protected class

Component.BltBufferStrategy

extends BufferStrategy
java.lang.Object
   ↳ java.awt.image.BufferStrategy
     ↳ java.awt.Component.BltBufferStrategy

Class Overview

Inner class for blitting offscreen surfaces to a component.

Summary

Fields
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
Protected Constructors
Component.BltBufferStrategy(int numBuffers, BufferCapabilities caps)
Creates a new blt buffer strategy around a component
Public Methods
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).
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.
void show()
Makes the next available buffer visible.
Protected Methods
void createBackBuffers(int numBuffers)
Creates the back buffers
void revalidate()
Restore the drawing buffer if it has been lost
[Expand]
Inherited Methods
From class java.awt.image.BufferStrategy
From class java.lang.Object

Fields

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

Protected Constructors

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

Public Methods

public boolean contentsLost ()

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.

Returns
  • whether the drawing buffer was lost since the last call to getDrawGraphics

public boolean contentsRestored ()

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.

Returns
  • whether the drawing buffer was recently restored from a lost state and reinitialized to the default background color (white)

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.

public BufferCapabilities getCapabilities ()

Returns the BufferCapabilities for this BufferStrategy.

Returns
  • the buffering capabilities of this strategy

public Graphics getDrawGraphics ()

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.

Returns
  • the draw graphics

public void show ()

Makes the next available buffer visible.

Protected Methods

protected void createBackBuffers (int numBuffers)

Creates the back buffers

protected void revalidate ()

Restore the drawing buffer if it has been lost