[banshee] [PlayQueue] Add Shuffle action

[Gabriel Burt <gburt src gnome org>]

commit 668b3a665fa5912d355a5e25546235f101ef705b
Author: Gabriel Burt <gabriel burt gmail com>
Date:   Sat Aug 14 12:58:47 2010 -0700

    [PlayQueue] Add Shuffle action
    
    Only available when in manual mode (not Auto DJ); fixes bgo#539607

 .../Banshee.PlayQueue/PlayQueueActions.cs          |   21 +++-
 .../Banshee.PlayQueue/PlayQueueSource.cs           |  126 +++++++++++++-------
 .../Banshee.PlayQueue/Resources/ActiveSourceUI.xml |    1 +
 .../Banshee.PlayQueue/Resources/GlobalUI.xml       |    3 +-
 4 files changed, 100 insertions(+), 51 deletions(-)
---
diff --git a/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueActions.cs b/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueActions.cs
index 6ebe4d8..fd24691 100644
--- a/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueActions.cs
+++ b/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueActions.cs
@@ -56,23 +56,26 @@ namespace Banshee.PlayQueue
                 new ActionEntry ("RefreshPlayQueueAction", Stock.Refresh,
                     Catalog.GetString ("Refresh"), null,
                     Catalog.GetString ("Refresh random tracks in the play queue"),
-                    OnRefreshPlayQueue)
-            );
+                    OnRefreshPlayQueue),
+
+                new ActionEntry ("ShufflePlayQueue", null,
+                    Catalog.GetString ("Shuffle"), null,
+                    Catalog.GetString ("Randomize the playback order of items in the play queue"),
+                    OnShufflePlayQueue),
 
-            AddImportant (
                 new ActionEntry ("AddPlayQueueTracksAction", Stock.Add,
                     Catalog.GetString ("Add More"), null,
                     Catalog.GetString ("Add more random tracks to the play queue"),
-                    OnAddPlayQueueTracks)
-            );
+                    OnAddPlayQueueTracks),
 
-            AddImportant (
                 new ActionEntry ("ClearPlayQueueAction", Stock.Clear,
                     Catalog.GetString ("Clear"), null,
                     Catalog.GetString ("Remove all tracks from the play queue"),
                     OnClearPlayQueue)
             );
 
+            this["ShufflePlayQueue"].IconName = "media-playlist-shuffle";
+
             Add (new ToggleActionEntry [] {
                 new ToggleActionEntry ("ClearPlayQueueOnQuitAction", null,
                     Catalog.GetString ("Clear on Quit"), null,
@@ -119,6 +122,11 @@ namespace Banshee.PlayQueue
             playqueue.AddMoreRandomTracks ();
         }
 
+        private void OnShufflePlayQueue (object o, EventArgs args)
+        {
+            playqueue.Shuffle ();
+        }
+
         private void OnClearPlayQueueOnQuit (object o, EventArgs args)
         {
             ToggleAction action = this["ClearPlayQueueOnQuitAction"] as Gtk.ToggleAction;
@@ -144,6 +152,7 @@ namespace Banshee.PlayQueue
                 DatabaseSource db_source = source as DatabaseSource ?? source.Parent as DatabaseSource;
                 UpdateAction ("RefreshPlayQueueAction", playqueue.Populate);
                 UpdateAction ("AddPlayQueueTracksAction", playqueue.Populate);
+                UpdateAction ("ShufflePlayQueue", !playqueue.Populate, playqueue.Count > 1);
                 UpdateAction ("ClearPlayQueueAction", !playqueue.Populate, playqueue.Count > 0);
                 UpdateAction ("ClearPlayQueueOnQuitAction", !playqueue.Populate);
                 UpdateAction ("AddToPlayQueueAction", db_source != null && db_source != playqueue, true);
diff --git a/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueSource.cs b/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueSource.cs
index 84ce2e2..ea85d49 100644
--- a/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueSource.cs
+++ b/src/Extensions/Banshee.PlayQueue/Banshee.PlayQueue/PlayQueueSource.cs
@@ -167,6 +167,54 @@ namespace Banshee.PlayQueue
             return header_widget;
         }
 
