Player controls now get dynamically assigned to view model base classes.

This gives view models more freedom in how play events from the player are handled

Aurora/Design/Views/Songs/SongsViewModel.cs

@@ -11,14 +11,20 @@ namespace Aurora.Design.Views.Songs
         #region Fields
         private ObservableCollection<BaseMedia> _songsList;
         private BaseMedia _selectedSong;
+        private BaseMedia _playingSong;
+        private PlayerService _player;
 
         #endregion Fields
 
         #region Constructor
         public SongsViewModel()
         {
+            _player = PlayerService.Instance;
             _songsList = new ObservableCollection<BaseMedia>();
-            PlayCommand = new Command(PlayExecute);
+            PlayCommand = new Command(PlayExecute, PlayCanExecute);
+
+            _player.PlaybackStateChanged += OnPlaybackStateChanged;
+
             Initialize();
         }
 
@@ -37,6 +43,12 @@ namespace Aurora.Design.Views.Songs
             set { SetProperty(ref _selectedSong, value); }
         }
 
+        public BaseMedia PlayingSong
+        {
+            get { return _playingSong; }
+            set { SetProperty(ref _playingSong, value); }
+        }
+
         public Command PlayCommand { get; private set; }
 
         #endregion Properties
@@ -48,13 +60,84 @@ namespace Aurora.Design.Views.Songs
             SongsList = LibraryService.Instance.GetLibrary();
         }
 
-        public void PlayExecute()
-        {
-            PlayerService.Instance.LoadMedia(_selectedSong);
-            PlayerService.Instance.Play();
-        }
-
         #endregion Methods
 
+        #region Commmands
+        public override bool PreviousCanExecute()
+        {
+            return true;
+        }
+        public override void PreviousExecute()
+        {
+
+        }
+
+        public override bool PlayCanExecute()
+        {
+            switch (_player.PlaybackState)
+            {
+                case PlaybackState.Buffering:
+                    {
+                        return true;
+                    }
+                case PlaybackState.Playing:
+                    {
+                        return true;
+                    }
+                case PlaybackState.Stopped:
+                    {
+                        return true;
+                    }
+            }
+            return false;
+        }
+
+        public async override void PlayExecute()
+        {
+            if (!_player.IsMediaLoaded(_selectedSong))
+            {
+                await _player.LoadMedia(_selectedSong).ConfigureAwait(true);
+            }
+
+            _player.Play();
+            switch (_player.PlaybackState)
+            {
+                case PlaybackState.Buffering:
+                    {
+                        _player.Play();
+                        break;
+                    }
+                case PlaybackState.Playing:
+                    {
+                        _player.Pause();
+                        break;
+                    }
+            }
+        }
+
+        public override bool NextCanExecute()
+        {
+            return true;
+        }
+
+        public override void NextExecute()
+        {
+
+        }
+
+        #endregion Commands
+
+        #region Events
+        /// <summary>
+        /// PlayerService playback state changed event handler.
+        /// </summary>
+        /// <param name="sender">The sending object.</param>
+        /// <param name="args">Event arguments.</param>
+        public void OnPlaybackStateChanged(object sender, PlaybackStateChangedEventArgs args)
+        {
+            OnPropertyChanged("PlayButtonText");
+        }
+
+        #endregion Events
     }
 }