panel: Rewrite the app menu to use the new "sync" pattern

The existing app menu was a kludge of legacy code that tried to manage
a bunch of state, and had a number of issues:

 * It didn't properly manage visibility when combined with multiple
   apps and the overview.

 * It didn't properly manage reactivity when tabbing away from a busy
   app to another app.

 * It didn't properly disconnect signals when going from one app
   to nothing.

and countless others. Rewrite it to use the new "sync" code pattern,
where we centralize all state management and do transitions from that,
rather than strange and quirky control flow.

https://bugzilla.gnome.org/show_bug.cgi?id=705898

diff --git a/js/ui/panel.js b/js/ui/panel.js
index ed4931f0b1641eb47d3f6279fe5696a1560080f0..3f207819fda48609ea3f36a80fe03e8fc6196e29 100644 (file)
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -189,7 +189,6 @@ const AppMenuButton = new Lang.Class({
 
         this.actor.bind_property("reactive", this.actor, "can-focus", 0);
         this.actor.reactive = false;
-        this._targetIsCurrent = false;
 
         this._container = new Shell.GenericContainer();
         bin.set_child(this._container);
@@ -224,12 +223,8 @@ const AppMenuButton = new Lang.Class({
         this._visible = !Main.overview.visible;
         if (!this._visible)
             this.actor.hide();
-        this._overviewHidingId = Main.overview.connect('hiding', Lang.bind(this, function () {
-            this.show();
-        }));
-        this._overviewShowingId = Main.overview.connect('showing', Lang.bind(this, function () {
-            this.hide();
-        }));
+        this._overviewHidingId = Main.overview.connect('hiding', Lang.bind(this, this._sync));
+        this._overviewShowingId = Main.overview.connect('showing', Lang.bind(this, this._sync));
 
         this._stop = true;
 
@@ -252,14 +247,8 @@ const AppMenuButton = new Lang.Class({
             return;
 
         this._visible = true;
-        this.actor.show();
-
-        if (!this._targetIsCurrent)
-            return;
-
         this.actor.reactive = true;
-
-        Tweener.removeTweens(this.actor);
+        this.actor.show();
         Tweener.addTween(this.actor,
                          { opacity: 255,
                            time: Overview.ANIMATION_TIME,
@@ -272,12 +261,6 @@ const AppMenuButton = new Lang.Class({
 
         this._visible = false;
         this.actor.reactive = false;
-        if (!this._targetIsCurrent) {
-            this.actor.hide();
-            return;
-        }
-
-        Tweener.removeTweens(this.actor);
         Tweener.addTween(this.actor,
                          { opacity: 0,
                            time: Overview.ANIMATION_TIME,
@@ -306,6 +289,9 @@ const AppMenuButton = new Lang.Class({
     },
 
     _syncIcon: function() {
+        if (!this._targetApp)
+            return;
+
         let icon = this._targetApp.get_faded_icon(2 * PANEL_ICON_SIZE, this._iconBox.text_direction);
         this._iconBox.set_child(icon);
     },
@@ -332,7 +318,6 @@ const AppMenuButton = new Lang.Class({
             return;
 
         this._stop = true;
-        this.actor.reactive = true;
 
         if (this._spinner == null)
             return;
@@ -352,7 +337,6 @@ const AppMenuButton = new Lang.Class({
 
     startAnimation: function() {
         this._stop = false;
-        this.actor.reactive = false;
 
         if (this._spinner == null)
             return;
@@ -448,98 +432,70 @@ const AppMenuButton = new Lang.Class({
         this._sync();
     },
 
-    _sync: function() {
+    _findTargetApp: function() {
+        let workspace = global.screen.get_active_workspace();
         let tracker = Shell.WindowTracker.get_default();
         let focusedApp = tracker.focus_app;
-        let lastStartedApp = null;
-        let workspace = global.screen.get_active_workspace();
+        if (focusedApp && focusedApp.is_on_workspace(workspace))
+            return focusedApp;
+
         for (let i = 0; i < this._startingApps.length; i++)
             if (this._startingApps[i].is_on_workspace(workspace))
-                lastStartedApp = this._startingApps[i];
-
-        let targetApp = focusedApp != null ? focusedApp : lastStartedApp;
+                return this._startingApps[i];
 
-        if (targetApp == null) {
-            if (!this._targetIsCurrent)
-                return;
-
-            this.actor.reactive = false;
-            this._targetIsCurrent = false;
-
-            Tweener.removeTweens(this.actor);
-            Tweener.addTween(this.actor, { opacity: 0,
-                                           time: Overview.ANIMATION_TIME,
-                                           transition: 'easeOutQuad' });
-            return;
-        }
+        return null;
+    },
 
