M7350/base/docs/html/guide/topics/search/search-dialog.jd

page.title=Using the Android Search Dialog
parent.title=Search
parent.link=index.html
@jd:body

<div id="qv-wrapper">
<div id="qv">
<h2>In this document</h2>
<ol>
<li><a href="#TheBasics">The Basics</a></li>
<li><a href="#SearchableConfiguration">Creating a Searchable Configuration</a></li>
<li><a href="#SearchableActivity">Creating a Searchable Activity</a>
  <ol>
    <li><a href="#DeclaringSearchableActivity">Declaring a searchable Activity</a></li>
    <li><a href="#PerformingSearch">Performing a search</a></li>
  </ol>
</li>
<li><a href="#InvokingTheSearchDialog">Invoking the Search Dialog</a>
  <ol>
    <li><a href="#LifeCycle">The impact of the search dialog on your Activity life-cycle</a></li>
  </ol>
</li>
<li><a href="#SearchContextData">Passing Search Context Data</a></li>
<li><a href="#VoiceSearch">Adding Voice Search</a></li>
</ol>

<h2>Key classes</h2>
<ol>
<li>{@link android.app.SearchManager}</li>
</ol>

<h2>Related samples</h2>
<ol>
<li><a href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable
Dictionary</a></li>
</ol>

<h2>Downloads</h2>
<ol>
<li><a href="{@docRoot}shareables/search_icons.zip">search_icons.zip</a></li>
</ol>

<h2>See also</h2>
<ol>
<li><a href="adding-recent-query-suggestions.html">Adding Recent Query Suggestions</a></li>
<li><a href="adding-custom-suggestions.html">Adding Custom Suggestions</a></li>
<li><a href="searchable-config.html">Searchable Configuration</a></li>
</ol>

</div>
</div>

<p>When you want to implement search in your application, the last thing you should have to worry
about is where to put the search box. When you implement search with the Android search framework,
you don't have to. When the user invokes search, a search dialog appears at the top of the screen
with your application icon to the left of the search box. When the user executes the search, your
application receives the query so it can search your application's data. An example of the search
dialog is shown in figure 1.</p>

<p>This guide shows you how to set up your application to provide search in the search
dialog. When you use the search dialog, you provide a standardized search
experience and can add features such as voice search and search suggestions.</p>


<h2 id="TheBasics">The Basics</h2>

<div class="figure" style="width:250px">
<img src="{@docRoot}images/search/search-ui.png" alt="" height="417" />
<p class="img-caption"><strong>Figure 1.</strong> Screenshot of an application's search dialog.</p>
</div>

<p>The Android search framework manages the search dialog for your application. You never need
to draw it or worry about where it is, and your Activity is not interrupted when the search dialog
appears. The Search Manager ({@link android.app.SearchManager}) is the component that does this work
for you. It manages the life of the search dialog and sends your application the user's search
query.</p>

<p>When the user executes a search, the Search Manager creates an {@link android.content.Intent} to
pass the search query to the Activity that you've declared to handle searches. Basically, all you
need is an Activity that receives the search Intent, performs the search, and presents the results.
Specifically, you need the following:</p>

<dl>
  <dt>A searchable configuration</dt>
  <dd>An XML file that configures the search dialog and includes settings for features such as voice
search, search suggestion, and the hint text.</dd>
  <dt>A searchable Activity</dt>
  <dd>The {@link android.app.Activity} that receives the search query, then searches your data and
displays the search results.</dd>
  <dt>A mechanism by which the user can invoke search</dt>
  <dd>The device search key invokes the search dialog, by default. However, a dedicated search key
is not guaranteed on all devices, so provide another means by which the user can invoke a search,
such as a search button in the Options Menu or elsewhere in the Activity UI.</dd>
</dl>



<h2 id="SearchableConfiguration">Creating a Searchable Configuration</h2>

<p>The searchable configuration is an XML file that defines several settings for the search
dialog in your application. This file is traditionally named {@code searchable.xml} and must be
saved in the {@code res/xml/} project directory.</p>

<p>The file must consist of the {@code &lt;searchable&gt;} element as the root node and specify one
or more attributes that configure your search dialog. For example:</p>

