gamecanvas.java

J2me唆哈的代码

/*
 * Created on 2005-12-19 by pcy
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package javax.microedition.lcdui.game;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

public abstract class GameCanvas extends Canvas {
    
    /**
     * The bit representing the UP key.  This constant has a value of 
     * <code>0x0002</code> (1 << Canvas.UP).
     */
    public static final int UP_PRESSED = 1 << Canvas.UP;
    
    /**
     * The bit representing the DOWN key.  This constant has a value of 
     * <code>0x0040</code> (1 << Canvas.DOWN).
     */
    public static final int DOWN_PRESSED = 1 << Canvas.DOWN;

    /**
     * The bit representing the LEFT key.  This constant has a value of 
     * <code>0x0004</code> (1 << Canvas.LEFT).
     */
    public static final int LEFT_PRESSED = 1 << Canvas.LEFT;

    /**
     * The bit representing the RIGHT key.  This constant has a value of 
     * <code>0x0020</code> (1 << Canvas.RIGHT).
     */
    public static final int RIGHT_PRESSED = 1 << Canvas.RIGHT;

    /**
     * The bit representing the FIRE key.  This constant has a value of 
     * <code>0x0100</code> (1 << Canvas.FIRE).
     */
    public static final int FIRE_PRESSED = 1 << Canvas.FIRE;

    /**
     * The bit representing the GAME_A key (may not be supported on all 
     * devices).  This constant has a value of 
     * <code>0x0200</code> (1 << Canvas.GAME_A).
     */
    public static final int GAME_A_PRESSED = 1 << Canvas.GAME_A;

    /**
     * The bit representing the GAME_B key (may not be supported on all 
     * devices).  This constant has a value of 
     * <code>0x0400</code> (1 << Canvas.GAME_B).
     */
    public static final int GAME_B_PRESSED = 1 << Canvas.GAME_B;

    /**
     * The bit representing the GAME_C key (may not be supported on all 
     * devices).  This constant has a value of 
     * <code>0x0800</code> (1 << Canvas.GAME_C).
     */
    public static final int GAME_C_PRESSED = 1 << Canvas.GAME_C;

    /**
     * The bit representing the GAME_D key (may not be supported on all 
     * devices).  This constant has a value of 
     * <code>0x1000</code> (1 << Canvas.GAME_D).
     */
    public static final int GAME_D_PRESSED = 1 << Canvas.GAME_D;

    /**
     * Height available to draw on in full screen mode.
     *
     */
    private int screenWidth;

    /**
     * Width available to draw on in full screen mode.
     *
     */
    private int screenHeight;

    /** 
     * currently every GameCanvas has one offscreen buffer
     * can be optimized so that we put a limit on no of offscreen buffers
     * an application can have
     */
    private Image offscreen_buffer;
    
    private boolean suppressKeyEvents;
    
    public GameCanvas(boolean suppressKeyEvents) {
        super();
        this.suppressKeyEvents=suppressKeyEvents;
        screenWidth=getWidth();
        screenHeight=getHeight();
        offscreen_buffer=Image.createImage(screenWidth,screenHeight);
    }
    
    protected Graphics getGraphics(){
        return offscreen_buffer.getGraphics();
    }
    
    public int getKeyState(){
        return 0;
    }
    
    public void paint(Graphics g) {
        // TODO Auto-generated method stub
        g.drawImage(offscreen_buffer,0,0,Graphics.LEFT|Graphics.TOP);
    }
    
    public void flushGraphics(int x, int y, int width, int height){
        if (width < 1 || height < 1) {
            return;
        }
        repaint(x,y,width,height);
    }
    
    public void flushGraphics(){
        repaint();
    }
}