M7350/base/docs/html/resources/tutorials/views/hello-autocomplete.jd

page.title=Auto Complete
parent.title=Hello, Views
parent.link=index.html
@jd:body

<p>To create a text entry widget that provides auto-complete suggestions, use
the {@link android.widget.AutoCompleteTextView} widget. Suggestions are received from a
collection of strings associated with the widget through an {@link
android.widget.ArrayAdapter}.</p>

<p>In this tutorial, you will create a {@link android.widget.AutoCompleteTextView} widget that
provides suggestions for a country name.</p>


<ol>
  <li>Start a new project named <em>HelloAutoComplete</em>.</li>
  <li>Create an XML file named <code>list_item.xml</code> and save it inside the
<code>res/layout/</code> folder. Edit the file to look like this:
<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="10dp"
    android:textSize="16sp"
    android:textColor="#000">
&lt;/TextView>
</pre>
  <p>This file defines a simple {@link android.widget.TextView} that will be used for each
item that appears in the list of suggestions.</p>
  </li>
  <li>Open the <code>res/layout/main.xml</code> file and insert the following:
<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="horizontal"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
    android:padding="5dp">
    &lt;TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Country" />
    &lt;AutoCompleteTextView android:id="@+id/autocomplete_country"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"/>
&lt;/LinearLayout>
</pre>
  <p>The {@link android.widget.TextView} is a label that introduces the {@link
android.widget.AutoCompleteTextView} widget.
</li>

<li>Open <code>HelloAutoComplete.java</code> and insert the following code for the {@link
android.app.Activity#onCreate(Bundle) onCreate()} method:
<pre>
&#64;Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.autocomplete_country);
    ArrayAdapter&lt;String> adapter = new ArrayAdapter&lt;String>(this, R.layout.list_item, COUNTRIES);
    textView.setAdapter(adapter);
}
</pre>

<p>After the content view is set to the <code>main.xml</code> layout, the {@link
android.widget.AutoCompleteTextView} widget is captured from the layout with {@link
android.app.Activity#findViewById(int)}. A new {@link
android.widget.ArrayAdapter} is then initialized to bind the <code>list_item.xml</code> layout
to each list item in the <code>COUNTRIES</code> string array (defined in the next step).
Finally, {@link android.widget.AutoCompleteTextView#setAdapter(T) setAdapter()} is called to
associate the {@link android.widget.ArrayAdapter} with the
{@link android.widget.AutoCompleteTextView} widget so that the string array will populate
the list of suggestions.</p>
</li>

