Java Callback類代碼示例

import com.sun.jna.Callback; //導入依賴的package包/類
/**
 * Connects a callback to a signal.
 * <p>
 * This differs to {@link GObject#connect} in that it hooks up Bus signals
 * to the sync callback, not the generic GObject signal mechanism.
 * 
 * @param signal the name of the signal to connect to.
 * @param listenerClass the class of the {@code listener}
 * @param listener the listener to associate with the {@code callback}
 * @param callback the callback to call when the signal is emitted.
 */
@Override
public synchronized <T> void connect(String signal, Class<T> listenerClass, T listener,
        final Callback callback) {
    if (listenerClass.getEnclosingClass() != Bus.class) {
        super.connect(signal, listenerClass, listener, callback);
        return;
    }
    MessageType type = MessageType.forName(signal);
    if (type == MessageType.UNKNOWN && "message".equals(signal)) {
        type = MessageType.ANY;
    }
    if (type == MessageType.UNKNOWN) {
        throw new IllegalArgumentException("Illegal signal: " + signal);
    }
    final Map<Class<?>, Map<Object, MessageProxy>> signals = getListenerMap();
    Map<Object, MessageProxy> m = signals.get(type);
    if (m == null) {
        m = new HashMap<Object, MessageProxy>();
        signals.put(listenerClass, m);
    }
    MessageProxy proxy = new MessageProxy(type, (BusCallback) callback);
    m.put(listener, proxy);
    messageProxies.add(proxy);
    
    addWatch();
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
NativeLong C_OpenSession
(
        NativeLong            slotID,        /* the slot's ID */
        NativeLong            flags,         /* from CK_SESSION_INFO */
        Pointer               pApplication,  /* passed to callback */
        Callback              Notify,        /* callback function */
        NativeLongByReference phSession      /* gets session handle */
);
 

import com.sun.jna.Callback; //導入依賴的package包/類
public static final GlibAPI.GDestroyNotify createDestroyNotify(Callback callback) {
	if (callback == null)
		return null;
	
	final CallbackData data = new CallbackData();
	GlibAPI.GDestroyNotify destroy = new GlibAPI.GDestroyNotify() {
		public void callback(Pointer ignored) {
			outstandingCallbacks.remove(data);
		}
	};
	data.callback = callback;
	data.destroy = destroy;
	outstandingCallbacks.add(data);
	return destroy;
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
public synchronized long connect(String signal, Callback closure) {
	NativeLong connectID = GSignalAPI.gsignal.g_signal_connect_data(GObject.this, signal, closure, null, null, 0);
	if (connectID.intValue() == 0) {
		throw new IllegalArgumentException(String.format("Failed to connect signal '%s'", signal));
	}
	long id = connectID.longValue();
	signalHandlers.put(id, closure);
	return id;
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
public synchronized long connectNotify(final String propName, final Callback callback) {
	/*
	 * FIXME - need to hold this trampoline's lifecycle to the signal
	 * connection
	 */
	NotifyCallback trampoline = new NotifyCallback() {

		public void onNotify(GObject object, GParamSpec param, Pointer data) {
			Method[] methods = callback.getClass().getDeclaredMethods();
			if (methods.length != 1)
				throw new RuntimeException(String.format("Callback %s must declare exactly one method", callback
						.getClass()));
			Method meth = methods[0];
			meth.setAccessible(true);
			Class<?>[] params = meth.getParameterTypes();
			if (params.length != 2)
				throw new RuntimeException(String.format("Callback %s entry must have exactly two parameters",
						callback.getClass()));
			Object propValue = get(propName);
			try {
				methods[0].invoke(callback, new Object[] { object, propValue });
			} catch (Exception e) {
				throw new RuntimeException(e);
			}
		}
	};
	return connect("notify::" + propName, trampoline);
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
public synchronized void disconnect(long id) {
	Callback cb = signalHandlers.get(id);
	if (cb == null)
		throw new IllegalArgumentException("Invalid signal handler id:" + id);
	GSignalAPI.gsignal.g_signal_handler_disconnect(GObject.this, new NativeLong(id));
	signalHandlers.remove(id);
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
public static <C extends Callback> C pin(final C callback, final IPinListener<C> listener) {
  synchronized (pin_lock) {
    pinned.add(callback);
  }

  synchronized (listeners_lock) {
    if (listener != null) {
      listeners.put(callback, listener);
    }
  }

  return callback;
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
@SuppressWarnings("unchecked")
public static <C extends Callback> C unpin(final C callback) {
  if (callback == null) {
    return null;
  }

  final IPinListener<C> listener;

  synchronized (pin_lock) {
    pinned.remove(callback);
  }

  synchronized (listeners_lock) {
    listener = (IPinListener<C>)listeners.remove(callback);
  }

  if (listener != null) {
    if (listener.unpinned(callback)) {
      if (callback instanceof PinnableCallback) {
        ((PinnableCallback)callback).dispose();
      }
    }
    //If the listener returns false, then we do not
    //explicitly call dispose on the callback -- the user will
    //need to take care of that himself.
  } else {
    if (callback instanceof PinnableCallback) {
      ((PinnableCallback)callback).dispose();
    }
  }

  return callback;
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
private static ID createDelegate(String name, Pointer pointer, Callback callback) {
  ID delegateClass = allocateObjcClassPair(getObjcClass("NSObject"), name);
  if (!ID.NIL.equals(delegateClass)) {
    if (!addMethod(delegateClass, pointer, callback, "[email protected]")) {
      throw new RuntimeException("Cannot add observer method");
    }
    registerObjcClassPair(delegateClass);
  }
  return invoke(name, "new");
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
private static void addFoundationMethod(@NotNull ID delegate, @NotNull String selector, @NotNull Callback callback, @NotNull String types) {
  if (!Foundation.addMethod(delegate, Foundation.createSelector(selector), callback, types)) {
    throw new RuntimeException("Unable to add method " + selector + " to objective-c delegate class!");
  }
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
NativeLong g_signal_connect_data(GObject obj, String signal, Callback callback, Pointer data,
GClosureNotify destroy_data, int connect_flags);
 

import com.sun.jna.Callback; //導入依賴的package包/類
protected NativeLong g_signal_connect(String signal, Callback callback) {
    logger.entering("GObject", "g_signal_connect", new Object[] { signal, callback });
    return GOBJECT_API.g_signal_connect_data(this, signal, callback, null, null, 0);
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
protected GCallback(NativeLong id, Callback cb) {
    this.id = id != null ? id : new NativeLong(0);
    this.cb = cb;
    this.connected = this.id.intValue() != 0;
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
protected SignalCallback(String signal, Callback cb) {
    super(g_signal_connect(signal, cb), cb);
    if (!connected) {
        throw new IllegalArgumentException(String.format("Failed to connect signal '%s'", signal));
    }
}
 

import com.sun.jna.Callback; //導入依賴的package包/類
public <T> void connect(Class<T> listenerClass, T listener, Callback cb) {
    String signal = listenerClass.getSimpleName().toLowerCase().replaceAll("_", "-");
    connect(signal, listenerClass, listener, cb);
}