<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;searchable xmlns:android="http://schemas.android.com/apk/res/android"
    android:label="@string/app_label"
    android:hint="@string/search_hint" >
&lt;/searchable>
</pre>

<p>The {@code android:label} attribute is the only required attribute and points to a string
resource, which should be the same as the application name. This label isn't actually visible to the
user until you enable suggestions for Quick Search Box, at which point, this label is visible in the
list of Searchable items in the system Settings.</p>

<p>Though it's not required, we recommend that you always include the {@code android:hint}
attribute, which provides a hint string in the search dialog's text box before the user
enters their query. The hint is important because it provides important clues to users about what
they can search.</p>

<p class="note"><strong>Tip:</strong> For consistency among other
Android applications, you should format the string for {@code android:hint} as "Search
<em>&lt;content-or-product&gt;</em>". For example, "Search songs and artists" or "Search
YouTube".</p>

<p>The {@code &lt;searchable&gt;} element accepts several other attributes. Most attributes apply
only when configuring features such as search suggestions and voice search.</p>

<p>For more details about the searchable configuration file, see the <a
href="{@docRoot}guide/topics/search/searchable-config.html">Searchable Configuration</a>
reference.</p>



<h2 id="SearchableActivity">Creating a Searchable Activity</h2>

<p>When the user executes a search from the search dialog, the Search Manager takes the query
and sends it to your searchable {@link android.app.Activity} in the {@link
android.content.Intent#ACTION_SEARCH} {@link android.content.Intent}. Your searchable Activity
then searches your data using the query and presents the results to the user.</p>

<p>In order for the Search Manager to know where to deliver the search query, you must declare your
searchable Activity in the Android manifest file.</p>


<h3 id="DeclaringSearchableActivity">Declaring a searchable Activity</h3>

<p>If you don't have one already, create an {@link android.app.Activity} that performs
searches and present search results. To set up this Activity as your searchable Activity:</p>
<ol>
  <li>Declare the Activity to accept the {@link android.content.Intent#ACTION_SEARCH} {@link
android.content.Intent}, in an <a
href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code &lt;intent-filter&gt;}</a>
element.</li>
  <li>Apply the searchable configuration, in a <a
href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
element.</li>
</ol>

<p>For example:</p>

<pre>
&lt;application ... >
    &lt;activity android:name=".MySearchableActivity" >
        &lt;intent-filter>
            &lt;action android:name="android.intent.action.SEARCH" />
        &lt;/intent-filter>
        &lt;meta-data android:name="android.app.searchable"
                   android:resource="@xml/searchable"/>
    &lt;/activity>
    ...
&lt;/application>
</pre>

<p>The {@code &lt;meta-data&gt;} element must include the {@code android:name} attribute with a
value of {@code "android.app.searchable"} and the {@code android:resource} attribute with a
reference to the searchable configuration file (in this example, it
refers to the {@code res/xml/searchable.xml} file).</p>

<p class="note"><strong>Note:</strong> The {@code &lt;intent-filter&gt;} does not need a <a
href="{@docRoot}guide/topics/manifest/category-element.html">{@code &lt;category&gt;}</a> with the
{@code DEFAULT} value, because the Search Manager delivers the {@link
android.content.Intent#ACTION_SEARCH} Intent explicitly to your searchable Activity by name.</p>

<p>The search dialog is not, by default, available from every Activity of your
application. Rather, the search dialog is presented to users only when they
invoke search from a searchable context of your application. A searchable context is any Activity
for which you have
declared searchable meta-data in the manifest file. For example, the searchable Activity itself
(declared in the manifest snippet above) is
a searchable context because it includes meta-data that defines the
searchable configuration. Any other Activity in your application is not a searchable context, by
default, and thus, does not reveal the search dialog. However, you probably do want the search
dialog available from your other activities (and to launch the searchable Activity when the user
executes a search). You can do exactly that.</p>

<p>If you want all of your activities to provide the search dialog, add another {@code
&lt;meta-data&gt;} element inside the {@code
&lt;application&gt;} element. Use this element to declare the existing searchable Activity as the
default searchable Activity. For example:</p>

