edu.umd.cs.piccolox.nodes
Class PNodeCache

java.lang.Object
  edu.umd.cs.piccolo.PNode
      edu.umd.cs.piccolox.nodes.PNodeCache

All Implemented Interfaces:

Printable, Serializable, Cloneable

public class PNodeCache
extends PNode

PNodeCache caches a visual representation of it's children into an image and uses this cached image for painting instead of painting it's children directly. This is intended to be used in two ways.

First it can be used as a simple optimization technique. If a node has many descendents it may be faster to paint the cached image representation instead of painting each node.

Second PNodeCache provides a place where "image" effects such as blurring and drop shadows can be added to the Piccolo scene graph. This can be done by overriding the method createImageCache and returing an image with the desired effect applied.

Version:

1.0

Author:

Jesse Grosjean

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class edu.umd.cs.piccolo.PNode

PNode.PSceneGraphDelegate

Field Summary

Fields inherited from class edu.umd.cs.piccolo.PNode

FILL_STRATEGY_ASPECT_COVER, FILL_STRATEGY_ASPECT_FIT, FILL_STRATEGY_EXACT_FIT, PROPERTY_BOUNDS, PROPERTY_CHILDREN, PROPERTY_CHILDREN_PICKABLE, PROPERTY_CLIENT_PROPERTIES, PROPERTY_CODE_BOUNDS, PROPERTY_CODE_CHILDREN, PROPERTY_CODE_CHILDREN_PICKABLE, PROPERTY_CODE_CLIENT_PROPERTIES, PROPERTY_CODE_FULL_BOUNDS, PROPERTY_CODE_PAINT, PROPERTY_CODE_PARENT, PROPERTY_CODE_PICKABLE, PROPERTY_CODE_TRANSFORM, PROPERTY_CODE_TRANSPARENCY, PROPERTY_CODE_VISIBLE, PROPERTY_FULL_BOUNDS, PROPERTY_PAINT, PROPERTY_PARENT, PROPERTY_PICKABLE, PROPERTY_TRANSFORM, PROPERTY_TRANSPARENCY, PROPERTY_VISIBLE, SCENE_GRAPH_DELEGATE

Fields inherited from interface java.awt.print.Printable

NO_SUCH_PAGE, PAGE_EXISTS

Constructor Summary

PNodeCache()

Method Summary

Image	createImageCache(Dimension2D cacheOffsetRef) Override this method to customize the image cache creation process.
void	fullPaint(PPaintContext paintContext) Repaints this node, using the cached result if possible.
Image	getImageCache() Returns an image that is a cached representation of its children.
void	invalidateCache() Clears the cache, forcing it to be recalculated on the next call to getImageCache.
void	invalidatePaint() Intercepts the normal invalidatePaint mechanism so that the node will not be repainted unless it's cache has been invalidated.
protected boolean	pickAfterChildren(PPickPath pickPath) By always returning false, makes the PNodeCache instance NOT pickable.
void	repaintFrom(PBounds localBounds, PNode childOrThis) Handles a repaint event issued from a node in this node's tree.

