Android SurfaceView with Thread

안드로이드의 SurfaceView 에서 Thread를 사용하는 예

SurfaceView에서는 화면에 그리기 위한 메소드를 직접 정의해야 하고 그 메소드를 쓰레드에서 직접호출하여 화면에 출력할 수 있다

MainActivity.java

package com.example.androidapp;


import android.app.Activity;
import android.graphics.Point;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.TextView;

public class MainActivity extends Activity {
	
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new Tank(this));
	}

}

Tank.java

package com.example.androidapp;

import android.content.Context;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.util.Log;

public class Tank extends SurfaceView implements SurfaceHolder.Callback {
	
	Canvas cacheCanvas;
	Bitmap backBuffer;
	SurfaceHolder mHolder;
	
	public Tank(Context context) {
		super(context);
		init();
	}

	public Tank(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	int width, height, sx, sy;
	Bitmap bitmapTank, invTank, tank;
	
	Matrix matrix, horInvMatrix;
	int delta = -5;
	private void init() {
		mHolder = getHolder();
		mHolder.addCallback(this);
	}

	private void draw() {//자동으로 호출되는 onDraw() 와 같은 메소드가 없기 때문에 직접 그리는 메소드를 정의한다
		Canvas canvas = null;
		try{
			canvas = mHolder.lockCanvas(null);
			//back buffer에 그려진 비트맵을 스크린 버퍼에 그린다
			canvas.drawColor(Color.WHITE);
			canvas.drawBitmap(backBuffer, sx, sy, null);
		}catch(Exception ex){
			ex.printStackTrace();
		}finally {
			mHolder.unlockCanvasAndPost(canvas);
		}
	}
	
	public void surfaceCreated(SurfaceHolder holder) {
		width = getWidth();
		height = getHeight();
		cacheCanvas = new Canvas();
		
		bitmapTank = BitmapFactory.decodeResource(getResources(), R.drawable.tank);
		
		backBuffer = Bitmap.createBitmap(
				bitmapTank.getWidth(), bitmapTank.getHeight(), Bitmap.Config.ARGB_8888);
		cacheCanvas.setBitmap(backBuffer);
		cacheCanvas.drawColor(Color.WHITE);
		
		sx = width/2-(bitmapTank.getWidth()/2);
		sy = height/2-(bitmapTank.getHeight()/2);
		
		matrix = new Matrix();
		
		horInvMatrix = new Matrix();
		horInvMatrix.setScale(-1, 1);
		//원본 비트맵을 좌우로 뒤집어서 복사하여 사본 비트맵을 생성한다
		invTank = Bitmap.createBitmap(bitmapTank, 0, 0, bitmapTank.getWidth(), bitmapTank.getHeight(), horInvMatrix, false);
		tank = bitmapTank;
		new Thread(){
			public void run() {
				while(true) {
					if(sx<=0) {
						tank = invTank;
						delta *= -1;
					}else if(sx >= width-backBuffer.getWidth()){
						tank = bitmapTank;
						delta *= -1;
					}
					cacheCanvas.drawBitmap(tank, matrix, null); //back buffer에 그린다
					sx+=delta;
					draw();
					try {
						Thread.sleep(50);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			};
		}.start();
	}
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {}

	public void surfaceDestroyed(SurfaceHolder holder) {}
}