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/dash.js

@@ -347,10 +347,8 @@ var DashActor = new Lang.Class({
 
 const baseIconSizes = [ 16, 22, 24, 32, 48, 64 ];
 
-var Dash = new Lang.Class({
-    Name: 'Dash',
-
-    _init() {
+var Dash = class Dash {
+    constructor() {
         this._maxHeight = -1;
         this.iconSize = 64;
         this._shownInitially = false;
@@ -407,7 +405,7 @@ var Dash = new Lang.Class({
         // Translators: this is the name of the dock/favorites area on
         // the left of the overview
         Main.ctrlAltTabManager.addGroup(this.actor, _("Dash"), 'user-bookmarks-symbolic');
-    },
+    }
 
     _onDragBegin() {
         this._dragCancelled = false;
@@ -421,26 +419,26 @@ var Dash = new Lang.Class({
             this._box.insert_child_at_index(this._emptyDropTarget, 0);
             this._emptyDropTarget.show(true);
         }
-    },
+    }
 
     _onDragCancelled() {
         this._dragCancelled = true;
         this._endDrag();
-    },
+    }
 
     _onDragEnd() {
         if (this._dragCancelled)
             return;
 
         this._endDrag();
-    },
+    }
 
     _endDrag() {
         this._clearDragPlaceholder();
         this._clearEmptyDropTarget();
         this._showAppsIcon.setDragApp(null);
         DND.removeDragMonitor(this._dragMonitor);
-    },
+    }
 
     _onDragMotion(dragEvent) {
         let app = getAppFromSource(dragEvent.source);
@@ -459,18 +457,18 @@ var Dash = new Lang.Class({
             this._showAppsIcon.setDragApp(null);
 
         return DND.DragMotionResult.CONTINUE;
-    },
+    }
 
     _appIdListToHash(apps) {
         let ids = {};
         for (let i = 0; i < apps.length; i++)
             ids[apps[i].get_id()] = apps[i];
         return ids;
-    },
+    }
 
     _queueRedisplay() {
         Main.queueDeferredWork(this._workId);
-    },
+    }
 
     _hookUpLabel(item, appIcon) {
         item.child.connect('notify::hover', () => {
@@ -490,7 +488,7 @@ var Dash = new Lang.Class({
                 this._syncLabel(item, appIcon);
             });
         }
-    },
+    }
 
     _createAppItem(app) {
         let appIcon = new AppDisplay.AppIcon(app,
@@ -524,7 +522,7 @@ var Dash = new Lang.Class({
         this._hookUpLabel(item, appIcon);
 
         return item;
-    },
+    }
 
     _itemMenuStateChanged(item, opened) {
         // When the menu closes, it calls sync_hover, which means
@@ -537,7 +535,7 @@ var Dash = new Lang.Class({
 
             item.hideLabel();
         }
-    },
+    }
 
     _syncLabel(item, appIcon) {
         let shouldShow = appIcon ? appIcon.shouldShowTooltip() : item.child.get_hover();
@@ -573,7 +571,7 @@ var Dash = new Lang.Class({
                 GLib.Source.set_name_by_id(this._resetHoverTimeoutId, '[gnome-shell] this._labelShowing');
             }
         }
-    },
+    }
 
     _adjustIconSize() {
         // For the icon size, we only consider children which are "proper"
@@ -663,7 +661,7 @@ var Dash = new Lang.Class({
                                transition: 'easeOutQuad',
                              });
         }
-    },
+    }
 
     _redisplay() {
         let favorites = AppFavorites.getAppFavorites().getFavoriteMap();
@@ -792,7 +790,7 @@ var Dash = new Lang.Class({
         // Workaround for https://bugzilla.gnome.org/show_bug.cgi?id=692744
         // Without it, StBoxLayout may use a stale size cache
         this._box.queue_relayout();
-    },
+    }
 
     _clearDragPlaceholder() {
         if (this._dragPlaceholder) {
@@ -804,14 +802,14 @@ var Dash = new Lang.Class({
             this._dragPlaceholder = null;
         }
         this._dragPlaceholderPos = -1;
-    },
+    }
 
     _clearEmptyDropTarget() {
         if (this._emptyDropTarget) {
             this._emptyDropTarget.animateOutAndDestroy();
             this._emptyDropTarget = null;
         }
-    },
+    }
 
     handleDragOver(source, actor, x, y, time) {
         let app = getAppFromSource(source);
@@ -888,7 +886,7 @@ var Dash = new Lang.Class({
             return DND.DragMotionResult.MOVE_DROP;
 
         return DND.DragMotionResult.COPY_DROP;
-    },
+    }
 
     // Draggable target interface
     acceptDrop(source, actor, x, y, time) {
@@ -938,6 +936,5 @@ var Dash = new Lang.Class({
 
         return true;
     }
-});
-
+};
 Signals.addSignalMethods(Dash.prototype);