water drop animations /circular ripple animations in android ?

package com.example.samplebutton;

import android.animation.ObjectAnimator;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RadialGradient;
import android.graphics.Region;
import android.graphics.Shader;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.animation.AccelerateInterpolator;
import android.widget.Button;
import android.widget.RelativeLayout;

public class MainActivity extends Activity {

Button button;
RelativeLayout relatv;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
relatv=(RelativeLayout)findViewById(R.id.relatv);
// button = (Button) findViewById(R.id.lll);

MyButton butto=new MyButton(MainActivity.this);
relatv.addView(butto);


}

// ///////////////////

public class MyButton extends Button {

private float mDownX;
private float mDownY;

private float mRadius;

private Paint mPaint;

public MyButton(final Context context) {
super(context);
init();
}

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

public MyButton(final Context context, final AttributeSet attrs,
final int defStyle) {
super(context, attrs, defStyle);
init();
}

private void init() {
mPaint = new Paint();
mPaint.setAlpha(100);
}

@Override
public boolean onTouchEvent(@NonNull final MotionEvent event) {
if (event.getActionMasked() == MotionEvent.ACTION_UP) {
mDownX = event.getX();
mDownY = event.getY();

ObjectAnimator animator = ObjectAnimator.ofFloat(this,
"radius", 0, getWidth() * 3.0f);
animator.setInterpolator(new AccelerateInterpolator());
animator.setDuration(400);
animator.start();
}
return super.onTouchEvent(event);
}

public void setRadius(final float radius) {
mRadius = radius;
if (mRadius > 0) {
RadialGradient radialGradient = new RadialGradient(mDownX,
mDownY, mRadius * 3, Color.TRANSPARENT, Color.BLACK,
Shader.TileMode.MIRROR);
mPaint.setShader(radialGradient);
}
invalidate();
}

private Path mPath = new Path();
private Path mPath2 = new Path();

@Override
protected void onDraw(@NonNull final Canvas canvas) {
super.onDraw(canvas);

mPath2.reset();
mPath2.addCircle(mDownX, mDownY, mRadius, Path.Direction.CW);

canvas.clipPath(mPath2);

mPath.reset();
mPath.addCircle(mDownX, mDownY, mRadius / 3, Path.Direction.CW);

canvas.clipPath(mPath, Region.Op.DIFFERENCE);

canvas.drawCircle(mDownX, mDownY, mRadius, mPaint);
}
}

// ///////////////////////

}