871 lines
43 KiB
Plaintext
871 lines
43 KiB
Plaintext
page.title=Creating a Search Interface
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page.tags="searchview"
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@jd:body
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<div id="qv-wrapper">
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<div id="qv">
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<h2>In this document</h2>
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<ol>
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<li><a href="#TheBasics">The Basics</a></li>
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<li><a href="#SearchableConfiguration">Creating a Searchable Configuration</a></li>
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<li><a href="#SearchableActivity">Creating a Searchable Activity</a>
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<ol>
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<li><a href="#DeclaringSearchableActivity">Declaring a searchable activity</a></li>
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<li><a href="#PerformingSearch">Performing a search</a></li>
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</ol>
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</li>
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<li><a href="#SearchDialog">Using the Search Dialog</a>
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<ol>
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<li><a href="#InvokingTheSearchDialog">Invoking the search dialog</a></li>
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<li><a href="#LifeCycle">The impact of the search dialog on your activity lifecycle</a></li>
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<li><a href="#SearchContextData">Passing search context data</a></li>
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</ol>
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</li>
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<li><a href="#UsingSearchWidget">Using the Search Widget</a>
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<ol>
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<li><a href="#ConfiguringWidget">Configuring the search widget</a></li>
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<li><a href="#WidgetFeatures">Other search widget features</a></li>
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<li><a href="#UsingBoth">Using both the widget and the dialog</a></li>
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</ol>
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</li>
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<li><a href="#VoiceSearch">Adding Voice Search</a></li>
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<li><a href="#SearchSuggestions">Adding Search Suggestions</a></li>
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</ol>
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<h2>Key classes</h2>
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<ol>
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<li>{@link android.app.SearchManager}</li>
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<li>{@link android.widget.SearchView}</li>
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</ol>
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<h2>Related samples</h2>
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<ol>
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<li><a href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable
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Dictionary</a></li>
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<li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/view/SearchViewActionBar.html">SearchView
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in the Action Bar</a></li>
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<li><a href="{@docRoot}resources/samples/ApiDemos/src/com/example/android/apis/view/SearchViewFilterMode.html">SearchView
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filter mode</a></li>
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</ol>
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<h2>Downloads</h2>
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<ol>
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<li><a href="{@docRoot}design/downloads/index.html#action-bar-icon-pack">Action Bar
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Icon Pack</a></li>
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</ol>
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</div>
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</div>
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<p>When you're ready to add search functionality to your application, Android helps you implement
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the user interface with either a search dialog that appears at the top of the activity window or a
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search widget that you can insert in your layout. Both the search dialog and the widget can deliver
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the user's search query to a specific activity in your application. This way, the user can initiate
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a search from any activity where the search dialog or widget is available, and the system starts the
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appropriate activity to perform the search and present results.</p>
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<p>Other features available for the search dialog and widget include:</p>
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<ul>
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<li>Voice search</li>
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<li>Search suggestions based on recent queries</li>
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<li>Search suggestions that match actual results in your application data</li>
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</ul>
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<p>This guide shows you how to set up your application to provide a search interface
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that's assisted by the Android system to deliver search queries, using either the
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search dialog or the search widget.</p>
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<h2 id="TheBasics">The Basics</h2>
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<div class="figure" style="width:250px">
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<img src="{@docRoot}images/search/search-ui.png" alt="" height="417" />
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<p class="img-caption"><strong>Figure 1.</strong> Screenshot of an application's search dialog.</p>
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</div>
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<p>Before you begin, you should decide whether you'll implement your search interface using the
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search dialog or the search widget. Both provide the same search features, but in slightly different
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ways:</p>
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<ul>
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<li>The <strong>search dialog</strong> is a UI component that's controlled by the Android system.
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When activated by the user, the search dialog appears at the top of the activity, as shown in figure
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1.
