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


Java™ Platform
Standard Ed. 6

java.awt
Class Component.BltBufferStrategy

java.lang.Object
  extended by java.awt.image.BufferStrategy
      extended by java.awt.Component.BltBufferStrategy
Enclosing class:
Component

protected class Component.BltBufferStrategy
extends BufferStrategy

Inner class for blitting offscreen surfaces to a component.

Since:
1.4

Field Summary
protected  VolatileImage[] backBuffers
          The back buffers
protected  BufferCapabilities caps
          The buffering capabilities
protected  int height
           
protected  boolean validatedContents
          Whether or not the drawing buffer has been recently restored from a lost state.
protected  int width
          Size of the back buffers
 
Constructor Summary
protected Component.BltBufferStrategy(int numBuffers, BufferCapabilities caps)
          Creates a new blt buffer strategy around a component
 
Method Summary
 boolean contentsLost()
          Returns whether the drawing buffer was lost since the last call to getDrawGraphics.
 boolean contentsRestored()
          Returns whether the drawing buffer was recently restored from a lost state and reinitialized to the default background color (white).
protected  void createBackBuffers(int numBuffers)
          Creates the back buffers
 void dispose()
          Releases system resources currently consumed by this BufferStrategy and removes it from the associated Component.
 BufferCapabilities getCapabilities()
          Returns the BufferCapabilities for this BufferStrategy.
 Graphics getDrawGraphics()
          Creates a graphics context for the drawing buffer.
protected  void revalidate()
          Restore the drawing buffer if it has been lost
 void show()
          Makes the next available buffer visible.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

caps

protected BufferCapabilities caps
The buffering capabilities


backBuffers

protected VolatileImage[] backBuffers
The back buffers


validatedContents

protected boolean validatedContents
Whether or not the drawing buffer has been recently restored from a lost state.


width

protected int width
Size of the back buffers


height

protected int height
Constructor Detail

Component.BltBufferStrategy

protected Component.BltBufferStrategy(int numBuffers,
                                      BufferCapabilities caps)
Creates a new blt buffer strategy around a component

Parameters:
numBuffers - number of buffers to create, including the front buffer
caps - the capabilities of the buffers
Method Detail

dispose

public void dispose()
Releases system resources currently consumed by this BufferStrategy and removes it from the associated Component. After invoking this method, getBufferStrategy will return null. Trying to use a BufferStrategy after it has been disposed will result in undefined behavior.

Overrides:
dispose in class BufferStrategy
Since:
1.6
See Also:
Component.createBufferStrategy(int), Component.getBufferStrategy()

createBackBuffers

protected void createBackBuffers(int numBuffers)
Creates the back buffers


getCapabilities

public BufferCapabilities getCapabilities()
Description copied from class: BufferStrategy
Returns the BufferCapabilities for this BufferStrategy.

Specified by:
getCapabilities in class BufferStrategy
Returns:
the buffering capabilities of this strategy

getDrawGraphics

public Graphics getDrawGraphics()
Description copied from class: BufferStrategy
Creates a graphics context for the drawing buffer. This method may not be synchronized for performance reasons; use of this method by multiple threads should be handled at the application level. Disposal of the graphics object obtained must be handled by the application.

Specified by:
getDrawGraphics in class BufferStrategy
Returns:
the draw graphics

show

public void show()
Makes the next available buffer visible.

Specified by:
show in class BufferStrategy

revalidate

protected void revalidate()
Restore the drawing buffer if it has been lost


contentsLost

public boolean contentsLost()
Description copied from class: BufferStrategy
Returns whether the drawing buffer was lost since the last call to getDrawGraphics. Since the buffers in a buffer strategy are usually type VolatileImage, they may become lost. For a discussion on lost buffers, see VolatileImage.

Specified by:
contentsLost in class BufferStrategy
Returns:
whether the drawing buffer was lost since the last call to getDrawGraphics
See Also:
VolatileImage

contentsRestored

public boolean contentsRestored()
Description copied from class: BufferStrategy
Returns whether the drawing buffer was recently restored from a lost state and reinitialized to the default background color (white). Since the buffers in a buffer strategy are usually type VolatileImage, they may become lost. If a surface has been recently restored from a lost state since the last call to getDrawGraphics, it may require repainting. For a discussion on lost buffers, see VolatileImage.

Specified by:
contentsRestored in class BufferStrategy
Returns:
whether the drawing buffer was recently restored from a lost state and reinitialized to the default background color (white)
See Also:
VolatileImage

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.