Home | History | Annotate | Download | only in search
      1 page.title=Creating a Search Interface
      2 parent.title=Search
      3 parent.link=index.html
      4 @jd:body
      5 
      6 <div id="qv-wrapper">
      7 <div id="qv">
      8 
      9 
     10 <h2>In this document</h2>
     11 <ol>
     12   <li><a href="#TheBasics">The Basics</a></li>
     13   <li><a href="#SearchableConfiguration">Creating a Searchable Configuration</a></li>
     14   <li><a href="#SearchableActivity">Creating a Searchable Activity</a>
     15     <ol>
     16       <li><a href="#DeclaringSearchableActivity">Declaring a searchable activity</a></li>
     17       <li><a href="#PerformingSearch">Performing a search</a></li>
     18     </ol>
     19   </li>
     20   <li><a href="#SearchDialog">Using the Search Dialog</a>
     21     <ol>
     22       <li><a href="#InvokingTheSearchDialog">Invoking the search dialog</a></li>
     23       <li><a href="#LifeCycle">The impact of the search dialog on your activity lifecycle</a></li>
     24       <li><a href="#SearchContextData">Passing search context data</a></li>
     25     </ol>
     26   </li>
     27   <li><a href="#UsingSearchWidget">Using the Search Widget</a>
     28     <ol>
     29       <li><a href="#ConfiguringWidget">Configuring the search widget</a></li>
     30       <li><a href="#WidgetFeatures">Other search widget features</a></li>
     31       <li><a href="#UsingBoth">Using both the widget and the dialog</a></li>
     32     </ol>
     33   </li>
     34   <li><a href="#VoiceSearch">Adding Voice Search</a></li>
     35   <li><a href="#SearchSuggestions">Adding Search Suggestions</a></li>
     36 </ol>
     37 
     38 <h2>Key classes</h2>
     39 <ol>
     40 <li>{@link android.app.SearchManager}</li>
     41 <li>{@link android.widget.SearchView}</li>
     42 </ol>
     43 
     44 <h2>Related samples</h2>
     45 <ol>
     46 <li><a href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable
     47 Dictionary</a></li>
     48 <li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/view/SearchViewActionBar.html">SearchView
     49     in the Action Bar</a></li>
     50 <li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/view/SearchViewFilterMode.html">SearchView
     51     filter mode</a></li>
     52 </ol>
     53 
     54 <h2>Downloads</h2>
     55 <ol>
     56 <li><a href="{@docRoot}design/downloads/index.html#action-bar-icon-pack">Action Bar
     57 Icon Pack</a></li>
     58 </ol>
     59 
     60 </div>
     61 </div>
     62 
     63 <p>When you're ready to add search functionality to your application, Android helps you implement
     64 the user interface with either a search dialog that appears at the top of the activity window or a
     65 search widget that you can insert in your layout. Both the search dialog and the widget can deliver
     66 the user's search query to a specific activity in your application. This way, the user can initiate
     67 a search from any activity where the search dialog or widget is available, and the system starts the
     68 appropriate activity to perform the search and present results.</p>
     69 
     70 <p>Other features available for the search dialog and widget include:</p>
     71 
     72 <ul>
     73   <li>Voice search</li>
     74   <li>Search suggestions based on recent queries</li>
     75   <li>Search suggestions that match actual results in your application data</li>
     76 </ul>
     77 
     78 <p>This guide shows you how to set up your application to provide a search interface
     79 that's assisted by the Android system to deliver search queries, using either the
     80 search dialog or the search widget.</p>
     81 
     82 
     83 <h2 id="TheBasics">The Basics</h2>
     84 
     85 <div class="figure" style="width:250px">
     86 <img src="{@docRoot}images/search/search-ui.png" alt="" height="417" />
     87 <p class="img-caption"><strong>Figure 1.</strong> Screenshot of an application's search dialog.</p>
     88 </div>
     89 
     90 <p>Before you begin, you should decide whether you'll implement your search interface using the
     91 search dialog or the search widget. Both provide the same search features, but in slightly different
     92 ways:</p>
     93 
     94 <ul>
     95   <li>The <strong>search dialog</strong> is a UI component that's controlled by the Android system.
     96 When activated by the user, the search dialog appears at the top of the activity, as shown in figure
     97 1.
     98     <p>The Android system controls all events in the search dialog. When the user
     99 submits a query, the system delivers the query to the activity that you specify to
    100 handle searches. The dialog can also provide search suggestions while the user types.</p></li>
    101 
    102   <li>The <strong>search widget</strong> is an instance of {@link android.widget.SearchView} that
    103 you can place anywhere in your layout. By default, the search widget behaves like a standard {@link
    104 android.widget.EditText} widget and doesn't do anything, but you can configure it so that the
    105 Android system handles all input events, delivers queries to the appropriate activity, and provides
    106 search suggestions (just like the search dialog). However, the search widget is available only in
