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Component.FlipBufferStrategy (Java 2 Platform SE v1.4.1) - JDK 5 Documentation v1.4.1, Java 2 SDK 英文文档

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java.awt
Class Component.FlipBufferStrategy

java.lang.Object
  |
  +--java.awt.image.BufferStrategy
        |
        +--java.awt.Component.FlipBufferStrategy

Enclosing class:

Component

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protected class Component.FlipBufferStrategy

extends BufferStrategy

Inner class for flipping buffers on a component. That component must be a Canvas or Window.

Since:

1.4

See Also:

Canvas, Window, BufferStrategy

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Field Summary
protected  BufferCapabilities	caps           The buffering capabilities
protected  Image	drawBuffer           The drawing buffer
protected  VolatileImage	drawVBuffer           The drawing buffer as a volatile image
protected  int	numBuffers           The number of buffers
protected  boolean	validatedContents           Whether or not the drawing buffer has been recently restored from a lost state.

 

Constructor Summary
protected	Component.FlipBufferStrategy(int numBuffers, BufferCapabilities caps)           Creates a new flipping buffer strategy for this 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	createBuffers(int numBuffers, BufferCapabilities caps)           Creates one or more complex, flipping buffers with the given capabilities.
protected  void	destroyBuffers()           Destroys the buffers created through this object
protected  void	flip(BufferCapabilities.FlipContents flipAction)           Flipping moves the contents of the back buffer to the front buffer, either by copying or by moving the video pointer.
protected  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 by either blitting or flipping.

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Field Detail

numBuffers

protected int numBuffers

The number of buffers

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caps

protected BufferCapabilities caps

The buffering capabilities

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drawBuffer

protected Image drawBuffer

The drawing buffer

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drawVBuffer

protected VolatileImage drawVBuffer

The drawing buffer as a volatile image

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validatedContents

protected boolean validatedContents

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

Constructor Detail

Component.FlipBufferStrategy

protected Component.FlipBufferStrategy(int numBuffers,
                                       BufferCapabilities caps)
                                throws AWTException

Creates a new flipping buffer strategy for this component. The component must be a Canvas or Window.

Parameters:

numBuffers - the number of buffers

caps - the capabilities of the buffers

Throws:

AWTException - if the capabilities supplied could not be supported or met

ClassCastException - if the component is not a canvas or window.

See Also:

Canvas, Window

Method Detail

createBuffers

protected void createBuffers(int numBuffers,
                             BufferCapabilities caps)
                      throws AWTException

Creates one or more complex, flipping buffers with the given capabilities.

Parameters:

numBuffers - number of buffers to create; must be greater than one

caps - the capabilities of the buffers. BufferCapabilities.isPageFlipping must be true.

Throws:

AWTException - if the capabilities supplied could not be supported or met

IllegalStateException - if the component has no peer

IllegalArgumentException - if numBuffers is less than two, or if BufferCapabilities.isPageFlipping is not true.

See Also:

java.awt.image.BufferCapabilities#isPageFlipping

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getBackBuffer

protected Image getBackBuffer()

Throws:

IllegalStateException - if the buffers have not yet been created

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flip

protected void flip(BufferCapabilities.FlipContents flipAction)

Flipping moves the contents of the back buffer to the front buffer, either by copying or by moving the video pointer.

Parameters:

flipAction - an integer value describing the flipping action for the contents of the back buffer. This should be one of the values of the BufferCapabilities.FlipContents property.

Throws:

IllegalStateException - if the buffers have not yet been created

See Also:

java.awt.image.BufferCapabilities#FlipContents

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destroyBuffers

protected void destroyBuffers()

Destroys the buffers created through this object

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getCapabilities

public BufferCapabilities getCapabilities()

Specified by:

getCapabilities in class BufferStrategy

Returns:

the buffering capabilities of this strategy

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getDrawGraphics

public Graphics getDrawGraphics()

Specified by:

getDrawGraphics in class BufferStrategy

Returns:

the graphics on 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 must be handled by the application.

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revalidate

protected void revalidate()

Restore the drawing buffer if it has been lost

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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

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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

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show

public void show()

Makes the next available buffer visible by either blitting or flipping.

Specified by:

show in class BufferStrategy

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.