import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.SystemClock;
import android.util.Log;
import android.view.Menu;
import android.widget.Chronometer;
 
public class CustomChronometerActivity extends Activity {
	private static final String TAG = "CustomChronometerActivity";
	private static final String MS_ELAPSED = "com.etc.etc.MsElapsed";
 
	private MyChronometer chrono;
 
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
 
        //start the chronometer
        chrono = new MyChronometer(this);
        chrono.start();
        setContentView(chrono);
    }
 
	@Override
	protected void onPause() {
		Log.i(TAG, "onPause()");
		super.onPause();
		chrono.stop();
	}
 
	@Override
	protected void onResume() {
		Log.i(TAG, "onResume()");
		super.onResume();
		chrono.start();
	}
 
	@Override
	protected void onSaveInstanceState(Bundle outState) {
		super.onSaveInstanceState(outState);
		Log.i(TAG, "onSaveInstanceState()");
		chrono.stop();
		outState.putInt(MS_ELAPSED, chrono.getMsElapsed());
	}
 
	@Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
		super.onRestoreInstanceState(savedInstanceState);
		Log.i(TAG, "onRestoreInstanceState()");
		int ms = savedInstanceState.getInt(MS_ELAPSED);
		chrono.setMsElapsed(ms);
		chrono.start();
	}
 
	class MyChronometer extends Chronometer {
 
		public int msElapsed;
		public boolean isRunning = false;
 
		public MyChronometer(Context context) {
			super(context);
		}
 
		public int getMsElapsed() {
			return msElapsed;
		}
 
		public void setMsElapsed(int ms) {
			setBase(getBase() - ms);
			msElapsed  = ms;
		}
 
		@Override
		public void start() {
			super.start();
			setBase(SystemClock.elapsedRealtime() - msElapsed);
			isRunning = true;
		}
 
		@Override
		public void stop() {
			super.stop();
			if(isRunning) {
				msElapsed = (int)(SystemClock.elapsedRealtime() - this.getBase());
			}
			isRunning = false;
		}
	}
}