Playback engine can be changed in the application. Fix VLC backend not applying volume settings on first run.

src/main/java/musicplayer/SwingUIModule.java

@@ -1,6 +1,7 @@
 package musicplayer;
 
 import com.google.inject.AbstractModule;
+import com.google.inject.Provides;
 import com.google.inject.Singleton;
 import musicplayer.callbacks.PlayerCallbackInterface;
 import musicplayer.db.HibernateDatabase;
@@ -13,15 +14,26 @@ import musicplayer.player.VLCPlayer;
 import musicplayer.playlist.IPlaylist;
 import musicplayer.playlist.JTablePlaylist;
 import musicplayer.swingui.PlayerGUI;
+import musicplayer.util.ConfigManager;
 
 class SwingUIModule extends AbstractModule {
 
     @Override
     protected void configure() {
-        bind(IPlayer.class).to(GStreamerPlayer.class).in(Singleton.class);
         bind(IDatabase.class).to(HibernateDatabase.class).in(Singleton.class);
         bind(IPlaylist.class).to(JTablePlaylist.class).in(Singleton.class);
         bind(ILibrary.class).to(JTreeLibrary.class).in(Singleton.class);
         bind(PlayerCallbackInterface.class).to(PlayerGUI.class);
     }
+
+    @Provides
+    @Singleton
+    private IPlayer providePlayer(GStreamerPlayer gStreamerPlayer, VLCPlayer vlcPlayer){
+        String engineName = ConfigManager.getPlayerEngine();
+        switch (engineName){
+            case "GStreamer": return gStreamerPlayer;
+            case "VLC": return vlcPlayer;
+            default: return gStreamerPlayer;
+        }
+    }
 }

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

@@ -189,9 +189,14 @@ public class VLCPlayer implements IPlayer {
 
         @Override
         public void playing(MediaPlayer mediaPlayer) {
-            mediaPlayer.setVolume(currentVolume);
             if(callbackInterface != null)
                 callbackInterface.setSeekBarDuration((int) (mediaPlayer.getLength() / 1000));
+            while(true){ // Can't change volume till it is *actually* playing
+                if (mediaPlayer.getTime() != 0){
+                    mediaPlayer.setVolume(currentVolume);
+                    break;
+                }
+            }
         }
 
         @Override

src/main/java/musicplayer/swingui/LibraryConfigGUI.java

@@ -12,6 +12,7 @@ class LibraryConfigGUI {
     private JList<File> listLibraryFolders;
     private final LibraryListModel<File> listModel = new LibraryListModel<>();
     private JPanel mainPanel;
+    private static final String[] engineNames = {"GStreamer", "VLC"};
 
     public LibraryConfigGUI(){
         JFrame frame = new JFrame();
@@ -44,9 +45,23 @@ class LibraryConfigGUI {
         removeButton.setText("Remove");
         removeButton.addActionListener(e -> removeSelected());
         panel2.add(removeButton, constraints);
+        mainPanel.add(engineConfigUI(), BorderLayout.SOUTH);
         return mainPanel;
     }
 
+    private JPanel engineConfigUI() {
+        JPanel container = new JPanel(new BorderLayout());
+        container.add(new JLabel("Select Engine: "), BorderLayout.WEST);
+        JComboBox<String> comboBox = new JComboBox<>(engineNames);
+        comboBox.setSelectedItem(ConfigManager.getPlayerEngine());
+        comboBox.addActionListener(e -> {
+            ConfigManager.setPlayerEngine((String)comboBox.getSelectedItem());
+            JOptionPane.showMessageDialog(mainPanel, "Engine changes will be applied on restart.");
+        });
+        container.add(comboBox, BorderLayout.CENTER);
+        return container;
+    }
+
     private void updateLibraryListContents(){
         listModel.setFolderList(ConfigManager.getLibraryDirectories());
     }

src/main/java/musicplayer/util/ConfigManager.java

@@ -20,6 +20,7 @@ public final class ConfigManager {
     private static final String databaseKey = "databaseDir";
     private static final String libraryDisplayKey = "libraryDisplayKey";
     private static final String lastVolumeKey = "volume";
+    private static final String engineKey = "engine";
 
     /**
      * @return List of directories used for music library indexing.
@@ -92,7 +93,7 @@ public final class ConfigManager {
             }
         } catch (IOException ignored) {
         }
-        return 100;
+        return 0;
     }
 
     public static void setLastVolume(Integer index){
@@ -100,6 +101,22 @@ public final class ConfigManager {
         writeSettings();
     }
 
+    public static String getPlayerEngine(){
+        try (FileInputStream inputStream = new FileInputStream(propertiesFile)) {
+            librarySettings.load(inputStream);
+            if (librarySettings.containsKey(engineKey)) {
+                return librarySettings.getProperty(engineKey);
+            }
+        } catch (IOException ignored) {
+        }
+        return "GStreamer";
+    }
+
+    public static void setPlayerEngine(String engineName){
+        librarySettings.setProperty(engineKey, engineName);
+        writeSettings();
+    }
+
     private static void writeSettings() {
         try (FileWriter fileWriter = new FileWriter(settingsFilename)) {
             librarySettings.store(fileWriter, "");

src/test/java/musicplayer/player/VLCPlayerTest.java

@@ -4,6 +4,7 @@ import musicplayer.library.ILibrary;
 import musicplayer.model.Song;
 import musicplayer.playlist.IPlaylist;
 import musicplayer.playlist.JTablePlaylist;
+import musicplayer.util.ConfigManager;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -66,12 +67,19 @@ public class VLCPlayerTest {
         assertFalse(player.isPlaying());
     }
 
+    @Test
+    public void testSetVolume() throws Exception {
+        assertEquals(ConfigManager.getLastVolume(), player.getVolume());
+        int newVolume = 25;
+        player.setVolume(25);
+        assertEquals(newVolume, player.getVolume());
+    }
+
     @Test
     public void testSeek() throws Exception {
         player.playSong(Optional.of(sampleSong));
         assertTrue(player.isPlaying());
         player.seek(100);
-        System.out.println(player.currentSongPosition());
         assertTrue(player.currentSongPosition() >= 100);
     }
 }