package com.demo;

import java.util.Vector;

import android.app.Activity;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Paint.Style;import android.os.Bundle;import android.view.MotionEvent;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.ViewGroup.LayoutParams;

public class SurfaceViewDemoActivity extends Activity {

    SurfaceHolder sh = null;    Vector<Float> vx = new Vector<Float>();    Vector<Float> vy = new Vector<Float>();

    @Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);

        SurView surView = new SurView(this);        setContentView(surView);

    }

class SurView extends SurfaceView implements SurfaceHolder.Callback {

public SurView(Context context) {super(context);

            sh = getHolder();            sh.addCallback(this);        }

        @Overridepublic void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {// TODO Auto-generated method stub

        }

        @Overridepublic void surfaceCreated(SurfaceHolder holder) {new Thread(new SurLoop()).start();

        }

        @Overridepublic void surfaceDestroyed(SurfaceHolder holder) {// TODO Auto-generated method stub

        }

public void doDraw(Canvas canvas) {super.onDraw(canvas);            canvas.drawColor(Color.GRAY);            Paint paint = new Paint();            paint.setAntiAlias(true);            paint.setColor(Color.BLUE);            paint.setStyle(Style.STROKE);for (int i = 0; i < vx.size(); i++) {                canvas.drawCircle(vx.elementAt(i), vy.elementAt(i), 10, paint);            }        }

        @Overridepublic boolean onTouchEvent(MotionEvent event) {

if (event.getAction() == MotionEvent.ACTION_DOWN) {                vx.add(event.getX());                vy.add(event.getY());            }return true;        }

class SurLoop implements Runnable {

            @Overridepublic void run() {while (true) {try {                        Canvas canvas = sh.lockCanvas();                        doDraw(canvas);                        sh.unlockCanvasAndPost(canvas);                        Thread.sleep(20);                    } catch (Exception e) {                    }                }            }        }

    }

}