GStreamerPlayer no longer proxies via PlayerGUI to interact with a playlist.

src/main/java/musicplayer/PlayerGUI.java

@@ -47,18 +47,6 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         this.playlist = playlist;
         this.library = library;
         createUI();
-        Thread seekBarUpdater = new Thread(() -> {
-            boolean running = true;
-            while (running) {
-                try {
-                    Thread.sleep(1000);
-                    setSeekBarPosition(player.currentSongPosition());
-                } catch (InterruptedException e) {
-                    running = false;
-                }
-            }
-        }, "seekbar");
-        seekBarUpdater.start();
         try {
             Logger logger = Logger.getLogger(GlobalScreen.class.getPackage().getName());
             logger.setLevel(Level.WARNING);
@@ -107,41 +95,6 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         });
     }
 
-    /**
-     * Set the highlighted song in the playlist to this song.
-     *
-     * @param playingSong Song to be highlighted in the playlist.
-     */
-    @Override
-    public void setSongHighlighting(Song playingSong) {
-        playlist.setPlayingSong(playingSong);
-    }
-
-    private void playSong(Optional<Song> song){
-        try {
-            player.playSong(song);
-        } catch (StartPlayingException e) {
-            JOptionPane.showMessageDialog(this, "Failed to play " + song.get().toString() + ".\n" +
-                    "If file path contains non-ASCII characters, please restart the application with UTF-8 encoding.");
-        }
-    }
-
-    /**
-     * Get the next song in the playlist and dispatch it to the Player to be played.
-     */
-    public void playNextSong() {
-        SwingUtilities.invokeLater(() -> seekBar.setValue(0));
-        playSong(playlist.getNext(player.getCurrentSong()));
-    }
-
-    /**
-     * Get the previous song in the playlist and dispatch it to the Player to be played.
-     */
-    public void playPreviousSong() {
-        SwingUtilities.invokeLater(() -> seekBar.setValue(0));
-        playSong(playlist.getPrevious(player.getCurrentSong()));
-    }
-
     /**
      * Set the maximum value of the seekBar.
      *
@@ -151,14 +104,9 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         SwingUtilities.invokeLater(() -> seekBar.setMaximum(seconds));
     }
 
-    @Override
+    private void showError(StartPlayingException ex){
-    public void removeInvalidSong(Song invalidSong) {
+        JOptionPane.showMessageDialog(this, "Failed to play " + ex.getSong().toString() + ".\n" +
-        playlist.delete(invalidSong);
+                "If file path contains non-ASCII characters, please restart the application with UTF-8 encoding.");
-    }
-
-    public void playerStopped(){
-        setSongHighlighting(player.getCurrentSong());
-        playlist.setPlayingSong(null);
     }
 
     /*
@@ -204,15 +152,18 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         playButton.setName("playButton");
         playButton.setIcon(Icons.playIcon);
         playButton.setMnemonic('P');
-        playButton.addActionListener(e -> playSong(playlist.getActive()));
+        playButton.addActionListener(e -> {
+            try {
+                player.play();
+            } catch (StartPlayingException e1) {
+                showError(e1);
+            }
+        });
         controlBar.add(playButton);
         JButton pauseButton = new JButton();
         pauseButton.setIcon(Icons.pauseIcon);
         pauseButton.setMnemonic('E');
-        pauseButton.addActionListener(e -> {
+        pauseButton.addActionListener(e -> player.pause());
-            player.pause();
-            setSongHighlighting(player.getCurrentSong()); // Resume won't function if a different song is selected.
-        });
         controlBar.add(pauseButton);
         JButton stopButton = new JButton();
         stopButton.setIcon(Icons.stopIcon);
@@ -222,12 +173,24 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         JButton previousButton = new JButton();
         previousButton.setIcon(Icons.prevIcon);
         previousButton.setMnemonic('R');
-        previousButton.addActionListener(e -> playPreviousSong());
+        previousButton.addActionListener(e -> {
+            try {
+                player.previous();
+            } catch (StartPlayingException e1) {
+                showError(e1);
+            }
+        });
         controlBar.add(previousButton);
         JButton nextButton = new JButton();
         nextButton.setIcon(Icons.nextIcon);
         nextButton.setMnemonic('N');
-        nextButton.addActionListener(e -> playNextSong());
+        nextButton.addActionListener(e -> {
+            try {
+                player.next();
+            } catch (StartPlayingException e1) {
+                showError(e1);
+            }
+        });
         controlBar.add(nextButton);
         toolBar.add(controlBar);
         toolBar.add(createVolumeControls());
@@ -399,22 +362,27 @@ public class PlayerGUI extends JPanel implements PlayerCallbackInterface {
         @Override
         public void nativeKeyTyped(NativeKeyEvent nativeKeyEvent) {
             if(modified){
-                switch(nativeKeyEvent.getRawCode()){
+                try {
+                    switch (nativeKeyEvent.getRawCode()) {
                         case playPause:
-                        if(player.isPlaying()){
+                            if (player.isPlaying()) {
                                 player.pause();
-                            setSongHighlighting(player.getCurrentSong()); // Resume won't function if a different song is selected.
+                            } else {
-                        }
+                                player.play();
-                        else{
-                            playSong(playlist.getActive());
                             }
                             break;
                         case stop:
-                        player.stop(); break;
+                            player.stop();
+                            break;
                         case previous:
-                        playPreviousSong(); break;
+                            player.previous();
+                            break;
                         case next:
-                        playNextSong(); break;
+                            player.next();
+                            break;
+                    }
+                }catch (StartPlayingException ex){
+                    showError(ex);
                 }
             }
         }

src/main/java/musicplayer/StartPlayingException.java

@@ -9,4 +9,8 @@ public class StartPlayingException extends Exception {
     public StartPlayingException(Song song){
         this.song = song;
     }
+
+    public Song getSong() {
+        return song;
+    }
 }

src/main/java/musicplayer/callbacks/PlayerCallbackInterface.java

@@ -7,32 +7,13 @@ import musicplayer.model.Song;
 @ImplementedBy(PlayerGUI.class)
 public interface PlayerCallbackInterface {
 
