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