    107 Android 3.0 (API Level 11) and higher.
    108 
    109 <p class="note"><strong>Note:</strong> If you want, you can handle all user input into the
    110 search widget yourself, using various callback methods and listeners. This document, however,
    111 focuses on how to integrate the search widget with the system for an assisted search
    112 implementation. If you want to handle all user input yourself, read the reference documentation for
    113 {@link android.widget.SearchView} and its nested interfaces. </p></li>
    114 </ul>
    115 
    116 <p>When the user executes a search from the search dialog or a search widget, the system creates an
    117 {@link android.content.Intent} and stores the user query in it. The system then starts the activity
    118 that you've declared to handle searches (the "searchable activity") and delivers it the intent. To
    119 set up your application for this kind of assisted search, you need the following:</p>
    120 
    121 <ul>
    122   <li>A searchable configuration
    123   <p>An XML file that configures some settings for the search dialog or widget. It includes settings
    124 for features such as voice search, search suggestion, and hint text for the search box.</p></li>
    125   <li>A searchable activity
    126   <p>The {@link android.app.Activity} that receives the search query, searches your
    127 data, and displays the search results.</p></li>
    128   <li>A search interface, provided by either:
    129     <ul>
    130       <li>The search dialog
    131         <p>By default, the search dialog is hidden, but appears at the top of the screen when
    132           you call {@link android.app.Activity#onSearchRequested()} (when the user presses your
    133           Search button).</p>
    134       </li>
    135       <li>Or, a {@link android.widget.SearchView} widget
    136         <p>Using the search widget allows you to put the search box anywhere in your activity.
    137 Instead of putting it in your activity layout, you should usually use
    138 {@link android.widget.SearchView} as an 
    139 <a href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view in the Action Bar</a>.</p>
    140       </li>
    141     </ul>
    142   </li>
    143 </ul>
    144 
    145 <p>The rest of this document shows you how to create the searchable configuration, searchable
    146 activity, and implement a search interface with either the search dialog or search widget.</p>
    147 
    148 
    149 <h2 id="SearchableConfiguration">Creating a Searchable Configuration</h2>
    150 
    151 <p>The first thing you need is an XML file called the searchable configuration. It configures
    152 certain UI aspects of the search dialog or widget and defines how features such as suggestions and
    153 voice search behave. This file is traditionally named {@code searchable.xml} and must be saved in
    154 the {@code res/xml/} project directory.</p>
    155 
    156 <p class="note"><strong>Note:</strong> The system uses this file to instantiate a {@link
    157 android.app.SearchableInfo} object, but you cannot create this object yourself at
    158 runtime&mdash;you must declare the searchable configuration in XML.</p>
    159 
    160 <p>The searchable configuration file must include the <a
    161 href="{@docRoot}guide/topics/search/searchable-config.html#searchable-element">{@code
    162 &lt;searchable&gt;}</a> element as the root node and specify one
    163 or more attributes. For example:</p>
    164 
    165 <pre>
    166 &lt;?xml version="1.0" encoding="utf-8"?>
    167 &lt;searchable xmlns:android="http://schemas.android.com/apk/res/android"
    168     android:label="@string/app_label"
    169     android:hint="@string/search_hint" >
    170 &lt;/searchable>
    171 </pre>
    172 
    173 <p>The {@code android:label} attribute is the only required attribute. It points to a string
    174 resource, which should be the application name. This label isn't actually visible to the
    175 user until you enable search suggestions for Quick Search Box. At that point, this label is visible
    176 in the list of Searchable items in the system Settings.</p>
    177 
    178 <p>Though it's not required, we recommend that you always include the {@code android:hint}
    179 attribute, which provides a hint string in the search box before users
    180 enters a query. The hint is important because it provides important clues to users about what
    181 they can search.</p>
    182 
    183 <p class="note"><strong>Tip:</strong> For consistency among other
    184 Android applications, you should format the string for {@code android:hint} as "Search
    185 &lt;content-or-product&gt;". For example, "Search songs and artists" or "Search
    186 YouTube".</p>
    187 
    188 <p>The <a
    189 href="{@docRoot}guide/topics/search/searchable-config.html#searchable-element">{@code
    190 &lt;searchable&gt;}</a> element accepts several other attributes. However, you don't need
    191 most attributes until you add features such as <a href="#SearchSuggestions">search suggestions</a>
    192 and <a href="#VoiceSearch">voice search</a>. For detailed information about the searchable
    193 configuration file, see the <a
    194 href="{@docRoot}guide/topics/search/searchable-config.html">Searchable Configuration</a> reference
    195 document.</p>
    196 
    197 
    198 
    199 <h2 id="SearchableActivity">Creating a Searchable Activity</h2>
    200 
    201 <p>A searchable activity is the {@link android.app.Activity} in your application that performs
    202 searches based on a query string and presents the search results.</p>
    203 
    204 <p>When the user executes a search in the search dialog or widget, the system starts your
    205 searchable activity and delivers it the search query in an {@link
    206 android.content.Intent} with the  {@link android.content.Intent#ACTION_SEARCH} action. Your
    207 searchable activity retrieves the query from the intent's {@link android.app.SearchManager#QUERY
    208 QUERY} extra, then searches your data and presents the results.</p>
    209 
    210 <p>Because you may include the search dialog or widget in any other activity in your application,
    211 the system must know which activity is your searchable activity, so it can properly deliver the
    212 search query. So, you must first declare your searchable activity in the Android manifest file.</p>
    213 
    214 
    215 <h3 id="DeclaringSearchableActivity">Declaring a searchable activity</h3>
    216 
    217 <p>If you don't have one already, create an {@link android.app.Activity} that will perform
    218 searches and present results. You don't need to implement the search functionality yet&mdash;just
    219 create an activity that you can declare in the manifest. Inside the manifest's <a
    220 href="{@docRoot}guide/topics/manifest/activity-element.html">{@code &lt;activity&gt;}</a>
    221 element:</p>
    222 <ol>
    223   <li>Declare the activity to accept the {@link android.content.Intent#ACTION_SEARCH} intent, in an
    224 <a href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code
    225 &lt;intent-filter&gt;}</a>
    226 element.</li>
    227   <li>Specify the searchable configuration to use, in a <a
    228 href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    229 element.</li>
    230 </ol>
    231 
    232 <p>For example:</p>
    233 
    234 <pre>
    235 &lt;application ... >
    236     &lt;activity android:name=".SearchableActivity" >
    237         &lt;intent-filter>
    238             &lt;action android:name="android.intent.action.SEARCH" />
    239         &lt;/intent-filter>
    240         &lt;meta-data android:name="android.app.searchable"
    241                    android:resource="@xml/searchable"/>
    242     &lt;/activity>
    243     ...
