android SurfaceView绘制 重新学习--控制动画移动

public class MySurfaceView extends SurfaceView implements Callback, Runnable {
private Thread th;
private SurfaceHolder sfh;
private int SH, SW;
private Canvas canvas;
private Paint p;
private Paint p2;
private Resources res;
private Bitmap bmp;
private int bmp_x = 100, bmp_y = 300;
private boolean LEFT, RIGHT;
private int animation_left[] = { 0, 1, 2 };
private int animation_right[] = { 3, 4, 5 };
private int animation_init[] = animation_left;
private int anim_count;
// 一张图上图的数量
private static final int bm_count = 6;
private boolean threadFlag;

public MySurfaceView(Context context) {
super(context);
this.setKeepScreenOn(true);
res = this.getResources();
bmp = BitmapFactory.decodeResource(res, R.drawable.move_bitmap);
sfh = this.getHolder();
sfh.addCallback(this);
p = new Paint();
p.setColor(Color.YELLOW);
p2 = new Paint();
p2.setColor(Color.RED);
p.setAntiAlias(true);
setFocusable(true);
}

public void surfaceCreated(SurfaceHolder holder) {
SH = this.getHeight();
SW = this.getWidth();
threadFlag = true;
th = new Thread(this);
th.start();
}

public void draw() {
canvas = sfh.lockCanvas();
if (canvas != null) {
canvas.drawRect(0, 0, SW, SH, p);
canvas.save();
canvas.drawText("奋斗的小猿", bmp_x + 5, bmp_y - 10, p2);
canvas.clipRect(bmp_x, bmp_y, bmp_x + bmp.getWidth() / bm_count, bmp_y + bmp.getHeight());
if (animation_init == animation_left) {
canvas.drawBitmap(bmp, bmp_x - animation_left[anim_count] * (bmp.getWidth() / bm_count), bmp_y, p);
} else if (animation_init == animation_right) {
canvas.drawBitmap(bmp, bmp_x - animation_right[anim_count] * (bmp.getWidth() / bm_count), bmp_y, p);
}
canvas.restore();
sfh.unlockCanvasAndPost(canvas);
}
}

public void cycle() {
if (LEFT) {
bmp_x -= 5;
if (bmp_x <= 0) {
bmp_x = 0;
}
} else if (RIGHT) {
bmp_x += 5;
if ((bmp_x + bmp.getWidth() / bm_count) >= SW) {
bmp_x = SW - bmp.getWidth() / bm_count;
}
}
if (LEFT || RIGHT) {
if (anim_count < 2) {
anim_count++;
} else {
anim_count = 0;
}
}
if (LEFT == false && RIGHT == false) {
anim_count = 0;
}
}

@Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
if (event.getX() < 100) {
if (LEFT == false) {
animation_init = animation_left;
LEFT = true;
}
} else if (event.getX() > (SW - 100)) {
if (RIGHT == false) {
animation_init = animation_right;
RIGHT = true;
}
}
} else if (event.getAction() == MotionEvent.ACTION_UP) {
if (LEFT) {
LEFT = false;
} else if (RIGHT) {
RIGHT = false;
}
}

return true;
}

public void run() {
while (threadFlag) {
draw();
cycle();
try {
Thread.sleep(20);
} catch (Exception ex) {
}
}
}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}

public void surfaceDestroyed(SurfaceHolder holder) {
threadFlag = false;
}
}