Textview zoom Animation

package com.kapse.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnTouchListener {

    TextView textView;
    final static float move = 100;
    float ratio = 1.0f;
    int baseDist;
    float baseRatio;

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


        textView = findViewById(R.id.textviewID);
        textView.setTextSize(ratio+20);


    }

    @Override    public boolean onTouch(View v, MotionEvent event) {
        return false;
    }

    @Override    public boolean onTouchEvent(MotionEvent event) {
        if (event.getPointerCount()==2)
        {
            int action = event.getAction();
            int mainaction = action&MotionEvent.ACTION_MASK;
            if (mainaction == MotionEvent.ACTION_POINTER_DOWN)
            {
                baseDist = getDistance(event);
                baseRatio = ratio;
            }
            else            {
                float scale = (getDistance(event)-baseDist)/move;
                float factor = (float) Math.pow(2,scale);
                ratio = Math.min(1024.0f,Math.max(0.1f, baseRatio*factor)); // এখানে ১০২৪ এর জায়গায় ১০০ বা ৫০ দিলে ও হবে কারন এইটা টেক্সস্ট লাস্ট জুম কে বুঝায়                textView.setTextSize(ratio+20);
            }
        }
        return true;
    }

    private int getDistance(MotionEvent event) {
        int dx = (int) (event.getX(0)-event.getX(1));
        int dy = (int) (event.getY(0)-event.getY(1));
        return  (int) (Math.sqrt(dx*dx+dy*dy));
    }
}