+        // Randomizes the ViewOrder of all the enabled, unplayed/playing songs
+        public void Shuffle ()
+        {
+            if (!Populate) {
+                if (current_track == null)
+                    return;
+
+                int enabled_count = EnabledCount;
+                int first_view_order = (int)CurrentTrackViewOrder;
+                int last_view_order = first_view_order + enabled_count;
+
+                // If the current track is playing, don't shuffle it
+                if (ServiceManager.PlayerEngine.IsPlaying (current_track))
+                    first_view_order++;
+
+                // Nothing to do if less than 2 tracks
+                if (last_view_order - first_view_order < 2)
+                    return;
+
+                // Save the current_track index, so we can update the current track
+                // to be whatever one is at that position after we shuffle them -- assuming
+                // the current_track isn't already playing.
+                int current_index = TrackModel.IndexOf (current_track);
+
+                // Setup a function that will return a random ViewOrder in the range we want
+                var rand = new Random ();
+                var func_id = "play-queue-shuffle-order-" + rand.NextDouble ().ToString ();
+                var view_orders = Enumerable.Range (first_view_order, last_view_order)
+                                            .OrderBy (a => rand.NextDouble ())
+                                            .ToList ();
+                int i = 0;
+                BinaryFunction.Add (func_id, (f, b) => view_orders[i++]);
+
+                ServiceManager.DbConnection.Execute (
+                    "UPDATE CorePlaylistEntries SET ViewOrder = HYENA_BINARY_FUNCTION (?, NULL, NULL) WHERE PlaylistID = ? AND ViewOrder >= ?",
+                    func_id, DbId, first_view_order
+                );
+
+                BinaryFunction.Remove (func_id);
+                Reload ();
+
+                // Update the current track unless it was playing (and therefore wasn't moved)
+                if (!ServiceManager.PlayerEngine.IsPlaying (current_track)) {
+                    SetCurrentTrack (TrackModel[current_index] as DatabaseTrackInfo);
+                }
+            }
+        }
+
 #region IPlayQueue, IDBusExportable
 
         public void EnqueueUri (string uri)
@@ -253,6 +301,23 @@ namespace Banshee.PlayQueue
             get { return "PlayQueue"; }
         }
 
+        private long CurrentTrackViewOrder {
+            get {
+                // Get the ViewOrder of the current_track
+                return current_track == null
+                    ? ServiceManager.DbConnection.Query<long> (@"
+                        SELECT MAX(ViewOrder) + 1
+                        FROM CorePlaylistEntries
+                        WHERE PlaylistID = ?",
+                        DbId)
+                    : ServiceManager.DbConnection.Query<long> (@"
+                        SELECT ViewOrder
+                        FROM CorePlaylistEntries
+                        WHERE PlaylistID = ? AND EntryID = ?",
+                        DbId, Convert.ToInt64 (current_track.CacheEntryId));
+            }
+        }
+
 #endregion
 
         public override bool AddSelectedTracks (Source source)
@@ -263,20 +328,7 @@ namespace Banshee.PlayQueue
                     return false;
                 }
 
-                // Get the ViewOrder of the current_track
-                long current_view_order = current_track == null ?
-                    ServiceManager.DbConnection.Query<long> (@"
-                        SELECT MAX(ViewOrder) + 1
-                        FROM CorePlaylistEntries
-                        WHERE PlaylistID = ?",
-                        DbId
-                    ) :
-                    ServiceManager.DbConnection.Query<long> (@"
-                        SELECT ViewOrder
-                        FROM CorePlaylistEntries
-                        WHERE PlaylistID = ? AND EntryID = ?",
-                        DbId, Convert.ToInt64 (current_track.CacheEntryId)
-                );
+                long current_view_order = CurrentTrackViewOrder;
 
                 // If the current_track is not playing, insert before it.
                 int index = -1;
@@ -664,17 +716,6 @@ namespace Banshee.PlayQueue
             current_track = track;
         }
 
