Updated JavaDoc.

src/main/java/musicplayer/library/JTreeLibrary.java

@@ -84,6 +84,9 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
         }
     }
 
+    /**
+     * Display a message in the Library area to tell the user that the library is empty.
+     */
     private void showEmpty(){
         DefaultTreeModel failedModel = new DefaultTreeModel(new DefaultMutableTreeNode());
         DefaultMutableTreeNode failedParentNode = (DefaultMutableTreeNode) failedModel.getRoot();
@@ -92,6 +95,9 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
         libraryTree.setModel(failedModel);
     }
 
+    /**
+     * Show a list of all songs in the library area.
+     */
     @Override
     public void showSongs() {
         Optional<List<Song>> dbQuery = database.listAllT(Song.class);
@@ -106,6 +112,11 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
             showEmpty();
     }
 
+    /**
+     * Show a list of all songs in the library area, grouped by a certain related type.
+     * @param grouping Type by which songs will be grouped.
+     * @param <T> Type by which songs will be grouped.
+     */
     @Override
     public <T extends HasSongs & Comparable<T>> void showGroupedSongs(Class<T> grouping) {
         Optional<List<T>> dbQuery = database.listAllT(grouping);
@@ -125,6 +136,9 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
 
     }
 
+    /**
+     * Set the library to updating mode and start processing songs in library folders.
+     */
     @Override
     public void updateLibrary() {
         if(!libraryUpdating.get()) {
@@ -141,6 +155,9 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
         }
     }
 
+    /**
+     * Refresh the content currently displayed in the library view.
+     */
     @Override
     public void refreshLibrary() {
         if(!libraryUpdating.get()) { // Don't try to refresh while updating!!
@@ -160,23 +177,37 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
         }
     }
 
+    /**
+     * The library was updated but there was an error (partial update may have occurred).
+     * @param message Error message.
+     */
     @Override
     public void libraryUpdated(String message) {
         JOptionPane.showMessageDialog(this, message, "Update Error", JOptionPane.ERROR_MESSAGE);
         libraryUpdated();
     }
 
+    /**
+     * Library updated successfully.
+     */
     public void libraryUpdated() {
         libraryUpdating.set(false);
         refreshLibrary();
     }
 
+    /**
+     * Show data on the current update item being indexed.
+     * @param name Data about the file/folder to be shown to the user.
+     */
     @Override
     public void currentlyUpdating(String name) {
         updatingNode.setUserObject(name);
         ((DefaultTreeModel)libraryTree.getModel()).nodeChanged(updatingNode);
     }
 
+    /**
+     * Double click a library item to add it to the playlist.
+     */
     private class LibraryMouseAdapter extends MouseAdapter {
         @Override
         public void mousePressed(MouseEvent e) {
@@ -197,6 +228,9 @@ public class JTreeLibrary extends JPanel implements ILibrary, LibraryCallbackInt
         }
     }
 
+    /**
+     * Renderer for showing album art next to library album items.
+     */
     private class LibraryTreeCellRenderer implements TreeCellRenderer {
 
         private final JLabel label;

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

@@ -77,15 +77,27 @@ public class GStreamerPlayer implements IPlayer{
         setVolume(ConfigManager.getLastVolume());
     }
 
+    /**
+     * Reset the position of the seekbar.
+     */
     private void resetSeek(){
         if(callbackInterface != null)
             callbackInterface.setSeekBarPosition(0);
     }
 
+    /**
+     * Play the currently active song in the playlist.
+     * @throws StartPlayingException
+     */
     public void play() throws StartPlayingException {
         playSong(playlist.getActive());
     }
 
+    /**
+     * Play a song
+     * @param inputSong Song to play.
+     * @throws StartPlayingException
+     */
     private void playSong(Song inputSong) throws StartPlayingException {
         if (playBin.getState() == State.PLAYING)
             stop();
@@ -186,9 +198,11 @@ public class GStreamerPlayer implements IPlayer{
      * @param volume New volume in percent.
      */
     public void setVolume(int volume){
+        if(volume >= 0 && volume <= 100) {
             currentVolume = volume;
             playBin.setVolumePercent(volume);
         }
+    }
 
