/*
* org.openmicroscopy.shoola.util.ui.OSMenuHandler
*
*------------------------------------------------------------------------------
* Copyright (C) 2006-2007 University of Dundee. All rights reserved.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*------------------------------------------------------------------------------
*/
package org.openmicroscopy.shoola.util.ui;
//Java imports
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
//Third-party libraries
//Application-internal dependencies
/**
* Hooks existing about/quit functionality from an
* application into handlers for the Mac OS X application menu.
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author Donald MacDonald
* <a href="mailto:donald@lifesci.dundee.ac.uk">donald@lifesci.dundee.ac.uk</a>
* @version 3.0
* <small>
* (<b>Internal version:</b> $Revision: $Date: $)
* </small>
* @since OME3.0
*/
public class OSMenuAdapter
implements InvocationHandler
{
/** The reference class. */
private static final String APPLE_CLASS = "com.apple.eawt.Application";
/** The reference class listener. */
private static final String APPLE_CLASS_LISTENER =
"com.apple.eawt.ApplicationListener";
/** The object that will perform the task. */
private Object targetObject;
/** The method to call */
private Method targetMethod;
/** The name of the EAWT method it intends to listen for. */
private String proxySignature;
/** The application. */
private static Object macOSXApplication;
/**
* Creates an adapter to the handle the <code>Quit</code>
* behaviour.
*
* @param target The object that will perform the task.
* @param handler The method to call.
* @throws Throwable If an error occurs while creating the adapter.
*/
public static void setQuitHandler(Object target, Method handler)
throws Throwable
{
setHandler(new OSMenuAdapter("handleQuit", target, handler));
}
/**
* Creates an adapter to the handle the <code>About</code>
* behaviour.
*
* @param target The object that will perform the task.
* @param handler The method to call.
* @throws Throwable If an error occurs while creating the adapter.
*/
public static void setAboutHandler(Object target, Method handler)
throws Throwable
{
boolean enableAboutMenu = (target != null && handler != null);
if (enableAboutMenu) {
setHandler(new OSMenuAdapter("handleAbout", target, handler));
}
// If we're setting a handler, enable the About menu item by calling
// com.apple.eawt.Application reflectively
Method enableAboutMethod =
macOSXApplication.getClass().getDeclaredMethod(
"setEnabledAboutMenu", new Class[] { boolean.class });
enableAboutMethod.invoke(macOSXApplication, new Object[] {
Boolean.valueOf(enableAboutMenu) });
}
/**
* Creates a new instance.
*
* @param proxySignature The name of the EAWT method it intends to listen
* for e.g. handleQuit.
* @param target The object that will perform the task.
* @param handler The method to call.
*/
private OSMenuAdapter(String proxySignature, Object target, Method handler)
{
this.proxySignature = proxySignature;
this.targetObject = target;
this.targetMethod = handler;
}
/**
* Sets the adapter.
*
* @param adapter The adapter to set.
* @throws Throwable If the class is not found of the method does not exist.
*/
private static void setHandler(OSMenuAdapter adapter)
throws Throwable
{
Class klass = Class.forName(APPLE_CLASS);
if (macOSXApplication == null)
macOSXApplication = klass.getConstructor(
(Class[]) null).newInstance((Object[]) null);
Class listenerClass = Class.forName(APPLE_CLASS_LISTENER);
Method addListenerMethod =
klass.getDeclaredMethod("addApplicationListener",
new Class[] { listenerClass });
// Create a proxy object around this handler that can
//be reflectively added as an Apple ApplicationListener
Object proxy = Proxy.newProxyInstance(
OSMenuAdapter.class.getClassLoader(),
new Class[] { listenerClass }, adapter);
addListenerMethod.invoke(macOSXApplication, new Object[] { proxy });
}
/**
* Performs any operation on the event.
* Returns <code>true</code> if the event is <code>null</code> or
* returns the value of the invocation.
*
* @param event The event to handle.
* @return See above.
* @throws InvocationTargetException
* @throws IllegalAccessException
*/
private boolean callTarget(Object event)
throws InvocationTargetException, IllegalAccessException
{
Object result = targetMethod.invoke(targetObject, (Object[]) null);
if (result == null) {
if (proxySignature.equals("handleQuit")) return false;
return true;
}
return Boolean.valueOf(result.toString()).booleanValue();
}
/**
* Controls if the passed method is the correct one e.g. handleAbout.
*
* @param method The method to handle.
* @param args The passed arguments.
* @return <code>true</code> if the method is the correct one,
* <code>false</code> otherwise.
*/
private boolean isCorrectMethod(Method method, Object[] args)
{
return (targetMethod != null &&
proxySignature.equals(method.getName()) && args.length == 1);
}
/**
* Notifies that the event is handled and cancels the default behaviour.
*
* @param event The event to handle.
* @param handled The value to pass to the method e.g. <code>true</code>
* for <code>About</code>, <code>false</code>
* for <code>Quit</code>.
* @throws Throwable if the adapter was not able to handle the application
* event.
*/
private void setApplicationEventHandled(Object event, boolean handled)
throws Throwable
{
if (event == null) return;
Class klass = event.getClass();
Method setHandledMethod = klass.getDeclaredMethod("setHandled",
new Class[] { boolean.class });
setHandledMethod.invoke(event,
new Object[] { Boolean.valueOf(handled) });
}
/**
* Implemented as specified by the {@link InvocationHandler} interface.
* @see InvocationHandler#invoke(Object, Method, Object[])
*/
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable
{
if (isCorrectMethod(method, args))
setApplicationEventHandled(args[0], callTarget(args[0]));
return null;
}
}