Added mechanism for reporting the "playing" state of the music server.

Automatically query the playing state after requesting a command that is
likely to modify it.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@632 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/robodj/src/java/robodj/util/ServerControl.java

@@ -1,5 +1,5 @@
 //
-// $Id: ServerControl.java,v 1.4 2002/02/22 08:37:34 mdb Exp $
+// $Id: ServerControl.java,v 1.5 2002/03/03 17:21:29 mdb Exp $
 
 package robodj.util;
 
@@ -7,6 +7,9 @@ import java.io.*;
 import java.net.*;
 import java.util.ArrayList;
 import java.util.StringTokenizer;
+import javax.swing.SwingUtilities;
+
+import com.samskivert.util.StringUtil;
 
 import robodj.Log;
 
@@ -15,7 +18,24 @@ import robodj.Log;
  * network interface.
  */
 public class ServerControl
+    implements Runnable
 {
+    /**
+     * Used to report changes to the playing song.
+     */
+    public static interface PlayingListener
+    {
+        /**
+         * Called when the playing song is known to have changed to the
+         * specified songid.
+         *
+         * @param songid the id of the song that's playing or -1 if
+         * nothing is playing.
+         * @param paused true if the music daemon is paused.
+         */
+        public void playingUpdated (int songid, boolean paused);
+    }
+
     public ServerControl (String host, int port)
         throws IOException
     {
@@ -27,19 +47,32 @@ public class ServerControl
         _out = new PrintWriter(_conn.getOutputStream());
     }
 
+    public void addPlayingListener (PlayingListener listener)
+    {
+        _listeners.add(listener);
+    }
+
+    public void removePlayingListener (PlayingListener listener)
+    {
+        _listeners.remove(listener);
+    }
+
     public void pause ()
     {
         sendCommand("PAUSE");
+        refreshPlaying();
     }
 
     public void play ()
     {
         sendCommand("PLAY");
+        refreshPlaying();
     }
 
     public void stop ()
     {
         sendCommand("STOP");
+        refreshPlaying();
     }
 
     public void clear ()
@@ -47,9 +80,16 @@ public class ServerControl
         sendCommand("CLEAR");
     }
 
+    public void back ()
+    {
+        sendCommand("BACK");
+        refreshPlaying();
+    }
+
     public void skip ()
     {
         sendCommand("SKIP");
+        refreshPlaying();
     }
 
     public void append (int eid, int sid, String trackPath)
@@ -60,21 +100,48 @@ public class ServerControl
     public void remove (int sid)
     {
         sendCommand("REMOVE " + sid);
+        refreshPlaying();
     }
 
     public void removeGroup (int sid, int count)
     {
         sendCommand("REMOVEGRP " + sid + " " + count);
+        refreshPlaying();
     }
 
     public void skipto (int sid)
     {
         sendCommand("SKIPTO " + sid);
+        refreshPlaying();
     }
 
-    public String getPlaying ()
+    public int getPlaying ()
     {
-        return sendCommand("PLAYING");
+        refreshPlaying();
+        return _playingSongId;
+    }
+
+    public void refreshPlaying ()
+    {
+        String playing = sendCommand("PLAYING");
+
+        // figure out if we're paused
+        _paused = (playing.indexOf("paused") != -1);
+
+        // figure out what song is playing
+        playing = StringUtil.split(playing, ":")[1].trim();
+        _playingSongId = -1;
+        if (!playing.equals("<none>")) {
+            try {
+                _playingSongId = Integer.parseInt(playing);
+            } catch (NumberFormatException nfe) {
+                Log.warning("Unable to parse currently playing id '" +
+                            playing + "'.");
+            }
+        }
+
+        // let our listeners know about the new info
+        SwingUtilities.invokeLater(this);
     }
 
     public String[] getPlaylist ()
@@ -114,6 +181,22 @@ public class ServerControl
         return plist;
     }
 
+    public void run ()
+    {
+        // notify our playing listeners
+        for (int i = 0; i < _listeners.size(); i++) {
+            PlayingListener listener = (PlayingListener)_listeners.get(i);
+            try {
+                listener.playingUpdated(_playingSongId, _paused);
+            } catch (Exception e) {
+                Log.warning("PlayingListener choked during update " +
+                            "[listener=" + listener +
+                            ", songid=" + _playingSongId + "].");
+                Log.logStackTrace(e);
+            }
+        }
+    }
+
     protected String sendCommand (String command)
     {
         try {
@@ -133,4 +216,14 @@ public class ServerControl
     protected Socket _conn;
     protected PrintWriter _out;
     protected BufferedReader _in;
+
+    /** A list of entities that are informed when the playing song
+     * changes. */
+    protected ArrayList _listeners = new ArrayList();
+
+    /** The most recently fetched playing song id. */
+    protected int _playingSongId;
+
+    /** The most recently fetched paused state. */
+    protected boolean _paused;
 }