org.piratis.j2me.core.game
Class Canvas

java.lang.Object
  javax.microedition.lcdui.Canvas
      org.piratis.j2me.core.game.Canvas

All Implemented Interfaces:

java.lang.Runnable

public class Canvas

extends javax.microedition.lcdui.Canvas

implements java.lang.Runnable

CoreCanvas Description

Version:

$Id: Canvas.java,v 1.3 2004/07/22 16:49:42 piratis Exp $

Author:

Jordi Martín

See Also:

Serialized Form

Field Summary

protected Display	display Canvas display
protected Image	offscreen Double buffering image

Constructor Summary

Canvas(Display display)
Creates a new instance of a CoreCanvas, with an empty (white pixels) buffer for offscreen processing.

Method Summary

void	flushGraphics() Flushes the off-screen buffer to the display.
Display	getDisplay()
protected Graphics	getGraphics() Returns the Graphics object for rendering a Game Canvas: it will be the Graphics object of the off-screen buffer.
protected void	keyPressed(int keyCode)
protected void	keyReleased(int keyCode)
protected void	paint(Graphics g)
protected void	paintBackground(Graphics g, BBox2D area) Paints the current background (if any).
void	run() To be called by a Display#callSerially(java.lang.Runnable) when requesting a new repaint.
protected void	setEngine(Engine newEngine) Sets its associated engine.

Methods inherited from class java.lang.Object

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

Field Detail

display

protected Display display

Canvas display

offscreen

protected Image offscreen

Double buffering image

Constructor Detail

Canvas

public Canvas(Display display)

Creates a new instance of a CoreCanvas, with an empty (white pixels) buffer for offscreen processing.

Parameters:

display - Canva's display

Method Detail

getGraphics

protected Graphics getGraphics()

Returns the Graphics object for rendering a Game Canvas: it will be the Graphics object of the off-screen buffer.

Painting operations will not be visible on the display as long as flushGraphics() is not called

Returns:

this off-screen's Graphic object

getDisplay

public Display getDisplay()

Returns:

the canvas' display

run

public void run()

To be called by a Display#callSerially(java.lang.Runnable) when requesting a new repaint. It is the same as calling flushGraphics().

Specified by:

run in interface java.lang.Runnable

See Also:

Runnable.run(), flushGraphics(), Display#callSerially(java.lang.Runnable)

paint

protected void paint(Graphics g)

See Also:

javax.microedition.lcdui.Displayable#paint(Graphics)

paintBackground

protected void paintBackground(Graphics g,
                               BBox2D area)

Paints the current background (if any). Default implementation clears the background with bgColor

Parameters:

g - graphics context

area - dirty region

setEngine

protected void setEngine(Engine newEngine)

Sets its associated engine. High coupling between Canvas and Engine!

Parameters:

newEngine - its engine

See Also:

Engine

flushGraphics

public void flushGraphics()

Flushes the off-screen buffer to the display.

keyPressed

protected void keyPressed(int keyCode)

keyReleased

protected void keyReleased(int keyCode)