    244 &lt;/application>
    245 </pre>
    246 
    247 <p>The {@code &lt;meta-data&gt;} element must include the {@code android:name} attribute with a
    248 value of {@code "android.app.searchable"} and the {@code android:resource} attribute with a
    249 reference to the searchable configuration file (in this example, it
    250 refers to the {@code res/xml/searchable.xml} file).</p>
    251 
    252 <p class="note"><strong>Note:</strong> The <a
    253 href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code
    254 &lt;intent-filter&gt;}</a> does not need a <a
    255 href="{@docRoot}guide/topics/manifest/category-element.html">{@code &lt;category&gt;}</a> with the
    256 {@code DEFAULT} value (which you usually see in <a
    257 href="{@docRoot}guide/topics/manifest/activity-element.html">{@code &lt;activity&gt;}</a> elements),
    258 because the system delivers the {@link android.content.Intent#ACTION_SEARCH} intent explicitly to
    259 your searchable activity, using its component name.</p>
    260 
    261 
    262 
    263 <h3 id="PerformingSearch">Performing a search</h3>
    264 
    265 <p>Once you have declared your searchable activity in the manifest, performing a search in your
    266 searchable activity involves three steps:</p>
    267 
    268 <ol>
    269   <li><a href="#ReceivingTheQuery">Receiving the query</a></li>
    270   <li><a href="#SearchingYourData">Searching your data</a></li>
    271   <li><a href="#PresentingTheResults">Presenting the results</a></li>
    272 </ol>
    273 
    274 <p>Traditionally, your search results should be presented in a {@link android.widget.ListView}, so
    275 you might want your searchable activity to extend {@link android.app.ListActivity}. It includes
    276 a default layout with a single {@link android.widget.ListView} and provides several
    277 convenience methods for working with the {@link android.widget.ListView}.</p>
    278 
    279 
    280 <h4 id="ReceivingTheQuery">Receiving the query</h4>
    281 
    282 <p>When a user executes a search from the search dialog or widget, the system starts your
    283 searchable activity and sends it a {@link android.content.Intent#ACTION_SEARCH} intent. This intent
    284 carries the search query in the
    285 {@link android.app.SearchManager#QUERY QUERY} string extra. You must check for
    286 this intent when the activity starts and extract the string. For example, here's how you can get the
    287 search query when your searchable activity starts:</p>
    288 
    289 <pre>
    290 &#64;Override
    291 public void onCreate(Bundle savedInstanceState) {
    292     super.onCreate(savedInstanceState);
    293     setContentView(R.layout.search);
    294 
    295     // Get the intent, verify the action and get the query
    296     Intent intent = getIntent();
    297     if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
    298       String query = intent.getStringExtra(SearchManager.QUERY);
    299       doMySearch(query);
    300     }
    301 }
    302 </pre>
    303 
    304 <p>The {@link android.app.SearchManager#QUERY QUERY} string is always included with
    305 the {@link android.content.Intent#ACTION_SEARCH} intent. In this example, the query is
    306 retrieved and passed to a local {@code doMySearch()} method where the actual search operation
    307 is done.</p>
    308 
    309 
    310 <h4 id="SearchingYourData">Searching your data</h4>
    311 
    312 <p>The process of storing and searching your data is unique to your application.
    313 You can store and search your data in many ways, but this guide does not show you how to store your
    314 data and search it. Storing and searching your data is something you should carefully consider in
    315 terms of your needs and your data format. However, here are some tips you might be able to
    316 apply:</p>
    317 
    318   <ul>
    319     <li>If your data is stored in a SQLite database on the device, performing a full-text search
    320 (using FTS3, rather than a {@code LIKE} query) can provide a more robust search across text data and
    321 can produce results significantly faster. See <a href="http://sqlite.org/fts3.html">sqlite.org</a>
    322 for information about FTS3 and the {@link android.database.sqlite.SQLiteDatabase} class for
    323 information about SQLite on Android. Also look at the <a
    324 href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
    325 application to see a complete SQLite implementation that performs searches with FTS3.</li>
    326     <li>If your data is stored online, then the perceived search performance might be
    327 inhibited by the user's data connection. You might want to display a spinning progress wheel until
    328 your search returns. See {@link android.net} for a reference of network APIs and <a
    329 href="{@docRoot}guide/topics/ui/dialogs.html#ProgressDialog">Creating a Progress Dialog</a>
    330 for information about how to display a progress wheel.</li>
    331   </ul>
    332 
    333 
    334 <div class="sidebox-wrapper">
    335 <div class="sidebox">
    336 <h2>About Adapters</h2>
    337 <p>An {@link android.widget.Adapter} binds each item from a set of data into a
    338 {@link android.view.View} object. When the {@link android.widget.Adapter}
    339 is applied to a {@link android.widget.ListView}, each piece of data is inserted as an individual
    340 view into the list. {@link
    341 android.widget.Adapter} is just an interface, so implementations such as {@link
    342 android.widget.CursorAdapter} (for binding data from a {@link android.database.Cursor}) are needed.
