/*
* @(#)SplashWindow.java 2.2.1 2006-05-27
*
* Copyright (c) 2003-2010 Werner Randelshofer
* Hausmatt 10, Immensee, CH-6405, Switzerland.
*
* This software is in the public domain.
* You are free to use, adapt, copy and license this work
* without having to attribute to Werner Randelshofer.
*/
import java.awt.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
/**
* A Splash window.
*
* Usage: MyApplication is your application class. Create a Splasher class which
* opens the splash window, invokes the main method of your Application class,
* and disposes the splash window afterwards.
* Please note that we want to keep the Splasher class and the SplashWindow class
* as small as possible. The less code and the less classes must be loaded into
* the JVM to open the splash screen, the faster it will appear.
*
* class Splasher {
* public static void main(String[] args) {
* SplashWindow.splash(Startup.class.getResource("splash.gif"));
* MyApplication.main(args);
* SplashWindow.disposeSplash();
* }
* }
*
*
* @author Werner Randelshofer
* @version 2.2.1 2006-05-27 Abort when splash image can not be loaded.
*/
public class SplashWindow extends Window {
/**
* The current instance of the splash window.
* (Singleton design pattern).
*/
private static SplashWindow instance;
/**
* The splash image which is displayed on the splash window.
*/
private Image image;
/**
* This attribute indicates whether the method
* paint(Graphics) has been called at least once since the
* construction of this window.
* This attribute is used to notify method splash(Image)
* that the window has been drawn at least once
* by the AWT event dispatcher thread.
* This attribute acts like a latch. Once set to true,
* it will never be changed back to false again.
*
* @see #paint
* @see #splash
*/
private boolean paintCalled = false;
/**
* Creates a new instance.
* @param parent the parent of the window.
* @param image the splash image.
*/
private SplashWindow(Frame parent, Image image) {
super(parent);
this.image = image;
// Load the image
MediaTracker mt = new MediaTracker(this);
mt.addImage(image,0);
try {
mt.waitForID(0);
} catch(InterruptedException ie){}
// Abort on failure
if (mt.isErrorID(0)) {
setSize(0,0);
System.err.println("Warning: SplashWindow couldn't load splash image.");
synchronized(this) {
paintCalled = true;
notifyAll();
}
return;
}
// Center the window on the screen
int imgWidth = image.getWidth(this);
int imgHeight = image.getHeight(this);
setSize(imgWidth, imgHeight);
Dimension screenDim = Toolkit.getDefaultToolkit().getScreenSize();
setLocation(
(screenDim.width - imgWidth) / 2,
(screenDim.height - imgHeight) / 2
);
// Users shall be able to close the splash window by
// clicking on its display area. This mouse listener
// listens for mouse clicks and disposes the splash window.
MouseAdapter disposeOnClick = new MouseAdapter() {
public void mouseClicked(MouseEvent evt) {
// Note: To avoid that method splash hangs, we
// must set paintCalled to true and call notifyAll.
// This is necessary because the mouse click may
// occur before the contents of the window
// has been painted.
synchronized(SplashWindow.this) {
SplashWindow.this.paintCalled = true;
SplashWindow.this.notifyAll();
}
dispose();
}
};
addMouseListener(disposeOnClick);
}
/**
* Updates the display area of the window.
*/
public void update(Graphics g) {
// Note: Since the paint method is going to draw an
// image that covers the complete area of the component we
// do not fill the component with its background color
// here. This avoids flickering.
paint(g);
}
/**
* Paints the image on the window.
*/
public void paint(Graphics g) {
g.drawImage(image, 0, 0, this);
// Notify method splash that the window
// has been painted.
// Note: To improve performance we do not enter
// the synchronized block unless we have to.
if (! paintCalled) {
paintCalled = true;
synchronized (this) { notifyAll(); }
}
}
/**
* Open's a splash window using the specified image.
* @param image The splash image.
*/
public static void splash(Image image) {
if (instance == null && image != null) {
Frame f = new Frame();
// Create the splash image
instance = new SplashWindow(f, image);
// Show the window.
instance.show();
// Note: To make sure the user gets a chance to see the
// splash window we wait until its paint method has been
// called at least once by the AWT event dispatcher thread.
// If more than one processor is available, we don't wait,
// and maximize CPU throughput instead.
if (! EventQueue.isDispatchThread()
&& Runtime.getRuntime().availableProcessors() == 1) {
synchronized (instance) {
while (! instance.paintCalled) {
try { instance.wait(); } catch (InterruptedException e) {}
}
}
}
}
}
/**
* Open's a splash window using the specified image.
* @param imageURL The url of the splash image.
*/
public static void splash(URL imageURL) {
if (imageURL != null) {
splash(Toolkit.getDefaultToolkit().createImage(imageURL));
}
}
/**
* Closes the splash window.
*/
public static void disposeSplash() {
if (instance != null) {
instance.getOwner().dispose();
instance = null;
}
}
/**
* Invokes the main method of the provided class name.
* @param args the command line arguments
*/
public static void invokeMain(String className, String[] args) {
try {
Class.forName(className)
.getMethod("main", new Class[] {String[].class})
.invoke(null, new Object[] {args});
} catch (Exception e) {
InternalError error = new InternalError("Failed to invoke main method");
error.initCause(e);
throw error;
}
}
}