[gnome-shell/wip/exalm/gestures2: 39/39] workspaceAnimation: Support multiple screens

[Alexander Mikhaylenko <alexm src gnome org>]

commit c3aa25e4e3e8b7749cc31db370e4e6c7befa487e
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Sun Jun 21 00:43:06 2020 +0500

    workspaceAnimation: Support multiple screens
    
    Currently, there's one animation for the whole canvas. While it looks fine
    with just one screen, it causes windows to move between screens when
    switching workspaces. Instead, have a separate animation on each screen,
    and sync their progress so that at any given time the progress "fraction"
    is the same between all screens. Clip all animations to their screens so
    that the windows don't leak to other screens.
    
    If a window is placed between every screen, can end up in multiple
    animations, in that case each part is still animated separately.
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-shell/issues/1213
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1326

 js/ui/workspaceAnimation.js | 340 +++++++++++++++++++++++++++-----------------
 1 file changed, 209 insertions(+), 131 deletions(-)
---
diff --git a/js/ui/workspaceAnimation.js b/js/ui/workspaceAnimation.js
index 5036ff743a..e0abb5256d 100644
--- a/js/ui/workspaceAnimation.js
+++ b/js/ui/workspaceAnimation.js
@@ -12,10 +12,11 @@ const WINDOW_ANIMATION_TIME = 250;
 
 const WorkspaceGroup = GObject.registerClass(
 class WorkspaceGroup extends Clutter.Actor {
-    _init(workspace, movingWindow) {
+    _init(workspace, monitor, movingWindow) {
         super._init();
 
         this._workspace = workspace;
+        this._monitor = monitor;
         this._movingWindow = movingWindow;
         this._windowRecords = [];
 
@@ -34,6 +35,11 @@ class WorkspaceGroup extends Clutter.Actor {
         if (!window.showing_on_its_workspace())
             return false;
 
+        const geometry = global.display.get_monitor_geometry(this._monitor.index);
+        const [intersects, intersection_] = window.get_frame_rect().intersect(geometry);
+        if (!intersects)
+            return false;
+
         const isSticky =
             window.is_on_all_workspaces() || window === this._movingWindow;
 
@@ -66,8 +72,8 @@ class WorkspaceGroup extends Clutter.Actor {
         for (const windowActor of windowActors) {
             const clone = new Clutter.Clone({
                 source: windowActor,
-                x: windowActor.x,
-                y: windowActor.y,
+                x: windowActor.x - this._monitor.x,
+                y: windowActor.y - this._monitor.y,
             });
 
             this.add_child(clone);
@@ -98,10 +104,20 @@ class WorkspaceGroup extends Clutter.Actor {
     }
 });
 
-const MonitorGroup = GObject.registerClass(
-class MonitorGroup extends Clutter.Actor {
-    _init(monitor) {
-        super._init();
+const MonitorGroup = GObject.registerClass({
+    Properties: {
+        'progress': GObject.ParamSpec.double(
+            'progress', 'progress', 'progress',
+            GObject.ParamFlags.READWRITE,
+            -Infinity, Infinity, 0),
+    },
+}, class MonitorGroup extends Clutter.Actor {
+    _init(monitor, workspaceIndices, movingWindow) {
+        super._init({
+            clip_to_allocation: true,
+        });
+
+        this._monitor = monitor;
 
         const constraint = new Layout.MonitorConstraint({ index: monitor.index });
         this.add_constraint(constraint);
@@ -110,6 +126,48 @@ class MonitorGroup extends Clutter.Actor {
 
         this.add_child(background);
 