    343 If none of the existing implementations work for your data, then you can implement your own from
    344 {@link android.widget.BaseAdapter}. Install the SDK Samples package for API Level 4 to see the
    345 original version of the Searchable Dictionary, which creates a custom adapter to read data from
    346 a file.</p>
    347 </div>
    348 </div>
    349 
    350 <p>Regardless of where your data lives and how you search it, we recommend that you return search
    351 results to your searchable activity with an {@link android.widget.Adapter}. This way, you can easily
    352 present all the search results in a {@link android.widget.ListView}. If your data comes from a
    353 SQLite database query, you can apply your results to a {@link android.widget.ListView}
    354 using a {@link android.widget.CursorAdapter}. If your data comes in some other type of format, then
    355 you can create an extension of {@link android.widget.BaseAdapter}.</p>
    356 
    357 
    358 <h4 id="PresentingTheResults">Presenting the results</h4>
    359 
    360 <p>As discussed above, the recommended UI for your search results is a {@link
    361 android.widget.ListView}, so you might want your searchable activity to extend {@link
    362 android.app.ListActivity}. You can then call {@link
    363 android.app.ListActivity#setListAdapter(ListAdapter) setListAdapter()}, passing it an {@link
    364 android.widget.Adapter} that is bound to your data. This injects all the
    365 search results into the activity {@link android.widget.ListView}.</p>
    366 
    367 <p>For more help presenting your results in a list, see the {@link android.app.ListActivity}
    368 documentation.</p>
    369 
    370 <p>Also see the <a
    371 href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
    372 for an a complete demonstration of how to search an SQLite database and use an
    373 {@link android.widget.Adapter} to provide results in a {@link android.widget.ListView}.</p>
    374 
    375 
    376 
    377 
    378 
    379 <h2 id="SearchDialog">Using the Search Dialog</h2>
    380 
    381 <div class="sidebox-wrapper">
    382 <div class="sidebox">
    383   <h2>Should I use the search dialog or the widget?</h2>
    384   <p>The answer depends mostly on whether you are developing for Android 3.0 (API Level 11 or
    385 higher), because the {@link android.widget.SearchView} widget was introduced in Android 3.0. So,
    386 if you are developing your application for a version of Android lower than 3.0, the search widget is
    387 not an option and you should use the search dialog to implement your search interface.</p>
    388   <p>If you <em>are</em> developing for Android 3.0 or higher, then the decision depends more on
    389 your needs. In most cases, we recommend that you use the search widget as an "action view" in the
    390 Action Bar. However, it might not be an option for you to put the search
    391 widget in the Action Bar for some reason (perhaps there's not enough space or you don't use the
    392 Action Bar). So, you might instead want to put the search widget somewhere in your activity layout.
    393 And if all else fails, you can still use the search dialog if you prefer to keep the search box
    394 hidden. In fact, you might want to offer both the dialog and the widget in some cases. For more
    395 information about the widget, skip to <a href="#UsingSearchWidget">Using the Search Widget</a>.</p>
    396 </div>
    397 </div>
    398 
    399 <p>The search dialog provides a floating search box at the top of the screen, with the application
    400 icon on the left. The search dialog can provide search suggestions as the user types and, when
    401 the user executes a search, the system sends the search query to a
    402 searchable activity that performs the search. However, if you are developing
    403 your application for devices running Android 3.0, you should consider using the search widget
    404 instead (see the side box).</p>
    405 
    406 <p>The search dialog is always hidden by default, until the user activates it. Your application
    407 can activate the search dialog by calling {@link
    408 android.app.Activity#onSearchRequested onSearchRequested()}. However, this method doesn't work
    409 until you enable the search dialog for the activity.</p>
    410 
    411 <p>To enable the search dialog, you must indicate to the system which searchable activity should
    412 receive search queries from the search dialog, in order to perform searches. For example, in the
    413 previous section about <a href="#SearchableActivity">Creating a Searchable Activity</a>, a
    414 searchable activity named {@code SearchableActivity} was created. If you want a separate activity,
    415 named {@code OtherActivity}, to show the search dialog and deliver searches to {@code
    416 SearchableActivity}, you must declare in the manifest that {@code SearchableActivity} is the
    417 searchable activity to use for the search dialog in {@code OtherActivity}.</p>
    418 
    419 <p>To declare the searchable activity for an activity's search dialog,
    420 add a <a href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    421 element inside the respective activity's <a
    422 href="{@docRoot}guide/topics/manifest/activity-element.html">{@code &lt;activity&gt;}</a> element.
    423 The <a href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    424 element must include the {@code android:value} attribute that specifies the searchable activity's
    425 class name and the {@code android:name} attribute with a value of {@code
    426 "android.app.default_searchable"}.</p>
    427 
    428 <p>For example, here is the declaration for
    429 both a searchable activity, {@code SearchableActivity}, and another activity, {@code
    430 OtherActivity}, which uses {@code SearchableActivity} to perform searches executed from its
    431 search dialog:</p>
    432 
    433 <pre>
    434 &lt;application ... >
    435     &lt;!-- this is the searchable activity; it performs searches --&gt;
    436     &lt;activity android:name=".SearchableActivity" >
    437         &lt;intent-filter>
    438             &lt;action android:name="android.intent.action.SEARCH" />
    439         &lt;/intent-filter>
    440         &lt;meta-data android:name="android.app.searchable"
    441                    android:resource="@xml/searchable"/>
    442     &lt;/activity>
    443 
    444     &lt;!-- this activity enables the search dialog to initiate searches
    445          in the SearchableActivity --&gt;
    446     &lt;activity android:name=".OtherActivity" ... >
    447         &lt;!-- enable the search dialog to send searches to SearchableActivity -->
    448         <b>&lt;meta-data android:name="android.app.default_searchable"
    449                    android:value=".SearchableActivity" /&gt;</b>
    450     &lt;/activity>
    451     ...
