Make a splash with Swing - JavaWorld Tip
104
Tutorial Details:
Java Tip 104: Make a splash with Swing
Java Tip 104: Make a splash with Swing
By: By Tony Colston
Create thread-safe splash screens using Swing
lmost all modern applications have a splash screen. Using a splash screen is a way to advertise your product. It is also used to indicate to the user that something is happening in your application during long startup times. Current literature explains how to create a splash screen but does not show how to integrate one into your application (see books by David Geary ). Users can quickly remove some splash screens by simply clicking anywhere on them. Some splash screens stay visible only until the application is loaded. Other splash screens are visible even after the user has started the application.
Wouldn't you like to be able to do all those things in Java? By using Swing with threads, you can!
Here is a first swing (no pun intended) at a class for a splash screen created for use in an application:
class SplashWindow1 extends JWindow
{
public SplashWindow1(String filename, Frame f)
{
super(f);
JLabel l = new JLabel(new ImageIcon(filename));
getContentPane().add(l, BorderLayout.CENTER);
pack();
Dimension screenSize =
Toolkit.getDefaultToolkit().getScreenSize();
Dimension labelSize = l.getPreferredSize();
setLocation(screenSize.width/2 - (labelSize.width/2),
screenSize.height/2 - (labelSize.height/2));
setVisible(true);
screenSize = null;
labelSize = null;
}
}
The SplashWindow1 class extends Swing's JWindow . JWindow is a heavyweight container. It also has none of the normal items that appear in other windows, such as a title bar, window management buttons, or even a visible frame edge. Therefore, JWindow is perfect for a splash screen. The code above assumes an image file is located in the current directory. Once the image is loaded by way of the ImageIcon , the image is placed in the center of the JWindow . The JWindow is packed to let Swing resize the window correctly, and then it is moved to the center of the screen and set visible. You can find a similar version of that code in the reference material in Resources .
If you were to actually run the above code, you would unfortunately have a nicely centered splash screen that will not close! To make it close, you must add code:
class SplashWindow2 extends JWindow
{
public SplashWindow2(String filename, Frame f)
{
super(f);
JLabel l = new JLabel(new ImageIcon(filename));
getContentPane().add(l, BorderLayout.CENTER);
pack();
Dimension screenSize =
Toolkit.getDefaultToolkit().getScreenSize();
Dimension labelSize = l.getPreferredSize();
setLocation(screenSize.width/2 - (labelSize.width/2),
screenSize.height/2 - (labelSize.height/2));
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
setVisible(false);
dispose();
}
});
setVisible(true);
}
}
The only difference in that version of the SplashWindow class is that there is now an anonymous MouseListener installed on the JWindow . That will allow the user to click on the splash screen to make it disappear.
At that point, you will have a nice splash screen that can be removed but will not disappear on its own. You will then have to add code to remove the splash screen after a certain amount of time. Then you should be thinking threads. And if you've worked with Swing at all, you know that making threaded calls can be tricky at best. For reasons why and a more in-depth explanation of threads and Swing, see Resources .
class SplashWindow3 extends JWindow
{
public SplashWindow3(String filename, Frame f, int waitTime)
{
super(f);
JLabel l = new JLabel(new ImageIcon(filename));
getContentPane().add(l, BorderLayout.CENTER);
pack();
Dimension screenSize =
Toolkit.getDefaultToolkit().getScreenSize();
Dimension labelSize = l.getPreferredSize();
setLocation(screenSize.width/2 - (labelSize.width/2),
screenSize.height/2 - (labelSize.height/2));
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
setVisible(false);
dispose();
}
});
final int pause = waitTime;
final Runnable closerRunner = new Runnable()
{
public void run()
{
setVisible(false);
dispose();
}
};
Runnable waitRunner = new Runnable()
{
public void run()
{
try
{
Thread.sleep(pause);
SwingUtilities.invokeAndWait(closerRunner);
}
catch(Exception e)
{
e.printStackTrace();
// can catch InvocationTargetException
// can catch InterruptedException
}
}
};
setVisible(true);
Thread splashThread = new Thread(waitRunner, "SplashThread");
splashThread.start();
}
}
The general idea here is to first create a Thread object that will pause for a specific amount of time. In the above code, the thread will pause for four seconds. When that thread wakes up, it will close the splash screen. Since Swing is not thread-safe, you should not affect the state of any UI component unless the code is being executed on the event-dispatching thread. The event-dispatching thread is the thread that handles drawing and event handling in Swing.
