.windowActor.connect('destroy', () => {
+                switchData.windows.splice(switchData.windows.indexOf(record), 1);
+            });
+        }
+    }
+
+    _finishWorkspaceSwitch(switchData) {
+        this._switchData = null;
+
+        for (const record of switchData.windows) {
+            record.windowActor.disconnect(record.windowDestroyId);
+            switchData.movingWindowBin.remove_child(record.windowActor);
+            record.parent.add_child(record.windowActor);
+
+            if (!record.windowActor.get_meta_window().get_workspace().active)
+                record.windowActor.hide();
+        }
+        switchData.container.destroy();
+        switchData.movingWindowBin.destroy();
+
+        this.movingWindow = null;
+    }
+
+    animateSwitch(shellwm, from, to, direction) {
+        this._prepareWorkspaceSwitch(from, to, direction);
+        this._switchData.inProgress = true;
+
+        const workspaceManager = global.workspace_manager;
+        const fromWs = workspaceManager.get_workspace_by_index(from);
+        const toWs = workspaceManager.get_workspace_by_index(to);
+
+        let [xDest, yDest] = this._getPositionForDirection(direction, fromWs, toWs);
+
+        /* @direction is the direction that the "camera" moves, so the
+         * screen contents have to move one screen's worth in the
+         * opposite direction.
+         */
+        xDest = -xDest;
+        yDest = -yDest;
+
+        this._switchData.container.ease({
+            x: xDest,
+            y: yDest,
+            duration: WINDOW_ANIMATION_TIME,
+            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            onComplete: () => this._switchWorkspaceDone(shellwm),
+        });
+    }
+
+    _switchWorkspaceDone(shellwm) {
+        this._finishWorkspaceSwitch(this._switchData);
+        shellwm.completed_switch_workspace();
+    }
+
+    _directionForProgress(progress) {
+        if (global.workspace_manager.layout_rows === -1) {
+            return progress > 0
+                ? Meta.MotionDirection.DOWN
+                : Meta.MotionDirection.UP;
+        } else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL) {
+            return progress > 0
+                ? Meta.MotionDirection.LEFT
+                : Meta.MotionDirection.RIGHT;
+        } else {
+            return progress > 0
+                ? Meta.MotionDirection.RIGHT
+                : Meta.MotionDirection.LEFT;
+        }
+    }
+
+    _getProgressRange() {
+        if (!this._switchData)
+            return [0, 0];
+
+        let lower = 0;
+        let upper = 0;
+
+        const horiz = global.workspace_manager.layout_rows !== -1;
+        let baseDistance;
+        if (horiz)
+            baseDistance = global.screen_width;
+        else
+            baseDistance = global.screen_height;
+
+        let direction = this._directionForProgress(-1);
+        let info = this._switchData.surroundings[direction];
+        if (info !== null) {
+            const distance = horiz ? info.xDest : info.yDest;
+            lower = -Math.abs(distance) / baseDistance;
+        }
+
+        direction = this._directionForProgress(1);
+        info = this._switchData.surroundings[direction];
+        if (info !== null) {
+            const distance = horiz ? info.xDest : info.yDest;
+            upper = Math.abs(distance) / baseDistance;
+        }
+
+        return [lower, upper];
+    }
+
+    _switchWorkspaceBegin(tracker, monitor) {
+        if (Meta.prefs_get_workspaces_only_on_primary() &&
+            monitor !== Main.layoutManager.primaryIndex)
+            return;
+
+        const workspaceManager = global.workspace_manager;
+        const horiz = workspaceManager.layout_rows !== -1;
+        tracker.orientation = horiz
+            ? Clutter.Orientation.HORIZONTAL
+            : Clutter.Orientation.VERTICAL;
+
+        const activeWorkspace = workspaceManager.get_active_workspace();
+
+        let baseDistance;
+        if (horiz)
+            baseDistance = global.screen_width;
+        else
+            baseDistance = global.screen_height;
+
+        let progress;
+        if (this._switchData && this._switchData.gestureActivated) {
+            this._switchData.container.remove_all_transitions();
+            if (!horiz)
+                progress = -this._switchData.container.y / baseDistance;
+            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
+                progress = this._switchData.container.x / baseDistance;
+            else
+                progress = -this._switchData.container.x / baseDistance;
+        } else {
+            this._prepareWorkspaceSwitch(activeWorkspace.index(), -1);
+            progress = 0;
+        }
+
+        const points = [];
+        const [lower, upper] = this._getProgressRange();
+
+        if (lower !== 0)
+            points.push(lower);
+
+        points.push(0);
+
+        if (upper !== 0)
+            points.push(upper);
+
+        tracker.confirmSwipe(baseDistance, points, progress, 0);
+    }
+
+    _switchWorkspaceUpdate(tracker, progress) {
+        if (!this._switchData)
+            return;
+
+        const direction = this._directionForProgress(progress);
+        const info = this._switchData.surroundings[direction];
+        let xPos = 0;
+        let yPos = 0;
+        if (info) {
+            if (global.workspace_manager.layout_rows === -1)
+                yPos = -Math.round(progress * global.screen_height);
+            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
+                xPos = Math.round(progress * global.screen_width);
+            else
+                xPos = -Math.round(progress * global.screen_width);
+        }
+
+        this._switchData.container.set_position(xPos, yPos);
+    }
+
+    _switchWorkspaceEnd(tracker, duration, endProgress) {
+        if (!this._switchData)
+            return;
+
+        const workspaceManager = global.workspace_manager;
+        const activeWorkspace = workspaceManager.get_active_workspace();
+        let newWs = activeWorkspace;
+        let xDest = 0;
+        let yDest = 0;
+        if (endProgress !== 0) {
+            const direction = this._directionForProgress(endProgress);
+            newWs = activeWorkspace.get_neighbor(direction);
+            xDest = -this._switchData.surroundings[direction].xDest;
+            yDest = -this._switchData.surroundings[direction].yDest;
+        }
+
+        const switchData = this._switchData;
+        switchData.gestureActivated = true;
+
+        this._switchData.container.ease({
+            x: xDest,
+            y: yDest,
+            duration,
+            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            onComplete: () => {
+                if (!newWs.active)
+                    newWs.activate(global.get_current_time());
+                this._finishWorkspaceSwitch(switchData);
+            },
+        });
+    }
+
+    _switchWorkspaceStop() {
+        this._switchData.container.x = 0;
+        this._switchData.container.y = 0;
+        this._finishWorkspaceSwitch(this._switchData);
+    }
+
+    get gestureActive() {
+        return this._switchData !== null && this._switchData.gestureActivated;
+    }
+
+    set movingWindow(movingWindow) {
+        this._movingWindow = movingWindow;
+    }
+
+    get movingWindow() {
+        return this._movingWindow;
+    }
+};