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<p>The Android system controls all events in the search dialog. When the user
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submits a query, the system delivers the query to the activity that you specify to
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handle searches. The dialog can also provide search suggestions while the user types.</p></li>
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<li>The <strong>search widget</strong> is an instance of {@link android.widget.SearchView} that
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you can place anywhere in your layout. By default, the search widget behaves like a standard {@link
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android.widget.EditText} widget and doesn't do anything, but you can configure it so that the
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Android system handles all input events, delivers queries to the appropriate activity, and provides
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search suggestions (just like the search dialog). However, the search widget is available only in
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Android 3.0 (API Level 11) and higher.
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<p class="note"><strong>Note:</strong> If you want, you can handle all user input into the
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search widget yourself, using various callback methods and listeners. This document, however,
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focuses on how to integrate the search widget with the system for an assisted search
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implementation. If you want to handle all user input yourself, read the reference documentation for
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{@link android.widget.SearchView} and its nested interfaces. </p></li>
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</ul>
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<p>When the user executes a search from the search dialog or a search widget, the system creates an
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{@link android.content.Intent} and stores the user query in it. The system then starts the activity
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that you've declared to handle searches (the "searchable activity") and delivers it the intent. To
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set up your application for this kind of assisted search, you need the following:</p>
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<ul>
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<li>A searchable configuration
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<p>An XML file that configures some settings for the search dialog or widget. It includes settings
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for features such as voice search, search suggestion, and hint text for the search box.</p></li>
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<li>A searchable activity
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<p>The {@link android.app.Activity} that receives the search query, searches your
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data, and displays the search results.</p></li>
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<li>A search interface, provided by either:
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<ul>
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<li>The search dialog
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<p>By default, the search dialog is hidden, but appears at the top of the screen when
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you call {@link android.app.Activity#onSearchRequested()} (when the user presses your
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Search button).</p>
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</li>
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<li>Or, a {@link android.widget.SearchView} widget
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<p>Using the search widget allows you to put the search box anywhere in your activity.
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Instead of putting it in your activity layout, you should usually use
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{@link android.widget.SearchView} as an
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<a href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view in the Action Bar</a>.</p>
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</li>
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</ul>
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</li>
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</ul>
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<p>The rest of this document shows you how to create the searchable configuration, searchable
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activity, and implement a search interface with either the search dialog or search widget.</p>
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<h2 id="SearchableConfiguration">Creating a Searchable Configuration</h2>
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<p>The first thing you need is an XML file called the searchable configuration. It configures
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certain UI aspects of the search dialog or widget and defines how features such as suggestions and
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voice search behave. This file is traditionally named {@code searchable.xml} and must be saved in
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the {@code res/xml/} project directory.</p>
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<p class="note"><strong>Note:</strong> The system uses this file to instantiate a {@link
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android.app.SearchableInfo} object, but you cannot create this object yourself at
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runtime—you must declare the searchable configuration in XML.</p>
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<p>The searchable configuration file must include the <a
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href="{@docRoot}guide/topics/search/searchable-config.html#searchable-element">{@code
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<searchable>}</a> element as the root node and specify one
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or more attributes. For example:</p>
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<pre>
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<?xml version="1.0" encoding="utf-8"?>
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<searchable xmlns:android="http://schemas.android.com/apk/res/android"
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android:label="@string/app_label"
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android:hint="@string/search_hint" >
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</searchable>
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</pre>
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<p>The {@code android:label} attribute is the only required attribute. It points to a string
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resource, which should be the application name. This label isn't actually visible to the
