[gnome-shell/wip/exalm/gestures: 1/13] workspacesView: Use shared adjustment

[Alexander Mikhaylenko <alexm src gnome org>]

commit 83b7e0e7d38de2210b9db63c5394fe2104f8c5c5
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Sun Jul 7 22:51:55 2019 +0500

    workspacesView: Use shared adjustment
    
    Instead of having a scroll adjustment in each WorkspacesView, and using the
    one from primary screen in WorkspacesDisplay, have just one adjustment in
    WorkspacesDisplay, and sync the changes between WorkspacesView.
    
    This will allow to share the adjustment between WorkspacesDisplay and
    ThumbnailsBox in the next commits.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/605

 js/ui/workspacesView.js | 153 ++++++++++++++++++++++++++----------------------
 1 file changed, 84 insertions(+), 69 deletions(-)
---
diff --git a/js/ui/workspacesView.js b/js/ui/workspacesView.js
index 417b8fcee1..0e1d440bd0 100644
--- a/js/ui/workspacesView.js
+++ b/js/ui/workspacesView.js
@@ -85,17 +85,6 @@ var WorkspacesView = class extends WorkspacesViewBase {
         this._animating = false; // tweening
         this._scrolling = false; // swipe-scrolling
         this._gestureActive = false; // touch(pad) gestures
-        this._animatingScroll = false; // programmatically updating the adjustment
-
-        let activeWorkspaceIndex = workspaceManager.get_active_workspace_index();
-        this.scrollAdjustment = new St.Adjustment({ value: activeWorkspaceIndex,
-                                                    lower: 0,
-                                                    page_increment: 1,
-                                                    page_size: 1,
-                                                    step_increment: 0,
-                                                    upper: workspaceManager.n_workspaces });
-        this.scrollAdjustment.connect('notify::value',
-                                      this._onScroll.bind(this));
 
         this._workspaces = [];
         this._updateWorkspaces();
@@ -107,7 +96,7 @@ var WorkspacesView = class extends WorkspacesViewBase {
                 this._workspaces.sort((a, b) => {
                     return a.metaWorkspace.index() - b.metaWorkspace.index();
                 });
-                this._updateWorkspaceActors(false);
+                this.updateWorkspaceActors(false);
             });
 
 
@@ -117,9 +106,6 @@ var WorkspacesView = class extends WorkspacesViewBase {
                                     this._fullGeometry.width, this._fullGeometry.height);
             });
 
-        this._switchWorkspaceNotifyId =
-            global.window_manager.connect('switch-workspace',
-                                          this._activeWorkspaceChanged.bind(this));
     }
 
     _setReservedSlot(window) {
@@ -150,7 +136,7 @@ var WorkspacesView = class extends WorkspacesViewBase {
             else
                 this._workspaces[w].fadeToOverview();
         }
-        this._updateWorkspaceActors(false);
+        this.updateWorkspaceActors(false);
     }
 
     animateFromOverview(animationType) {
@@ -173,13 +159,12 @@ var WorkspacesView = class extends WorkspacesViewBase {
         let workspaceManager = global.workspace_manager;
         let active = workspaceManager.get_active_workspace_index();
 
-        this._updateWorkspaceActors(true);
-        this._updateScrollAdjustment(active);
+        this.updateWorkspaceActors(true);
     }
 
     // Update workspace actors parameters
     // @showAnimation: iff %true, transition between states
-    _updateWorkspaceActors(showAnimation) {
+    updateWorkspaceActors(showAnimation) {
         let workspaceManager = global.workspace_manager;
         let active = workspaceManager.get_active_workspace_index();
 
@@ -239,28 +224,10 @@ var WorkspacesView = class extends WorkspacesViewBase {
         }
     }
 
-    _updateScrollAdjustment(index) {
-        if (this._scrolling || this._gestureActive)
-            return;
-
-        this._animatingScroll = true;
-
-        Tweener.addTween(this.scrollAdjustment, {
-            value: index,
-            time: WORKSPACE_SWITCH_TIME / 1000,
-            transition: 'easeOutQuad',
-            onComplete: () => {
-                this._animatingScroll = false;
-            }
-        });
-    }
-
     _updateWorkspaces() {
         let workspaceManager = global.workspace_manager;
         let newNumWorkspaces = workspaceManager.n_workspaces;
 
-        this.scrollAdjustment.upper = newNumWorkspaces;
-
         for (let j = 0; j < newNumWorkspaces; j++) {
             let metaWorkspace = workspaceManager.get_workspace_by_index(j);
             let workspace;
@@ -280,26 +247,17 @@ var WorkspacesView = class extends WorkspacesViewBase {
         }
 
         if (this._fullGeometry) {
-            this._updateWorkspaceActors(false);
+            this.updateWorkspaceActors(false);
             this._syncFullGeometry();
         }
         if (this._actualGeometry)
             this._syncActualGeometry();
     }
 
-    _activeWorkspaceChanged(_wm, _from, _to, _direction) {
-        if (this._scrolling)
-            return;
-
-        this._scrollToActive();
-    }
-
     _onDestroy() {
         super._onDestroy();
 
-        this.scrollAdjustment.run_dispose();
         Main.overview.disconnect(this._overviewShownId);
-        global.window_manager.disconnect(this._switchWorkspaceNotifyId);
         let workspaceManager = global.workspace_manager;
         workspaceManager.disconnect(this._updateWorkspacesId);
         workspaceManager.disconnect(this._reorderWorkspacesId);
@@ -313,7 +271,6 @@ var WorkspacesView = class extends WorkspacesViewBase {
         this._scrolling = false;
 
         // Make sure title captions etc are shown as necessary
-        this._scrollToActive();
         this._updateVisibility();
     }
 
