Class Component.FlipBufferStrategy
- java.lang.Object
-
- java.awt.image.BufferStrategy
-
- java.awt.Component.FlipBufferStrategy
- Enclosing class:
- Component
protected class Component.FlipBufferStrategy extends BufferStrategy
Inner class for flipping buffers on a component. That component must be a Canvas
or Window
or Applet
.
- Since:
- 1.4
- See Also:
-
Canvas
,Window
,Applet
,BufferStrategy
Field Summary
Modifier and Type | Field | Description |
---|---|---|
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
Modifier | Constructor | Description |
---|---|---|
protected | FlipBufferStrategy(int numBuffers,
BufferCapabilities caps) | Creates a new flipping buffer strategy for this component. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
boolean | contentsLost() | Returns whether the drawing buffer was lost since the last call to |
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 |
void | dispose() | Releases system resources currently consumed by this |
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() | Returns the |
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 by either blitting or flipping. |
Methods declared in 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
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
- ifnumBuffers
is less than two, or ifBufferCapabilities.isPageFlipping
is nottrue
. - 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 betrue
. - 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 ifBufferCapabilities.isPageFlipping
is nottrue
. - 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 theBufferCapabilities.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 classBufferStrategy
- 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 classBufferStrategy
- 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 classBufferStrategy
- 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 classBufferStrategy
- 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 classBufferStrategy
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 classBufferStrategy
- Since:
- 1.6
- See Also:
-
Window.createBufferStrategy(int)
,Canvas.createBufferStrategy(int)
,Window.getBufferStrategy()
,Canvas.getBufferStrategy()