ViewAnimator.java :  » Graphics-3D-2D-OpenGL » android-gl » edu » union » android » Android Open Source

package edu.union.android;

import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.view.View;

public class ViewAnimator extends Handler {
  boolean running;
  View view;
  long nextTime;
  long step;
  
  public static final int NEXT = 0;
  
  public ViewAnimator(View view) {
    this(view, 30);
  }
  
  public ViewAnimator(View view, int fps) {
    this.running = false;
    this.view = view;
    this.step = 1000/fps;
  }
  
  public void start() {
    if (!running) {
      running = true;
      Message msg = obtainMessage(NEXT);
      sendMessageAtTime(msg, SystemClock.uptimeMillis());
      nextTime = SystemClock.uptimeMillis()+step;
    }
  }
  
  public void stop() {
    running = false;
  }
  
  public void handleMessage(Message msg) {
    if (running && msg.what == NEXT) {
      view.invalidate();
      msg = obtainMessage(NEXT);
      long current = SystemClock.uptimeMillis();
      if (nextTime < current) {
        nextTime = nextTime + step;
      }
      sendMessageAtTime(msg, nextTime);
      nextTime += step;
    }
  }
}