Java Module java.desktop Package java.awt Class Component.FlipBufferStrategy（JDK11）

Field Detail

• numBuffers

  protected int numBuffers

  The number of buffers

• caps

  protected BufferCapabilities caps

  The buffering capabilities

• drawBuffer

  protected Image drawBuffer

  The drawing buffer

• drawVBuffer

  protected VolatileImage drawVBuffer

  The drawing buffer as a volatile image

• validatedContents

  protected boolean validatedContents

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

Constructor Detail

• FlipBufferStrategy

  protected FlipBufferStrategy​(int numBuffers,
                               BufferCapabilities caps)
                        throws AWTException

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

  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.

  IllegalStateException - if the component has no peer

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

  See Also:

  Canvas, Window, Applet, createBuffers(int, BufferCapabilities)

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:

  BufferCapabilities.isPageFlipping()

• getBackBuffer

  protected Image getBackBuffer()

  Returns:

  direct access to the back buffer, as an image.

  Throws:

  IllegalStateException - if the buffers have not yet been created

• 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:

  BufferCapabilities.getFlipContents()

• destroyBuffers

  protected void destroyBuffers()

  Destroys the buffers created through this object

• 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 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.

• 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

• show

  public void show()

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

  Specified by:

  show in class BufferStrategy

• 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:

  Window.createBufferStrategy(int), Canvas.createBufferStrategy(int), Window.getBufferStrategy(), Canvas.getBufferStrategy()