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user until you enable search suggestions for Quick Search Box. At that point, this label is visible
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in the list of Searchable items in the system Settings.</p>
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<p>Though it's not required, we recommend that you always include the {@code android:hint}
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attribute, which provides a hint string in the search box before users
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enters a query. The hint is important because it provides important clues to users about what
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they can search.</p>
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<p class="note"><strong>Tip:</strong> For consistency among other
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Android applications, you should format the string for {@code android:hint} as "Search
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<content-or-product>". For example, "Search songs and artists" or "Search
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YouTube".</p>
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<p>The <a
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href="{@docRoot}guide/topics/search/searchable-config.html#searchable-element">{@code
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<searchable>}</a> element accepts several other attributes. However, you don't need
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most attributes until you add features such as <a href="#SearchSuggestions">search suggestions</a>
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and <a href="#VoiceSearch">voice search</a>. For detailed information about the searchable
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configuration file, see the <a
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href="{@docRoot}guide/topics/search/searchable-config.html">Searchable Configuration</a> reference
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document.</p>
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<h2 id="SearchableActivity">Creating a Searchable Activity</h2>
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<p>A searchable activity is the {@link android.app.Activity} in your application that performs
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searches based on a query string and presents the search results.</p>
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<p>When the user executes a search in the search dialog or widget, the system starts your
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searchable activity and delivers it the search query in an {@link
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android.content.Intent} with the {@link android.content.Intent#ACTION_SEARCH} action. Your
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searchable activity retrieves the query from the intent's {@link android.app.SearchManager#QUERY
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QUERY} extra, then searches your data and presents the results.</p>
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<p>Because you may include the search dialog or widget in any other activity in your application,
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the system must know which activity is your searchable activity, so it can properly deliver the
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search query. So, you must first declare your searchable activity in the Android manifest file.</p>
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<h3 id="DeclaringSearchableActivity">Declaring a searchable activity</h3>
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<p>If you don't have one already, create an {@link android.app.Activity} that will perform
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searches and present results. You don't need to implement the search functionality yet—just
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create an activity that you can declare in the manifest. Inside the manifest's <a
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href="{@docRoot}guide/topics/manifest/activity-element.html">{@code <activity>}</a>
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element:</p>
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<ol>
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<li>Declare the activity to accept the {@link android.content.Intent#ACTION_SEARCH} intent, in an
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<a href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code
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<intent-filter>}</a>
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element.</li>
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<li>Specify the searchable configuration to use, in a <a
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href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
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element.</li>
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</ol>
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<p>For example:</p>
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<pre>
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<application ... >
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<activity android:name=".SearchableActivity" >
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<intent-filter>
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<action android:name="android.intent.action.SEARCH" />
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</intent-filter>
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<meta-data android:name="android.app.searchable"
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android:resource="@xml/searchable"/>
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</activity>
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...
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</application>
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</pre>
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<p>The {@code <meta-data>} element must include the {@code android:name} attribute with a
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value of {@code "android.app.searchable"} and the {@code android:resource} attribute with a
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reference to the searchable configuration file (in this example, it
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refers to the {@code res/xml/searchable.xml} file).</p>
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<p class="note"><strong>Note:</strong> The <a
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href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code
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<intent-filter>}</a> does not need a <a
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href="{@docRoot}guide/topics/manifest/category-element.html">{@code <category>}</a> with the
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{@code DEFAULT} value (which you usually see in <a
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href="{@docRoot}guide/topics/manifest/activity-element.html">{@code <activity>}</a> elements),
