workspacesView: Use SwipeTracker

Replace existing panning, touchpad scrolling and four-finger gesture by
SwipeTracker.

Change programmatic workspace animation to use easeOutCubic interpolator
to match the gesture.

Also change the dragging distance to always match the current monitor.

Fixes touchpad parts of https://gitlab.gnome.org/GNOME/gnome-shell/issues/1338

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/826

js/ui/workspacesView.js

@@ -4,7 +4,7 @@
 const { Clutter, Gio, GLib, GObject, Meta, Shell, St } = imports.gi;
 
 const Main = imports.ui.main;
-const WindowManager = imports.ui.windowManager;
+const SwipeTracker = imports.ui.swipeTracker;
 const Workspace = imports.ui.workspace;
 
 var WORKSPACE_SWITCH_TIME = 250;
@@ -79,7 +79,6 @@ class WorkspacesView extends WorkspacesViewBase {
         super._init(monitorIndex);
 
         this._animating = false; // tweening
-        this._scrolling = false; // swipe-scrolling
         this._gestureActive = false; // touch(pad) gestures
 
         this._scrollAdjustment = scrollAdjustment;
@@ -183,7 +182,7 @@ class WorkspacesView extends WorkspacesViewBase {
             if (showAnimation) {
                 let easeParams = Object.assign(params, {
                     duration: WORKSPACE_SWITCH_TIME,
-                    mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+                    mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
                 });
                 // we have to call _updateVisibility() once before the
                 // animation and once afterwards - it does not really
@@ -211,7 +210,7 @@ class WorkspacesView extends WorkspacesViewBase {
         for (let w = 0; w < this._workspaces.length; w++) {
             let workspace = this._workspaces[w];
 
-            if (this._animating || this._scrolling || this._gestureActive)
+            if (this._animating || this._gestureActive)
                 workspace.show();
             else if (this._inDrag)
                 workspace.visible = Math.abs(w - active) <= 1;
@@ -268,18 +267,6 @@ class WorkspacesView extends WorkspacesViewBase {
         workspaceManager.disconnect(this._reorderWorkspacesId);
     }
 
-    startSwipeScroll() {
-        this._scrolling = true;
-    }
-
-    endSwipeScroll() {
-        this._scrolling = false;
-
-        // Make sure title captions etc are shown as necessary
-        this._updateWorkspaceActors(true);
-        this._updateVisibility();
-    }
-
     startTouchGesture() {
         this._gestureActive = true;
     }
@@ -395,12 +382,6 @@ class ExtraWorkspaceView extends WorkspacesViewBase {
         this._workspace.syncStacking(stackIndices);
     }
 
-    startSwipeScroll() {
-    }
-
-    endSwipeScroll() {
-    }
-
     startTouchGesture() {
     }
 
@@ -438,42 +419,14 @@ class WorkspacesDisplay extends St.Widget {
         });
         Main.overview.addAction(clickAction);
         this.bind_property('mapped', clickAction, 'enabled', GObject.BindingFlags.SYNC_CREATE);
+        this._clickAction = clickAction;
 
