Re: Adding ExitListeners to Netbeans generated Desktop Application?

Rexx Magnus, 07.08.2008 11:41:


Not necessarily. You can add a hook without needing the Apple libraries at compile time.
Of course if anything changes in the Apple interfaces this will stop working, but I don't think there is a way around that.

Here is the code.

I removed error handling and logging, but I guess you get the Idea.
I simply check for the OS at startup (before initializing any GUI!) and then call installApplicationHandler()

public class MacOSHelper
  implements InvocationHandler
{
  private Object proxy;

  public MacOSHelper()
  {
  }

  public void installApplicationHandler()
  {
    Class appClass = Class.forName("com.apple.eawt.Application");
    Object application = appClass.newInstance();
    if (application != null)
    {
      Class listener = Class.forName("com.apple.eawt.ApplicationListener");
      this.proxy = Proxy.newProxyInstance(listener.getClassLoader(), new Class[] { listener },this);
      Method add = appClass.getMethod("addApplicationListener", new Class[] { listener });
      if (add != null)
      {
        // Register the proxy as the ApplicationListener. Calling events on the Listener
        // will result in calling the invoke method from this class.
        add.invoke(application, this.proxy);
      }
    
      // Now register for the Preferences... menu
      Method enablePrefs = appClass.getMethod("setEnabledPreferencesMenu", boolean.class);
      enablePrefs.invoke(application, Boolean.TRUE);
    }
  }

  public Object invoke(Object prx, Method method, Object[] args)
    throws Throwable
  {
    String methodName = method.getName();
    if ("handleQuit".equals(methodName))
    {
      // According to the Apple docs, one should call ApplicationEvent.setHandled(false);
      // in order to be able to cancel exiting.
      // See http://developer.apple.com/samplecode/OSXAdapter/listing2.html
      setHandled(args[0], false);
      System.exit(0);
    }
    else if ("handleAbout".equals(methodName))
    {
      // Show about dialog
      setHandled(args[0], true);
    }
    else if ("handlePreferences".equals(methodName))
    {
      // Show Options dialog
      setHandled(args[0], true);
    }
    else
    {
      LogMgr.logInfo("MacOSHelper.invoke()", "Ignoring unknown event.");
    }
    return null;
  }

  private void setHandled(Object event, boolean flag)
  {
    Method setHandled = event.getClass().getMethod("setHandled", boolean.class);
    setHandled.invoke(event, Boolean.valueOf(flag));
  }

}