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because the system delivers the {@link android.content.Intent#ACTION_SEARCH} intent explicitly to
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your searchable activity, using its component name.</p>
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<h3 id="PerformingSearch">Performing a search</h3>
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<p>Once you have declared your searchable activity in the manifest, performing a search in your
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searchable activity involves three steps:</p>
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<ol>
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<li><a href="#ReceivingTheQuery">Receiving the query</a></li>
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<li><a href="#SearchingYourData">Searching your data</a></li>
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<li><a href="#PresentingTheResults">Presenting the results</a></li>
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</ol>
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<p>Traditionally, your search results should be presented in a {@link android.widget.ListView}, so
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you might want your searchable activity to extend {@link android.app.ListActivity}. It includes
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a default layout with a single {@link android.widget.ListView} and provides several
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convenience methods for working with the {@link android.widget.ListView}.</p>
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<h4 id="ReceivingTheQuery">Receiving the query</h4>
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<p>When a user executes a search from the search dialog or widget, the system starts your
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searchable activity and sends it a {@link android.content.Intent#ACTION_SEARCH} intent. This intent
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carries the search query in the
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{@link android.app.SearchManager#QUERY QUERY} string extra. You must check for
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this intent when the activity starts and extract the string. For example, here's how you can get the
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search query when your searchable activity starts:</p>
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<pre>
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@Override
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public void onCreate(Bundle savedInstanceState) {
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super.onCreate(savedInstanceState);
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setContentView(R.layout.search);
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// Get the intent, verify the action and get the query
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Intent intent = getIntent();
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if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
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String query = intent.getStringExtra(SearchManager.QUERY);
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doMySearch(query);
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}
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}
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</pre>
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<p>The {@link android.app.SearchManager#QUERY QUERY} string is always included with
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the {@link android.content.Intent#ACTION_SEARCH} intent. In this example, the query is
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retrieved and passed to a local {@code doMySearch()} method where the actual search operation
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is done.</p>
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<h4 id="SearchingYourData">Searching your data</h4>
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<p>The process of storing and searching your data is unique to your application.
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You can store and search your data in many ways, but this guide does not show you how to store your
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data and search it. Storing and searching your data is something you should carefully consider in
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terms of your needs and your data format. However, here are some tips you might be able to
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apply:</p>
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<ul>
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<li>If your data is stored in a SQLite database on the device, performing a full-text search
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(using FTS3, rather than a {@code LIKE} query) can provide a more robust search across text data and
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can produce results significantly faster. See <a href="http://sqlite.org/fts3.html">sqlite.org</a>
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for information about FTS3 and the {@link android.database.sqlite.SQLiteDatabase} class for
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information about SQLite on Android. Also look at the <a
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href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
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application to see a complete SQLite implementation that performs searches with FTS3.</li>
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<li>If your data is stored online, then the perceived search performance might be
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inhibited by the user's data connection. You might want to display a spinning progress wheel until
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your search returns. See {@link android.net} for a reference of network APIs and <a
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href="{@docRoot}guide/topics/ui/dialogs.html#ProgressDialog">Creating a Progress Dialog</a>
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for information about how to display a progress wheel.</li>
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</ul>
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<div class="sidebox-wrapper">
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<div class="sidebox">
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<h2>About Adapters</h2>
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<p>An {@link android.widget.Adapter} binds each item from a set of data into a
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{@link android.view.View} object. When the {@link android.widget.Adapter}
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is applied to a {@link android.widget.ListView}, each piece of data is inserted as an individual
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view into the list. {@link
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android.widget.Adapter} is just an interface, so implementations such as {@link
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android.widget.CursorAdapter} (for binding data from a {@link android.database.Cursor}) are needed.
