cleanup: Use inheritance for Actor classes instead of composition

Use GObject types when inheriting from native actor classes.

Related to https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/559

https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/89

extensions/window-list/extension.js

@@ -923,11 +923,11 @@ const WindowList = GObject.registerClass({
     }
 
     _updateKeyboardAnchor() {
-        if (!Main.keyboard.actor)
+        if (!Main.keyboard.keyboardActor)
             return;
 
         let translationY = Main.overview.visible ? 0 : this.height;
-        Main.keyboard.actor.translation_y = -translationY;
+        Main.keyboard.keyboardActor.translation_y = -translationY;
     }
 
     _onAppStateChanged(appSys, app) {

extensions/window-list/windowPicker.js

@@ -6,18 +6,18 @@ const Main = imports.ui.main;
 const Overview = imports.ui.overview;
 const { WorkspacesDisplay } = imports.ui.workspacesView;
 
-let MyWorkspacesDisplay = class extends WorkspacesDisplay {
-    constructor() {
-        super();
+let MyWorkspacesDisplay = GObject.registerClass({
+    GTypeName: 'WindowList_MyWorkspacesDisplay'
+}, class MyWorkspacesDisplay extends WorkspacesDisplay {
+    _init() {
+        super._init();
 
-        this.actor.add_constraint(
+        this.add_constraint(
             new Layout.MonitorConstraint({
                 primary: true,
                 work_area: true,
             }));
 
-        this.actor.connect('destroy', this._onDestroy.bind(this));
-
         this._workareasChangedId = global.display.connect('workareas-changed',
             this._onWorkAreasChanged.bind(this));
         this._onWorkAreasChanged();
@@ -50,8 +50,8 @@ let MyWorkspacesDisplay = class extends WorkspacesDisplay {
         super._updateWorkspacesViews();
 
         this._workspacesViews.forEach(v => {
-            Main.layoutManager.overviewGroup.remove_actor(v.actor);
-            Main.windowPicker.add_actor(v.actor);
+            Main.layoutManager.overviewGroup.remove_actor(v);
+            Main.windowPicker.add_actor(v);
         });
     }
 
@@ -59,8 +59,10 @@ let MyWorkspacesDisplay = class extends WorkspacesDisplay {
         if (this._workareasChangedId)
             global.display.disconnect(this._workareasChangedId);
         this._workareasChangedId = 0;
+
+        super._onDestroy();
     }
-};
+});
 
 var WindowPicker = GObject.registerClass({
     GTypeName: 'WindowListWindowPicker',
@@ -98,7 +100,7 @@ var WindowPicker = GObject.registerClass({
         Main.overview.addAction = a => this._backgroundGroup.add_action(a);
 
         this._workspacesDisplay = new MyWorkspacesDisplay();
-        this.add_child(this._workspacesDisplay.actor);
+        this.add_child(this._workspacesDisplay);
 
         Main.overview.addAction = addActionOrig;
 

extensions/windowsNavigator/extension.js

@@ -6,9 +6,11 @@ const Main = imports.ui.main;
 const Workspace = imports.ui.workspace;
 const WorkspacesView = imports.ui.workspacesView;
 
-var MyWindowOverlay = class extends Workspace.WindowOverlay {
-    constructor(windowClone, parentActor) {
-        super(windowClone, parentActor);
+var MyWindowOverlay = GObject.registerClass({
+    GTypeName: 'WindowsNavigator_MyWindowOverlay'
+}, class MyWindowOverlay extends Workspace.WindowOverlay {
+    _init(windowClone, parentActor) {
+        super._init(windowClone, parentActor);
 
         this._id = null;
         this._text = new St.Label({
@@ -39,21 +41,23 @@ var MyWindowOverlay = class extends Workspace.WindowOverlay {
         this._text.set_position(Math.floor(textX) + 5, Math.floor(textY) + 5);
         this._text.raise_top();
     }
-};
+});
 
-var MyWorkspace = class extends Workspace.Workspace {
-    constructor(metaWorkspace, monitorIndex) {
-        super(metaWorkspace, monitorIndex);
+var MyWorkspace = GObject.registerClass({
+    GTypeName: 'WindowsNavigator_MyWorkspace'
+}, class MyWorkspace extends Workspace.Workspace {
+    _init(metaWorkspace, monitorIndex) {
+        super._init(metaWorkspace, monitorIndex);
 
         if (metaWorkspace && metaWorkspace.index() < 9) {
             this._tip = new St.Label({
                 style_class: 'extension-windowsNavigator-window-tooltip',
                 visible: false,
             });
-            this.actor.add_actor(this._tip);
+            this.add_actor(this._tip);
 
-            this.actor.connect('notify::scale-x', () => {
-                this._tip.set_scale(1 / this.actor.scale_x, 1 / this.actor.scale_x);
+            this.connect('notify::scale-x', () => {
+                this._tip.set_scale(1 / this.scale_x, 1 / this.scale_x);
             });
         } else {
             this._tip = null;
@@ -67,7 +71,7 @@ var MyWorkspace = class extends Workspace.Workspace {
 
         // Hand code this instead of using _getSpacingAndPadding
         // because that fails on empty workspaces
-        let node = this.actor.get_theme_node();
+        let node = this.get_theme_node();
         let padding = {
             left: node.get_padding(St.Side.LEFT),
             top: node.get_padding(St.Side.TOP),
@@ -111,11 +115,13 @@ var MyWorkspace = class extends Workspace.Workspace {
                 this._windowOverlays[i].hideTooltip();
         }
     }
-};
+});
 
-var MyWorkspacesView = class extends WorkspacesView.WorkspacesView {
-    constructor(width, height, x, y, workspaces) {
-        super(width, height, x, y, workspaces);
+var MyWorkspacesView = GObject.registerClass({
+    GTypeName: 'WindowsNavigator_MyWorkspacesView'
+}, class MyWorkspacesView extends WorkspacesView.WorkspacesView {
+    _init(width, height, x, y, workspaces) {
+        super._init(width, height, x, y, workspaces);
 
         this._pickWorkspace = false;
         this._pickWindow = false;
@@ -238,7 +244,7 @@ var MyWorkspacesView = class extends WorkspacesView.WorkspacesView {
         }
         return false;
     }
-};
+});
 
 class Extension {
     constructor() {