Module java.desktop
Package java.awt

Class Component.BltBufferStrategy

  • Enclosing class:
    Component
    protected class Component.BltBufferStrategy
extends BufferStrategy
    Inner class for blitting offscreen surfaces to a component.
    Since:
    1.4

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected VolatileImage[] backBuffers
      The back buffers
      protected BufferCapabilities caps
      The buffering capabilities
      protected int height
      Height of the back buffers
      protected boolean validatedContents
      Whether or not the drawing buffer has been recently restored from a lost state.
      protected int width
      Width of the back buffers

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected BltBufferStrategy​(int numBuffers, BufferCapabilities caps)
      Creates a new blt buffer strategy around a component

    • Method Summary

      Modifier and Type Method Description
      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
      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.
      protected void revalidate()
      Restore the drawing buffer if it has been lost
      void show()
      Makes the next available buffer visible.

    • Field Detail

      • 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
        Width of the back buffers

      • height

        protected int height
        Height of the back buffers

    • Constructor Detail

      • BltBufferStrategy

        protected 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

    • Method Detail

      • createBackBuffers

        protected void createBackBuffers​(int numBuffers)
        Creates the back buffers
        Parameters:
        numBuffers - the number of buffers to create

      • 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 draw graphics

      • 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