javalib.worldcanvas
Class AppletCanvas

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.JPanel
                  javalib.worldcanvas.AppletCanvas

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable, Accessible

public class AppletCanvas
extends JPanel

A class to represent a canvas for the applet to draw on

Since:

November 28, 2007

Author:

Viera K. Proulx

See Also:

Serialized Form

Nested Class Summary

static class	AppletCanvas.Painter Panel that paints the internal buffered image that maintains the persistent graphics state of the buffered panel.
static class	AppletCanvas.Refresh Class Refresh encapsulates methods for graphics refresh.

Nested classes/interfaces inherited from class javax.swing.JPanel

JPanel.AccessibleJPanel

Nested classes/interfaces inherited from class javax.swing.JComponent

JComponent.AccessibleJComponent

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

Container.AccessibleAWTContainer

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

Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

protected BufferedImage	buffer The buffered image that maintains the persistent graphics state.
protected int	HEIGHT
AppletCanvas.Painter	painter The internal painter panel.
static AppletCanvas	theCanvas
protected int	WIDTH The width and height for this buffered panel.

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, PROPERTIES, SOMEBITS

Constructor Summary

AppletCanvas(int width, int height)
Create an instance of a CanvasPanel of the given dimensions.

Method Summary

void	clear() Fills this buffered panel with its background color or Paint.
void	clearPanel() Fills this buffered panel with its background color or Paint.
void	drawImage(ImageMaker imread, int x, int y) Draw the image provided by the ImageMaker on the Canvas at the given NW corner
void	drawImage(String fileName, Posn nw) Draw the image in the specified file at the location of the given NW corner
void	drawImage(WorldImage image) Draw the image on the Canvas at its pinhole location.
BufferedImage	getBuffer() Returns the internal buffered image for this panel.
Graphics2D	getBufferGraphics() Returns a Graphics2D object that permits painting to the internal buffered image for this panel.
int	getBufferHeight() Returns the height of the buffered image.
int	getBufferWidth() Returns the width of the buffered image.
JPanel	getInnerPanel() Returns the internal panel for this buffered panel, that is, the panel that paints the buffered image and handles the mouse and key adapters.
boolean	isFocusable() We must implement this method to make sure the canvas panel gets focus when moused over - and responds to the key events appropriately.
boolean	isRequestFocusEnabled() Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().
protected boolean	isWhite(Color c)
void	paintOver(Graphics2D g2) Override this paintOver method to add additional painting actions after the default buffer repaint is done during a repaint() call.
void	requestFocus() Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().
boolean	requestFocusInWindow() Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().
void	setBufferSize(int width, int height) Sets the size of the buffered image to the given height and width.
void	setFocusable(boolean focusable) Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().
String	toIndentedString(String indent) Produce an indented String representation of this Canvas
String	toString() Produce a String representation of this Canvas

Methods inherited from class javax.swing.JPanel

getAccessibleContext, getUI, getUIClassID, paramString, setUI, updateUI

Methods inherited from class javax.swing.JComponent

addAncestorListener, addNotify, addVetoableChangeListener, computeVisibleRect, contains, createToolTip, disable, enable, firePropertyChange, firePropertyChange, firePropertyChange, fireVetoableChange, getActionForKeyStroke, getActionMap, getAlignmentX, getAlignmentY, getAncestorListeners, getAutoscrolls, getBaseline, getBaselineResizeBehavior, getBorder, getBounds, getClientProperty, getComponentGraphics, getComponentPopupMenu, getConditionForKeyStroke, getDebugGraphicsOptions, getDefaultLocale, getFontMetrics, getGraphics, getHeight, getInheritsPopupMenu, getInputMap, getInputMap, getInputVerifier, getInsets, getInsets, getListeners, getLocation, getMaximumSize, getMinimumSize, getNextFocusableComponent, getPopupLocation, getPreferredSize, getRegisteredKeyStrokes, getRootPane, getSize, getToolTipLocation, getToolTipText, getToolTipText, getTopLevelAncestor, getTransferHandler, getVerifyInputWhenFocusTarget, getVetoableChangeListeners, getVisibleRect, getWidth, getX, getY, grabFocus, isDoubleBuffered, isLightweightComponent, isManagingFocus, isOpaque, isOptimizedDrawingEnabled, isPaintingForPrint, isPaintingTile, isValidateRoot, paint, paintBorder, paintChildren, paintComponent, paintImmediately, paintImmediately, print, printAll, printBorder, printChildren, printComponent, processComponentKeyEvent, processKeyBinding, processKeyEvent, processMouseEvent, processMouseMotionEvent, putClientProperty, registerKeyboardAction, registerKeyboardAction, removeAncestorListener, removeNotify, removeVetoableChangeListener, repaint, repaint, requestDefaultFocus, requestFocus, requestFocusInWindow, resetKeyboardActions, reshape, revalidate, scrollRectToVisible, setActionMap, setAlignmentX, setAlignmentY, setAutoscrolls, setBackground, setBorder, setComponentPopupMenu, setDebugGraphicsOptions, setDefaultLocale, setDoubleBuffered, setEnabled, setFocusTraversalKeys, setFont, setForeground, setInheritsPopupMenu, 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, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getLayout, getMousePosition, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paintComponents, preferredSize, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, setComponentZOrder, setFocusCycleRoot, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, 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, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getForeground, getGraphicsConfiguration, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getToolkit, getTreeLock, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isEnabled, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isPreferredSizeSet, 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, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, resize, resize, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setFocusTraversalKeysEnabled, setIgnoreRepaint, setLocale, setLocation, setLocation, setName, setSize, setSize, show, show, size, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

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

Field Detail

buffer

protected BufferedImage buffer

The buffered image that maintains the persistent graphics state.