<pre>
&lt;application ... >
    &lt;activity android:name=".MySearchableActivity" >
        &lt;intent-filter>
            &lt;action android:name="android.intent.action.SEARCH" />
        &lt;/intent-filter>
        &lt;meta-data android:name="android.app.searchable"
                   android:resource="@xml/searchable"/>
    &lt;/activity>
    &lt;activity android:name=".AnotherActivity" ... >
    &lt;/activity>
    &lt;!-- declare the default searchable Activity for the whole app --&gt;
    <b>&lt;meta-data android:name="android.app.default_searchable"
               android:value=".MySearchableActivity" /&gt;</b>
    ...
&lt;/application>
</pre>

<p>The {@code &lt;meta-data&gt;} element with the {@code android:name} attribute value of
{@code "android.app.default_searchable"} specifies a default searchable Activity for the context in
which it is placed (which, in this case, is the entire application). The searchable Activity to
use is specified with the {@code android:value} attribute. All other activities in the
application, such as {@code AnotherActivity}, are now considered a searchable context and can invoke
the search dialog. When a search is executed, {@code MySearchableActivity} is launched to handle
the search query.</p>

<p>You can also control which activities provide search at a more granular level.
To specify only an individual Activity as a searchable context, place the {@code
&lt;meta-data&gt;} with the {@code
"android.app.default_searchable"} name inside the respective {@code &lt;activity&gt;}
element (rather than inside the {@code &lt;application&gt;} element). While uncommon, you
can also create more than one searchable Activity and provide each one in different contexts of your
application, either by declaring a different searchable Activity in each {@code &lt;activity&gt;}
element, or by declaring a default searchable Activity for the entire application and then
overriding it with a {@code &lt;meta-data&gt;} element inside certain activities. (You might do
this if you want to search different sets of data that cannot be handled by the same
searchable Activity, depending on the currently open Activity.)</p>


<h3 id="PerformingSearch">Performing a search</h3>

<p>Once you have declared your searchable Activity, performing a search for the user involves
three steps:</p>
<ol>
  <li><a href="#ReceivingTheQuery">Receiving the query</a></li>
  <li><a href="#SearchingYourData">Searching your data</a></li>
  <li><a href="#PresentingTheResults">Presenting the results</a></li>
</ol>

<p>Traditionally, your search results should be presented in a {@link android.widget.ListView}, so
you might want your searchable Activity to extend {@link android.app.ListActivity}, which
provides easy access to {@link android.widget.ListView} APIs. (See the <a
href="{@docRoot}resources/tutorials/views/hello-listview.html">List View Tutorial</a> for a simple
{@link android.app.ListActivity} sample.)</p>


<h4 id="ReceivingTheQuery">Receiving the query</h4>

<p>When a user executes a search from the search dialog, the Search Manager sends the {@link
android.content.Intent#ACTION_SEARCH} {@link android.content.Intent} to your searchable Activity.
This Intent carries the search query in the
{@link android.app.SearchManager#QUERY QUERY} string extra. You must check for
this Intent when the Activity starts and extract the string. For example, here's how you can get the
query when your Activity starts:</p>

<pre>
&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.search);

    Intent intent = getIntent();

    if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
      String query = intent.getStringExtra(SearchManager.QUERY);
      doMySearch(query);
    }
}
</pre>

<p>The {@link android.app.SearchManager#QUERY QUERY} string is always included with
the {@link android.content.Intent#ACTION_SEARCH} Intent. In this example, the query is
retrieved and passed to a local {@code doMySearch()} method where the actual search operation
is done.</p>


<h4 id="SearchingYourData">Searching your data</h4>

<p>The process of storing and searching your data is unique to your application.
You can store and search your data in many ways, but this guide does not show you how to store your
data and search it. Storing and searching your data is something you should carefully consider in
terms of your needs and your data. However, here are some tips you might be able to apply:</p>

