public class

RepaintManager

extends Object
java.lang.Object
   ↳ javax.swing.RepaintManager

Class Overview

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.

As of 1.6 RepaintManager handles repaint requests for Swing's top level components (JApplet, JWindow, JFrame and JDialog). Any calls to repaint on one of these will call into the appropriate addDirtyRegion method.

Summary

Public Constructors
RepaintManager()
Create a new RepaintManager instance.
Public Methods
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 addDirtyRegion(Window window, int x, int y, int w, int h)
Adds window to the list of Components that need to be repainted.
void addDirtyRegion(Applet applet, int x, int y, int w, int h)
Adds applet to the list of Components that need to be repainted.
synchronized 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(JComponent c)
Return the RepaintManager for the calling thread given a JComponent.
static RepaintManager currentManager(Component c)
Return the RepaintManager for the calling thread given a Component.
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.
Image getVolatileOffscreenBuffer(Component c, int proposedWidth, int proposedHeight)
Return a volatile offscreen buffer that should be used as a double buffer with the specified component c.
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 RepaintManager 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.
synchronized 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 setDoubleBufferMaximumSize(Dimension d)
Set the maximum double buffer size.
void setDoubleBufferingEnabled(boolean aFlag)
Enables or disables double buffering in this RepaintManager.
synchronized 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.
[Expand]
Inherited Methods
From class java.lang.Object

Public Constructors

public RepaintManager ()

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

Public Methods

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.

Parameters
c Component to repaint, null results in nothing happening.
x X coordinate of the region to repaint
y Y coordinate of the region to repaint
w Width of the region to repaint
h Height of the region to repaint
See Also

public void addDirtyRegion (Window window, int x, int y, int w, int h)

Adds window to the list of Components that need to be repainted.

Parameters
window Window to repaint, null results in nothing happening.
x X coordinate of the region to repaint
y Y coordinate of the region to repaint
w Width of the region to repaint
h Height of the region to repaint
See Also

public void addDirtyRegion (Applet applet, int x, int y, int w, int h)

Adds applet to the list of Components that need to be repainted.

Parameters
applet Applet to repaint, null results in nothing happening.
x X coordinate of the region to repaint
y Y coordinate of the region to repaint
w Width of the region to repaint
h Height of the region to repaint
See Also

public synchronized 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

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

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

public Rectangle getDirtyRegion (JComponent aComponent)

Return the current dirty region for a component. Return an empty rectangle if the component is not dirty.

public Dimension getDoubleBufferMaximumSize ()

Returns the maximum double buffer size.

Returns
  • a Dimension object representing the maximum size

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.

public Image getVolatileOffscreenBuffer (Component c, int proposedWidth, int proposedHeight)

Return a volatile offscreen buffer that should be used as a double buffer with the specified component c. The image returned will be an instance of VolatileImage, or null if a VolatileImage object could not be instantiated. This buffer might be smaller than (proposedWidth,proposedHeight). This happens when the maximum double buffer size has been set for this repaint manager.

See Also

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.

public boolean isDoubleBufferingEnabled ()

Returns true if this RepaintManager is double buffered. The default value for this property may vary from platform to platform. On platforms where native double buffering is supported in the AWT, the default value will be false to avoid unnecessary buffering in Swing. On platforms where native double buffering is not supported, the default value will be true.

Returns
  • true if this object is double buffered

public void markCompletelyClean (JComponent aComponent)

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

public void markCompletelyDirty (JComponent aComponent)

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

public void paintDirtyRegions ()

Paint all of the components that have been marked dirty.

See Also

public synchronized void removeInvalidComponent (JComponent component)

Remove a component from the list of invalid components.

See Also

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

public void setDoubleBufferMaximumSize (Dimension d)

Set the maximum double buffer size.

public void setDoubleBufferingEnabled (boolean aFlag)

Enables or disables double buffering in this RepaintManager. CAUTION: The default value for this property is set for optimal paint performance on the given platform and it is not recommended that programs modify this property directly.

Parameters
aFlag true to activate double buffering
See Also

public synchronized String toString ()

Returns a string that displays and identifies this object's properties.

Returns
  • a String representation of this object

public void validateInvalidComponents ()

Validate all of the components that have been marked invalid.

See Also