To get around that limitation, Swing designers gave the programmer the ability to add runnable objects to the UI event queue in a safe manner. In this case, you are going to use the runnable object's closeRunner to do the dirty work. You pass the runnable object to the static method SwingUtilities.invokeAndWait() . Then SwingUtilities.invokeAndWait() will execute all pending UI activity and execute the run method on the runnable object closeRunner , which is passed to the method. By using a separate thread to handle the splash screen's closing, the application that is displayed behind the splash screen is visible and responsive during the entire operation.
If you want a splash screen that is always visible and that the user cannot remove, you must remove the code that hides the splash screen. If you want a splash screen that the user must close manually, you can call the setVisible(false) and dispose() methods on the SplashWindow3 object just like any other JWindow .
Conclusion
By using the SwingUtilities.invokeAndWait() method, you can safely create a multithreaded Swing splash screen. A user can click on the splash screen to remove it, or the splash screen will disappear on its own after a set amount of time. The threading model that Swing supports will allow the application to remain responsive and usable behind the splash screen.
This page formated for crawlers and browsers that don't support scripts and tables.
Home
EZone
Read
Tutorial at: Click here to view the tutorial
Rate Tutorial: Make a splash with Swing - JavaWorld Tip
104
View Tutorial: Make a splash with Swing - JavaWorld Tip
104
Related
Tutorials:
 Reloading Applets
Reloading Applets
|
Applet to Applet
Communication
Applet to Applet
Communication
|
Java Tip 72: Press
Escape to close your Swing dialog windows
Java Tip 72: Press
Escape to close your Swing dialog windows
|
Implement a J2EE-aware application console in Swing
Implement a J2EE-aware application console in Swing
|
Eclipse casts shadows
Eclipse casts shadows
|
Profiling the
profilers
Profiling the
profilers
|
Worth
reading
Worth
reading
|
Interesting
...
Interesting
...
|
Filtering and Transforming Digital Images
Filtering and Transforming Digital Images
In this Issue
Welcome to the Core Java Technologies Tech Tips for April 7, 2004. Here you\'ll get tips on using core Java technologies and APIs, such as those in Java 2 Platform, Standard Edition (J2SE).
|
WebOnSwing 1.0 beta
WebOnSwing 1.0 beta
WebOnSwing is a revolutionary multiple environment application framework that allows you to create web applications in the same way you develope a desktop one. You dont need to use JSP files, special tags, XML files, requests, posts
|
Data Models for Desktop Apps
Data Models for Desktop Apps
This is the third article in a series that presents the prototype of a Java desktop application called JImaging. The first article described the three major Java GUI toolkits: AWT, Swing, and SWT. In the second article, I int
|
Developing Swing Components Using Simulators
Developing Swing Components Using Simulators
In this article, you'll learn about a technique for developing encapsulated components. You'll also learn about how to test graphical parts of your application that JUnit can't, such as layouts and other visua
|
JDemo
JDemo is the Java demonstration framework. Its concept is similar to the one of JUnit.
As supplement to test driven software development, JDemo provides a new approach of demo driven development: When developing software, you write short code snippets (
|
G (2D graphic library)
G is a generic graphics library built on top of Java 2D in order to make scene graph oriented 2D graphics available to client applications in a high level, easy to use way
|
Wi.Ser (WidgetServer) unified rich client framework
Wi.Ser is a Java/XML server-side GUI-framework which enables an application to run as either a monolithic Swing application, a thin-client/server Swing application, or as a Web application without any change!
|
InfoNode (Java Components)
InfoNode Docking Windows is a pure Java Swing based docking windows framework. The best way to see features of InfoNode Docking Windows is to try the Web Start demos.
|
Ease Swing development with the TableModel Free framework
This article introduces the TableModel Free (TMF) framework which eliminates the need to use TableModels with Swing JTables. The TMF framework allows for more configurable JTables by moving all of table-specific data outside of the compiled code and into
|
Getting Started With Bluetooth
JSR-82 brings Bluetooth API's to the J2ME environment. Read the tech tip and begin experimenting with Bluetooth today using the Wireless Toolkit 2.2 Beta.
|
Writing a Custom Counter Component
MIDP 2.0 introduced the javax.microedition.lcdui.CustomItem class. As the name implies, a developer can now create custom UI components by extending the CustomItem class. This tech tip designs and implements a UI component for displaying a numeric counter
|
Sanssouci is a Java framework for autogenerating fancy Swing-GUIs via introspection.
Sanssouci is a Java framework for autogenerating fancy Swing-GUIs via introspection which display objects directly to the user
|
|
|
|