-        let panAction = new Clutter.PanAction({ threshold_trigger_edge: Clutter.GestureTriggerEdge.AFTER });
+        this._swipeTracker = new SwipeTracker.SwipeTracker(
-        panAction.connect('pan', this._onPan.bind(this));
+            Main.layoutManager.overviewGroup, Shell.ActionMode.OVERVIEW);
-        panAction.connect('gesture-begin', () => {
+        this._swipeTracker.connect('begin', this._switchWorkspaceBegin.bind(this));
-            if (this._workspacesOnlyOnPrimary) {
+        this._swipeTracker.connect('update', this._switchWorkspaceUpdate.bind(this));
-                let event = Clutter.get_current_event();
+        this._swipeTracker.connect('end', this._switchWorkspaceEnd.bind(this));
-                if (this._getMonitorIndexForEvent(event) != this._primaryIndex)
+        this.bind_property('mapped', this._swipeTracker, 'enabled', GObject.BindingFlags.SYNC_CREATE);
-                    return false;
-            }
-
-            this._startSwipeScroll();
-            return true;
-        });
-        panAction.connect('gesture-cancel', () => {
-            clickAction.release();
-            this._endSwipeScroll();
-        });
-        panAction.connect('gesture-end', () => {
-            clickAction.release();
-            this._endSwipeScroll();
-        });
-        Main.overview.addAction(panAction);
-        this.bind_property('mapped', panAction, 'enabled', GObject.BindingFlags.SYNC_CREATE);
-
-        let allowedModes = Shell.ActionMode.OVERVIEW;
-        let switchGesture = new WindowManager.WorkspaceSwitchAction(allowedModes);
-        switchGesture.connect('motion', this._onSwitchWorkspaceMotion.bind(this));
-        switchGesture.connect('activated', this._onSwitchWorkspaceActivated.bind(this));
-        switchGesture.connect('cancel', this._endTouchGesture.bind(this));
-        Main.overview.addAction(switchGesture);
-        this.bind_property('mapped', switchGesture, 'enabled', GObject.BindingFlags.SYNC_CREATE);
-
-        switchGesture = new WindowManager.TouchpadWorkspaceSwitchAction(global.stage, allowedModes);
-        switchGesture.connect('motion', this._onSwitchWorkspaceMotion.bind(this));
-        switchGesture.connect('activated', this._onSwitchWorkspaceActivated.bind(this));
-        switchGesture.connect('cancel', this._endTouchGesture.bind(this));
 
         this._primaryIndex = Main.layoutManager.primaryIndex;
         this._workspacesViews = [];
@@ -491,7 +444,6 @@ class WorkspacesDisplay extends St.Widget {
 
         this._fullGeometry = null;
 
-        this._scrolling = false; // swipe-scrolling
         this._gestureActive = false; // touch(pad) gestures
         this._canScroll = true; // limiting scrolling speed
 
@@ -528,7 +480,7 @@ class WorkspacesDisplay extends St.Widget {
     }
 
     _activeWorkspaceChanged(_wm, _from, _to, _direction) {
-        if (this._scrolling)
+        if (this._gestureActive)
             return;
 
         this._scrollToActive();
@@ -542,77 +494,89 @@ class WorkspacesDisplay extends St.Widget {
     }
 
     _updateScrollAdjustment(index) {
-        if (this._scrolling || this._gestureActive)
+        if (this._gestureActive)
             return;
 
         this._scrollAdjustment.ease(index, {
-            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
             duration: WORKSPACE_SWITCH_TIME,
         });
     }
 
-    _onPan(action) {
+    _directionForProgress(progress) {
-        let [dist_, dx, dy] = action.get_motion_delta(0);
+        if (global.workspace_manager.layout_rows === -1) {
+            return progress > 0
+                ? Meta.MotionDirection.DOWN
+                : Meta.MotionDirection.UP;
+        } else if (this.text_direction === Clutter.TextDirection.RTL) {
+            return progress > 0
+                ? Meta.MotionDirection.LEFT
+                : Meta.MotionDirection.RIGHT;
+        } else {
+            return progress > 0
+                ? Meta.MotionDirection.RIGHT
+                : Meta.MotionDirection.LEFT;
+        }
+    }
+
+    _switchWorkspaceBegin(tracker, monitor) {
+        if (this._workspacesOnlyOnPrimary && monitor !== this._primaryIndex)
+            return;
+
+        let workspaceManager = global.workspace_manager;
         let adjustment = this._scrollAdjustment;
-        if (global.workspace_manager.layout_rows == -1)
+        if (this._gestureActive)
-            adjustment.value -= (dy / this.height) * adjustment.page_size;
+            adjustment.remove_transition('value');
-        else if (this.text_direction == Clutter.TextDirection.RTL)
-            adjustment.value += (dx / this.width) * adjustment.page_size;
-        else
-            adjustment.value -= (dx / this.width) * adjustment.page_size;
-        return false;
-    }
 
