java.awt
Class Component.BltBufferStrategy

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

protected class Component.BltBufferStrategy
extends BufferStrategy

Inner class for blitting offscreen surfaces to a component.

Since:
1.4
Author:
Michael Martak

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
(package private)  Image getBackBuffer()
           
 BufferCapabilities getCapabilities()
           
 Graphics getDrawGraphics()
           
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 - the component to use as the front buffer
caps - the capabilities of the buffers
Method Detail

createBackBuffers

protected void createBackBuffers(int numBuffers)
Creates the back buffers


getCapabilities

public BufferCapabilities getCapabilities()
Specified by:
getCapabilities in class BufferStrategy
Returns:
the buffering capabilities of this strategy

getDrawGraphics

public Graphics getDrawGraphics()
Specified by:
getDrawGraphics in class BufferStrategy
Returns:
the draw graphics

getBackBuffer

Image getBackBuffer()
Returns:
direct access to the back buffer, as an image. If there is no back buffer, returns null.

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