EditText with TextWatcher
Android EditText is a subclass of TextView. EditText is used for entering and modifying text. While using EditText width, we must specify its input type in inputType property of EditText which configures the keyboard according to input.
EditText uses TextWatcher interface to watch change made over EditText. For doing this, EditText calls the addTextChangedListener() method.
Methods of TextWatcher
- beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3): It is executed before making any change over EditText.
- onTextChanged(CharSequence cs, int arg1, int arg2, int arg3): It is executed while making any change over EditText.
- afterTextChanged(Editable arg0): It is executed after change made over EditText.
Example of EditText with TextWatcher()
In this example, we will implement EditText with TextWatcher to search data from ListView.
activity_main.xml
Create an activity_main.xml file in layout folder containing EditText and ListView.
File: activity_main.xml
<?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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.test.searchfromlistview.MainActivity">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/editText"
android:inputType="text"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView"
android:layout_below="@+id/editText"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.test.searchfromlistview.MainActivity">
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/editText"
android:inputType="text"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView"
android:layout_below="@+id/editText"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
Create another file list_item.xml in layout folder which contains data of ListView.
list_item.xm
File: list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/product_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="10dip"
android:textSize="16dip"
android:textStyle="bold"/>
</LinearLayout>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView android:id="@+id/product_name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:padding="10dip"
android:textSize="16dip"
android:textStyle="bold"/>
</LinearLayout>
Activity class
Activity class
package com.example.test.searchfromlistview;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private ListView lv;
private EditText editText;
private ArrayAdapter<String> adapter;
private String products[] = {"Apple", "Banana","Pinapple", "Orange", "Papaya", "Melon",
"Grapes", "Water Melon","Lychee", "Guava", "Mango", "Kivi"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView) findViewById(R.id.listView);
editText = (EditText) findViewById(R.id.editText);
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, products);
lv.setAdapter(adapter);
editText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
adapter.getFilter().filter(cs);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
Toast.makeText(getApplicationContext(),"before text change",Toast.LENGTH_LONG).show();
}
@Override
public void afterTextChanged(Editable arg0) {
Toast.makeText(getApplicationContext(),"after text change",Toast.LENGTH_LONG).show();
}
});
}
}
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.support.v7.app.AppCompatActivity;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private ListView lv;
private EditText editText;
private ArrayAdapter<String> adapter;
private String products[] = {"Apple", "Banana","Pinapple", "Orange", "Papaya", "Melon",
"Grapes", "Water Melon","Lychee", "Guava", "Mango", "Kivi"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView) findViewById(R.id.listView);
editText = (EditText) findViewById(R.id.editText);
adapter = new ArrayAdapter<String>(this, R.layout.list_item, R.id.product_name, products);
lv.setAdapter(adapter);
editText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
adapter.getFilter().filter(cs);
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
Toast.makeText(getApplicationContext(),"before text change",Toast.LENGTH_LONG).show();
}
@Override
public void afterTextChanged(Editable arg0) {
Toast.makeText(getApplicationContext(),"after text change",Toast.LENGTH_LONG).show();
}
});
}
}
Output