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If none of the existing implementations work for your data, then you can implement your own from
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{@link android.widget.BaseAdapter}. Install the SDK Samples package for API Level 4 to see the
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original version of the Searchable Dictionary, which creates a custom adapter to read data from
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a file.</p>
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</div>
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</div>
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<p>Regardless of where your data lives and how you search it, we recommend that you return search
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results to your searchable activity with an {@link android.widget.Adapter}. This way, you can easily
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present all the search results in a {@link android.widget.ListView}. If your data comes from a
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SQLite database query, you can apply your results to a {@link android.widget.ListView}
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using a {@link android.widget.CursorAdapter}. If your data comes in some other type of format, then
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you can create an extension of {@link android.widget.BaseAdapter}.</p>
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<h4 id="PresentingTheResults">Presenting the results</h4>
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<p>As discussed above, the recommended UI for your search results is a {@link
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android.widget.ListView}, so you might want your searchable activity to extend {@link
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android.app.ListActivity}. You can then call {@link
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android.app.ListActivity#setListAdapter(ListAdapter) setListAdapter()}, passing it an {@link
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android.widget.Adapter} that is bound to your data. This injects all the
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search results into the activity {@link android.widget.ListView}.</p>
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<p>For more help presenting your results in a list, see the {@link android.app.ListActivity}
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documentation.</p>
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<p>Also see the <a
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href="{@docRoot}resources/samples/SearchableDictionary/index.html">Searchable Dictionary</a> sample
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for an a complete demonstration of how to search an SQLite database and use an
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{@link android.widget.Adapter} to provide results in a {@link android.widget.ListView}.</p>
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<h2 id="SearchDialog">Using the Search Dialog</h2>
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<div class="sidebox-wrapper">
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<div class="sidebox">
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<h2>Should I use the search dialog or the widget?</h2>
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<p>The answer depends mostly on whether you are developing for Android 3.0 (API Level 11 or
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higher), because the {@link android.widget.SearchView} widget was introduced in Android 3.0. So,
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if you are developing your application for a version of Android lower than 3.0, the search widget is
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not an option and you should use the search dialog to implement your search interface.</p>
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<p>If you <em>are</em> developing for Android 3.0 or higher, then the decision depends more on
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your needs. In most cases, we recommend that you use the search widget as an "action view" in the
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Action Bar. However, it might not be an option for you to put the search
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widget in the Action Bar for some reason (perhaps there's not enough space or you don't use the
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Action Bar). So, you might instead want to put the search widget somewhere in your activity layout.
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And if all else fails, you can still use the search dialog if you prefer to keep the search box
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hidden. In fact, you might want to offer both the dialog and the widget in some cases. For more
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information about the widget, skip to <a href="#UsingSearchWidget">Using the Search Widget</a>.</p>
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</div>
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</div>
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<p>The search dialog provides a floating search box at the top of the screen, with the application
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icon on the left. The search dialog can provide search suggestions as the user types and, when
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the user executes a search, the system sends the search query to a
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searchable activity that performs the search. However, if you are developing
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your application for devices running Android 3.0, you should consider using the search widget
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instead (see the side box).</p>
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<p>The search dialog is always hidden by default, until the user activates it. Your application
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can activate the search dialog by calling {@link
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android.app.Activity#onSearchRequested onSearchRequested()}. However, this method doesn't work
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until you enable the search dialog for the activity.</p>
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<p>To enable the search dialog, you must indicate to the system which searchable activity should
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receive search queries from the search dialog, in order to perform searches. For example, in the
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previous section about <a href="#SearchableActivity">Creating a Searchable Activity</a>, a
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searchable activity named {@code SearchableActivity} was created. If you want a separate activity,
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named {@code OtherActivity}, to show the search dialog and deliver searches to {@code
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SearchableActivity}, you must declare in the manifest that {@code SearchableActivity} is the
|
|
searchable activity to use for the search dialog in {@code OtherActivity}.</p>
|
|
|
|
<p>To declare the searchable activity for an activity's search dialog,
|
|
add a <a href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
|
|
element inside the respective activity's <a
|
|
href="{@docRoot}guide/topics/manifest/activity-element.html">{@code <activity>}</a> element.
|
|
The <a href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
|
|
element must include the {@code android:value} attribute that specifies the searchable activity's
|
|
class name and the {@code android:name} attribute with a value of {@code
|
|
"android.app.default_searchable"}.</p>
|
|
|
|
<p>For example, here is the declaration for
|
|
both a searchable activity, {@code SearchableActivity}, and another activity, {@code
|
|
OtherActivity}, which uses {@code SearchableActivity} to perform searches executed from its
|
|
search dialog:</p>
|
|
|
|
<pre>
|
|
<application ... >
|
|
<!-- this is the searchable activity; it performs searches -->
|
|
<activity android:name=".SearchableActivity" >
|
|
<intent-filter>
|
|
<action android:name="android.intent.action.SEARCH" />
|
|
</intent-filter>
|
|
<meta-data android:name="android.app.searchable"
|
|
android:resource="@xml/searchable"/>
|
|
</activity>
|
|
|
|
<!-- this activity enables the search dialog to initiate searches
|
|
in the SearchableActivity -->
|
|
<activity android:name=".OtherActivity" ... >
|
|
<!-- enable the search dialog to send searches to SearchableActivity -->
|
|
<b><meta-data android:name="android.app.default_searchable"
|
|
android:value=".SearchableActivity" /></b>
|
|
</activity>
|
|
...