+        this._container = new Clutter.Actor();
+        this.add_child(this._container);
+
+        const stickyGroup = new WorkspaceGroup(null, monitor, movingWindow);
+        this.add_child(stickyGroup);
+
+        this._workspaceGroups = [];
+
+        const workspaceManager = global.workspace_manager;
+        const vertical = workspaceManager.layout_rows === -1;
+        const activeWorkspace = workspaceManager.get_active_workspace();
+
+        let x = 0;
+        let y = 0;
+
+        for (const i of workspaceIndices) {
+            const ws = workspaceManager.get_workspace_by_index(i);
+            const fullscreen = ws.list_windows().some(w => w.get_monitor() === monitor.index && 
w.is_fullscreen());
+
+            if (i > 0 && vertical && !fullscreen && monitor.index === Main.layoutManager.primaryIndex) {
+                // 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.
+                y -= Main.panel.height;
+            }
+
+            const group = new WorkspaceGroup(ws, monitor, movingWindow);
+
+            this._workspaceGroups.push(group);
+            this._container.add_child(group);
+            group.set_position(x, y);
+
+            if (vertical)
+                y += this.baseDistance;
+            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
+                x -= this.baseDistance;
+            else
+                x += this.baseDistance;
+        }
+
+        this.progress = this.getWorkspaceProgress(activeWorkspace);
+
         this._bgManager = new Background.BackgroundManager({
             container: background,
             monitorIndex: monitor.index,
@@ -122,6 +180,84 @@ class MonitorGroup extends Clutter.Actor {
     _onDestroy() {
         this._bgManager.destroy();
     }
+
+    get baseDistance() {
+        if (global.workspace_manager.layout_rows === -1)
+            return this._monitor.height;
+        else
+            return this._monitor.width;
+    }
+
+    get progress() {
+        if (global.workspace_manager.layout_rows === -1)
+            return -this._container.y / this.baseDistance;
+        else if (this.get_text_direction() === Clutter.TextDirection.RTL)
+            return this._container.x / this.baseDistance;
+        else
+            return -this._container.x / this.baseDistance;
+    }
+
+    set progress(p) {
+        if (global.workspace_manager.layout_rows === -1)
+            this._container.y = -Math.round(p * this.baseDistance);
+        else if (this.get_text_direction() === Clutter.TextDirection.RTL)
+            this._container.x = Math.round(p * this.baseDistance);
+        else
+            this._container.x = -Math.round(p * this.baseDistance);
+    }
+
+    get index() {
+        return this._monitor.index;
+    }
+
+    getWorkspaceProgress(workspace) {
+        const group = this._workspaceGroups.find(g =>
+            g.workspace.index() === workspace.index());
+        return this._getWorkspaceGroupProgress(group);
+    }
+
+    _getWorkspaceGroupProgress(group) {
+        if (global.workspace_manager.layout_rows === -1)
+            return group.y / this.baseDistance;
+        else if (this.get_text_direction() === Clutter.TextDirection.RTL)
+            return -group.x / this.baseDistance;
+        else
+            return group.x / this.baseDistance;
+    }
+
+    getSnapPoints() {
+        return this._workspaceGroups.map(g =>
+            this._getWorkspaceGroupProgress(g));
+    }
+
+    findClosestWorkspace(progress) {
+        const distances = this.getSnapPoints().map(p =>
+            Math.abs(p - progress));
+        const index = distances.indexOf(Math.min(...distances));
+        return this._workspaceGroups[index].workspace;
+    }
+
+    _interpolateProgress(progress, monitorGroup) {
+        if (this.index === monitorGroup.index)
+            return progress;
+
+        const points1 = monitorGroup.getSnapPoints();
+        const points2 = this.getSnapPoints();
+
+        const upper = points1.indexOf(points1.find(p => p >= progress));
+        const lower = points1.indexOf(points1.slice().reverse().find(p => p <= progress));
+
+        if (points1[upper] === points1[lower])
+            return points2[upper];
+
+        const t = (progress - points1[lower]) / (points1[upper] - points1[lower]);
+
+        return points2[lower] + (points2[upper] - points2[lower]) * t;
+    }
+
+    updateSwipeForMonitor(progress, monitorGroup) {
+        this.progress = this._interpolateProgress(progress, monitorGroup);
+    }
 });
 
 var WorkspaceAnimationController = class {
@@ -153,73 +289,39 @@ var WorkspaceAnimationController = class {
             return;
 
         const workspaceManager = global.workspace_manager;
-        const vertical = workspaceManager.layout_rows === -1;
         const nWorkspaces = workspaceManager.get_n_workspaces();
-        const activeWorkspaceIndex = workspaceManager.get_active_workspace_index();
 
         const switchData = {};
 
         this._switchData = switchData;
-        switchData.stickyGroup = new WorkspaceGroup(null, this.movingWindow);
-        switchData.workspaceGroups = [];
+        switchData.monitors = [];
+
         switchData.gestureActivated = false;
         switchData.inProgress = false;
 