-    _startSwipeScroll() {
+        tracker.orientation = workspaceManager.layout_rows !== -1
-        for (let i = 0; i < this._workspacesViews.length; i++)
+            ? Clutter.Orientation.HORIZONTAL
-            this._workspacesViews[i].startSwipeScroll();
+            : Clutter.Orientation.VERTICAL;
-        this._scrolling = true;
-    }
 
-    _endSwipeScroll() {
-        for (let i = 0; i < this._workspacesViews.length; i++)
-            this._workspacesViews[i].endSwipeScroll();
-        this._scrolling = false;
-        this._scrollToActive();
-    }
-
-    _startTouchGesture() {
         for (let i = 0; i < this._workspacesViews.length; i++)
             this._workspacesViews[i].startTouchGesture();
+
+        let monitors = Main.layoutManager.monitors;
+        let geometry = monitor === this._primaryIndex
+            ? this._fullGeometry : monitors[monitor];
+        let distance = global.workspace_manager.layout_rows === -1
+            ? geometry.height : geometry.width;
+
+        let progress = adjustment.value / adjustment.page_size;
+        let points = Array.from(
+            { length: workspaceManager.n_workspaces }, (v, i) => i);
+
+        tracker.confirmSwipe(distance, points, progress, Math.round(progress));
+
         this._gestureActive = true;
     }
 
+    _switchWorkspaceUpdate(tracker, progress) {
+        let adjustment = this._scrollAdjustment;
+        adjustment.value = progress * adjustment.page_size;
+    }
+
+    _switchWorkspaceEnd(tracker, duration, endProgress) {
+        this._clickAction.release();
+
+        let workspaceManager = global.workspace_manager;
+        let activeWorkspace = workspaceManager.get_active_workspace();
+        let newWs = workspaceManager.get_workspace_by_index(endProgress);
+
+        this._scrollAdjustment.ease(endProgress, {
+            mode: Clutter.AnimationMode.EASE_OUT_CUBIC,
+            duration,
+            onComplete: () => {
+                if (newWs !== activeWorkspace)
+                    newWs.activate(global.get_current_time());
+                this._endTouchGesture();
+            },
+        });
+    }
+
     _endTouchGesture() {
         for (let i = 0; i < this._workspacesViews.length; i++)
             this._workspacesViews[i].endTouchGesture();
         this._gestureActive = false;
-        this._scrollToActive();
-    }
-
-    _onSwitchWorkspaceMotion(action, xRel, yRel) {
-        // We don't have a way to hook into start of touchpad actions,
-        // luckily this is safe to call repeatedly.
-        this._startTouchGesture();
-
-        let workspaceManager = global.workspace_manager;
-        let active = workspaceManager.get_active_workspace_index();
-        let adjustment = this._scrollAdjustment;
-        if (workspaceManager.layout_rows == -1)
-            adjustment.value = (active - yRel / this.height) * adjustment.page_size;
-        else if (this.text_direction == Clutter.TextDirection.RTL)
-            adjustment.value = (active + xRel / this.width) * adjustment.page_size;
-        else
-            adjustment.value = (active - xRel / this.width) * adjustment.page_size;
-    }
-
-    _onSwitchWorkspaceActivated(action, direction) {
-        let workspaceManager = global.workspace_manager;
-        let activeWorkspace = workspaceManager.get_active_workspace();
-        let newWs = activeWorkspace.get_neighbor(direction);
-        if (newWs != activeWorkspace)
-            newWs.activate(global.get_current_time());
-
-        this._endTouchGesture();
     }
 
     vfunc_navigate_focus(from, direction) {
@@ -692,8 +656,6 @@ class WorkspacesDisplay extends St.Widget {
             else
                 view = new WorkspacesView(i, this._scrollAdjustment);
 
-            view.connect('scroll-event', this._onScrollEvent.bind(this));
-
             // HACK: Avoid spurious allocation changes while updating views
             view.hide();
 
@@ -793,6 +755,9 @@ class WorkspacesDisplay extends St.Widget {
     }
 
     _onScrollEvent(actor, event) {
+        if (this._swipeTracker.canHandleScrollEvent(event))
+            return Clutter.EVENT_PROPAGATE;
+
         if (!this.mapped)
             return Clutter.EVENT_PROPAGATE;