Class RepaintManager
- java.lang.Object
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- javax.swing.RepaintManager
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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.As of 1.6
RepaintManager
handles repaint requests for Swing's top level components (JApplet
,JWindow
,JFrame
andJDialog
). Any calls torepaint
on one of these will call into the appropriateaddDirtyRegion
method.
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Constructor Summary
Constructors Constructor and Description RepaintManager()
Create a new RepaintManager instance.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method and Description void
addDirtyRegion(Applet applet, int x, int y, int w, int h)
Addsapplet
to the list ofComponent
s that need to be repainted.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)
Addswindow
to the list ofComponent
s that need to be repainted.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 componentc
.Image
getVolatileOffscreenBuffer(Component c, int proposedWidth, int proposedHeight)
Return a volatile offscreen buffer that should be used as a double buffer with the specified componentc
.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.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 in this RepaintManager.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.
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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").
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Method Detail
currentManager
public static RepaintManager currentManager(Component c)
Return the RepaintManager for the calling thread given a Component.- Parameters:
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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:
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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:
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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.
removeInvalidComponent
public void removeInvalidComponent(JComponent component)
Remove a component from the list of invalid components.
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.- Parameters:
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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:
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JComponent.repaint(long, int, int, int, int)
addDirtyRegion
public void addDirtyRegion(Window window, int x, int y, int w, int h)
Addswindow
to the list ofComponent
s that need to be repainted.- Parameters:
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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 - Since:
- 1.6
- See Also:
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JFrame.repaint(long, int, int, int, int)
,JWindow.repaint(long, int, int, int, int)
,JDialog.repaint(long, int, int, int, int)
addDirtyRegion
public void addDirtyRegion(Applet applet, int x, int y, int w, int h)
Addsapplet
to the list ofComponent
s that need to be repainted.- Parameters:
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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 - Since:
- 1.6
- See Also:
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JApplet.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.
paintDirtyRegions
public void paintDirtyRegions()
Paint all of the components that have been marked dirty.
toString
public String toString()
Returns a string that displays and identifies this object's properties.
getOffscreenBuffer
public Image getOffscreenBuffer(Component c, int proposedWidth, int proposedHeight)
Return the offscreen buffer that should be used as a double buffer with the componentc
. 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.
getVolatileOffscreenBuffer
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 componentc
. 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.- Since:
- 1.4
- See Also:
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VolatileImage
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 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:
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aFlag
- true to activate double buffering - See Also:
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isDoubleBufferingEnabled()
isDoubleBufferingEnabled
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 befalse
to avoid unnecessary buffering in Swing. On platforms where native double buffering is not supported, the default value will betrue
.- Returns:
- true if this object is double buffered
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