java.awt
Class Component.BltBufferStrategy

java.lang.Object
  java.awt.image.BufferStrategy
      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

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