implement MediaMetadataRetriever on top of MediaPlayer

also add MediaPlayer.getDuration() and MediaPlayer.getCurrentPosition()

src/api-impl/android/media/MediaMetadataRetriever.java

@@ -0,0 +1,37 @@
+package android.media;
+
+import android.content.Context;
+import android.net.Uri;
+
+public class MediaMetadataRetriever {
+
+	private MediaPlayer mediaPlayer;
+
+	public void release() {
+		if (mediaPlayer != null)
+			mediaPlayer.release();
+	}
+
+	public void setDataSource(Context context, Uri uri) {
+		mediaPlayer = new MediaPlayer();
+		mediaPlayer.setDataSource(uri.getPath());
+	}
+
+	public void setDataSource(String path) {
+		mediaPlayer = new MediaPlayer();
+		mediaPlayer.setDataSource(path);
+	}
+
+	public byte[] getEmbeddedPicture() {
+		return null;
+	}
+
+	public String extractMetadata(int key) {
+		switch (key) {
+			case 9/*METADATA_KEY_DURATION*/:
+				return String.valueOf(mediaPlayer.getDuration());
+			default:
+				return null;
+		}
+	}
+}

src/api-impl/android/media/MediaPlayer.java

@@ -68,8 +68,18 @@ public class MediaPlayer {
 
 	public void setVolume(float leftVolume, float rightVolume) {}
 
+	public int getDuration() {
+		return native_getDuration(gtk_media_stream);
+	}
+
+	public int getCurrentPosition() {
+		return native_getCurrentPosition(gtk_media_stream);
+	}
+
 	public static native void native_prepare(long gtk_media_stream);
 	public native long native_setDataSource(String path);
 	public static native void native_setOnCompletionListener(long gtk_media_stream, MediaPlayer.OnCompletionListener listener);
 	public static native void native_start(long gtk_media_stream);
+	public static native int native_getDuration(long gtk_media_stream);
+	public static native int native_getCurrentPosition(long gtk_media_stream);
 }