Android AutoCompleteTextView Control


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A AutoCompleteTextView is a view that is similar to EditText, except that it shows a list of completion suggestions automatically while the user is typing.

The list of suggestions is displayed in drop down menu. The user can choose an item from there to replace the content of edit box with.

AutoCompleteTextView Attributes

Following are the important attributes related to AutoCompleteTextView control. You can check Android official documentation for complete list of attributes and related methods which you can use to change these attributes are run time.

Attribute Description
android:completionHint This defines the hint displayed in the drop down menu.
android:completionHintView This defines the hint view displayed in the drop down menu.
android:completionThreshold This defines the number of characters that the user must type before completion suggestions are displayed in a drop down menu.
android:dropDownAnchor This is the View to anchor the auto-complete dropdown to.
android:dropDownHeight This specifies the basic height of the dropdown.
android:dropDownHorizontalOffset The amount of pixels by which the drop down should be offset horizontally.
android:dropDownSelector This is the selector in a drop down list.
android:dropDownVerticalOffset The amount of pixels by which the drop down should be offset vertically.
android:dropDownWidth This specifies the basic width of the dropdown.
android:popupBackground This sets the background.

Example

This example will take you through simple steps to show how to create your own Android application using Linear Layout and AutoCompleteTextView.

Step Description
1 You will use Android Studio IDE to create an Android application and name it as GUIDemo3 under a package com.example.guidemo3 as explained in the Hello World Example chapter.
2 Modify src/MainActivity.java file to add a click event.
2 Modify the default content of res/layout/activity_main.xml file to include Android UI control.
3 Define necessary constants in res/values/strings.xml file
4 Run the application to launch Android emulator and verify the result of the changes done in the application.

Following is the content of the modified main activity file src/com.example.guidemo3/MainActivity.java. This file can include each of the fundamental lifecycle methods.

package com.example.guidemo3;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class MainActivity extends Activity {
   AutoCompleteTextView autocompletetextview;
   
   String[] arr = { "Paries,France", "PA,United States","Parana,Brazil", "Padua,Italy", "Pasadena,CA,United States"};
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      autocomplete = (AutoCompleteTextView)             
      findViewById(R.id.autoCompleteTextView1);

      ArrayAdapter<String> adapter = new ArrayAdapter<String>  
      (this,android.R.layout.select_dialog_item, arr);

      autocomplete.setThreshold(2);
      autocomplete.setAdapter(adapter);
   }
}

Following will be the content of res/layout/activity_main.xml 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"
   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=".MainActivity" >
   
   <TextView
      android:id="@+id/textView2"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="25dp"
      android:text="@string/example_autocompletetextview" />
      
   <AutoCompleteTextView
      android:id="@+id/autoCompleteTextView1"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_alignLeft="@+id/textView2"
      android:layout_below="@+id/textView2"
      android:layout_marginTop="54dp"
      android:ems="10" />
    
</RelativeLayout>

Following will be the content of res/values/strings.xml to define these new constants −

<?xml version="1.0" encoding="utf-8"?>
<resources>
   <string name="app_name">GUIDemo3</string>
   <string name="action_settings">Settings</string>
   <string name="example_autocompletetextview">Example showing AutoCompleteTextView</string>
</resources>

Following is the default content of AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.guidemo3"
   android:versionCode="1"
   android:versionName="1.0" >
   
   <uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="22" />
      
   <application
      android:allowBackup="true"
      android:icon="@drawable/ic_launcher"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" >
      
      <activity
         android:name="com.example.guidemo3.MainActivity"
         android:label="@string/app_name" >
      
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      
      </activity>
      
   </application>
</manifest>

Let's try to run your GUIDemo3 application. I assume you had created your AVD while doing environment setup. To run the app from Android Studio, open one of your project's activity files and click Run Eclipse Run Icon icon from the toolbar. Android Studio installs the app on your AVD and starts it and if everything is fine with your setup and application, it will display following Emulator window −

The following screen will appear after "pa" will be typed in AutoCompleteTextView −

Android AutoCompleteTextView Control

Exercise

I will recommend to try above example with different attributes of AutoCompleteTextView in Layout XML file as well at programming time to have different look and feel of the AutoCompleteTextView. Try to make it editable, change to font color, font family, width, textSize etc and see the result. You can also try above example with multiple AutoCompleteTextView controls in one activity.


android_user_interface_controls.htm

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