Initial callback support in libvlc + example on how to use in the java bindings

bindings/java/VLCExample.java

 import org.videolan.jvlc.AudioIntf;
 import org.videolan.jvlc.JVLC;
 import org.videolan.jvlc.VLCException;
+import org.videolan.jvlc.VolumeListener;
 
 
 public class VLCExample
@@ -83,6 +84,13 @@ public class VLCExample
                 jvlc.video.setSize(300, 300);
 
             }
+            jvlc.audio.addVolumeListener(new VolumeListener()
+            {
+				public void volumeChanged() {
+					System.out.println("====> From the listener: volume changed");
+				}
+            });
+
             System.out.print("Muting...");
             jvlc.audio.setMute(true);
             Thread.sleep(3000);

bindings/java/includes/Audio.h

@@ -79,6 +79,14 @@ JNIEXPORT jint JNICALL Java_org_videolan_jvlc_Audio__1getVolume
 JNIEXPORT void JNICALL Java_org_videolan_jvlc_Audio__1setVolume
   (JNIEnv *, jobject, jint);
 
+/*
+ * Class:     org_videolan_jvlc_Audio
+ * Method:    _install_callback
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL Java_org_videolan_jvlc_Audio__1install_1callback
+  (JNIEnv *, jobject);
+
 #ifdef __cplusplus
 }
 #endif

bindings/java/org/videolan/jvlc/Audio.java

 package org.videolan.jvlc;
 
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
 public class Audio implements AudioIntf {
 
 	private long libvlcInstance;
 
 	private native int _getTrack();
+
 	private native void _setTrack(int track);
+
 	private native int _getChannel();
+
 	private native void _setChannel(int channel);
+
 	private native boolean _getMute();
-    private native void		_setMute( boolean value );
+
+	private native void _setMute(boolean value);
+
 	private native void _toggleMute();
+
 	private native int _getVolume();
-    private native void		_setVolume( int volume );
 
-    public Audio( long instance ) {
+	private native void _setVolume(int volume);
+
+	private native void _install_callback();
+
+	private static Map objListeners = new HashMap();
+
+	public Audio(long instance) {
 		this.libvlcInstance = instance;
+		install_callaback();
+	}
+
+	private void install_callaback() {
+		objListeners.put(this, new HashSet());
+		_install_callback();
 	}
 
 	public int getTrack() throws VLCException {
 		return _getTrack();
 	}
 
-	public void setTrack( int track ) throws VLCException {
+	public void setTrack(int track) throws VLCException {
 		_setTrack(track);
 	}
 
@@ -30,7 +54,7 @@ public class Audio implements AudioIntf {
 		return _getChannel();
 	}
 
-	public void setChannel( int channel ) throws VLCException {
+	public void setChannel(int channel) throws VLCException {
 		_setChannel(channel);
 	}
 
@@ -38,8 +62,8 @@ public class Audio implements AudioIntf {
 		return _getMute();
 	}
 
-    public void setMute( boolean value ) throws VLCException {
-        _setMute( value );
+	public void setMute(boolean value) throws VLCException {
+		_setMute(value);
 
 	}
 
@@ -52,8 +76,34 @@ public class Audio implements AudioIntf {
 	}
 
 	public void setVolume(int volume) throws VLCException {
-        _setVolume( volume );
+		_setVolume(volume);
+	}
 
+	public boolean addVolumeListener(VolumeListener listener) {
+		HashSet listeners = (HashSet) objListeners.get(this);
+		return listeners.add(listener);
+	}
+
+	public boolean removeVolumeListener(VolumeListener listener) {
+		HashSet listeners = (HashSet) objListeners.get(this);
+		return listeners.remove(listener);
+	}
+
+	// this method is invoked natively
+	private static void wakeupListeners() {
+		Set audioObjects = objListeners.keySet();
+		Iterator audioObjectsIterator = audioObjects.iterator();
+		
+		while (audioObjectsIterator.hasNext()) {
+			Audio audioObject = (Audio) audioObjectsIterator.next();
+			HashSet listeners = (HashSet) objListeners.get(audioObject);
+
+			Iterator listenerIterator = listeners.iterator();
+			while (listenerIterator.hasNext()) {
+				VolumeListener listener = (VolumeListener) listenerIterator.next();
+				listener.volumeChanged();
+			}
+		}
 	}
 
 	public long getInstance() {

bindings/java/src/Makefile.am

@@ -7,7 +7,9 @@ libjvlc_la_SOURCES = \
 	utils.cc \
 	utils.h \
 	video-jni.cc \
-	vlm-jni.cc
+	vlm-jni.cc \
+	callback-jni.cc
+
 libjvlc_la_CPPFLAGS = `$(VLC_CONFIG) --cflags pic` $(JINCLUDES)
 libjvlc_la_LIBADD = ../../../src/libvlc-control.la $(LIBJINCLUDES)
 

