[banshee/gtk3] NotificationArea: Add support for GNOME Shell's notification scheme

[Bertrand Lorentz <blorentz src gnome org>]

commit 22df15d84e82e8df723de67aa140b302ccd1e48a
Author: Bertrand Lorentz <bertrand lorentz gmail com>
Date:   Sun Dec 11 19:48:49 2011 +0100

    NotificationArea: Add support for GNOME Shell's notification scheme
    
    Use the new features added in the latest version of the Desktop
    Notifications Specification: persistent notifications, image-data hint,
    and action icons.
    
    As a consequence, we now create a status icon only if the notification
    daemon doesn't support persistent notifications (or if it's not there at
    all).
    
    As those are all optional features, this should still work with older
    notification daemons. But we now always send paths to unscaled images,
    so the daemon should be able to handle scaling itself.

 .../NotificationAreaService.cs                     |  121 ++++++++++++++------
 1 files changed, 87 insertions(+), 34 deletions(-)
---
diff --git a/src/Extensions/Banshee.NotificationArea/Banshee.NotificationArea/NotificationAreaService.cs b/src/Extensions/Banshee.NotificationArea/Banshee.NotificationArea/NotificationAreaService.cs
index 2aac029..d85acdc 100644
--- a/src/Extensions/Banshee.NotificationArea/Banshee.NotificationArea/NotificationAreaService.cs
+++ b/src/Extensions/Banshee.NotificationArea/Banshee.NotificationArea/NotificationAreaService.cs
@@ -64,6 +64,8 @@ namespace Banshee.NotificationArea
         private RatingMenuItem rating_menu_item;
         private BansheeActionGroup actions;
         private bool? actions_supported;
+        private bool? action_icons_supported;
+        private bool? persistence_supported;
 
         private int ui_manager_id;
 
@@ -73,8 +75,6 @@ namespace Banshee.NotificationArea
         private TrackInfo current_track;
         private Notification current_nf;
 
-        private const int icon_size = 42;
-
         public NotificationAreaService ()
         {
         }
@@ -153,7 +153,6 @@ namespace Banshee.NotificationArea
             show_notifications = ShowNotifications;
 
             artwork_manager_service = ServiceManager.Get<ArtworkManager> ();
-            artwork_manager_service.AddCachedSize (icon_size);
         }
 
         public void Dispose ()
@@ -206,8 +205,35 @@ namespace Banshee.NotificationArea
             }
         }
 
+        private bool ActionIconsSupported {
+            get {
+                if (!action_icons_supported.HasValue) {
+                    action_icons_supported = Notifications.Global.Capabilities != null &&
+                        Array.IndexOf (Notifications.Global.Capabilities, "action-icons") > -1;
+                }
+
+                return action_icons_supported.Value;
+            }
+        }
+
+        private bool PersistenceSupported {
+            get {
+                if (!persistence_supported.HasValue) {
+                    persistence_supported = Notifications.Global.Capabilities != null &&
+                        Array.IndexOf (Notifications.Global.Capabilities, "persistence") > -1;
+                }
+
+                return persistence_supported.Value;
+            }
+        }
+
         private bool BuildNotificationArea ()
         {
+            if (PersistenceSupported) {
+                Log.Debug ("Notification daemon supports persistence, no status icon needed");
+                return true;
+            }
+
             notif_area = new GtkNotificationAreaBox (elements_service.PrimaryWindow);
 
             if (notif_area == null) {
@@ -330,9 +356,6 @@ namespace Banshee.NotificationArea
             try {
                 if (NotifyOnCloseSchema.Get ()) {
                     Gdk.Pixbuf image = IconThemeUtils.LoadIcon (48, Banshee.ServiceStack.Application.IconName);
-                    if (image != null) {
-                        image = image.ScaleSimple (icon_size, icon_size, Gdk.InterpType.Bilinear);
-                    }
 
                     Notification nf = new Notification (
                         Catalog.GetString ("Still Running"),
@@ -371,7 +394,9 @@ namespace Banshee.NotificationArea
                     break;
             }
 
-            notif_area.OnPlayerEvent (args);
+            if (notif_area != null) {
+                notif_area.OnPlayerEvent (args);
+            }
         }
 
         private void OnRatingChanged (object o, EventArgs args)
@@ -418,40 +443,33 @@ namespace Banshee.NotificationArea
                 return;
             }
 
-            foreach (var window in elements_service.ContentWindows) {
-                if (window.HasToplevelFocus) {
-                    return;
+            // If we have persistent notifications, we show a notification even if the main window has focus
+            // so that the information displayed (track title, etc.) gets updated.
+            if (!PersistenceSupported) {
+                foreach (var window in elements_service.ContentWindows) {
+                    if (window.HasToplevelFocus) {
+                        return;
+                    }
                 }
             }
 