  <ul>
    <li>If your data is stored in a SQLite database on the device, performing a full-text search
(using FTS3, rather than a LIKE query) can provide a more robust search across text data and can
produce results significantly faster. See <a href="http://sqlite.org/fts3.html">sqlite.org</a>
for information about FTS3 and the {@link android.database.sqlite.SQLiteDatabase} class for
information about SQLite on Android. Also look at the <a
href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
application to see a complete SQLite implementation that performs searches with FTS3.</li>
    <li>If your data is stored online, then the perceived search performance might be
inhibited by the user's data connection. You might want to display a spinning progress wheel until
your search returns. See {@link android.net} for a reference of network APIs and <a
href="{@docRoot}guide/topics/ui/dialogs.html#ProgressDialog">Creating a Progress Dialog</a> to see
how you can display a progress wheel.</li>
  </ul>


<div class="sidebox-wrapper">
<div class="sidebox">
<h2>About Adapters</h2>
<p>An Adapter binds individual items from a set of data into individual {@link
android.view.View} objects. When the Adapter
is applied to a {@link android.widget.ListView}, the Views are injected as individual items of the
list. {@link
android.widget.Adapter} is simply an interface, so implementations such as {@link
android.widget.CursorAdapter} (for binding data from a {@link android.database.Cursor}) are needed.
If none of the existing implementations work for your data, then you should implement your own from
{@link android.widget.BaseAdapter}. Install the SDK Samples package for API Level 4 to see the
original version of the Searchable Dictionary, which creates a custom BaseAdapter.</p>
</div>
</div>

<p>Regardless of where your data lives and how you search it, we recommend that you return search
results to your searchable Activity with an {@link android.widget.Adapter}. This way, you can easily
present all the search results in a {@link android.widget.ListView}. If your data comes from a
SQLite database query, then you can apply your results to a {@link android.widget.ListView}
using a {@link android.widget.CursorAdapter}. If your data comes in some other type of format, then
you can create an extension of the {@link android.widget.BaseAdapter}.</p>

<h4 id="PresentingTheResults">Presenting the results</h4>

<p>Presenting your search results is mostly a UI detail that is not handled by the search APIs.
However, one option is to create your searchable Activity to extend {@link
android.app.ListActivity} and call {@link
android.app.ListActivity#setListAdapter(ListAdapter)}, passing it an {@link
android.widget.Adapter} that is bound to your data. This injects all the
results into the Activity {@link android.widget.ListView}.</p>

<p>For more help presenting your results, see the {@link android.app.ListActivity}
documentation.</p>

<p>Also see the <a
href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
for an a complete demonstration of how to search an SQLite database and use an
{@link android.widget.Adapter} to provide results in a {@link android.widget.ListView}.</p>



<h2 id="InvokingTheSearchDialog">Invoking the Search Dialog</h2>

<p>Once you have a searchable Activity, invoking the search dialog is easy. Many Android
devices provide a dedicated SEARCH key, which reveals the search dialog when the user presses it
from a searchable context of your application. However, you should not assume that a SEARCH
key is available on the user's device and should always provide a search button in your UI that
invokes search.</p>

<p>To invoke search from your Activity, call {@link android.app.Activity#onSearchRequested()}.</p>

<p>For instance, you should provide a menu item in your <a
href="{@docRoot}guide/topics/ui/menus.html#options-menu">Options Menu</a> or a button in your UI to
invoke search with this method. The <a
href="{@docRoot}shareables/search_icons.zip">search_icons.zip</a> file includes icons for
medium and high density screens, which you can use for your search menu item or button (low density
screens automatically scale-down the hdpi image by one half). </p>

<!-- ... maybe this should go into the Creating Menus document ....
<p>If you chose to provide a shortcut key for the menu item,  using {@link
android.view.MenuItem#setAlphabeticShortcut(char)}, then SearchManager.MENU_KEY is the recommended
key character, representing the default search key.</p>
-->

<p>You can also enable "type-to-search" functionality, which reveals the search dialog when the
user starts typing on the keyboard and the keystrokes are inserted into the search dialog. You can
enable type-to-search in your Activity by calling
{@link android.app.Activity#setDefaultKeyMode(int) setDefaultKeyMode}({@link
android.app.Activity#DEFAULT_KEYS_SEARCH_LOCAL}) during your Activity's
{@link android.app.Activity#onCreate(Bundle) onCreate()} method.</p>