    452 &lt;/application>
    453 </pre>
    454 
    455 <p>Because the {@code OtherActivity} now includes a <a
    456 href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    457 element to declare which searchable activity to use for searches, the activity has enabled the
    458 search dialog.
    459 While the user is in this activity, the {@link
    460 android.app.Activity#onSearchRequested onSearchRequested()} method activates the search dialog.
    461 When the user executes the search, the system starts {@code SearchableActivity} and delivers it
    462 the {@link android.content.Intent#ACTION_SEARCH} intent.</p>
    463 
    464 <p class="note"><strong>Note:</strong> The searchable activity itself provides the search dialog
    465 by default, so you don't need to add this declaration to {@code SearchableActivity}.</p>
    466 
    467 <p>If you want every activity in your application to provide the search dialog, insert the above <a
    468 href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    469 element as a child of the <a
    470 href="{@docRoot}guide/topics/manifest/application-element.html">{@code &lt;application&gt;}</a>
    471 element, instead of each <a
    472 href="{@docRoot}guide/topics/manifest/activity-element.html">{@code &lt;activity&gt;}</a>. This
    473 way, every activity inherits the value, provides the search dialog, and delivers searches to
    474 the same searchable activity. (If you have multiple searchable activities, you can override the
    475 default searchable activity by placing a different <a
    476 href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code &lt;meta-data&gt;}</a>
    477 declaration inside individual activities.)</p>
    478 
    479 <p>With the search dialog now enabled for your activities, your application is ready to perform
    480 searches.</p>
    481 
    482 
    483 <h3 id="InvokingTheSearchDialog">Invoking the search dialog</h3>
    484 
    485 <p>Although some devices provide a dedicated Search button, the behavior of the button may vary
    486 between devices and many devices do not provide a Search button at all. So when using the search
    487 dialog, you <strong>must provide a search button in your UI</strong> that activates the search
    488 dialog by calling {@link android.app.Activity#onSearchRequested()}.</p>
    489 
    490 <p>For instance, you should add a Search button in your <a
    491 href="{@docRoot}guide/topics/ui/menus.html#options-menu">Options Menu</a> or UI
    492 layout that calls {@link android.app.Activity#onSearchRequested()}. For consistency with
    493 the Android system and other apps, you should label your button with the Android Search icon that's
    494 available from the <a href="{@docRoot}design/downloads/index.html#action-bar-icon-pack">Action Bar
    495 Icon Pack</a>.</p>
    496 
    497 <p class="note"><strong>Note:</strong> If your app uses the <a
    498 href="{@docRoot}guide/topics/ui/actionbar.html">action bar</a>, then you should not use
    499 the search dialog for your search interface. Instead, use the <a href="#UsingSearchWidget">search
    500 widget</a> as a collapsible view in the action bar.</p>
    501 
    502 <p>You can also enable "type-to-search" functionality, which activates the search dialog when the
    503 user starts typing on the keyboard&mdash;the keystrokes are inserted into the search dialog. You can
    504 enable type-to-search in your activity by calling
    505 {@link android.app.Activity#setDefaultKeyMode(int) setDefaultKeyMode}({@link
    506 android.app.Activity#DEFAULT_KEYS_SEARCH_LOCAL}) during your activity's
    507 {@link android.app.Activity#onCreate(Bundle) onCreate()} method.</p>
    508 
    509 
    510 <h3 id="LifeCycle">The impact of the search dialog on your activity lifecycle</h3>
    511 
    512 <p>The search dialog is a {@link android.app.Dialog} that floats at the top of the
    513 screen. It does not cause any change in the activity stack, so when the search dialog appears, no
    514 lifecycle methods (such as {@link android.app.Activity#onPause()}) are called. Your activity just
    515 loses input focus, as input focus is given to the search dialog.
    516 </p>
    517 
    518 <p>If you want to be notified when the search dialog is activated, override the {@link
    519 android.app.Activity#onSearchRequested()} method. When the system calls this method, it is an
    520 indication that your activity has lost input focus to the search dialog, so you can do any
    521 work appropriate for the event (such as pause
    522 a game). Unless you are <a
    523 href="#SearchContextData">passing search context data</a>
    524 (discussed below), you should end the method by calling the super class implementation. For
    525 example:</p>
    526 
    527 <pre>
    528 &#64;Override
    529 public boolean onSearchRequested() {
    530     pauseSomeStuff();
    531     return super.onSearchRequested();
    532 }
    533 </pre>
    534 
    535 <p>If the user cancels search by pressing the <em>Back</em> button, the search dialog closes and the
    536 activity
    537 regains input focus. You can register to be notified when the search dialog is
    538 closed with {@link android.app.SearchManager#setOnDismissListener(SearchManager.OnDismissListener)
    539 setOnDismissListener()}
    540 and/or {@link android.app.SearchManager#setOnCancelListener(SearchManager.OnCancelListener)
    541 setOnCancelListener()}. You
    542 should need to register only the {@link android.app.SearchManager.OnDismissListener