-        public long Offset {
-            get { return offset; }
-            protected set {
-                if (value != offset) {
-                    offset = value;
-                    DatabaseConfigurationClient.Client.Set (CurrentOffsetSchema, (int)offset);
-                    Reload ();
-                }
-            }
-        }
-
         public void Refresh ()
         {
             int index = current_track == null ? Count : TrackModel.IndexOf (current_track);
@@ -686,22 +727,11 @@ namespace Banshee.PlayQueue
 
             if (index + 1 < Count) {
                 // Get the ViewOrder of the current_track
-                long current_view_order = current_track == null ?
-                    ServiceManager.DbConnection.Query<long> (@"
-                        SELECT MAX(ViewOrder) + 1
-                        FROM CorePlaylistEntries
-                        WHERE PlaylistID = ?",
-                        DbId
-                    ) :
-                    ServiceManager.DbConnection.Query<long> (@"
-                        SELECT ViewOrder
-                        FROM CorePlaylistEntries
-                        WHERE PlaylistID = ? AND EntryID = ?",
-                        DbId, Convert.ToInt64 (current_track.CacheEntryId)
-                );
+                long current_view_order = CurrentTrackViewOrder;
+
                 // Get the list of generated tracks.
                 var generated = new HashSet<long> ();
-                foreach(long trackID in ServiceManager.DbConnection.QueryEnumerable<long> ( @"
+                foreach (long trackID in ServiceManager.DbConnection.QueryEnumerable<long> ( @"
                     SELECT TrackID
                     FROM CorePlaylistEntries
                     WHERE PlaylistID = ? AND Generated = 1 AND ViewOrder >= ?",
@@ -727,8 +757,7 @@ namespace Banshee.PlayQueue
                 if (removed) {
                     OnTracksRemoved ();
                 }
-            }
-            else if (Count == 0 || current_track == null) {
+            } else if (Count == 0 || current_track == null) {
                 UpdatePlayQueue ();
             }
         }
@@ -768,6 +797,17 @@ namespace Banshee.PlayQueue
             }
         }
 
+        public long Offset {
+            get { return offset; }
+            protected set {
+                if (value != offset) {
+                    offset = value;
+                    DatabaseConfigurationClient.Client.Set (CurrentOffsetSchema, (int)offset);
+                    Reload ();
+                }
+            }
+        }
+
         public override int EnabledCount {
             get {
                 return current_track == null ? 0 : Count - TrackModel.IndexOf (current_track);
@@ -775,9 +815,7 @@ namespace Banshee.PlayQueue
         }
 
         public override int FilteredCount {
-            get {
-                return EnabledCount;
-            }
+            get { return EnabledCount; }
         }
 
         public override bool CanRename {
diff --git a/src/Extensions/Banshee.PlayQueue/Resources/ActiveSourceUI.xml b/src/Extensions/Banshee.PlayQueue/Resources/ActiveSourceUI.xml
index e008c44..3c61776 100644
--- a/src/Extensions/Banshee.PlayQueue/Resources/ActiveSourceUI.xml
+++ b/src/Extensions/Banshee.PlayQueue/Resources/ActiveSourceUI.xml
@@ -2,6 +2,7 @@
     <toolbar name="HeaderToolbar">
         <placeholder name="SourceActions">
             <toolitem action="RefreshPlayQueueAction" />
+            <toolitem action="ShufflePlayQueue" />
             <toolitem action="AddPlayQueueTracksAction" />
             <toolitem action="ClearPlayQueueAction" />
         </placeholder>
diff --git a/src/Extensions/Banshee.PlayQueue/Resources/GlobalUI.xml b/src/Extensions/Banshee.PlayQueue/Resources/GlobalUI.xml
index 676fdd5..565604b 100644
--- a/src/Extensions/Banshee.PlayQueue/Resources/GlobalUI.xml
+++ b/src/Extensions/Banshee.PlayQueue/Resources/GlobalUI.xml
@@ -1,6 +1,7 @@
 <ui>
     <popup name="PlayQueueContextMenu">
         <menuitem action="RefreshPlayQueueAction"></menuitem>
+        <menuitem action="ShufflePlayQueue"></menuitem>
         <menuitem action="ClearPlayQueueAction"></menuitem>
         <menuitem action="ClearPlayQueueOnQuitAction"></menuitem>
         <menuitem action="AddPlayQueueTracksAction"></menuitem>
@@ -11,4 +12,4 @@
             <menuitem name="AddToPlayQueue" action="AddToPlayQueueAction"></menuitem>
         </placeholder>
     </popup>
-</ui>
\ No newline at end of file
+</ui>