include/vlc/libvlc.h

@@ -803,26 +803,27 @@ VLC_PUBLIC_API libvlc_log_message_t *libvlc_log_iterator_next( libvlc_log_iterat
  * Register for a callback notification
  * \param p_instance the libvlc instance
  * \param i_event_type the desired event mask to which we want to listen
- * \param pf_callback function the function to call when an_Event occurs
+ * \param f_callback the function to call when i_event_type occurs
+ * \param user_data user provided data to carry with the event
  * \param p_e an initialized exception pointer
  */
-/* void libvlc_callback_register_for_eventtype( libvlc_instance_t *p_instance, */
-/*                                              libvlc_event_type_t i_event_type, */
-/*                                              libvlc_callback_t pf_callback, */
-/*                                              libvlc_exception_t *p_e ); */
+VLC_PUBLIC_API void libvlc_callback_register_for_event( libvlc_instance_t *p_instance,
+                                                        libvlc_event_type_t i_event_type,
+                                                        libvlc_callback_t f_callback,
+                                                        void *user_data,
+                                                        libvlc_exception_t *p_e );
 
 /**
  * Unregister a callback notification
  * \param p_instance the libvlc instance
  * \param i_event_type the desired event mask to which we want to unregister
- * \param pf_function the function to call when an_Event occurs
+ * \param f_callback the function to call when i_event_type occurs
  * \param p_e an initialized exception pointer
  */
-/* void libvlc_callback_unregister_for_eventtype( libvlc_instance_t *p_instance, */
-/*                                                libvlc_event_type_t i_event_type, */
-/*                                                libvlc_callback_t pf_function, */
-/*                                                libvlc_exception_t *p_e ); */
-
+VLC_PUBLIC_API void libvlc_callback_unregister_for_event( libvlc_instance_t *p_instance,
+                                                          libvlc_event_type_t i_event_type,
+                                                          libvlc_callback_t f_callback,
+                                                          libvlc_exception_t *p_e );
 
 /** @} */
 

include/vlc/libvlc_structures.h

@@ -155,7 +155,14 @@ typedef struct
     char reserved[8]; /* For future use */
 } libvlc_event_t;
 
-typedef void ( *libvlc_callback_t )( struct libvlc_instance_t *, libvlc_event_t * );
+/**
+ * Callback function notification
+ * \param p_instance the libvlc instance
+ * \param p_event the event triggering the callback
+ * \param p_user_data user provided data
+ */
+
+typedef void ( *libvlc_callback_t )( struct libvlc_instance_t *, libvlc_event_t *, void * );
 
 /**@} */
 

src/Makefile.am

@@ -24,6 +24,7 @@ pkgincludedir = $(includedir)/vlc
 dist_pkginclude_HEADERS = \
 	../include/vlc/vlc.h \
 	../include/vlc/libvlc.h \
+	../include/vlc/libvlc_structures.h \
 	../include/vlc/mediacontrol.h \
 	../include/vlc/mediacontrol_structures.h \
 	$(NULL)
@@ -326,6 +327,7 @@ SOURCES_libvlc_control = \
 	control/input.c \
 	control/video.c \
 	control/audio.c \
+	control/callback.c \
 	control/mediacontrol_internal.h \
 	control/mediacontrol_core.c \
 	control/mediacontrol_util.c \

src/control/core.c

@@ -111,7 +111,7 @@ void libvlc_destroy( libvlc_instance_t *p_instance, libvlc_exception_t *p_e )
 
     while( p_listitem )
     {
-        struct libvlc_callback_entry_list *p_nextlistitem = p_listitem->next;
+        struct libvlc_callback_entry_list_t *p_nextlistitem = p_listitem->next;
         free( p_listitem );
         p_listitem = p_nextlistitem;
     }

src/control/libvlc_internal.h

@@ -49,8 +49,9 @@ VLC_EXPORT (int, libvlc_InternalAddIntf, ( libvlc_int_t *, const char *, vlc_boo
 
 struct libvlc_callback_entry_t
 {
-    libvlc_callback_t callback;
-    libvlc_event_type_t eventType;
+    libvlc_instance_t *p_instance;
+    libvlc_callback_t f_callback;
+    libvlc_event_type_t i_event_type;
     void *p_user_data;
 };
 
@@ -77,6 +78,22 @@ struct libvlc_input_t
     struct libvlc_instance_t *p_instance; ///< Parent instance
 };
 
+
+static inline void add_callback_entry( struct libvlc_callback_entry_t *entry,
+                                       struct libvlc_callback_entry_list_t **list )
+{
+    struct libvlc_callback_entry_list_t *new_listitem;
+    new_listitem = malloc( sizeof( struct libvlc_callback_entry_list_t ) );
+    new_listitem->elmt = entry;
+    new_listitem->next = *list;
+    new_listitem->prev = NULL;
+
+    if(*list)
+        (*list)->prev = new_listitem;
+
+    *list = new_listitem;
+}
+
 #define RAISENULL( psz,a... ) { libvlc_exception_raise( p_e, psz,##a ); \
                                 return NULL; }
 #define RAISEVOID( psz,a... ) { libvlc_exception_raise( p_e, psz,##a ); \