pointerdemo.java

J2ME手机游戏开发技术详解随书光盘

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class PointerDemo extends MIDlet {
    Display display;
    PointerCanvas  pc;
    public PointerDemo() {
        display = Display.getDisplay(this);
        pc= new PointerCanvas();
    }
    public void startApp () {
        display.setCurrent(pc);
    }
    public void pauseApp() {
    }
    public void destroyApp (boolean unconditional) {
        pc=null;
        display=null;
    }
    class PointerCanvas extends Canvas {
	String iconFiles[]={"/ami.png", "/bigs.png","/ganma.png", "/knuckles.png","/sonic.png","/tails.png"};
        String iconLabels[]={"Ami", "Bigs", "Ganma", "Knuckles", "Sonic", "Tails"};
        Image  icons[]= new Image[iconFiles.length];
        int  nrow=3;
        int  ncol=2;
        int  width, height;
        int deltax, deltay;
        public PointerCanvas() {
            for(int i=0; i<iconFiles.length; i++) {
                try{
                    icons[i]= Image.createImage(iconFiles[i]);
                }catch (Exception e) {
                    System.out.println("Error: "+ e.getMessage());
                }
            }
            width=getWidth();
            height=getHeight();
            deltax=width/ncol;
            deltay=(height-20)/nrow;
            System.out.println(hasPointerEvents()); 
            System.out.println(hasPointerMotionEvents());
        }
        protected void paint(Graphics g) {
            g.setColor(0xFFFFFF);
            g.fillRect(0, 0, width, height);
            g.setColor(0x000000);
            g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE));
            g.drawString("请选择游戏人物：",0,0,g.TOP|g.LEFT);
            g.setColor(0x000000);
            g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_SMALL));
            for(int r=0; r<nrow; r++) {
                for(int c=0; c<ncol; c++) {
                    Image img= icons[r*ncol+c];
                    g.drawImage(img, c*deltax+2, r*deltay+20,
                            Graphics.LEFT | Graphics.TOP);
                    g.drawRect(c*deltax,r*deltay+18,img.getWidth()+4,img.getHeight()+4);
                    g.drawString(iconLabels[r*ncol+c], c*deltax+img.getWidth()+3, 
                                 r*deltay+img.getHeight(), g.LEFT|g.BASELINE);                   
                }
            }
        }
        protected void pointerPressed(int x, int y) {
            int r=(y-20)/deltay;
            int c=x/deltax;
            int index=r*ncol+c;
            display.setCurrent(new ResultCanvas(this, iconLabels[index]));
        }
    }
    class ResultCanvas extends Canvas implements CommandListener {
        Displayable menu;
        Command backCommand = new Command("Back", Command.BACK, 1);
        String text;
        int  width, height;
        public ResultCanvas(Displayable d, String message) {
            menu=d;
            text=message;
            width=getWidth();
            height=getHeight();
            this.addCommand(backCommand);
            this.setCommandListener(this);
        }
        protected void paint(Graphics g) {
            g.setColor(0xFFFFFF);
            g.fillRect(0, 0, width, height);
            g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE));
            g.setColor(0x000000);            
            g.drawString("您选择了："+text, 10, 10, g.TOP|g.LEFT);
        }
         public void commandAction (Command c, Displayable s) {
            if(c==backCommand) {
                display.setCurrent(menu);
            }
        }
    }
}