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SplashScreen (Java Platform SE 6) - JDK 5 Documentation v6.0, Java 2 SDK 英文文档


Java™ Platform
Standard Ed. 6

java.awt
Class SplashScreen

java.lang.Object
  extended by java.awt.SplashScreen

public final class SplashScreen
extends Object

The splash screen can be created at application startup, before the Java Virtual Machine (JVM) starts. The splash screen is displayed as an undecorated window containing an image. You can use GIF, JPEG, and PNG files for the image. Animation (for GIF) and transparency (for GIF, PNG) are supported. The window is positioned at the center of the screen (the position on multi-monitor systems is not specified - it is platform and implementation dependent). The window is closed automatically as soon as the first window is displayed by Swing/AWT (may be also closed manually using the Java API, see below).

There are two ways to show the native splash screen:

The SplashScreen class provides the API for controlling the splash screen. This class may be used to close the splash screen, change the splash screen image, get the image position/size and paint in the splash screen. It cannot be used to create the splash screen; you should use the command line or manifest file option for that.

This class cannot be instantiated. Only a single instance of this class can exist, and it may be obtained using the getSplashScreen() static method. In case the splash screen has not been created at application startup via the command line or manifest file option, the getSplashScreen method returns null.

Since:
1.6

Method Summary
 void close()
          Hides the splash screen, closes the window, and releases all associated resources.
 Graphics2D createGraphics()
          Creates a graphics context (as a Graphics2D object) for the splash screen overlay image, which allows you to draw over the splash screen.
 Rectangle getBounds()
          Returns the bounds of the splash screen window as a Rectangle.
 URL getImageURL()
          Returns the current splash screen image.
 Dimension getSize()
          Returns the size of the splash screen window as a Dimension.
static SplashScreen getSplashScreen()
          Returns the SplashScreen object used for Java startup splash screen control.
 boolean isVisible()
          Determines whether the splash screen is visible.
 void setImageURL(URL imageURL)
          Changes the splash screen image.
 void update()
          Updates the splash window with current contents of the overlay image.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

getSplashScreen

public static SplashScreen getSplashScreen()
Returns the SplashScreen object used for Java startup splash screen control.

Returns:
the SplashScreen instance, or null if there is none or it has already been closed
Throws:
UnsupportedOperationException - if the splash screen feature is not supported by the current toolkit
HeadlessException - if GraphicsEnvironment.isHeadless() returns true

setImageURL

public void setImageURL(URL imageURL)
                 throws NullPointerException,
                        IOException,
                        IllegalStateException
Changes the splash screen image. The new image is loaded from the specified URL; GIF, JPEG and PNG image formats are supported. The method returns after the image has finished loading and the window has been updated. The splash screen window is resized according to the size of the image and is centered on the screen.

Parameters:
imageURL - the non-null URL for the new splash screen image
Throws:
NullPointerException - if imageURL is null
IOException - if there was an error while loading the image
IllegalStateException - if the splash screen has already been closed

getImageURL

public URL getImageURL()
                throws IllegalStateException
Returns the current splash screen image.

Returns:
URL for the current splash screen image file
Throws:
IllegalStateException - if the splash screen has already been closed

getBounds

public Rectangle getBounds()
                    throws IllegalStateException
Returns the bounds of the splash screen window as a Rectangle. This may be useful if, for example, you want to replace the splash screen with your window at the same location.

You cannot control the size or position of the splash screen. The splash screen size is adjusted automatically when the image changes.

Returns:
a Rectangle containing the splash screen bounds
Throws:
IllegalStateException - if the splash screen has already been closed

getSize

public Dimension getSize()
                  throws IllegalStateException
Returns the size of the splash screen window as a Dimension. This may be useful if, for example, you want to draw on the splash screen overlay surface.

You cannot control the size or position of the splash screen. The splash screen size is adjusted automatically when the image changes.

Returns:
a Dimension object indicating the splash screen size
Throws:
IllegalStateException - if the splash screen has already been closed

createGraphics

public Graphics2D createGraphics()
                          throws IllegalStateException
Creates a graphics context (as a Graphics2D object) for the splash screen overlay image, which allows you to draw over the splash screen. Note that you do not draw on the main image but on the image that is displayed over the main image using alpha blending. Also note that drawing on the overlay image does not necessarily update the contents of splash screen window. You should call update() on the SplashScreen when you want the splash screen to be updated immediately.

Returns:
graphics context for the splash screen overlay surface
Throws:
IllegalStateException - if the splash screen has already been closed

update

public void update()
            throws IllegalStateException
Updates the splash window with current contents of the overlay image.

Throws:
IllegalStateException - if the overlay image does not exist; for example, if createGraphics has never been called, or if the splash screen has already been closed

close

public void close()
           throws IllegalStateException
Hides the splash screen, closes the window, and releases all associated resources.

Throws:
IllegalStateException - if the splash screen has already been closed

isVisible

public boolean isVisible()
Determines whether the splash screen is visible. The splash screen may be hidden using close(), it is also hidden automatically when the first AWT/Swing window is made visible.

Returns:
true if the splash screen is visible (has not been closed yet), false otherwise

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2006 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.