-        switchData.container = new Clutter.Actor();
-        switchData.backgroundGroup = new Clutter.Actor();
-
-        for (const monitor of Main.layoutManager.monitors)
-            switchData.backgroundGroup.add_child(new MonitorGroup(monitor));
-
-        Main.uiGroup.insert_child_above(switchData.backgroundGroup, global.window_group);
-        Main.uiGroup.insert_child_above(switchData.container, switchData.backgroundGroup);
-        Main.uiGroup.insert_child_above(switchData.stickyGroup, switchData.container);
-
-        let x = 0;
-        let y = 0;
-
         if (!workspaceIndices)
             workspaceIndices = [...Array(nWorkspaces).keys()];
 
-        for (const i of workspaceIndices) {
-            const ws = workspaceManager.get_workspace_by_index(i);
-            const fullscreen = ws.list_windows().some(w => w.is_fullscreen());
+        const monitors = Meta.prefs_get_workspaces_only_on_primary()
+            ? [Main.layoutManager.primaryMonitor] : Main.layoutManager.monitors;
 
-            if (y > 0 && vertical && !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.
-                y -= Main.panel.height;
-            }
+        for (const monitor of monitors) {
+            if (Meta.prefs_get_workspaces_only_on_primary() &&
+                monitor.index !== Main.layoutManager.primaryIndex)
+                continue;
 
-            const group = new WorkspaceGroup(ws, this.movingWindow);
+            const group = new MonitorGroup(monitor, workspaceIndices, this.movingWindow);
 
-            switchData.workspaceGroups.push(group);
-            switchData.container.add_child(group);
-            switchData.container.set_child_above_sibling(group, null);
-            group.set_position(x, y);
+            Main.uiGroup.insert_child_above(group, global.window_group);
 
-            if (vertical)
-                y += global.screen_height;
-            else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
-                x -= global.screen_width;
-            else
-                x += global.screen_width;
+            switchData.monitors.push(group);
         }
-
-        const activeGroup = this._findWorkspaceGroupByIndex(activeWorkspaceIndex);
-        if (vertical)
-            switchData.container.y = -activeGroup.y;
-        else
-            switchData.container.x = -activeGroup.x;
     }
 
     _finishWorkspaceSwitch(switchData) {
         this._switchData = null;
 
-        switchData.backgroundGroup.destroy();
-        switchData.container.destroy();
-        switchData.stickyGroup.destroy();
+        switchData.monitors.forEach(m => m.destroy());
 
         this.movingWindow = null;
     }
@@ -253,45 +355,32 @@ var WorkspaceAnimationController = class {
         this._prepareWorkspaceSwitch(workspaceIndices);
         this._switchData.inProgress = true;
 
-        const fromGroup = this._findWorkspaceGroupByIndex(from);
-        const toGroup = this._findWorkspaceGroupByIndex(to);
-
-        this._switchData.container.x = -fromGroup.x;
-        this._switchData.container.y = -fromGroup.y;
-
-        this._switchData.container.ease({
-            x: -toGroup.x,
-            y: -toGroup.y,
-            duration: WINDOW_ANIMATION_TIME,
-            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
-            onComplete: () => {
-                this._finishWorkspaceSwitch(this._switchData);
-                onComplete();
-                this._swipeTracker.enabled = true;
-            },
-        });
-    }
+        const fromWs = global.workspace_manager.get_workspace_by_index(from);
+        const toWs = global.workspace_manager.get_workspace_by_index(to);
 
-    _getProgressForWorkspace(workspaceGroup) {
-        if (global.workspace_manager.layout_rows === -1)
-            return workspaceGroup.y / global.screen_height;
-        else if (Clutter.get_default_text_direction() === Clutter.TextDirection.RTL)
-            return -workspaceGroup.x / global.screen_width;
-        else
-            return workspaceGroup.x / global.screen_width;
-    }
+        for (const monitorGroup of this._switchData.monitors) {
+            monitorGroup.progress = monitorGroup.getWorkspaceProgress(fromWs);
+            const progress = monitorGroup.getWorkspaceProgress(toWs);
+
+            const params = {
+                duration: WINDOW_ANIMATION_TIME,
+                mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            };
+
+            if (monitorGroup.index === Main.layoutManager.primaryIndex) {
+                params.onComplete = () => {
+                    this._finishWorkspaceSwitch(this._switchData);
+                    onComplete();
+                    this._swipeTracker.enabled = true;
+                };
+            }
 