     /**
      * @return Current Player volume in percent.

src/main/java/musicplayer/player/VLCPlayer.java

@@ -66,11 +66,20 @@ public class VLCPlayer implements IPlayer {
         libvlcArgs.add("--aout=dummy");
     }
 
+    /**
+     * Play the currently active song in the playlist.
+     * @throws StartPlayingException
+     */
     @Override
     public void play() throws StartPlayingException {
         playSong(playlist.getActive());
     }
 
+    /**
+     * Play a song
+     * @param inputSong Song to play.
+     * @throws StartPlayingException
+     */
     @Override
     public void playSong(Optional<Song> inputSong) throws StartPlayingException {
         if(inputSong.isPresent()) {
@@ -78,6 +87,11 @@ public class VLCPlayer implements IPlayer {
         }
     }
 
+    /**
+     * Play a song
+     * @param inputSong Song to play.
+     * @throws StartPlayingException
+     */
     private void playSong(Song inputSong) throws StartPlayingException {
         resetSeek();
         if(inputSong == currentSong && mediaPlayer.getTime() > 0 && mediaPlayer.getTime() <= mediaPlayer.getLength()) { // Song ~should~ already be loaded, unpause instead?
@@ -97,22 +111,34 @@ public class VLCPlayer implements IPlayer {
             throw new StartPlayingException(inputSong);
     }
 
+    /**
+     * Reset the position of the seekbar.
+     */
     private void resetSeek(){
         if(callbackInterface != null)
             callbackInterface.setSeekBarPosition(0);
     }
 
+    /**
+     * Stop playback.
+     */
     @Override
     public void stop() {
         resetSeek();
         mediaPlayer.stop();
     }
 
+    /**
+     * Resume playback.
+     */
     @Override
     public void resume() {
         mediaPlayer.setPause(false);
     }
 
+    /**
+     * Pause playback.
+     */
     @Override
     public void pause() {
         mediaPlayer.setPause(true);
@@ -123,52 +149,89 @@ public class VLCPlayer implements IPlayer {
         }
     }
 
+    /**
+     * Play the next song in the playlist.
+     * @throws StartPlayingException
+     */
     @Override
     public void next() throws StartPlayingException {
         playSong(playlist.getNext(currentSong));
     }
 
+    /**
+     * Play the previous song in the playlist.
+     * @throws StartPlayingException
+     */
     @Override
     public void previous() throws StartPlayingException {
         playSong(playlist.getPrevious(currentSong));
     }
 
+    /**
+     * @return The song currently playing (or set as ready to play)
+     */
     @Override
     public Song getCurrentSong() {
         return currentSong;
     }
 
+    /**
+     * @return Current playback position in seconds.
+     */
     @Override
     public int currentSongPosition() {
         return (int)(mediaPlayer.getTime() / 1000);
     }
 
+    /**
+     * Set playback volume.
+     * @param volume Volume value between 0 & 100.
+     */
     @Override
     public void setVolume(int volume) {
+        if(volume >= 0 && volume <= 100) {
             currentVolume = volume;
             mediaPlayer.setVolume(volume);
         }
+    }
 
+    /**
+     * @return Current playback volume.
+     */
     @Override
     public int getVolume() {
         return (mediaPlayer.getVolume() >= 0) ? mediaPlayer.getVolume() : currentVolume;
     }
 
+    /**
+     * Move to desired position in playback.
+     * @param position Time to move to in seconds.
+     */
     @Override
     public void seek(int position) {
         mediaPlayer.setTime(position * 1000);
     }
 
+    /**
+     * @return Is the player currently playing.
+     */
     @Override
     public boolean isPlaying() {
         return mediaPlayer.isPlaying();
     }
 
+    /**
+     * Set the player to single song repeat mode.
+     * @param repeatMode Repeat one song?
+     */
     @Override
     public void setRepeat(boolean repeatMode) {
         this.repeatMode = repeatMode;
     }
 
+    /**
+     * @return Is the player set to repeat one song.
+     */
     @Override
     public boolean isRepeating() {
         return repeatMode;