HEIGHT

protected int HEIGHT

painter

public AppletCanvas.Painter painter

The internal painter panel.

theCanvas

public static AppletCanvas theCanvas

WIDTH

protected int WIDTH

The width and height for this buffered panel.

Constructor Detail

AppletCanvas

public AppletCanvas(int width,
                    int height)

Create an instance of a CanvasPanel of the given dimensions.

Parameters:

width - the width of the panel

height - the height of the panel

Method Detail

clear

public final void clear()

Fills this buffered panel with its background color or Paint.

clearPanel

public final void clearPanel()

Fills this buffered panel with its background color or Paint.

drawImage

public void drawImage(ImageMaker imread,
                      int x,
                      int y)

Draw the image provided by the ImageMaker on the Canvas at the given NW corner

Parameters:

imread - the image maker for the image file

x - the x coordinate for the image placement

y - the y coordinate for the image placement

drawImage

public void drawImage(String fileName,
                      Posn nw)

Draw the image in the specified file at the location of the given NW corner

Parameters:

fileName - the name of the image file

nw - the NW corner for the image placement

drawImage

public void drawImage(WorldImage image)

Draw the image on the Canvas at its pinhole location.

Parameters:

image - the image to be drawn

getBuffer

public final BufferedImage getBuffer()

Returns the internal buffered image for this panel.

getBufferGraphics

public final Graphics2D getBufferGraphics()

Returns a Graphics2D object that permits painting to the internal buffered image for this panel.

The user should always use this object to paint to the buffer and thus indirectly modify this buffered panel.

To make painting changes to the buffer visible, the repaint() method must explicitly be called. This allows a number of painting operations to be done prior to screen repaint.

getBufferHeight

public final int getBufferHeight()

Returns the height of the buffered image.

getBufferWidth

public final int getBufferWidth()

Returns the width of the buffered image.

getInnerPanel

public final JPanel getInnerPanel()

Returns the internal panel for this buffered panel, that is, the panel that paints the buffered image and handles the mouse and key adapters.

This panel may be used when access to the panel on which the graphics is drawn is needed.

Do not set a border on this internal panel. Set a border on the outer BufferedPanel object.

isFocusable

public boolean isFocusable()

We must implement this method to make sure the canvas panel gets focus when moused over - and responds to the key events appropriately.

Overrides:

isFocusable in class Component

isRequestFocusEnabled

public final boolean isRequestFocusEnabled()

Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().

Overrides:

isRequestFocusEnabled in class JComponent

isWhite

protected boolean isWhite(Color c)

paintOver

public void paintOver(Graphics2D g2)

Override this paintOver method to add additional painting actions after the default buffer repaint is done during a repaint() call.

The intention of this facility is to enable algorithmic painting to be done via the paintOver method on top of the default painting of the buffer image on the panel. This makes the buffer appear to be the background and what is painted via the paintOver method to be painted in the foreground.

The default implementation of the paintOver method is to do nothing. This enables overrides as desired.

As of 2.4.0, this method is called after both the painting of the buffer and the painting of the internal paintable sequence. Given the power inherent in painting both the buffer bitmap and the internal paintable sequence, it is rare that this method will need to be overridden.

Parameters:

g2 - the Graphics2D context for the buffer repaint operation

Since:

1.0.1

requestFocus

public final void requestFocus()

Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().

Overrides:

requestFocus in class JComponent

requestFocusInWindow

public final boolean requestFocusInWindow()

Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().

Overrides:

requestFocusInWindow in class JComponent

setBufferSize

public void setBufferSize(int width,
                          int height)

Sets the size of the buffered image to the given height and width.

If the given width or height is less than 1 pixel, it is set to 1 pixel.

Any image area gained by an size increase in either direction will be painted with the current background color.

Any image area lost by a size decrease in either direction will be clipped on the right and/or bottom of the image.

For a short time both the image of the previous size and an image of the new size are maintained in memory.

Parameters:

width - the new width for the image

height - the new height for the image

setFocusable

public final void setFocusable(boolean focusable)

Overrides to delegate to the inner panel that is the panel returned by getInnerPanel().

Overrides:

setFocusable in class Component

toIndentedString

public String toIndentedString(String indent)

Produce an indented String representation of this Canvas

Parameters:

indent - the desired indentation: ignored, because we only produce one line of text.

toString

public String toString()

Produce a String representation of this Canvas

Overrides:

toString in class Component