window-list: Do not inject WindowPicker into Main

This will become impossible once Main is converted to ESM. Instead,
use the Extension class itself to hold the window picker.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/268>

extensions/window-list/extension.js

@@ -878,7 +878,8 @@ class WindowList extends St.Widget {
     }
 
     _updateWindowListVisibility() {
-        let visible = !Main.windowPicker.visible;
+        const {windowPicker} = Extension.lookupByURL(import.meta.url);
+        const visible = !windowPicker.visible;
 
         this._windowList.ease({
             opacity: visible ? 255 : 0,
@@ -1111,10 +1112,10 @@ export default class WindowListExtension extends Extension {
         Main.layoutManager.connectObject('monitors-changed',
             () => this._buildWindowLists(), this);
 
-        Main.windowPicker = new WindowPicker();
+        this.windowPicker = new WindowPicker();
 
         Main.overview.hide = () => {
-            Main.windowPicker.close();
+            this.windowPicker.close();
             this._hideOverviewOrig.call(Main.overview);
         };
 
@@ -1146,8 +1147,8 @@ export default class WindowListExtension extends Extension {
         });
         this._windowLists = null;
 
-        Main.windowPicker.destroy();
-        delete Main.windowPicker;
+        this.windowPicker.destroy();
+        delete this.windowPicker;
 
         Main.overview.hide = this._hideOverviewOrig;
     }

extensions/window-list/windowPicker.js

@@ -3,6 +3,8 @@ import GObject from 'gi://GObject';
 import Shell from 'gi://Shell';
 import St from 'gi://St';
 
+import {Extension} from 'resource:///org/gnome/shell/extensions/extension.js';
+
 const Layout = imports.ui.layout;
 const Main = imports.ui.main;
 const {WorkspacesDisplay} = imports.ui.workspacesView;
@@ -34,6 +36,8 @@ class MyWorkspacesDisplay extends WorkspacesDisplay {
 
         super(controls, workspaceAdjustment, overviewAdjustment);
 
+        this._windowPicker = controls;
+
         this._workspaceAdjustment = workspaceAdjustment;
         this._workspaceAdjustment.actor = this;
 
@@ -49,7 +53,7 @@ class MyWorkspacesDisplay extends WorkspacesDisplay {
 
     prepareToEnterOverview(...args) {
         if (!this._scrollEventId) {
-            this._scrollEventId = Main.windowPicker.connect('scroll-event',
+            this._scrollEventId = this._windowPicker.connect('scroll-event',
                 this._onScrollEvent.bind(this));
         }
 
@@ -58,7 +62,7 @@ class MyWorkspacesDisplay extends WorkspacesDisplay {
 
     vfunc_hide(...args) {
         if (this._scrollEventId > 0)
-            Main.windowPicker.disconnect(this._scrollEventId);
+            this._windowPicker.disconnect(this._scrollEventId);
         this._scrollEventId = 0;
 
         super.vfunc_hide(...args);
@@ -325,15 +329,16 @@ export class WindowPickerToggle extends St.Button {
             toggle_mode: true,
         });
 
+        const {windowPicker} = Extension.lookupByURL(import.meta.url);
         this.connect('notify::checked', () => {
             if (this.checked)
-                Main.windowPicker.open();
+                windowPicker.open();
             else
-                Main.windowPicker.close();
+                windowPicker.close();
         });
 
-        Main.windowPicker.connect('open-state-changed', () => {
-            this.checked = Main.windowPicker.visible;
+        windowPicker.connect('open-state-changed', () => {
+            this.checked = windowPicker.visible;
         });
     }
 }