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# Class jclass.bwt.JCBufferedComponent

    java.lang.Object
       |
       +----java.awt.Component
               |
               +----java.awt.Canvas
                       |
                       +----jclass.bwt.JCComponent
                               |
                               +----jclass.bwt.JCBufferedComponent

public abstract class JCBufferedComponent
extends JCComponent

An abstract class which supports components with complex drawing that must be permanently double-buffered. The subclass' paintComponent() method is only called when the component is invalidated (e.g. resized). Otherwise the previously drawn off-screen image is used for repainting.

##

JCBufferedComponent()
  Creates a component.
JCBufferedComponent(Applet, String)
  Creates a component which reads parameters from the applet's HTML file.

##

getDoubleBufferGraphics()
  Creates a double-buffer image
getDoubleBufferImage()
  Returns the double-buffer image previously created in a call to getDoubleBufferGraphics.
invalidate()
  Nulls out the offscreen buffer as part of invalidation
paint(Graphics)
  An internal method used to handle repaint events.
reshape(int, int, int, int)
  Reshapes the Component to the specified bounding box.
setDoubleBuffer(boolean)
  Must be double-buffered.

##

JCBufferedComponent

     public JCBufferedComponent()

  Creates a component. No parameters are read from an HTML file.

JCBufferedComponent

     public JCBufferedComponent(Applet applet,
                                String name)

  Creates a component which reads parameters from the applet's HTML file.

  Parameters:
    applet - the applet whose PARAM tags are to be read
    name - if this is not null, only parameters preceded by this name are read
  See Also:
    getParameter

##

setDoubleBuffer

     public void setDoubleBuffer(boolean v)

  Must be double-buffered.

  Overrides:
    setDoubleBuffer in class JCComponent

invalidate

     public void invalidate()

  Nulls out the offscreen buffer as part of invalidation

  Overrides:
    invalidate in class Component

getDoubleBufferImage

     public Image getDoubleBufferImage()

  Returns the double-buffer image previously created in a call to getDoubleBufferGraphics.

  Overrides:
    getDoubleBufferImage in class JCComponent

reshape

     public void reshape(int x,
                         int y,
                         int width,
                         int height)

  Reshapes the Component to the specified bounding box.

  Overrides:
    reshape in class JCComponent

getDoubleBufferGraphics

     public synchronized Graphics getDoubleBufferGraphics()

  Creates a double-buffer image

  Overrides:
    getDoubleBufferGraphics in class JCComponent

paint

     public void paint(Graphics gc)

  An internal method used to handle repaint events.

  Overrides:
    paint in class JCComponent

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