Use CountDownTimer to do something repeatly, second example.

It is another approach to do the same job as the previous example "Use CountDownTimer to do something repeatly, updating custom view". Instead of implementing CountDownTimer inside custom view as self running function of custom view, this example implement CountDownTimer in MainActivity, and handle all the timing functions. The custom view simple display the graphic only.


MainActivity.java

package com.example.androidcountdowntimer;

import android.app.Activity;
import android.os.Bundle;
import android.os.CountDownTimer;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity{
 
 CountDownTimer countDownTimer;
  
 int state;
 final static int STATE_IDLE = 0;
 final static int STATE_RED = 1;
 final static int STATE_GREEN = 2;
 final static int STATE_BLUE = 3;

 TextView myState, myCounter;
 Button btnStart;
 
 SpotView mySpotView;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  mySpotView = (SpotView)findViewById(R.id.myspotview);

  myState = (TextView) findViewById(R.id.mystate);
  
  myCounter = (TextView) findViewById(R.id.mycounter);
  btnStart = (Button) findViewById(R.id.start);
  btnStart.setOnClickListener(btnStartOnClickListener);
  
  state = STATE_IDLE;

 }
 
 OnClickListener btnStartOnClickListener = 
  new OnClickListener(){

   @Override
   public void onClick(View v) {
    
    if(countDownTimer!=null){
       countDownTimer.cancel();   
    }
    
    state = STATE_RED;
    
    countDownTimer = new CountDownTimer(3000, 500) {

     @Override
     public void onTick(long millisUntilFinished) {
      myCounter.setText("onTick: " + millisUntilFinished);
     }

     @Override
     public void onFinish() {
      if(state == STATE_RED){
       state = STATE_GREEN;
       mySpotView.setSpots(false, true, false);
       myState.setText("GREEN");
      }else if(state == STATE_GREEN){
       state = STATE_BLUE;
       mySpotView.setSpots(false, false, true);
       myState.setText("BLUE");
      }else if(state == STATE_BLUE){
       state = STATE_RED;
       mySpotView.setSpots(true, false, false);
       myState.setText("RED");
      }
      
      countDownTimer.start(); 
     }
    };
    
    mySpotView.setSpots(true, false, false);
    myState.setText("RED");
    countDownTimer.start();
   }  
 };

}

SpotView.java

package com.example.androidcountdowntimer;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

public class SpotView extends View{
 
 boolean spotRedOn, spotGreenOn, spotBlueOn;
 
 Paint paintRed, paintGreen, paintBlue;

 public SpotView(Context context) {
  super(context);
  init();
 }

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

 public SpotView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  init();
 }
 
 private void init(){

  paintRed = new Paint();
  paintRed.setColor(Color.RED);
  paintRed.setStrokeWidth(1);
  paintRed.setStyle(Paint.Style.FILL);
  
  paintGreen = new Paint();
  paintGreen.setColor(Color.GREEN);
  paintGreen.setStrokeWidth(1);
  paintGreen.setStyle(Paint.Style.FILL);
  
  paintBlue = new Paint();
  paintBlue.setColor(Color.BLUE);
  paintBlue.setStrokeWidth(1);
  paintBlue.setStyle(Paint.Style.FILL);
  
  spotRedOn = spotGreenOn = spotBlueOn = false;
 }

 
 public void setSpots(boolean r, boolean g, boolean b){
  spotRedOn = r;
  spotGreenOn = g;
  spotBlueOn = b;
  invalidate();
 }

 @Override
 protected void onDraw(Canvas canvas) {
  
  float w = getWidth();
  float h = getHeight();
  
  if(spotRedOn){
   canvas.drawCircle(w/4, h/2, 100, paintRed);
  }
  
  if(spotGreenOn){
   canvas.drawCircle(w/2, h/2, 100, paintGreen);
  }
  
  if(spotBlueOn){
   canvas.drawCircle(3*w/4, h/2, 100, paintBlue);
  }
 }

}

Keep using the same layout in previous example.