JavaTM 2 Platform
Std. Ed. v1.3

javax.swing
Class RepaintManager

java.lang.Object
  |
  +--javax.swing.RepaintManager

public class RepaintManager
extends Object

This class manages repaint requests, allowing the number of repaints to be minimized, for example by collapsing multiple requests into a single repaint for members of a component tree.


Constructor Summary
RepaintManager()
          Create a new RepaintManager instance.
 
Method Summary
 void addDirtyRegion(JComponent c, int x, int y, int w, int h)
          Add a component in the list of components that should be refreshed.
 void addInvalidComponent(JComponent invalidComponent)
          Mark the component as in need of layout and queue a runnable for the event dispatching thread that will validate the components first isValidateRoot() ancestor.
static RepaintManager currentManager(Component c)
          Return the RepaintManager for the calling thread given a Component.
static RepaintManager currentManager(JComponent c)
          Return the RepaintManager for the calling thread given a JComponent.
 Rectangle getDirtyRegion(JComponent aComponent)
          Return the current dirty region for a component.
 Dimension getDoubleBufferMaximumSize()
          Returns the maximum double buffer size.
 Image getOffscreenBuffer(Component c, int proposedWidth, int proposedHeight)
          Return the offscreen buffer that should be used as a double buffer with the component c By default there is a double buffer per RepaintManager.
 boolean isCompletelyDirty(JComponent aComponent)
          Convenience method that returns true if aComponent will be completely painted during the next paintDirtyRegions().
 boolean isDoubleBufferingEnabled()
          Returns true if this object is double buffered.
 void markCompletelyClean(JComponent aComponent)
          Mark a component completely clean.
 void markCompletelyDirty(JComponent aComponent)
          Mark a component completely dirty.
 void paintDirtyRegions()
          Paint all of the components that have been marked dirty.
 void removeInvalidComponent(JComponent component)
          Remove a component from the list of invalid components.
static void setCurrentManager(RepaintManager aRepaintManager)
          Set the RepaintManager that should be used for the calling thread.
 void setDoubleBufferingEnabled(boolean aFlag)
          Enables or disables double buffering.
 void setDoubleBufferMaximumSize(Dimension d)
          Set the maximum double buffer size.
 String toString()
          Returns a string that displays and identifies this object's properties.
 void validateInvalidComponents()
          Validate all of the components that have been marked invalid.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

RepaintManager

public RepaintManager()
Create a new RepaintManager instance. You rarely call this constructor. directly. To get the default RepaintManager, use RepaintManager.currentManager(JComponent) (normally "this").
Method Detail

currentManager

public static RepaintManager currentManager(Component c)
Return the RepaintManager for the calling thread given a Component.
Parameters:
c - a Component -- unused in the default implementation, but could be used by an overridden version to return a different RepaintManager depending on the Component
Returns:
the RepaintManager object

currentManager

public static RepaintManager currentManager(JComponent c)
Return the RepaintManager for the calling thread given a JComponent.

Note: This method exists for backward binary compatibility with earlier versions of the Swing library. It simply returns the result returned by currentManager(Component).

Parameters:
c - a JComponent -- unused
Returns:
the RepaintManager object

setCurrentManager

public static void setCurrentManager(RepaintManager aRepaintManager)
Set the RepaintManager that should be used for the calling thread. aRepaintManager will become the current RepaintManager for the calling thread's thread group.
Parameters:
aRepaintManager - the RepaintManager object to use

addInvalidComponent

public void addInvalidComponent(JComponent invalidComponent)
Mark the component as in need of layout and queue a runnable for the event dispatching thread that will validate the components first isValidateRoot() ancestor.
See Also:
JComponent.isValidateRoot(), removeInvalidComponent(javax.swing.JComponent)

removeInvalidComponent

public void removeInvalidComponent(JComponent component)
Remove a component from the list of invalid components.
See Also:
addInvalidComponent(javax.swing.JComponent)

addDirtyRegion

public void addDirtyRegion(JComponent c,
                           int x,
                           int y,
                           int w,
                           int h)
Add a component in the list of components that should be refreshed. If c already has a dirty region, the rectangle (x,y,w,h) will be unioned with the region that should be redrawn.
See Also:
JComponent.repaint(long, int, int, int, int)

getDirtyRegion

public Rectangle getDirtyRegion(JComponent aComponent)
Return the current dirty region for a component. Return an empty rectangle if the component is not dirty.

markCompletelyDirty

public void markCompletelyDirty(JComponent aComponent)
Mark a component completely dirty. aComponent will be completely painted during the next paintDirtyRegions() call.

markCompletelyClean

public void markCompletelyClean(JComponent aComponent)
Mark a component completely clean. aComponent will not get painted during the next paintDirtyRegions() call.

isCompletelyDirty

public boolean isCompletelyDirty(JComponent aComponent)
Convenience method that returns true if aComponent will be completely painted during the next paintDirtyRegions(). If computing dirty regions is expensive for your component, use this method and avoid computing dirty region if it return true.

validateInvalidComponents

public void validateInvalidComponents()
Validate all of the components that have been marked invalid.
See Also:
addInvalidComponent(javax.swing.JComponent)

paintDirtyRegions

public void paintDirtyRegions()
Paint all of the components that have been marked dirty.
See Also:
addDirtyRegion(javax.swing.JComponent, int, int, int, int)

toString

public String toString()
Returns a string that displays and identifies this object's properties.
Overrides:
toString in class Object
Returns:
a String representation of this object

getOffscreenBuffer

public Image getOffscreenBuffer(Component c,
                                int proposedWidth,
                                int proposedHeight)
Return the offscreen buffer that should be used as a double buffer with the component c By default there is a double buffer per RepaintManager. The buffer might be smaller than (proposedWidth,proposedHeight) This happens when the maximum double buffer size as been set for the receiving repaint manager.

setDoubleBufferMaximumSize

public void setDoubleBufferMaximumSize(Dimension d)
Set the maximum double buffer size.

getDoubleBufferMaximumSize

public Dimension getDoubleBufferMaximumSize()
Returns the maximum double buffer size.
Returns:
a Dimension object representing the maximum size

setDoubleBufferingEnabled

public void setDoubleBufferingEnabled(boolean aFlag)
Enables or disables double buffering.
Parameters:
aFlag - true to activate double buffering

isDoubleBufferingEnabled

public boolean isDoubleBufferingEnabled()
Returns true if this object is double buffered.
Returns:
true if this object is double buffered

JavaTM 2 Platform
Std. Ed. v1.3

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