org.freehep.swing.graphics
Class BackedPanel

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JPanel
                  org.freehep.swing.graphics.BackedPanel

All Implemented Interfaces:

Accessible, ImageObserver, MenuContainer, Serializable

Direct Known Subclasses:

Canvas3D

public class BackedPanel

extends JPanel

implements Serializable

This class extends JPanel by adding a backing store. This is intended to be used in situations in which redrawing the contents of the panel is extremely expensive. To keep things simple, this component does NOT support borders. If a border is desired, then this component should be embedded within another container which has one. Likewise, children components should NOT be added to this component.

Version:

$Id: BackedPanel.java,v 1.7 2004/01/16 23:05:11 duns Exp $

Author:

Charles Loomis, Mark Donszelmann

See Also:

Serialized Form

Source Code:

BackedPanel.java

Nested Class Summary

Nested classes inherited from class javax.swing.JPanel

JPanel.AccessibleJPanel

Nested classes inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

Nested classes inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

protected BufferedImage	backingImage The backing image itself.
protected Rectangle	clip Rectangle to hold the clipping bounds.

Fields inherited from class javax.swing.JComponent

accessibleContext, listenerList, TOOL_TIP_TEXT_KEY, ui, UNDEFINED_CONDITION, WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, WHEN_FOCUSED, WHEN_IN_FOCUSED_WINDOW

Fields inherited from class java.awt.Component

BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT

Fields inherited from interface java.awt.image.ImageObserver

ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH

Constructor Summary

BackedPanel(boolean opaque)
Creates a new BackedPanel with a width and height set to zero, and the backing image and graphics object to null.

Method Summary

Graphics	getGraphics() Return the graphics object for the backing image.
Object	getLock() Get the object which acts as a lock on the backing image.
void	paintBorder(Graphics g) Since this component does not support borders, override this method to do nothing.
void	paintChildren(Graphics g) Since this component should not contain children, override this method to do nothing.
void	paintComponent(Graphics g) Paint this panel by flushing the backing image to the screen.
void	printBorder(Graphics g) Since this component does not support borders, override this method to do nothing.
void	printChildren(Graphics g) Since this component should not contain children, override this method to do nothing.
void	printComponent(Graphics g) Printing should be handled directly by the component which paints into the backing store.
void	setBorder(Border border) This component does not support borders.
void	setBounds(int x, int y, int w, int h) Resize and move a component.

Methods inherited from class javax.swing.JPanel

getAccessibleContext, getUI, getUIClassID, paramString, setUI, updateUI

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBorder, getBounds, getClientProperty, getComponentGraphics, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getHeight, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isOptimizedDrawingEnabled, isPaintingTile, isPreferredSizeSet, isRequestFocusEnabled, isValidateRoot, paint, paintImmediately, paintImmediately, print, printAll, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFont, setForeground, setInputMap, setInputVerifier, setMaximumSize, setMinimumSize, setNextFocusableComponent, setOpaque, setPreferredSize, setRequestFocusEnabled, setToolTipText, setTransferHandler, setUI, setVerifyInputWhenFocusTarget, setVisible, unregisterKeyboardAction, update

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setLayout, transferFocusBackward, transferFocusDownCycle, validate, validateTree

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, createImage, createImage, createVolatileImage, createVolatileImage, disableEvents, dispatchEvent, enable, enableEvents, enableInputMethods, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMouseWheelListeners, getName, getParent, getPeer, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processMouseEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, repaint, repaint, repaint, resize, resize, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusable, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

backingImage

protected BufferedImage backingImage

The backing image itself.

clip

protected Rectangle clip

Rectangle to hold the clipping bounds.

Constructor Detail

BackedPanel

public BackedPanel(boolean opaque)

Creates a new BackedPanel with a width and height set to zero, and the backing image and graphics object to null. By default, the Swing double buffering is turned off (since we're writing to a backing image anyway). The caller of this constructor selects whether this is a transparent or opaque panel.

Parameters:

opaque - transparent panel

Method Detail

getGraphics

public Graphics getGraphics()

Return the graphics object for the backing image. All drawing goes to this image first. Only on a repaint() is the image flushed to the screen.

Returns:

Graphics of backing image

getLock

public Object getLock()

Get the object which acts as a lock on the backing image. Drawing to the graphics context supplied by getGraphics() or the image returned from getBackingImage() should be synchronized to this object.

Returns:

lock for the backing image

paintComponent

public void paintComponent(Graphics g)

Paint this panel by flushing the backing image to the screen.

Parameters:

g - Graphics object to draw backing store into

paintBorder

public void paintBorder(Graphics g)

Since this component does not support borders, override this method to do nothing.

Parameters:

g - ignored Graphics context

paintChildren

public void paintChildren(Graphics g)

Since this component should not contain children, override this method to do nothing.

Parameters:

g - ignored Graphics context

printComponent

public void printComponent(Graphics g)

Printing should be handled directly by the component which paints into the backing store. Hence, this method does nothing.

Parameters:

g - ignored Graphics context

printBorder

public void printBorder(Graphics g)

Since this component does not support borders, override this method to do nothing.

Parameters:

g - ignored Graphics context

printChildren

public void printChildren(Graphics g)

Since this component should not contain children, override this method to do nothing.

Parameters:

g - ignored Graphics context

setBorder

public final void setBorder(Border border)

This component does not support borders. If this method is called with any non-null argument, then an IllegalArgumentException is thrown. If a border is desired, then this component should be embedded within another container which has one.

Parameters:

border - must be null

setBounds

public void setBounds(int x,
                      int y,
                      int w,
                      int h)

Resize and move a component.