<h3 id="LifeCycle">The impact of the search dialog on your Activity lifecycle</h3>

<p>The search dialog is a {@link android.app.Dialog} that floats at the top of the
screen. It does not cause any change in the Activity stack, so when the search dialog appears, no
lifecycle methods for the currently open Activity (such as {@link
android.app.Activity#onPause()}) are called. Your Activity just loses input focus as it is given to
the search dialog.
</p>

<p>If you want to be notified when search is invoked, override the {@link
android.app.Activity#onSearchRequested()} method. When the system calls this method, you can do any
work you want to when your Activity looses input focus to the search dialog (such as pause
animations). Unless you are <a href="#SearchContextData">passing search context data</a>
(discussed below), you should end the method by calling the super class implementation. For
example:</p>

<pre>
&#64;Override
public boolean onSearchRequested() {
    pauseSomeStuff();
    return super.onSearchRequested();
}
</pre>

<p>If the user cancels search by pressing the BACK key, the Activity in which search was
invoked re-gains input focus. You can register to be notified when the search dialog is
closed with {@link android.app.SearchManager#setOnDismissListener(SearchManager.OnDismissListener)
setOnDismissListener()}
and/or {@link android.app.SearchManager#setOnCancelListener(SearchManager.OnCancelListener)
setOnCancelListener()}. You
should need to register only the {@link android.app.SearchManager.OnDismissListener
OnDismissListener}, because it is called every time the search dialog closes. The {@link
android.app.SearchManager.OnCancelListener OnCancelListener} only pertains to events in which the
user explicitly exited the search dialog, so it is not called when a search is executed (in which
case, the search dialog naturally disappears).</p>

<p>If the current Activity is not the searchable Activity, then the normal Activity lifecycle
events are triggered once the user executes a search (the current Activity receives {@link
android.app.Activity#onPause()} and so forth, as
described in <a href="{@docRoot}guide/topics/fundamentals.html#lcycles">Application
Fundamentals</a>). If, however, the current Activity is the searchable Activity, then one of two
things happens:</p>

<ol type="a">
  <li>By default, the searchable Activity receives the {@link
android.content.Intent#ACTION_SEARCH} Intent with a call to {@link
android.app.Activity#onCreate(Bundle) onCreate()} and a new instance of the
Activity is brought to the top of the Activity stack. There are now two instances of your
searchable Activity in the Activity stack (so pressing the BACK key goes back to the previous
instance of the searchable Activity, rather than exiting the searchable Activity).</li>
  <li>If you set {@code android:launchMode} to "singleTop", then the
searchable Activity receives the {@link android.content.Intent#ACTION_SEARCH} Intent with a call
to {@link android.app.Activity#onNewIntent(Intent)}, passing the new {@link
android.content.Intent#ACTION_SEARCH} Intent here. For example, here's how you might handle
this case, in which the searchable Activity's launch mode is "singleTop":
<pre>
&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.search);
    handleIntent(getIntent());
}

&#64;Override
protected void onNewIntent(Intent intent) {
    setIntent(intent);
    handleIntent(intent);
}

private void handleIntent(Intent intent) {
    if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
      String query = intent.getStringExtra(SearchManager.QUERY);
      doMySearch(query);
    }
}
</pre>

<p>Compared to the example code in the section about <a href="#PerformingSearch">Performing a
Search</a>, all the code to handle the
search Intent is now in the {@code handleIntent()} method, so that both {@link
android.app.Activity#onCreate(Bundle)
onCreate()} and {@link android.app.Activity#onNewIntent(Intent) onNewIntent()} can execute it.</p>

<p>When the system calls {@link android.app.Activity#onNewIntent(Intent)}, the Activity has
not been restarted, so the {@link android.app.Activity#getIntent()} method
returns the same Intent that was received with {@link
android.app.Activity#onCreate(Bundle) onCreate()}. This is why you should call {@link
android.app.Activity#setIntent(Intent)} inside {@link
android.app.Activity#onNewIntent(Intent)} (so that the Intent saved by the Activity is updated in
case you call {@link android.app.Activity#getIntent()} in the future).</p>

