Monitor user action on EditText

This example implement TextWatcher for EditText, such that we can detect user action on EditText, no extra “Enter” button is need.

package com.blogspot.android_er.androidedittextchanged;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

EditText editText;
TextView tvMsg, tvInfo;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText)findViewById(R.id.edittext);
tvMsg = (TextView)findViewById(R.id.msg);
tvInfo = (TextView)findViewById(R.id.info);

editText.addTextChangedListener(myTextWatcher);
}

TextWatcher myTextWatcher = new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence,
int i, int i1, int i2) {
tvInfo.setText("beforeTextChanged(): \n"
+ charSequence + "\n"
+ i + "\n"
+ i1 + "\n"
+ i2);
}

@Override
public void onTextChanged(CharSequence charSequence,
int i, int i1, int i2) {
tvInfo.setText("onTextChanged(): \n"
+ charSequence + "\n"
+ i + "\n"
+ i1 + "\n"
+ i2);
tvMsg.setText(charSequence);
}

@Override
public void afterTextChanged(Editable editable) {
/*
String s = editable.toString();
tvInfo.setText("afterTextChanged(): \n"
+ s);
*/
}
};
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:layout_margin="20dp"
android:orientation="vertical"
tools:context="com.blogspot.android_er.androidedittextchanged.MainActivity">

<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://android-er.blogspot.com/"
android:textStyle="bold"/>

<EditText
android:id="@+id/edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter text"
android:textSize="24dp"/>
<TextView
android:id="@+id/msg"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textSize="24dp"/>
<TextView
android:id="@+id/info"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textStyle="italic"
android:textSize="20dp"/>

</LinearLayout>


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