Android selects TextView text

I read a post on the Internet to learn how to freely select TextView text. I want to analyze the source code, but the network speed is not good. I can't open it online after I download the source code.

I will post the implementation code, basically the code on that post: after reading the source code, I will add it.

package com.example.view;import android.content.Context;import android.graphics.Color;import android.text.Layout;import android.text.Selection;import android.text.method.MovementMethod;import android.util.AttributeSet;import android.view.ContextMenu;import android.view.Gravity;import android.view.MotionEvent;import android.widget.EditText;public class SelectedTextView extends EditText{private int off;public SelectedTextView(Context context) {super(context);init();}public SelectedTextView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);init();}public SelectedTextView(Context context, AttributeSet attrs) {super(context, attrs);init();}private void init(){setGravity(Gravity.TOP);this.setBackgroundColor(Color.WHITE);}@Overrideprotected boolean getDefaultEditable() {return false;} @Overridepublic boolean onTouchEvent(MotionEvent event) {int  action = event.getAction();          Layout layout = getLayout();          int  line =  0 ;          switch (action) {          case  MotionEvent.ACTION_DOWN:              line = layout.getLineForVertical(getScrollY()+ (int )event.getY());                      off = layout.getOffsetForHorizontal(line, (int )event.getX());              Selection.setSelection(getEditableText(), off);              break ;          case  MotionEvent.ACTION_MOVE:          case  MotionEvent.ACTION_UP:              line = layout.getLineForVertical(getScrollY()+(int )event.getY());               int  curOff = layout.getOffsetForHorizontal(line, ( int )event.getX());                          Selection.setSelection(getEditableText(), off, curOff);              break ;          }          return   true ;  } }

Layout File

<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" >    <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_centerHorizontal="true"        android:layout_centerVertical="true"        android:padding="@dimen/padding_medium"        android:text="@string/hello_world"        tools:context=".MainActivity" />    <com.example.view.SelectedTextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="abcdefghijklmnopqrstuvwxyzxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"        /></RelativeLayout>