    543 OnDismissListener}, because it is called every time the search dialog closes. The {@link
    544 android.app.SearchManager.OnCancelListener OnCancelListener} only pertains to events in which the
    545 user explicitly exited the search dialog, so it is not called when a search is executed (in which
    546 case, the search dialog naturally disappears).</p>
    547 
    548 <p>If the current activity is not the searchable activity, then the normal activity lifecycle
    549 events are triggered once the user executes a search (the current activity receives {@link
    550 android.app.Activity#onPause()} and so forth, as
    551 described in the <a
    552 href="{@docRoot}guide/components/activities.html#Lifecycle">Activities</a>
    553 document). If, however, the current activity is the searchable activity, then one of two
    554 things happens:</p>
    555 
    556 <ol type="a">
    557   <li>By default, the searchable activity receives the {@link
    558 android.content.Intent#ACTION_SEARCH} intent with a call to {@link
    559 android.app.Activity#onCreate(Bundle) onCreate()} and a new instance of the
    560 activity is brought to the top of the activity stack. There are now two instances of your
    561 searchable activity in the activity stack (so pressing the <em>Back</em> button goes back to the
    562 previous
    563 instance of the searchable activity, rather than exiting the searchable activity).</li>
    564   <li>If you set {@code android:launchMode} to <code>"singleTop"</code>, then the
    565 searchable activity receives the {@link android.content.Intent#ACTION_SEARCH} intent with a call
    566 to {@link android.app.Activity#onNewIntent(Intent)}, passing the new {@link
    567 android.content.Intent#ACTION_SEARCH} intent here. For example, here's how you might handle
    568 this case, in which the searchable activity's launch mode is <code>"singleTop"</code>:
    569 <pre>
    570 &#64;Override
    571 public void onCreate(Bundle savedInstanceState) {
    572     super.onCreate(savedInstanceState);
    573     setContentView(R.layout.search);
    574     handleIntent(getIntent());
    575 }
    576 
    577 &#64;Override
    578 protected void onNewIntent(Intent intent) {
    579     setIntent(intent);
    580     handleIntent(intent);
    581 }
    582 
    583 private void handleIntent(Intent intent) {
    584     if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
    585       String query = intent.getStringExtra(SearchManager.QUERY);
    586       doMySearch(query);
    587     }
    588 }
    589 </pre>
    590 
    591 <p>Compared to the example code in the section about <a href="#PerformingSearch">Performing a
    592 Search</a>, all the code to handle the
    593 search intent is now in the {@code handleIntent()} method, so that both {@link
    594 android.app.Activity#onCreate(Bundle)
    595 onCreate()} and {@link android.app.Activity#onNewIntent(Intent) onNewIntent()} can execute it.</p>
    596 
    597 <p>When the system calls {@link android.app.Activity#onNewIntent(Intent)}, the activity has
    598 not been restarted, so the {@link android.app.Activity#getIntent()} method
    599 returns the same intent that was received with {@link
    600 android.app.Activity#onCreate(Bundle) onCreate()}. This is why you should call {@link
    601 android.app.Activity#setIntent(Intent)} inside {@link
    602 android.app.Activity#onNewIntent(Intent)} (so that the intent saved by the activity is updated in
    603 case you call {@link android.app.Activity#getIntent()} in the future).</p>
    604 
    605 </li>
    606 </ol>
    607 
    608 <p>The second scenario using <code>"singleTop"</code> launch mode is usually ideal, because chances
    609 are good that once a search is done, the user will perform additional searches and it's a bad
    610 experience if your application creates multiple instances of the searchable activity. So, we
    611 recommend that you set your searchable activity to <code>"singleTop"</code> launch mode in the
    612 application manifest. For example:</p>
    613 
    614 <pre>
    615 &lt;activity android:name=".SearchableActivity"
    616           <b>android:launchMode="singleTop"</b> >
    617     &lt;intent-filter>
    618         &lt;action android:name="android.intent.action.SEARCH" />
    619     &lt;/intent-filter>
    620     &lt;meta-data android:name="android.app.searchable"
    621                       android:resource="@xml/searchable"/>
    622   &lt;/activity>
    623 </pre>
    624 
    625 
    626 
    627 <h3 id="SearchContextData">Passing search context data</h3>
    628 
    629 <p>In some cases, you can make necessary refinements to the search query inside the searchable
    630 activity, for every search made. However, if you want to refine your search criteria based on the
    631 activity from which the user is performing a search, you can provide additional data in the intent
    632 that the system sends to your searchable activity. You can pass the additional data in the {@link
    633 android.app.SearchManager#APP_DATA} {@link android.os.Bundle}, which is included in the {@link
    634 android.content.Intent#ACTION_SEARCH} intent.</p>
    635 
    636 <p>To pass this kind of data to your searchable activity, override the {@link
    637 android.app.Activity#onSearchRequested()} method for the activity from which the user can perform a
    638 search, create a {@link android.os.Bundle} with the additional data, and call {@link
    639 android.app.Activity#startSearch startSearch()} to activate the search dialog.