-            bool is_notification_daemon = false;
-            try {
-                var name = Notifications.Global.ServerInformation.Name;
-                is_notification_daemon = name == "notification-daemon" || name == "Notification Daemon";
-            } catch {
-                // This will be reached if no notification daemon is running
-                return;
-            }
-
             string message = GetByFrom (
                 current_track.ArtistName, current_track.DisplayArtistName,
                 current_track.AlbumTitle, current_track.DisplayAlbumTitle);
 
             string image = null;
 
-            image = is_notification_daemon
-                ? CoverArtSpec.GetPathForSize (current_track.ArtworkId, icon_size)
-                : CoverArtSpec.GetPath (current_track.ArtworkId);
+            image = CoverArtSpec.GetPath (current_track.ArtworkId);
 
             if (!File.Exists (new SafeUri(image))) {
                 if (artwork_manager_service != null) {
                     // artwork does not exist, try looking up the pixbuf to trigger scaling or conversion
-                    Gdk.Pixbuf tmp_pixbuf = is_notification_daemon
-                        ? artwork_manager_service.LookupScalePixbuf (current_track.ArtworkId, icon_size)
-                        : artwork_manager_service.LookupPixbuf (current_track.ArtworkId);
+                    Gdk.Pixbuf tmp_pixbuf = artwork_manager_service.LookupPixbuf (current_track.ArtworkId);
 
                     if (tmp_pixbuf == null) {
-                        image = "audio-x-generic";
+                        // TODO: image should be set to "audio-x-generic", but icon names are not supported by the
+                        // notification daemon in GNOME Shell. See https://bugzilla.gnome.org/show_bug.cgi?id=665957
+                        image = null;
                     } else {
                         tmp_pixbuf.Dispose ();
                     }
@@ -461,18 +479,45 @@ namespace Banshee.NotificationArea
             try {
                 if (current_nf == null) {
                     current_nf = new Notification (current_track.DisplayTrackTitle,
-                        message, image, notif_area.Widget);
+                        message, Banshee.ServiceStack.Application.IconName);
                 } else {
                     current_nf.Summary = current_track.DisplayTrackTitle;
                     current_nf.Body = message;
-                    current_nf.IconName = image;
-                    current_nf.AttachToWidget (notif_area.Widget);
+                    current_nf.IconName = Banshee.ServiceStack.Application.IconName;
+                    if (notif_area != null) {
+                        current_nf.AttachToWidget (notif_area.Widget);
+                    }
                 }
                 current_nf.Urgency = Urgency.Low;
                 current_nf.Timeout = 4500;
+
                 if (!current_track.IsLive && ActionsSupported && interface_action_service.PlaybackActions["NextAction"].Sensitive) {
-                    current_nf.AddAction ("skip-song", Catalog.GetString("Skip this item"), OnSongSkipped);
+                    if (ActionIconsSupported) {
+                        current_nf.AddHint ("action-icons", true);
+
+                        // We need to use an icon name as the action id, so that the notification uses that icon
+                        current_nf.AddAction ("media-skip-backward",
+                            Catalog.GetString("Previous"), OnPreviousTrack);
+
+                        bool is_playing = ServiceManager.PlayerEngine.IsPlaying ();
+                        current_nf.AddAction (is_playing ? "media-playback-pause" : "media-playback-start",
+                            interface_action_service.PlaybackActions["PlayPauseAction"].Label, OnPlayPause);
+                    }
+
+                    current_nf.AddAction ("media-skip-forward",
+                        Catalog.GetString("Skip this item"), OnNextTrack);
+                }
+
+                if (image == null) {
+                    current_nf.RemoveHint ("image-path");
+                } else {
+                    current_nf.AddHint ("image-path", image);
                 }
+
+                if (PersistenceSupported) {
+                    current_nf.AddHint ("resident", true);
+                }
+
                 current_nf.Show ();
             } catch (Exception e) {
                 Hyena.Log.Warning (Catalog.GetString ("Cannot show notification"), e.Message, false);
@@ -515,11 +560,19 @@ namespace Banshee.NotificationArea
             return markup;
         }
 
-        private void OnSongSkipped (object o, ActionArgs args)
+        private void OnPreviousTrack (object o, ActionArgs args)
         {
-            if (args.Action == "skip-song") {
-                ServiceManager.PlaybackController.Next ();
-            }
+            ServiceManager.PlaybackController.Previous ();
+        }
+
+        private void OnPlayPause (object o, ActionArgs args)
+        {
+            ServiceManager.PlayerEngine.TogglePlaying ();
+        }
+
+        private void OnNextTrack (object o, ActionArgs args)
+        {
+            ServiceManager.PlaybackController.Next ();
         }
 
         public bool ShowNotifications {