Methods inherited from class edu.umd.cs.piccolo.PNode

addActivity, addAttribute, addChild, addChild, addChildren, addClientProperty, addInputEventListener, addPropertyChangeListener, addPropertyChangeListener, animateToBounds, animateToColor, animateToPositionScaleRotation, animateToRelativePosition, animateToTransform, animateToTransparency, animateTransformToBounds, centerBoundsOnPoint, centerFullBoundsOnPoint, clone, computeFullBounds, endResizeBounds, findIntersectingNodes, fireChildPropertyChange, firePropertyChange, fullIntersects, fullPick, getAllNodes, getAllNodes, getAttribute, getAttribute, getBooleanAttribute, getBounds, getBoundsChanged, getBoundsReference, getBoundsVolatile, getChild, getChildBoundsInvalid, getChildBoundsVolatile, getChildPaintInvalid, getChildrenCount, getChildrenIterator, getChildrenPickable, getChildrenReference, getClientProperties, getClientProperty, getClientPropertyKeysEnumeration, getClientPropertyKeysIterator, getDoubleAttribute, getFullBounds, getFullBoundsInvalid, getFullBoundsReference, getGlobalBounds, getGlobalFullBounds, getGlobalRotation, getGlobalScale, getGlobalToLocalTransform, getGlobalTranslation, getHeight, getInputEventListeners, getIntegerAttribute, getInverseTransform, getListenerList, getLocalToGlobalTransform, getName, getOccluded, getOffset, getPaint, getPaintInvalid, getParent, getPickable, getPropertyChangeParentMask, getRoot, getRotation, getScale, getTransform, getTransformReference, getTransparency, getUnionOfChildrenBounds, getVisible, getWidth, getX, getXOffset, getY, getYOffset, globalToLocal, globalToLocal, globalToLocal, indexOfChild, internalUpdateBounds, intersects, invalidateFullBounds, invalidateLayout, isAncestorOf, isDescendentOf, isDescendentOfRoot, isOpaque, layoutChildren, lerp, localToGlobal, localToGlobal, localToGlobal, localToParent, localToParent, localToParent, moveInBackOf, moveInFrontOf, moveToBack, moveToFront, offset, paint, paintAfterChildren, paramString, parentBoundsChanged, parentToLocal, parentToLocal, parentToLocal, pick, position, print, print, removeAllChildren, removeChild, removeChild, removeChildren, removeFromParent, removeInputEventListener, removePropertyChangeListener, removePropertyChangeListener, repaint, reparent, replaceWith, resetBounds, rotate, rotateAboutPoint, rotateAboutPoint, rotateInPlace, scale, scaleAboutPoint, scaleAboutPoint, setBounds, setBounds, setBoundsChanged, setChildBoundsInvalid, setChildBoundsVolatile, setChildPaintInvalid, setChildrenPickable, setFullBoundsInvalid, setGlobalRotation, setGlobalScale, setGlobalTranslation, setHeight, setName, setOccluded, setOffset, setOffset, setPaint, setPaintInvalid, setParent, setPickable, setPropertyChangeParentMask, setRotation, setScale, setTransform, setTransparency, setVisible, setWidth, setX, setY, signalBoundsChanged, startResizeBounds, toImage, toImage, toImage, toImage, transformBy, translate, validateFullBounds, validateFullPaint

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PNodeCache

public PNodeCache()

Method Detail

createImageCache

public Image createImageCache(Dimension2D cacheOffsetRef)

Override this method to customize the image cache creation process. For example if you want to create a shadow effect you would do that here. Fill in the cacheOffsetRef if needed to make your image cache line up with the nodes children.

Parameters:

cacheOffsetRef - output parameter that can be changed to make the cached offset line up with the node's children

Returns:

an image representing this node

getImageCache

public Image getImageCache()

Returns an image that is a cached representation of its children.

Returns:

image representation of its children

invalidateCache

public void invalidateCache()

Clears the cache, forcing it to be recalculated on the next call to getImageCache.

invalidatePaint

public void invalidatePaint()

Intercepts the normal invalidatePaint mechanism so that the node will not be repainted unless it's cache has been invalidated.

Overrides:

invalidatePaint in class PNode

repaintFrom

public void repaintFrom(PBounds localBounds,
                        PNode childOrThis)

Handles a repaint event issued from a node in this node's tree.

Overrides:

repaintFrom in class PNode

Parameters:

localBounds - local bounds of this node that need repainting

childOrThis - the node that emitted the repaint notification

fullPaint

public void fullPaint(PPaintContext paintContext)

Repaints this node, using the cached result if possible.

Overrides:

fullPaint in class PNode

Parameters:

paintContext - context in which painting should occur

pickAfterChildren

protected boolean pickAfterChildren(PPickPath pickPath)

By always returning false, makes the PNodeCache instance NOT pickable.

Overrides:

pickAfterChildren in class PNode

Parameters:

pickPath - path which this node is being tested for inclusion

Returns:

always returns false