[gnome-shell/gbsneto/new-lock-screen-part2: 21/32] unlockDialog: Introduce UnlockDialogLayout

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

commit 295d2b2b12d3de03548639c012f0ef039c649b86
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Fri Nov 29 13:36:47 2019 -0300

    unlockDialog: Introduce UnlockDialogLayout
    
    This is the layout manager responsible for ensuring
    that the clock is always at the third of the screen
    height, and the notifications can push it to above.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/872

 js/ui/unlockDialog.js | 79 +++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 71 insertions(+), 8 deletions(-)
---
diff --git a/js/ui/unlockDialog.js b/js/ui/unlockDialog.js
index 697c96bf79..180bd082d0 100644
--- a/js/ui/unlockDialog.js
+++ b/js/ui/unlockDialog.js
@@ -319,6 +319,66 @@ class UnlockDialogClock extends St.BoxLayout {
     }
 });
 
+var UnlockDialogLayout = GObject.registerClass(
+class UnlockDialogLayout extends Clutter.LayoutManager {
+    _init(authBox, notifications) {
+        super._init();
+
+        this._authBox = authBox;
+        this._notifications = notifications;
+    }
+
+    vfunc_get_preferred_width(container, forHeight) {
+        return this._authBox.get_preferred_width(forHeight);
+    }
+
+    vfunc_get_preferred_height(container, forWidth) {
+        return this._authBox.get_preferred_height(forWidth);
+    }
+
+    vfunc_allocate(container, box, flags) {
+        let [width, height] = box.get_size();
+
+        let tenthOfHeight = height / 10.0;
+        let thirdOfHeight = height / 3.0;
+
+        let [, , authBoxWidth, authBoxHeight] =
+            this._authBox.get_preferred_size();
+
+        let [, , notificationsWidth, notificationsHeight] =
+            this._notifications.get_preferred_size();
+
+        let columnWidth = Math.max(authBoxWidth, notificationsWidth);
+
+        let columnX1 = Math.floor(width / 2.0 - columnWidth / 2.0);
+        let actorBox = new Clutter.ActorBox();
+
+        // Notifications
+        let maxNotificationsHeight = Math.min(
+            notificationsHeight,
+            height - tenthOfHeight - authBoxHeight);
+
+        actorBox.x1 = columnX1;
+        actorBox.y1 = height - maxNotificationsHeight;
+        actorBox.x2 = columnX1 + columnWidth;
+        actorBox.y2 = actorBox.y1 + maxNotificationsHeight;
+
+        this._notifications.allocate(actorBox, flags);
+
+        // Authentication Box
+        let authBoxY = Math.min(
+            thirdOfHeight,
+            height - authBoxHeight - maxNotificationsHeight);
+
+        actorBox.x1 = columnX1;
+        actorBox.y1 = authBoxY;
+        actorBox.x2 = columnX1 + columnWidth;
+        actorBox.y2 = authBoxY + authBoxHeight;
+
+        this._authBox.allocate(actorBox, flags);
+    }
+});
+
 var UnlockDialog = GObject.registerClass({
     Signals: {
         'failed': {},
@@ -348,13 +408,7 @@ var UnlockDialog = GObject.registerClass({
         this._userName = GLib.get_user_name();
         this._user = this._userManager.get_user(this._userName);
 
-        this._promptBox = new St.BoxLayout({ vertical: true,
-                                             x_align: Clutter.ActorAlign.CENTER,
-                                             y_align: Clutter.ActorAlign.CENTER,
-                                             x_expand: true,
-                                             y_expand: true });
-        this.add_child(this._promptBox);
-        this._promptBox.add_constraint(new Layout.MonitorConstraint({ primary: true }));
+        this._promptBox = new St.BoxLayout({ vertical: true });
 
         this._clock = new Clock();
         this._promptBox.add_child(this._clock);
@@ -393,7 +447,16 @@ var UnlockDialog = GObject.registerClass({
         this._wakeUpScreenId = this._notificationsBox.connect('wake-up-screen', () => {
             this.emit('wake-up-screen');
         });
-        this._promptBox.add_child(this._notificationsBox);
+
+        // Main Box
+        let mainBox = new Clutter.Actor();
+        mainBox.add_constraint(new Layout.MonitorConstraint({ primary: true }));
+        mainBox.add_child(this._promptBox);
+        mainBox.add_child(this._notificationsBox);
+        mainBox.layout_manager = new UnlockDialogLayout(
+            this._promptBox,
+            this._notificationsBox);
+        this.add_child(mainBox);
 
         this._idleMonitor = Meta.IdleMonitor.get_core();
         this._idleWatchId = this._idleMonitor.add_idle_watch(IDLE_TIMEOUT * 1000, this._escape.bind(this));