<li>Inside the <code>HelloAutoComplete</code> class, add the string array:
<pre>
static final String[] COUNTRIES = new String[] {
  "Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra",
  "Angola", "Anguilla", "Antarctica", "Antigua and Barbuda", "Argentina",
  "Armenia", "Aruba", "Australia", "Austria", "Azerbaijan",
  "Bahrain", "Bangladesh", "Barbados", "Belarus", "Belgium",
  "Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",
  "Bosnia and Herzegovina", "Botswana", "Bouvet Island", "Brazil", "British Indian Ocean Territory",
  "British Virgin Islands", "Brunei", "Bulgaria", "Burkina Faso", "Burundi",
  "Cote d'Ivoire", "Cambodia", "Cameroon", "Canada", "Cape Verde",
  "Cayman Islands", "Central African Republic", "Chad", "Chile", "China",
  "Christmas Island", "Cocos (Keeling) Islands", "Colombia", "Comoros", "Congo",
  "Cook Islands", "Costa Rica", "Croatia", "Cuba", "Cyprus", "Czech Republic",
  "Democratic Republic of the Congo", "Denmark", "Djibouti", "Dominica", "Dominican Republic",
  "East Timor", "Ecuador", "Egypt", "El Salvador", "Equatorial Guinea", "Eritrea",
  "Estonia", "Ethiopia", "Faeroe Islands", "Falkland Islands", "Fiji", "Finland",
  "Former Yugoslav Republic of Macedonia", "France", "French Guiana", "French Polynesia",
  "French Southern Territories", "Gabon", "Georgia", "Germany", "Ghana", "Gibraltar",
  "Greece", "Greenland", "Grenada", "Guadeloupe", "Guam", "Guatemala", "Guinea", "Guinea-Bissau",
  "Guyana", "Haiti", "Heard Island and McDonald Islands", "Honduras", "Hong Kong", "Hungary",
  "Iceland", "India", "Indonesia", "Iran", "Iraq", "Ireland", "Israel", "Italy", "Jamaica",
  "Japan", "Jordan", "Kazakhstan", "Kenya", "Kiribati", "Kuwait", "Kyrgyzstan", "Laos",
  "Latvia", "Lebanon", "Lesotho", "Liberia", "Libya", "Liechtenstein", "Lithuania", "Luxembourg",
  "Macau", "Madagascar", "Malawi", "Malaysia", "Maldives", "Mali", "Malta", "Marshall Islands",
  "Martinique", "Mauritania", "Mauritius", "Mayotte", "Mexico", "Micronesia", "Moldova",
  "Monaco", "Mongolia", "Montserrat", "Morocco", "Mozambique", "Myanmar", "Namibia",
  "Nauru", "Nepal", "Netherlands", "Netherlands Antilles", "New Caledonia", "New Zealand",
  "Nicaragua", "Niger", "Nigeria", "Niue", "Norfolk Island", "North Korea", "Northern Marianas",
  "Norway", "Oman", "Pakistan", "Palau", "Panama", "Papua New Guinea", "Paraguay", "Peru",
  "Philippines", "Pitcairn Islands", "Poland", "Portugal", "Puerto Rico", "Qatar",
  "Reunion", "Romania", "Russia", "Rwanda", "Sqo Tome and Principe", "Saint Helena",
  "Saint Kitts and Nevis", "Saint Lucia", "Saint Pierre and Miquelon",
  "Saint Vincent and the Grenadines", "Samoa", "San Marino", "Saudi Arabia", "Senegal",
  "Seychelles", "Sierra Leone", "Singapore", "Slovakia", "Slovenia", "Solomon Islands",
  "Somalia", "South Africa", "South Georgia and the South Sandwich Islands", "South Korea",
  "Spain", "Sri Lanka", "Sudan", "Suriname", "Svalbard and Jan Mayen", "Swaziland", "Sweden",
  "Switzerland", "Syria", "Taiwan", "Tajikistan", "Tanzania", "Thailand", "The Bahamas",
  "The Gambia", "Togo", "Tokelau", "Tonga", "Trinidad and Tobago", "Tunisia", "Turkey",
  "Turkmenistan", "Turks and Caicos Islands", "Tuvalu", "Virgin Islands", "Uganda",
  "Ukraine", "United Arab Emirates", "United Kingdom",
  "United States", "United States Minor Outlying Islands", "Uruguay", "Uzbekistan",
  "Vanuatu", "Vatican City", "Venezuela", "Vietnam", "Wallis and Futuna", "Western Sahara",
  "Yemen", "Yugoslavia", "Zambia", "Zimbabwe"
};
</pre>
<p>This is the list of suggestions that will be provided in a drop-down list when the user types into
the {@link android.widget.AutoCompleteTextView} widget.</p>
</li>

<li>Run the application.</li>
</ol>
<p>As you type, you should see something like this:</p>
<img src="images/hello-autocomplete.png" width="150px" />


<h2>More Information</h2>

<p>Note that using a hard-coded string array is not a recommended design practice because your
application code should focus on behavior, not content. Application content such as strings
should be externalized from the code in order to make modifications to the content easier and
facilitate localization of the content. The hard-coded strings are used in this tutorial only to
make it simple and focus on the {@link android.widget.AutoCompleteTextView} widget.
Instead, your application should declare such string arrays in an XML file. This can be done
with a {@code &lt;string-array&lt;} resource in your project {@code res/values/strings.xml} file.
For example:</p>
<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;resources>
    &lt;string-array name="countries_array">
        &lt;item>Bahrain&lt;/item>
        &lt;item>Bangladesh&lt;/item>
        &lt;item>Barbados&lt;/item>
        &lt;item>Belarus&lt;/item>
        &lt;item>Belgium&lt;/item>
        &lt;item>Belize&lt;/item>
        &lt;item>Benin&lt;/item>
    &lt;/string-array>
&lt;/resources>
</pre>
<p>To use these resource strings for the {@link android.widget.ArrayAdapter}, replace the original
{@link android.widget.ArrayAdapter} constructor line with the following:</p>
<pre>
String[] countries = getResources().getStringArray(R.array.countries_array);
ArrayAdapter&lt;String> adapter = new ArrayAdapter&lt;String>(this, R.layout.list_item, countries);
</pre>


<h3>References</h3>
<ul>
	<li>{@link android.widget.ArrayAdapter}</li>
	<li>{@link android.widget.AutoCompleteTextView}</li>
</ul>