@@ -325,16 +282,12 @@ var WorkspacesView = class extends WorkspacesViewBase {
         this._gestureActive = false;
 
         // Make sure title captions etc are shown as necessary
-        this._scrollToActive();
         this._updateVisibility();
     }
 
     // sync the workspaces' positions to the value of the scroll adjustment
     // and change the active workspace if appropriate
-    _onScroll(adj) {
-        if (this._animatingScroll)
-            return;
-
+    onScroll(adj) {
         let workspaceManager = global.workspace_manager;
         let active = workspaceManager.get_active_workspace_index();
         let current = Math.round(adj.value);
@@ -432,6 +385,9 @@ var ExtraWorkspaceView = class extends WorkspacesViewBase {
         this._workspace.syncStacking(stackIndices);
     }
 
+    updateWorkspaceActors(_showAnimation) {
+    }
+
     startSwipeScroll() {
     }
 
@@ -443,6 +399,9 @@ var ExtraWorkspaceView = class extends WorkspacesViewBase {
 
     endTouchGesture() {
     }
+
+    onScroll(_adj) {
+    }
 };
 
 var DelegateFocusNavigator = GObject.registerClass(
@@ -459,6 +418,24 @@ var WorkspacesDisplay = class {
         this.actor.connect('notify::allocation', this._updateWorkspacesActualGeometry.bind(this));
         this.actor.connect('parent-set', this._parentSet.bind(this));
 
+        let workspaceManager = global.workspace_manager;
+        let activeWorkspaceIndex = workspaceManager.get_active_workspace_index();
+        this._scrollAdjustment = new St.Adjustment({ value: activeWorkspaceIndex,
+                                                     lower: 0,
+                                                     page_increment: 1,
+                                                     page_size: 1,
+                                                     step_increment: 0,
+                                                     upper: workspaceManager.n_workspaces });
+
+        this._updateWorkspaces();
+        workspaceManager.connect('notify::n-workspaces',
+                                 this._updateWorkspaces.bind(this));
+        this._scrollAdjustment.connect('notify::value',
+                                       this._scrollValueChanged.bind(this));
+
+        global.window_manager.connect('switch-workspace',
+                                      this._activeWorkspaceChanged.bind(this));
+
         let clickAction = new Clutter.ClickAction();
         clickAction.connect('clicked', action => {
             // Only switch to the workspace when there's no application
@@ -528,6 +505,50 @@ var WorkspacesDisplay = class {
         this._keyPressEventId = 0;
 
         this._fullGeometry = null;
+
+        this._scrolling = false; // swipe-scrolling
+        this._gestureActive = false; // touch(pad) gestures
+        this._animatingScroll = false; // programmatically updating the adjustment
+    }
+
+    _updateWorkspaces() {
+        let workspaceManager = global.workspace_manager;
+        let newNumWorkspaces = workspaceManager.n_workspaces;
+
+        this._scrollAdjustment.upper = newNumWorkspaces;
+    }
+
+    _activeWorkspaceChanged(_wm, _from, _to, _direction) {
+        if (this._scrolling)
+            return;
+
+        this._scrollToActive();
+    }
+
+    _scrollToActive() {
+        let workspaceManager = global.workspace_manager;
+        let active = workspaceManager.get_active_workspace_index();
+
+        for (let i = 0; i < this._workspacesViews.length; i++)
+            this._workspacesViews[i].updateWorkspaceActors(true);
+
+        this._updateScrollAdjustment(active);
+    }
+
+    _updateScrollAdjustment(index) {
+        if (this._scrolling || this._gestureActive)
+            return;
+
+        this._animatingScroll = true;
+
+        Tweener.addTween(this._scrollAdjustment, {
+            value: index,
+            time: WORKSPACE_SWITCH_TIME / 1000,
+            transition: 'easeOutQuad',
+            onComplete: () => {
+                this._animatingScroll = false;
+            }
+        });
     }
 
     _onPan(action) {
@@ -545,21 +566,27 @@ var WorkspacesDisplay = class {
     _startSwipeScroll() {
         for (let i = 0; i < this._workspacesViews.length; i++)
             this._workspacesViews[i].startSwipeScroll();
+        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();
+        this._gestureActive = true;
     }
 
     _endTouchGesture() {
         for (let i = 0; i < this._workspacesViews.length; i++)
             this._workspacesViews[i].endTouchGesture();
+        this._gestureActive = false;
+        this._scrollToActive();
     }
 
     _onSwitchWorkspaceMotion(action, xRel, yRel) {
@@ -666,11 +693,6 @@ var WorkspacesDisplay = class {
                 view = new WorkspacesView(i);
 
             view.actor.connect('scroll-event', this._onScrollEvent.bind(this));
-            if (i == this._primaryIndex) {
-                this._scrollAdjustment = view.scrollAdjustment;
-                this._scrollAdjustment.connect('notify::value',
-                                               this._scrollValueChanged.bind(this));
-            }
 
             // HACK: Avoid spurious allocation changes while updating views
             view.actor.hide();
@@ -686,18 +708,11 @@ var WorkspacesDisplay = class {
     }
 
     _scrollValueChanged() {
-        for (let i = 0; i < this._workspacesViews.length; i++) {
-            if (i == this._primaryIndex)
-                continue;
-
-            let adjustment = this._workspacesViews[i].scrollAdjustment;
-            if (!adjustment)
-                continue;
+        if (this._animatingScroll)
+            return;
 
-            // the adjustments work in terms of workspaces, so the
-            // values map directly
-            adjustment.value = this._scrollAdjustment.value;
-        }
+        for (let i = 0; i < this._workspacesViews.length; i++)
+            this._workspacesViews[i].onScroll(this._scrollAdjustment);
     }
 
     _getMonitorIndexForEvent(event) {