Android: append a character to my textview after every second

I want to append a dot(.) to my textview after every second. When it reaches 3 dots, it should reset to a single dot and continue the loop like this:

mytext.
mytext..
mytext...
mytext.
mytext..
mytext...

and so on

My java code:

MaterialTextView txt = alertdialog.findViewById(R.id.dialogtext);

new Timer().scheduleAtFixedRate(new TimerTask(){
    @Override
    public void run(){
        for(int i=0; i<3; i++){
            for(int j=0; j<i; j++){
                   //I am stuck here                         
            }
        }
    }
},0,1000);

I have no idea, how to write the logic for getting my desired objective. Please guide me.

>Solution :

If you want to apply this like googles speech listener starts "Listening…"

Then you can use this below example.

Shape: Create a Drawable shape, (name: dot_background)

<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="oval">
  <solid android:color="#808080" />
</shape>

xml part , (name: activity_main)

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/dots_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">

<ImageView
    android:id="@+id/dot1"
    android:layout_width="12dp"
    android:layout_height="12dp"
    android:background="@drawable/dot_background"
    android:visibility="invisible" />

<ImageView
    android:id="@+id/dot2"
    android:layout_width="12dp"
    android:layout_height="12dp"
    android:background="@drawable/dot_background"
    android:visibility="invisible" />

<ImageView
    android:id="@+id/dot3"
    android:layout_width="12dp"
    android:layout_height="12dp"
    android:background="@drawable/dot_background"
    android:visibility="invisible" />

</LinearLayout>

Java File:

    import android.os.Bundle;
    import android.os.Handler;
    import android.support.v7.app.AppCompatActivity;
    import android.view.animation.AlphaAnimation;
    import android.view.animation.Animation;
    import android.widget.ImageView;
    import android.widget.LinearLayout;

    public class MainActivity extends AppCompatActivity {

        private static final long DOTS_ANIMATION_DELAY = 500; // Delay between dot visibility changes

        private LinearLayout dotsContainer;
        private Handler handler;
        private Runnable dotsAnimationRunnable;
        private boolean isVisible = false;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            dotsContainer = findViewById(R.id.dots_container);
            handler = new Handler();

            dotsAnimationRunnable = new Runnable() {
                @Override
                public void run() {
                    toggleDotsVisibility();
                    handler.postDelayed(this, DOTS_ANIMATION_DELAY);
                }
            };
        }

        @Override
        protected void onResume() {
            super.onResume();
            startDotsAnimation();
        }

        @Override
        protected void onPause() {
            super.onPause();
            stopDotsAnimation();
        }

        private void startDotsAnimation() {
            handler.postDelayed(dotsAnimationRunnable, DOTS_ANIMATION_DELAY);
        }

        private void stopDotsAnimation() {
            handler.removeCallbacks(dotsAnimationRunnable);
        }

        private void toggleDotsVisibility() {
            for (int i = 0; i < dotsContainer.getChildCount(); i++) {
                ImageView dot = (ImageView) dotsContainer.getChildAt(i);
                if (isVisible) {
                    fadeOut(dot);
                } else {
                    fadeIn(dot);
                }
            }
            isVisible = !isVisible;
        }

        private void fadeIn(ImageView dot) {
            Animation fadeInAnimation = new AlphaAnimation(0, 1);
            fadeInAnimation.setDuration(300);
            dot.startAnimation(fadeInAnimation);
            dot.setVisibility(ImageView.VISIBLE);
        }

        private void fadeOut(ImageView dot) {
            Animation fadeOutAnimation = new AlphaAnimation(1, 0);
            fadeOutAnimation.setDuration(300);
            dot.startAnimation(fadeOutAnimation);
            dot.setVisibility(ImageView.INVISIBLE);
        }
    }