-    /**
-     * Set the song currently shown to the user as playing.
-     * @param playingSong Song currently playing.
-     */
-    void setSongHighlighting(Song playingSong);
-
     /**
      * Set the seekbar position.
+     *
      * @param seconds Position to set the seekbar to.
      */
     void setSeekBarDuration(int seconds);
 
-    /**
+    void setSeekBarPosition(int position);
-     * Remove a song from the current playlist.
-     * @param invalidSong Song to remove.
-     */
-    void removeInvalidSong(Song invalidSong);
-
-    /**
-     * Playback has ceased.
-     */
-    void playerStopped();
-
-    /**
-     * Start playing the next song.
-     */
-    void playNextSong();
 
 }

src/main/java/musicplayer/player/GStreamerPlayer.java

@@ -4,6 +4,7 @@ import com.google.inject.Inject;
 import musicplayer.StartPlayingException;
 import musicplayer.callbacks.PlayerCallbackInterface;
 import musicplayer.model.Song;
+import musicplayer.playlist.IPlaylist;
 import org.gstreamer.ClockTime;
 import org.gstreamer.ElementFactory;
 import org.gstreamer.Gst;
@@ -22,14 +23,16 @@ public class GStreamerPlayer implements IPlayer{
     private Song currentSong;
     private final PlayerCallbackInterface callbackInterface;
     private int currentVolume = 100;
+    private final IPlaylist playlist;
 
     /**
      * Manages GStreamer based playback operations.
      * @param callbackInterface Interface on which UI updates can be called.
      */
     @Inject
-    public GStreamerPlayer(PlayerCallbackInterface callbackInterface) {
+    public GStreamerPlayer(PlayerCallbackInterface callbackInterface, IPlaylist playlist) {
         this.callbackInterface = callbackInterface;
+        this.playlist = playlist;
         Gst.init();
         playBin = new PlayBin2("BusMessages");
         playBin.setVideoSink(ElementFactory.make("fakesink", "videosink"));
@@ -38,16 +41,39 @@ public class GStreamerPlayer implements IPlayer{
             Thread callbackThing = new Thread(() -> {
                 try {
                     Thread.sleep(1000); // Song is about to finish, wait so we don't cut it off early.
-                } catch (InterruptedException e) {
+                    playSong(playlist.getNext(currentSong));
+                } catch (InterruptedException | StartPlayingException e) {
                     e.printStackTrace();
                 }
-                callbackInterface.playNextSong();
             });
             callbackThing.start();
         });
+        if (callbackInterface != null) {
+            Thread seekBarUpdater = new Thread(() -> {
+                boolean running = true;
+                while (running) {
+                    try {
+                        Thread.sleep(1000);
+                        if (isPlaying())
+                            callbackInterface.setSeekBarPosition(currentSongPosition());
+                    } catch (InterruptedException e) {
+                        running = false;
+                    }
+                }
+            }, "seekbar");
+            seekBarUpdater.start();
+        }
         currentVolume = getVolume();
     }
 
+    private void resetSeek(){
+        callbackInterface.setSeekBarPosition(0);
+    }
+
+    public void play() throws StartPlayingException {
+        playSong(playlist.getActive());
+    }
+
     /**
      * Set a source Song file and start playing it via GStreamer.
      * @param inputSong Song to play.
@@ -60,13 +86,14 @@ public class GStreamerPlayer implements IPlayer{
                 resume();
                 return;
             }
+            resetSeek();
             playBin.setState(State.READY);
             currentSong = inputSong.get();
-            callbackInterface.setSongHighlighting(currentSong);
+            playlist.setPlayingSong(currentSong);
             File songFile = currentSong.getSongFile();
             if (!songFile.exists()) {
-                callbackInterface.playNextSong();
+                playlist.delete(currentSong);
-                callbackInterface.removeInvalidSong(currentSong);
+                next();
                 return;
             }
             playBin.setURI(songFile.toURI());
@@ -95,7 +122,8 @@ public class GStreamerPlayer implements IPlayer{
             playBin.stop();
             internalThread.stop();
             thread = null;
-            callbackInterface.playerStopped();
+            resetSeek();
+            playlist.setPlayingSong(currentSong);
         }
     }
 
@@ -110,9 +138,18 @@ public class GStreamerPlayer implements IPlayer{
      * Pause the currently playing song.
      */
     public void pause() {
+        playlist.setPlayingSong(currentSong);
         playBin.pause();
     }
 
+    public void next() throws StartPlayingException {
+        playSong(playlist.getNext(currentSong));
+    }
+
+    public void previous() throws StartPlayingException{
+        playSong(playlist.getPrevious(currentSong));
+    }
+
     /**
      * @return The Song currently being played or ready to be played.
      */

src/main/java/musicplayer/player/IPlayer.java

@@ -6,10 +6,13 @@ import musicplayer.model.Song;
 import java.util.Optional;
 
 public interface IPlayer {
+    void play() throws StartPlayingException;
     void playSong(Optional<Song> inputSong) throws StartPlayingException;
     void stop();
     void resume();
     void pause();
+    void next() throws StartPlayingException;
+    void previous() throws StartPlayingException;
     Song getCurrentSong();
     int currentSongPosition();
     void setVolume(int volume);