    640 For example:</p>
    641 
    642 <pre>
    643 &#64;Override
    644 public boolean onSearchRequested() {
    645      Bundle appData = new Bundle();
    646      appData.putBoolean(SearchableActivity.JARGON, true);
    647      startSearch(null, false, appData, false);
    648      return true;
    649  }
    650 </pre>
    651 
    652 <p>Returning "true" indicates that you have successfully handled this callback event and
    653 called {@link android.app.Activity#startSearch startSearch()} to activate
    654 the search dialog. Once the user submits a query, it's delivered to your
    655 searchable activity along with the data you've added. You can extract the extra data from the {@link
    656 android.app.SearchManager#APP_DATA} {@link android.os.Bundle} to refine the search. For example:</p>
    657 
    658 <pre>
    659 Bundle appData = getIntent().getBundleExtra(SearchManager.APP_DATA);
    660 if (appData != null) {
    661     boolean jargon = appData.getBoolean(SearchableActivity.JARGON);
    662 }
    663 </pre>
    664 
    665 <p class="caution"><strong>Caution:</strong> Never call the {@link
    666 android.app.Activity#startSearch(String,boolean,Bundle,boolean) startSearch()} method from outside
    667 the {@link android.app.Activity#onSearchRequested()} callback method. To activate the search dialog
    668 in your activity, always call {@link android.app.Activity#onSearchRequested()}. Otherwise, {@link
    669 android.app.Activity#onSearchRequested()} is not called and customizations (such as the addition of
    670 {@code appData} in the above example) are missed.</p>
    671 
    672 
    673 
    674 <h2 id="UsingSearchWidget">Using the Search Widget</h2>
    675 
    676 <div class="figure" style="width:429px;margin:0">
    677   <img src="{@docRoot}images/ui/actionbar-actionview.png" alt="" />
    678   <p class="img-caption"><strong>Figure 2.</strong> The {@link
    679 android.widget.SearchView} widget as an "action view" in the Action Bar.</p>
    680 </div>
    681 
    682 <p>The {@link android.widget.SearchView} widget is available in Android 3.0 and higher. If
    683 you're developing your application for Android 3.0 and have decided to use the search widget, we
    684 recommend that you insert the search widget as an <a
    685 href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view in the Action Bar</a>,
    686 instead of using the search dialog (and instead of placing the search widget in your activity
    687 layout). For example, figure 2 shows the search widget in the Action Bar.</p>
    688 
    689 <p>The search widget provides the same functionality as the search dialog. It starts the appropriate
    690 activity when the user executes a search, and it can provide search suggestions and perform voice
    691 search.</p>
    692 
    693 <p class="note"><strong>Note:</strong> When you use the search widget as an action view, you
    694 still might need to support using the search dialog, for cases in which the search widget does
    695 not fit in the Action Bar. See the following section about <a href="#UsingBoth">Using both
    696 the widget and the dialog</a>.</p>
    697 
    698 
    699 <h3 id="ConfiguringWidget">Configuring the search widget</h3>
    700 
    701 <p>After you've created a  <a href="#SearchableConfiguration">searchable configuration</a> and a <a
    702 href="#SearchableActivity">searchable activity</a>, as discussed above, you need to enable assisted
    703 search for each {@link android.widget.SearchView}. You can do so by calling {@link
    704 android.widget.SearchView#setSearchableInfo setSearchableInfo()} and passing it the {@link
    705 android.app.SearchableInfo} object that represents your searchable configuration.</p>
    706 
    707 <p>You can get a reference to the {@link android.app.SearchableInfo} by calling {@link
    708 android.app.SearchManager#getSearchableInfo getSearchableInfo()} on {@link
    709 android.app.SearchManager}.</p>
    710 
    711 <p>For example, if you're using a {@link android.widget.SearchView} as an action view in the <a
    712 href="{@docRoot}guide/topics/ui/actionbar.html">Action Bar</a>, you should enable the widget
    713 during the {@link android.app.Activity#onCreateOptionsMenu onCreateOptionsMenu()} callback:</p>
    714 
    715 <pre>
    716 &#64;Override
    717 public boolean onCreateOptionsMenu(Menu menu) {
    718     // Inflate the options menu from XML
    719     MenuInflater inflater = getMenuInflater();
    720     inflater.inflate(R.menu.options_menu, menu);
    721 
    722     // Get the SearchView and set the searchable configuration
    723     SearchManager searchManager = (SearchManager) {@link android.app.Activity#getSystemService getSystemService}(Context.SEARCH_SERVICE);
    724     SearchView searchView = (SearchView) menu.findItem(R.id.menu_search).getActionView();
    725     searchView.setSearchableInfo(searchManager.getSearchableInfo({@link android.app.Activity#getComponentName()}));
    726     searchView.setIconifiedByDefault(false); // Do not iconify the widget; expand it by default
    727 
    728     return true;
    729 }
    730 </pre>
    731 
    732 <p>That's all you need. The search widget is now configured and the system will deliver search
    733 queries to your searchable activity. You can also enable <a href="#SearchSuggestions">search
    734 suggestions</a> for the search widget.</p>
    735 
    736 <p class="note"><strong>Note:</strong> If you want to handle all user input yourself, you can do so
    737 with some callback methods and event listeners. For more information, see the reference
    738 documentation for {@link android.widget.SearchView} and its nested interfaces for the
    739 appropriate event listeners.</p>
    740 
    741 <p>For more information about action views in the Action Bar, read the <a
    742 href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">Action Bar</a> developer guide (which
    743 includes sample code for adding a search widget as an action view).</p>
    744 
    745 
    746 <h3 id="WidgetFeatures">Other search widget features</h3>
    747 
    748 <p>The {@link android.widget.SearchView} widget allows for a few additional features you might
    749 want:</p>
    750 
    751 <dl>
    752   <dt>A submit button</dt>
    753   <dd>By default, there's no button to submit a search query, so the user must press the
    754 "Return" key on the keyboard to initiate a search. You can add a "submit" button by calling
    755 {@link android.widget.SearchView#setSubmitButtonEnabled setSubmitButtonEnabled(true)}.</dd>
    756   <dt>Query refinement for search suggestions</dt>
    757   <dd>When you've enabled search suggestions, you usually expect users to simply select a
    758 suggestion, but they might also want to refine the suggested search query. You can add a button
    759 alongside each suggestion that inserts the suggestion in the search box for refinement by the
    760 user, by calling {@link android.widget.SearchView#setQueryRefinementEnabled
    761 setQueryRefinementEnabled(true)}.</dd>
    762   <dt>The ability to toggle the search box visibility</dt>
    763   <dd>By default, the search widget is "iconified," meaning that it is represented only by a
    764 search icon (a magnifying glass), and expands to show the search box when the user touches it.
