OSXAdapter.java

package com.myjavaworld.jftp;

import java.awt.Image;
import java.awt.Toolkit;
import java.awt.Window;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * Helper class for integrating with Mac OS X. The design intent here is to not
 * refer any Mac OS X specific classes, instead use reflection to use the Mac OS
 * X specific APIs.
 * 
 * @author Sai Pullabhotla
 * 
 */
public class OSXAdapter {

	/**
	 * A reference to the Mac OS X Application - com.apple.eawt.Application
	 */
	private static Object macOSXApplication = null;

	/**
	 * A reference to the JFTP application
	 */
	private static JFTPApplication jftpApplication = null;

	/**
	 * A common event handler for various types of Mac OS X events
	 */
	private static MacOSXEventHandler eventHandler = null;

	/**
	 * Handler for events generated by Mac OS X.
	 * 
	 * @author Sai Pullabhotla
	 * 
	 */
	private static class MacOSXEventHandler implements InvocationHandler {

		public Object invoke(Object proxy, Method method, Object[] args)
				throws Throwable {
			// System.out.println("Proxy is null: " + (proxy == null));
			// We are only interested in handling the about, preferences and
			// quit events.
			if ("handleAbout".equals(method.getName())) {
				jftpApplication.showAboutDialog();
			} else if ("handlePreferences".equals(method.getName())) {
				jftpApplication.showPreferencesDialog();
			} else if ("handleQuitRequestWith".equals(method.getName())) {
				jftpApplication.quit();
			}
			return null;
		}
	}

	/**
	 * Initializes this Adapter for the given JFTPApplication.
	 * 
	 * @param jftpApplication
	 *            a reference to the JFTPApplication
	 */
	public static void init(JFTPApplication jftpApplication) {
		OSXAdapter.jftpApplication = jftpApplication;
		createMacOSXApplication();
		if (macOSXApplication == null) {
			return;
		}
		eventHandler = new MacOSXEventHandler();
		handleDockIcon();
		registerQuitHandler();
		registerAboutHandler();
		registerPreferencesHandler();
	}

	/**
	 * Registers a handler for handling About event.
	 */
	private static void registerAboutHandler() {
		registerHandler("com.apple.eawt.AboutHandler", "setAboutHandler");
	}

	/**
	 * Registers a handler for handling Quit event.
	 */
	private static void registerQuitHandler() {
		registerHandler("com.apple.eawt.QuitHandler", "setQuitHandler");
	}

	/**
	 * Registers a handler for handling Preferences event.
	 */
	private static void registerPreferencesHandler() {
		registerHandler("com.apple.eawt.PreferencesHandler",
				"setPreferencesHandler");
	}

	/**
	 * Registers a handler for a specific event.
	 * 
	 * @param handlerClassName
	 *            the event handler interface name (e.g.
	 *            com.apple.eawt.AboutHandler).
	 * @param registrationMethodName
	 *            the name of the method defined in the
	 *            com.apple.eawt.Application class for registering the above
	 *            event handler.
	 */
	private static void registerHandler(String handlerClassName,
			String registrationMethodName) {
		try {
			Class<?> handlerClass = Class.forName(handlerClassName);
			// Create a proxy for the given interface. We use our common class,
			// MacOSXEventHandler for handling all events.
			Object proxy = Proxy.newProxyInstance(
					handlerClass.getClassLoader(),
					new Class[] { handlerClass }, eventHandler);
			// Invoke the event handler registration method on the Application
			// object.
			Method method = macOSXApplication.getClass().getMethod(
					registrationMethodName, handlerClass);
			method.invoke(macOSXApplication, proxy);
		} catch (Throwable t) {
			System.err.println("Unable to register event handler: "
					+ handlerClassName);
			t.printStackTrace();
		}
	}

	/**
	 * Utility method for enabling full-screen mode for the specified window.
	 * 
	 * @param window
	 *            the reference to the window object
	 */
	public static void enableFullScreenMode(Window window) {
		if (macOSXApplication == null) {
			return;
		}
		try {
			Class<?> c = Class.forName("com.apple.eawt.FullScreenUtilities");
			Method method = c.getMethod("setWindowCanFullScreen", new Class[] {
					Window.class, boolean.class });
			method.invoke(null, window, true);
		} catch (Throwable t) {
			System.err.println("Unable to set fullscreen mode for window");
			t.printStackTrace();
		}
	}

	/**
	 * Sets the dock icon for the application.
	 */
	private static void handleDockIcon() {
		try {
			Method method = macOSXApplication.getClass().getMethod(
					"setDockIconImage", Image.class);
			Image image = Toolkit.getDefaultToolkit().getImage(
					JFTP.class.getResource("jftp128.gif"));
			method.invoke(macOSXApplication, new Object[] { image });
		} catch (Throwable t) {
			System.err.println("Unable to set the dock icon");
			t.printStackTrace();
		}
	}

	/**
	 * Reflectively gets a reference to the Mac OS X Application object and
	 * assigns it to the class variable for later use.
	 */
	private static void createMacOSXApplication() {
		String applicationClassName = "com.apple.eawt.Application";
		try {
			Class<?> applicationClass = Class.forName(applicationClassName);
			Method method = applicationClass.getMethod("getApplication");
			macOSXApplication = method.invoke(null);
		} catch (Throwable exp) {
			System.err.println("Unable to get a reference to: "
					+ applicationClassName);
			exp.printStackTrace();
		}
	}

}