[gnome-shell] ScreenShield: animate new notifications

[Giovanni Campagna <gcampagna src gnome org>]

commit 24f142df1dfa09933b662d35943ad9135adf11e1
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Mon Dec 3 19:43:04 2012 +0100

    ScreenShield: animate new notifications
    
    Showing the new message at full size marks an abrubt change and looks
    bad. Instead, gradually animate from 0px to full natural height.
    Includes hacks to workaround flickering scrollbars while the animation
    is in progress.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=687660

 js/ui/screenShield.js |   31 +++++++++++++++++++++++++------
 1 files changed, 25 insertions(+), 6 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index b99645e..f85871f 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -106,14 +106,14 @@ const NotificationsBox = new Lang.Class({
         this._musicBin = new St.Bin({ style_class: 'screen-shield-notifications-box',
                                       visible: false });
 
-        let scrollView = new St.ScrollView({ x_fill: false, x_align: St.Align.START,
-                                             hscrollbar_policy: Gtk.PolicyType.NEVER });
+        this._scrollView = new St.ScrollView({ x_fill: false, x_align: St.Align.START,
+                                               hscrollbar_policy: Gtk.PolicyType.NEVER });
         this._notificationBox = new St.BoxLayout({ vertical: true,
                                                    style_class: 'screen-shield-notifications-box' });
-        scrollView.add_actor(this._notificationBox);
+        this._scrollView.add_actor(this._notificationBox);
 
         this.actor.add(this._musicBin);
-        this.actor.add(scrollView, { x_fill: true, x_align: St.Align.START });
+        this.actor.add(this._scrollView, { x_fill: true, x_align: St.Align.START });
 
         this._sources = new Hash.Map();
         Main.messageTray.getSources().forEach(Lang.bind(this, function(source) {
@@ -239,7 +239,7 @@ const NotificationsBox = new Lang.Class({
             (source.unseenCount > (musicNotification ? 1 : 0));
     },
 
-    _sourceAdded: function(tray, source, dontUpdateVisibility) {
+    _sourceAdded: function(tray, source, initial) {
         // Ignore transient sources
         if (source.isTransient)
             return;
@@ -286,8 +286,27 @@ const NotificationsBox = new Lang.Class({
 
         this._sources.set(source, obj);
 
-        if (!dontUpdateVisibility)
+        if (!initial) {
+            // block scrollbars while animating, if they're not needed now
+            let boxHeight = this._notificationBox.height;
+            if (this._scrollView.height >= boxHeight)
+                this._scrollView.vscrollbar_policy = Gtk.PolicyType.NEVER;
+
+            let widget = obj.sourceBox;
+            let [, natHeight] = widget.get_preferred_height(-1);
+            widget.height = 0;
+            Tweener.addTween(widget,
+                             { height: natHeight,
+                               transition: 'easeOutQuad',
+                               time: 0.25,
+                               onComplete: function() {
+                                   this._scrollView.vscrollbar_policy = Gtk.PolicyType.AUTOMATIC;
+                                   widget.set_height(-1);
+                               },
+                               onCompleteScope: this
+                             });
             this._updateVisibility();
+        }
     },
 
     _titleChanged: function(source, obj) {