-    _findWorkspaceGroupByIndex(index) {
-        return this._switchData.workspaceGroups.find(g => g.workspace.index() === index);
+            monitorGroup.ease_property('progress', progress, params);
+        }
     }
 
-    _findClosestWorkspaceGroup(progress) {
-        const distances = this._switchData.workspaceGroups.map(g => {
-            const workspaceProgress = this._getProgressForWorkspace(g);
-            return Math.abs(workspaceProgress - progress);
-        });
-        const index = distances.indexOf(Math.min(...distances));
-        return this._switchData.workspaceGroups[index];
+    _findMonitorGroup(monitorIndex) {
+        return this._switchData.monitors.find(m => m.index === monitorIndex);
     }
 
     _switchWorkspaceBegin(tracker, monitor) {
@@ -305,31 +394,22 @@ var WorkspaceAnimationController = class {
             ? Clutter.Orientation.HORIZONTAL
             : Clutter.Orientation.VERTICAL;
 
-        const baseDistance = horiz ? global.screen_width : global.screen_height;
-
-        let progress;
-        let cancelProgress;
         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;
-
-            const wsGroup = this._findClosestWorkspaceGroup(progress);
-            cancelProgress = this._getProgressForWorkspaceGroup(wsGroup);
+            for (const group of this._switchData.monitors)
+                group.remove_all_transitions();
         } else {
             this._prepareWorkspaceSwitch();
+        }
 
-            const activeIndex = workspaceManager.get_active_workspace_index();
-            const wsGroup = this._findWorkspaceGroupByIndex(activeIndex);
+        const monitorGroup = this._findMonitorGroup(monitor);
+        const baseDistance = monitorGroup.baseDistance;
+        const progress = monitorGroup.progress;
 
-            progress = cancelProgress = this._getProgressForWorkspace(wsGroup);
-        }
+        const closestWs = monitorGroup.findClosestWorkspace(progress);
+        const cancelProgress = monitorGroup.getWorkspaceProgress(closestWs);
+        const points = monitorGroup.getSnapPoints();
 
-        const points = this._switchData.workspaceGroups.map(this._getProgressForWorkspace);
+        this._switchData.baseMonitorGroup = monitorGroup;
 
         tracker.confirmSwipe(baseDistance, points, progress, cancelProgress);
     }
@@ -338,39 +418,37 @@ var WorkspaceAnimationController = class {
         if (!this._switchData)
             return;
 
-        let xPos = 0;
-        let yPos = 0;
-
-        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);
+        for (const monitorGroup of this._switchData.monitors)
+            monitorGroup.updateSwipeForMonitor(progress, this._switchData.baseMonitorGroup);
     }
 
     _switchWorkspaceEnd(tracker, duration, endProgress) {
         if (!this._switchData)
             return;
 
-        const newGroup = this._findClosestWorkspaceGroup(endProgress);
-
         const switchData = this._switchData;
         switchData.gestureActivated = true;
 
-        this._switchData.container.ease({
-            x: -newGroup.x,
-            y: -newGroup.y,
-            duration,
-            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
-            onComplete: () => {
-                if (!newGroup.workspace.active)
-                    newGroup.workspace.activate(global.get_current_time());
-                this._finishWorkspaceSwitch(switchData);
-            },
-        });
+        const newWs = switchData.baseMonitorGroup.findClosestWorkspace(endProgress);
+
+        for (const monitorGroup of this._switchData.monitors) {
+            const progress = monitorGroup.getWorkspaceProgress(newWs);
+
+            const params = {
+                duration,
+                mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            };
+
+            if (monitorGroup.index === Main.layoutManager.primaryIndex) {
+                params.onComplete = () => {
+                    if (!newWs.active)
+                        newWs.activate(global.get_current_time());
+                    this._finishWorkspaceSwitch(switchData);
+                };
+            }
+
+            monitorGroup.ease_property('progress', progress, params);
+        }
     }
 
     get gestureActive() {