[gnome-shell] unlockDialog: Use inheritance instead of composition

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 856c32db919560a68b9aa3a7d2e21444ce9400aa
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Sep 20 13:17:40 2019 +0200

    unlockDialog: Use inheritance instead of composition
    
    The screen shield creates the unlock dialog based on the session mode.
    
    However since commit 0c0d76f7d6990 turned LoginDialog into an actor
    subclass (while UnlockDialog kept using the delegate pattern), it is
    no longer possible to handle both objects the same way without warnings.
    
    Allow this again by turning UnlockDialog into an actor subclass as well.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/736

 js/ui/unlockDialog.js | 46 ++++++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 20 deletions(-)
---
diff --git a/js/ui/unlockDialog.js b/js/ui/unlockDialog.js
index 08dbfdd068..5af1b4823f 100644
--- a/js/ui/unlockDialog.js
+++ b/js/ui/unlockDialog.js
@@ -2,8 +2,7 @@
 /* exported UnlockDialog */
 
 const { AccountsService, Atk, Clutter,
-        Gdm, Gio, GLib, Meta, Shell, St } = imports.gi;
-const Signals = imports.signals;
+        Gdm, Gio, GLib, GObject, Meta, Shell, St } = imports.gi;
 
 const Layout = imports.ui.layout;
 const Main = imports.ui.main;
@@ -13,15 +12,19 @@ const AuthPrompt = imports.gdm.authPrompt;
 // The timeout before going back automatically to the lock screen (in seconds)
 const IDLE_TIMEOUT = 2 * 60;
 
-var UnlockDialog = class {
-    constructor(parentActor) {
-        this.actor = new St.Widget({ accessible_role: Atk.Role.WINDOW,
-                                     style_class: 'login-dialog',
-                                     layout_manager: new Clutter.BoxLayout(),
-                                     visible: false });
+var UnlockDialog = GObject.registerClass({
+    Signals: { 'failed': {} },
+}, class UnlockDialog extends St.Widget {
+    _init(parentActor) {
+        super._init({
+            accessible_role: Atk.Role.WINDOW,
+            style_class: 'login-dialog',
+            layout_manager: new Clutter.BoxLayout(),
+            visible: false,
+        });
 
-        this.actor.add_constraint(new Layout.MonitorConstraint({ primary: true }));
-        parentActor.add_child(this.actor);
+        this.add_constraint(new Layout.MonitorConstraint({ primary: true }));
+        parentActor.add_child(this);
 
         this._userManager = AccountsService.UserManager.get_default();
         this._userName = GLib.get_user_name();
@@ -32,7 +35,7 @@ var UnlockDialog = class {
                                              y_align: Clutter.ActorAlign.CENTER,
                                              x_expand: true,
                                              y_expand: true });
-        this.actor.add_child(this._promptBox);
+        this.add_child(this._promptBox);
 
         this._authPrompt = new AuthPrompt.AuthPrompt(new Gdm.Client(), 
AuthPrompt.AuthPromptMode.UNLOCK_ONLY);
         this._authPrompt.connect('failed', this._fail.bind(this));
@@ -64,10 +67,12 @@ var UnlockDialog = class {
         this._authPrompt.reset();
         this._updateSensitivity(true);
 
-        Main.ctrlAltTabManager.addGroup(this.actor, _("Unlock Window"), 'dialog-password-symbolic');
+        Main.ctrlAltTabManager.addGroup(this, _("Unlock Window"), 'dialog-password-symbolic');
 
         this._idleMonitor = Meta.IdleMonitor.get_core();
         this._idleWatchId = this._idleMonitor.add_idle_watch(IDLE_TIMEOUT * 1000, this._escape.bind(this));
+
+        this.connect('destroy', this._onDestroy.bind(this));
     }
 
     _updateSensitivity(sensitive) {
@@ -106,9 +111,8 @@ var UnlockDialog = class {
         this._authPrompt.cancel();
     }
 
-    destroy() {
+    _onDestroy() {
         this.popModal();
-        this.actor.destroy();
 
         if (this._idleWatchId) {
             this._idleMonitor.remove_watch(this._idleWatchId);
@@ -131,13 +135,16 @@ var UnlockDialog = class {
     }
 
     open(timestamp) {
-        this.actor.show();
+        this.show();
 
         if (this._isModal)
             return true;
 
-        if (!Main.pushModal(this.actor, { timestamp: timestamp,
-                                          actionMode: Shell.ActionMode.UNLOCK_SCREEN }))
+        let modalParams = {
+            timestamp,
+            actionMode: Shell.ActionMode.UNLOCK_SCREEN,
+        };
+        if (!Main.pushModal(this, modalParams))
             return false;
 
         this._isModal = true;
@@ -147,9 +154,8 @@ var UnlockDialog = class {
 
     popModal(timestamp) {
         if (this._isModal) {
-            Main.popModal(this.actor, timestamp);
+            Main.popModal(this, timestamp);
             this._isModal = false;
         }
     }
-};
-Signals.addSignalMethods(UnlockDialog.prototype);
+});