org.bidib.wizard.splash.SplashWindow Maven / Gradle / Ivy
package org.bidib.wizard.splash;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.net.URL;
/**
* 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
*/
public class SplashWindow extends Window {
/**
* serial version uid
*/
private static final long serialVersionUID = 1L;
/**
* 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;
/**
* version info
*/
private String _versionInfo = "development private build";
/**
* version font
*/
private Font _versionFont = new Font("Arial", Font.PLAIN, 9);
/**
* 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;
String buildInfo = SplashWindow.class.getPackage().getImplementationVersion();
if (buildInfo != null) {
_versionInfo = buildInfo;
}
// Load the image
MediaTracker mt = new MediaTracker(this);
mt.addImage(image, 0);
try {
mt.waitForID(0);
}
catch (InterruptedException ie) {
}
// 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) {
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(image, 0, 0, this);
if (_versionInfo != null) {
g2d.setFont(_versionFont);
FontMetrics metrics = g2d.getFontMetrics();
int width = metrics.stringWidth(_versionInfo);
g2d.drawString(_versionInfo, 325 - width, 145);
}
// 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.setVisible(true);
// 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;
}
}
}
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