Preparation to music streaming - Picking from Gelli

app/src/main/java/com/cappielloantonio/play/service/playback/Playback.java

@@ -0,0 +1,39 @@
+package com.cappielloantonio.play.service.playback;
+
+import com.cappielloantonio.play.model.Song;
+
+public interface Playback {
+    void setDataSource(Song song);
+
+    void queueDataSource(Song song);
+
+    void setCallbacks(PlaybackCallbacks callbacks);
+
+    boolean isReady();
+
+    boolean isPlaying();
+
+    void start();
+
+    void pause();
+
+    void stop();
+
+    int getProgress();
+
+    int getDuration();
+
+    void setProgress(int progress);
+
+    void setVolume(int volume);
+
+    int getVolume();
+
+    interface PlaybackCallbacks {
+        void onTrackStarted();
+
+        void onTrackWentToNext();
+
+        void onTrackEnded();
+    }
+}