cleanup: Port non-GObject classes to JS6 classes

ES6 finally adds standard class syntax to the language, so we can
replace our custom Lang.Class framework with the new syntax. Any
classes that inherit from GObject will need special treatment,
so limit the port to regular javascript classes for now.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/361

js/ui/animation.js

@@ -2,7 +2,6 @@
 
 const GLib = imports.gi.GLib;
 const Gio = imports.gi.Gio;
-const Lang = imports.lang;
 const Mainloop = imports.mainloop;
 const St = imports.gi.St;
 const Signals = imports.signals;
@@ -14,10 +13,8 @@ var ANIMATED_ICON_UPDATE_TIMEOUT = 16;
 var SPINNER_ANIMATION_TIME = 0.3;
 var SPINNER_ANIMATION_DELAY = 1.0;
 
-var Animation = new Lang.Class({
-    Name: 'Animation',
-
-    _init(file, width, height, speed) {
+var Animation = class {
+    constructor(file, width, height, speed) {
         this.actor = new St.Bin();
         this.actor.connect('destroy', this._onDestroy.bind(this));
         this._speed = speed;
@@ -31,7 +28,7 @@ var Animation = new Lang.Class({
         this._animations = St.TextureCache.get_default().load_sliced_image (file, width, height, scaleFactor,
                                                                             this._animationsLoaded.bind(this));
         this.actor.set_child(this._animations);
-    },
+    }
 
     play() {
         if (this._isLoaded && this._timeoutId == 0) {
@@ -43,7 +40,7 @@ var Animation = new Lang.Class({
         }
 
         this._isPlaying = true;
-    },
+    }
 
     stop() {
         if (this._timeoutId > 0) {
@@ -52,7 +49,7 @@ var Animation = new Lang.Class({
         }
 
         this._isPlaying = false;
-    },
+    }
 
     _showFrame(frame) {
         let oldFrameActor = this._animations.get_child_at_index(this._frame);
@@ -64,56 +61,50 @@ var Animation = new Lang.Class({
         let newFrameActor = this._animations.get_child_at_index(this._frame);
         if (newFrameActor)
             newFrameActor.show();
-    },
+    }
 
     _update() {
         this._showFrame(this._frame + 1);
         return GLib.SOURCE_CONTINUE;
-    },
+    }
 
     _animationsLoaded() {
         this._isLoaded = this._animations.get_n_children() > 0;
 
         if (this._isPlaying)
             this.play();
-    },
+    }
 
     _onDestroy() {
         this.stop();
     }
-});
+};
 
-var AnimatedIcon = new Lang.Class({
-    Name: 'AnimatedIcon',
-    Extends: Animation,
-
-    _init(file, size) {
-        this.parent(file, size, size, ANIMATED_ICON_UPDATE_TIMEOUT);
+var AnimatedIcon = class extends Animation {
+    constructor(file, size) {
+        super(file, size, size, ANIMATED_ICON_UPDATE_TIMEOUT);
     }
-});
+};
 
-var Spinner = new Lang.Class({
-    Name: 'Spinner',
-    Extends: AnimatedIcon,
-
-    _init(size, animate=false) {
+var Spinner = class extends AnimatedIcon {
+    constructor(size, animate=false) {
         let file = Gio.File.new_for_uri('resource:///org/gnome/shell/theme/process-working.svg');
-        this.parent(file, size);
+        super(file, size);
 
         this.actor.opacity = 0;
         this._animate = animate;
-    },
+    }
 
     _onDestroy() {
         this._animate = false;
-        this.parent();
-    },
+        super._onDestroy();
+    }
 
     play() {
         Tweener.removeTweens(this.actor);
 
         if (this._animate) {
-            this.parent();
+            super.play();
             Tweener.addTween(this.actor, {
                 opacity: 255,
                 delay: SPINNER_ANIMATION_DELAY,
@@ -122,9 +113,9 @@ var Spinner = new Lang.Class({
             });
         } else {
             this.actor.opacity = 255;
-            this.parent();
+            super.play();
         }
-    },
+    }
 
     stop() {
         Tweener.removeTweens(this.actor);
@@ -140,7 +131,7 @@ var Spinner = new Lang.Class({
             });
         } else {
             this.actor.opacity = 0;
-            this.parent();
+            super.stop();
         }
     }
-});
+};