</li>
</ol>

<p>The second scenario using "singleTop" launch mode is usually ideal, because chances are good that
once a search is done, the user will perform additional searches and it's a bad experience if your
application creates multiple instances of the searchable Activity. So, we recommend that you set
your searchable Activity to "singleTop" launch mode in the application
manifest. For example:</p>

<pre>
&lt;activity android:name=".MySearchableActivity"
          <b>android:launchMode="singleTop"</b> >
    &lt;intent-filter>
        &lt;action android:name="android.intent.action.SEARCH" />
    &lt;/intent-filter>
    &lt;meta-data android:name="android.app.searchable"
                      android:resource="@xml/searchable"/>
  &lt;/activity>
</pre>



<h2 id="SearchContextData">Passing Search Context Data</h2>

<p>To refine your search criteria from the current Activity instead of depending only on the user's
search query, you can provide additional data in the Intent that the Search Manager sends to your
searchable Activity. In a simple case, you can make your refinements inside the searchable
Activity, for every search made, but if your
search criteria varies from one searchable context to another, then you can pass whatever data
is necessary to refine your search in the {@link android.app.SearchManager#APP_DATA} {@link
android.os.Bundle}, which is included in the {@link android.content.Intent#ACTION_SEARCH}
Intent.</p>

<p>To pass this kind of data to your searchable Activity, override  {@link
android.app.Activity#onSearchRequested()} method for the Activity in which search can be invoked.
For example:</p>

<pre>
&#64;Override
public boolean onSearchRequested() {
     Bundle appData = new Bundle();
     appData.putBoolean(MySearchableActivity.JARGON, true);
     startSearch(null, false, appData, false);
     return true;
 }
</pre>

<p>Returning "true" indicates that you have successfully handled this callback event. Then in your
searchable Activity, you can extract the data placed inside {@code appdata} from the {@link
android.app.SearchManager#APP_DATA} {@link android.os.Bundle} to refine the search. For example:</p>

<pre>
Bundle appData = getIntent().getBundleExtra(SearchManager.APP_DATA);
if (appData != null) {
    boolean jargon = appData.getBoolean(MySearchableActivity.JARGON);
}
</pre>

<p class="caution"><strong>Caution:</strong> Never call the {@link
android.app.Activity#startSearch(String,boolean,Bundle,boolean) startSearch()} method from outside
the {@link android.app.Activity#onSearchRequested()} callback method. To invoke the search dialog
in your Activity, always call {@link android.app.Activity#onSearchRequested()}. Otherwise, {@link
android.app.Activity#onSearchRequested()} is not called and customizations (such as the addition of
{@code appData} in the above example) are missed.</p>


<h2 id="VoiceSearch">Adding Voice Search</h2>

<p>You can add voice search functionality to your search dialog by adding the {@code
android:voiceSearchMode} attribute to your searchable configuration. This adds a voice search
button in the search dialog that launches a voice prompt. When the user
has finished speaking, the transcribed search query is sent to your searchable
Activity.</p>

<p>For example:</p>

<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;searchable xmlns:android="http://schemas.android.com/apk/res/android"
    android:label="@string/search_label"
    android:hint="@string/search_hint"
    <b>android:voiceSearchMode="showVoiceSearchButton|launchRecognizer"</b> >
&lt;/searchable>
</pre>

<p>The value {@code showVoiceSearchButton} is required to enable voice
search, while the second value, {@code launchRecognizer}, specifies that the voice search button
should launch a recognizer that returns the transcribed text to the searchable Activity.</p>

<p>You can provide additional attributes to specify the voice search behavior, such
as the language to be expected and the maximum number of results to return. See the <a
href="searchable-config.html">Searchable Configuration</a> reference for more information about the
available attributes.</p>

<p class="note"><strong>Note:</strong> Carefully consider whether voice search is appropriate for
your application. All searches performed with the voice search button are immediately sent to
your searchable Activity without a chance for the user to review the transcribed query. Sufficiently
test the voice recognition and ensure that it understands the types of queries that
the user might submit inside your application.</p>