-        if (!targetApp.is_on_workspace(workspace))
-            return;
+    _sync: function() {
+        let targetApp = this._findTargetApp();
 
-        if (!this._targetIsCurrent) {
-            this.actor.reactive = true;
-            this._targetIsCurrent = true;
+        if (this._targetApp != targetApp) {
+            if (this._appMenuNotifyId) {
+                this._targetApp.disconnect(this._appMenuNotifyId);
+                this._appMenuNotifyId = 0;
+            }
+            if (this._actionGroupNotifyId) {
+                this._targetApp.disconnect(this._actionGroupNotifyId);
+                this._actionGroupNotifyId = 0;
+            }
 
-            Tweener.removeTweens(this.actor);
-            Tweener.addTween(this.actor, { opacity: 255,
-                                           time: Overview.ANIMATION_TIME,
-                                           transition: 'easeOutQuad' });
-        }
+            this._targetApp = targetApp;
 
-        if (targetApp == this._targetApp) {
-            if (targetApp &&
-                targetApp.get_state() != Shell.AppState.STARTING &&
-                targetApp.get_state() != Shell.AppState.BUSY) {
-                this.stopAnimation();
-                this._maybeSetMenu();
-            } else if (targetApp &&
-                       targetApp.get_state() == Shell.AppState.BUSY) {
-                this.startAnimation();
+            if (this._targetApp) {
+                this._appMenuNotifyId = this._targetApp.connect('notify::menu', Lang.bind(this, this._sync));
+                this._actionGroupNotifyId = this._targetApp.connect('notify::action-group', Lang.bind(this, this._sync));
+                this._label.setText(this._targetApp.get_name());
+                this.actor.set_accessible_name(this._targetApp.get_name());
             }
-            return;
-        }
-
-        if (this._spinner)
-            this._spinner.actor.hide();
-        if (this._iconBox.child != null)
-            this._iconBox.child.destroy();
-        this._iconBox.hide();
-        this._arrow.hide();
-        this._label.setText('');
-
-        if (this._appMenuNotifyId)
-            this._targetApp.disconnect(this._appMenuNotifyId);
-        if (this._actionGroupNotifyId)
-            this._targetApp.disconnect(this._actionGroupNotifyId);
-        if (targetApp) {
-            this._appMenuNotifyId = targetApp.connect('notify::menu', Lang.bind(this, this._sync));
-            this._actionGroupNotifyId = targetApp.connect('notify::action-group', Lang.bind(this, this._sync));
-        } else {
-            this._appMenuNotifyId = 0;
-            this._actionGroupNotifyId = 0;
         }
 
-        this._targetApp = targetApp;
-        this._label.setText(targetApp.get_name());
-        this.actor.set_accessible_name(targetApp.get_name());
-
-        this._syncIcon();
-        this._arrow.show();
-        this._iconBox.show();
+        let visible = (this._targetApp != null && !Main.overview.visibleTarget);
+        if (visible)
+            this.show();
+        else
+            this.hide();
 
-        if (targetApp.get_state() == Shell.AppState.STARTING ||
-            targetApp.get_state() == Shell.AppState.BUSY)
+        let isBusy = (this._targetApp != null &&
+                      (this._targetApp.get_state() == Shell.AppState.STARTING ||
+                       this._targetApp.get_state() == Shell.AppState.BUSY));
+        if (isBusy)
             this.startAnimation();
         else
-            this._maybeSetMenu();
+            this.stopAnimation();
 
+        this.actor.reactive = (visible && !isBusy);
+
+        this._syncIcon();
+        this._maybeSetMenu();
         this.emit('changed');
     },
 
     _maybeSetMenu: function() {
         let menu;
 
-        if (this._targetApp.action_group && this._targetApp.menu) {
+        if (this._targetApp == null) {
+            menu = null;
+        } else if (this._targetApp.action_group && this._targetApp.menu) {
             if (this.menu instanceof RemoteMenu.RemoteMenu &&
                 this.menu.actionGroup == this._targetApp.action_group)
                 return;
@@ -551,7 +507,7 @@ const AppMenuButton = new Lang.Class({
             }));
 
         } else {
-            if (this.menu.isDummyQuitMenu)
+            if (this.menu && this.menu.isDummyQuitMenu)
                 return;
 
             // fallback to older menu
@@ -563,7 +519,8 @@ const AppMenuButton = new Lang.Class({
         }
 
         this.setMenu(menu);
-        this._menuManager.addMenu(menu);
+        if (menu)
+            this._menuManager.addMenu(menu);
     },
 
     destroy: function() {