[gnome-shell/gbsneto/new-lock-screen-part2: 19/22] unlockDialog: Introduce UnlockDialogLayout

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

commit f7ee3c31d72c247fccded91797353b83c7ff68a5
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 1abe48c22c..23a88bed71 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);
@@ -394,7 +448,16 @@ 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));