org.jscience.awt
Class DoubleBufferedCanvas

java.lang.Object
  java.awt.Component
      java.awt.Canvas
          org.jscience.awt.DoubleBufferedCanvas

All Implemented Interfaces:

java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable, javax.accessibility.Accessible

Direct Known Subclasses:

CategoryGraph2D, ContourPlot, Graph2D, LineGraph3D, LineTrace

public abstract class DoubleBufferedCanvas
extends java.awt.Canvas

The DoubleBufferedCanvas class provides double buffering functionality. Painting events simply cause the offscreen buffer to be painted. It is the responsibility of sub-classes to explicitly update the offscreen buffer. The offscreen buffer can be updated in two ways.

1. Override the offscreenPaint method and use the redraw method. Passive rendering.
2. Draw to the graphics context returned by the getOffscreenGraphics method and use the repaint method. Active rendering.

The first way alone should be sufficient for most purposes.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.awt.Canvas

java.awt.Canvas.AccessibleAWTCanvas

Nested classes/interfaces inherited from class java.awt.Component

java.awt.Component.AccessibleAWTComponent, java.awt.Component.BaselineResizeBehavior, java.awt.Component.BltBufferStrategy, java.awt.Component.FlipBufferStrategy

Field Summary

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

DoubleBufferedCanvas()
Constructs a double buffered canvas.

Method Summary

protected java.awt.Graphics	getOffscreenGraphics() Returns the offscreen graphics context or null if not available.
protected abstract void	offscreenPaint(java.awt.Graphics g) Paints the canvas off-screen.
void	paint(java.awt.Graphics g) Paints the canvas using double buffering.
void	print(java.awt.Graphics g) Prints the canvas.
void	redraw() Redraws the canvas.
void	update(java.awt.Graphics g) Updates the canvas.

Methods inherited from class java.awt.Canvas

addNotify, createBufferStrategy, createBufferStrategy, getAccessibleContext, getBufferStrategy

Methods inherited from class java.awt.Component

action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAlignmentX, getAlignmentY, getBackground, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMinimumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, minimumSize, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, paramString, postEvent, preferredSize, prepareImage, prepareImage, printAll, processComponentEvent, processEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

DoubleBufferedCanvas

public DoubleBufferedCanvas()

Constructs a double buffered canvas.

Method Detail

paint

public final void paint(java.awt.Graphics g)

Paints the canvas using double buffering.

Overrides:

paint in class java.awt.Canvas

See Also:

offscreenPaint(java.awt.Graphics)

update

public final void update(java.awt.Graphics g)

Updates the canvas.

Overrides:

update in class java.awt.Canvas

Parameters:

g - DOCUMENT ME!

print

public final void print(java.awt.Graphics g)

Prints the canvas.

Overrides:

print in class java.awt.Component

Parameters:

g - DOCUMENT ME!

redraw

public final void redraw()

Redraws the canvas. This method may safely be called from outside the event-dispatching thread.

getOffscreenGraphics

protected final java.awt.Graphics getOffscreenGraphics()

Returns the offscreen graphics context or null if not available.

Returns:

DOCUMENT ME!

offscreenPaint

protected abstract void offscreenPaint(java.awt.Graphics g)

Paints the canvas off-screen. Override this method instead of paint(Graphics g).

Parameters:

g - DOCUMENT ME!