Pinching and Zooming in and out

[geraldinejns]

I am using at this time the zoomControls to zoom in and out. Instead of using zoomControl from the palette, I want to be able to use my fingers. How can i write code for this. Or what does the code look like for this. The code below works fine. I want to be able to use my forefinger and thumb to zoom in and out.

MainActivity code below

package com.example.geral_000.myapplication;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.ZoomControls;

public class MainActivity extends AppCompatActivity {

ZoomControls zoomIt;
ImageView image;

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

zoomIt = (ZoomControls) findViewById(R.id.zoomControls);
image = (ImageView) findViewById(R.id.imageView);

zoomIt.setOnZoomInClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
float x = image.getScaleX();
float y = image.getScaleY();

image.setScaleX((int) (x+1));
image.setScaleY((int) (y+1));}
});

zoomIt.setOnZoomInClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {

float x = image.getScaleX();
float y = image.getScaleY();

image.setScaleX((int) (x-1));
image.setScaleY((int) (y-1));
}
});
}

}

activity_main below

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
androidaddingBottom="@dimen/activity_vertical_margin"
androidaddingLeft="@dimen/activity_horizontal_margin"
androidaddingRight="@dimen/activity_horizontal_margin"
androidaddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.geral_000.myapplication.MainActivity">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:id="@+id/textView" />

<ZoomControls
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/zoomControls"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:src="@drawable/give_back"
android:layout_centerVertical="true"
android:layout_toRightOf="@+id/textView"
android:layout_toEndOf="@+id/textView"
android:focusableInTouchMode="false" />
</RelativeLayout>