    765 As shown above, you can show the search box by default, by calling {@link
    766 android.widget.SearchView#setIconifiedByDefault setIconifiedByDefault(false)}. You can also
    767 toggle the search widget appearance by calling {@link android.widget.SearchView#setIconified
    768 setIconified()}.</dd>
    769 </dl>
    770 
    771 <p>There are several other APIs in the {@link android.widget.SearchView} class that allow you to
    772 customize the search widget. However, most of them are used only when you handle all
    773 user input yourself, instead of using the Android system to deliver search queries and display
    774 search suggestions.</p>
    775 
    776 
    777 <h3 id="UsingBoth">Using both the widget and the dialog</h3>
    778 
    779 <p>If you insert the search widget in the Action Bar as an <a
    780 href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view</a>, and you enable it to
    781 appear in the Action Bar "if there is room" (by setting {@code
    782 android:showAsAction="ifRoom"}), then there is a chance that the search widget will not appear
    783 as an action view, but the menu item will appear in the overflow menu. For example, when your
    784 application runs on a smaller screen, there might not be enough room in the Action Bar to display
    785 the search widget along with other action items or navigation elements, so the menu item will
    786 instead appear in the overflow menu. When placed in the overflow menu, the item works like an
    787 ordinary menu item and does not display the action view (the search widget).</p>
    788 
    789 <p>To handle this situation, the menu item to which you've attached the search widget should
    790 activate the search dialog when the user selects it from the overflow menu. In order for it to do
    791 so, you must implement {@link android.app.Activity#onOptionsItemSelected onOptionsItemSelected()} to
    792 handle the "Search" menu item and open the search dialog by calling {@link
    793 android.app.Activity#onSearchRequested onSearchRequested()}.</p>
    794 
    795 <p>For more information about how items in the Action Bar work and how to handle this situation, see
    796 the <a href="{@docRoot}guide/topics/ui/actionbar.html">Action
    797 Bar</a> developer guide.</p>
    798 
    799 <p>Also see the <a
    800 href="{@docRoot}resources/samples/SearchableDictionary/src/com/example/android/searchabledict/SearchableDictionary.html"
    801 >Searchable Dictionary</a> for an example implementation using
    802 both the dialog and the widget.</p>
    803 
    804 
    805 
    806 <h2 id="VoiceSearch">Adding Voice Search</h2>
    807 
    808 <p>You can add voice search functionality to your search dialog or widget by adding the {@code
    809 android:voiceSearchMode} attribute to your searchable configuration. This adds a voice search
    810 button that launches a voice prompt. When the user
    811 has finished speaking, the transcribed search query is sent to your searchable
    812 activity.</p>
    813 
    814 <p>For example:</p>
    815 
    816 <pre>
    817 &lt;?xml version="1.0" encoding="utf-8"?>
    818 &lt;searchable xmlns:android="http://schemas.android.com/apk/res/android"
    819     android:label="@string/search_label"
    820     android:hint="@string/search_hint"
    821     <b>android:voiceSearchMode="showVoiceSearchButton|launchRecognizer"</b> >
    822 &lt;/searchable>
    823 </pre>
    824 
    825 <p>The value {@code showVoiceSearchButton} is required to enable voice
    826 search, while the second value, {@code launchRecognizer}, specifies that the voice search button
    827 should launch a recognizer that returns the transcribed text to the searchable activity.</p>
    828 
    829 <p>You can provide additional attributes to specify the voice search behavior, such
    830 as the language to be expected and the maximum number of results to return. See the <a
    831 href="searchable-config.html">Searchable Configuration</a> reference for more information about the
    832 available attributes.</p>
    833 
    834 <p class="note"><strong>Note:</strong> Carefully consider whether voice search is appropriate for
    835 your application. All searches performed with the voice search button are immediately sent to
    836 your searchable activity without a chance for the user to review the transcribed query. Sufficiently
    837 test the voice recognition and ensure that it understands the types of queries that
    838 the user might submit inside your application.</p>
    839 
    840 
    841 
    842 <h2 id="SearchSuggestions">Adding Search Suggestions</h2>
    843 
    844 <div class="figure" style="width:250px;margin:0">
    845 <img src="{@docRoot}images/search/search-suggest-custom.png" alt="" height="417" />
    846 <p class="img-caption"><strong>Figure 3.</strong> Screenshot of a search dialog with custom
    847 search suggestions.</p>
    848 </div>
    849 
    850 <p>Both the search dialog and the search widget can provide search suggestions as the user
    851 types, with assistance from the Android system. The system manages the list of suggestions and
    852 handles the event when the user selects a suggestion.</p>
    853 
    854 <p>You can provide two kinds of search suggestions:</p>
    855 
    856 <dl>
    857   <dt>Recent query search suggestions</dt>
    858   <dd>These suggestions are simply words that the user previously used as search queries in
    859 your application.
    860   <p>See <a href="adding-recent-query-suggestions.html">Adding Recent Query
    861 Suggestions</a>.</p></dd>
    862   <dt>Custom search suggestions</dt>
    863   <dd>These are search suggestions that you provide from your own data source, to help users
    864 immediately select the correct spelling or item they are searching for. Figure 3 shows an
    865 example of custom suggestions for a dictionary application&mdash;the user can select a suggestion
    866 to instantly go to the definition.
    867   <p>See <a href="adding-custom-suggestions.html">Adding Custom
    868 Suggestions</a></p></dd>
    869 </dl>
    870 
    871