|
|
</application>
|
|
</pre>
|
|
|
|
<p>Because the {@code OtherActivity} now includes a <a
|
|
href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
|
|
element to declare which searchable activity to use for searches, the activity has enabled the
|
|
search dialog.
|
|
While the user is in this activity, the {@link
|
|
android.app.Activity#onSearchRequested onSearchRequested()} method activates the search dialog.
|
|
When the user executes the search, the system starts {@code SearchableActivity} and delivers it
|
|
the {@link android.content.Intent#ACTION_SEARCH} intent.</p>
|
|
|
|
<p class="note"><strong>Note:</strong> The searchable activity itself provides the search dialog
|
|
by default, so you don't need to add this declaration to {@code SearchableActivity}.</p>
|
|
|
|
<p>If you want every activity in your application to provide the search dialog, insert the above <a
|
|
href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
|
|
element as a child of the <a
|
|
href="{@docRoot}guide/topics/manifest/application-element.html">{@code <application>}</a>
|
|
element, instead of each <a
|
|
href="{@docRoot}guide/topics/manifest/activity-element.html">{@code <activity>}</a>. This
|
|
way, every activity inherits the value, provides the search dialog, and delivers searches to
|
|
the same searchable activity. (If you have multiple searchable activities, you can override the
|
|
default searchable activity by placing a different <a
|
|
href="{@docRoot}guide/topics/manifest/meta-data-element.html">{@code <meta-data>}</a>
|
|
declaration inside individual activities.)</p>
|
|
|
|
<p>With the search dialog now enabled for your activities, your application is ready to perform
|
|
searches.</p>
|
|
|
|
|
|
<h3 id="InvokingTheSearchDialog">Invoking the search dialog</h3>
|
|
|
|
<p>Although some devices provide a dedicated Search button, the behavior of the button may vary
|
|
between devices and many devices do not provide a Search button at all. So when using the search
|
|
dialog, you <strong>must provide a search button in your UI</strong> that activates the search
|
|
dialog by calling {@link android.app.Activity#onSearchRequested()}.</p>
|
|
|
|
<p>For instance, you should add a Search button in your <a
|
|
href="{@docRoot}guide/topics/ui/menus.html#options-menu">Options Menu</a> or UI
|
|
layout that calls {@link android.app.Activity#onSearchRequested()}. For consistency with
|
|
the Android system and other apps, you should label your button with the Android Search icon that's
|
|
available from the <a href="{@docRoot}design/downloads/index.html#action-bar-icon-pack">Action Bar
|
|
Icon Pack</a>.</p>
|
|
|
|
<p class="note"><strong>Note:</strong> If your app uses the <a
|
|
href="{@docRoot}guide/topics/ui/actionbar.html">action bar</a>, then you should not use
|
|
the search dialog for your search interface. Instead, use the <a href="#UsingSearchWidget">search
|
|
widget</a> as a collapsible view in the action bar.</p>
|
|
|
|
<p>You can also enable "type-to-search" functionality, which activates the search dialog when the
|
|
user starts typing on the keyboard—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 (such as {@link android.app.Activity#onPause()}) are called. Your activity just
|
|
loses input focus, as input focus is given to the search dialog.
|
|
</p>
|
|
|
|
<p>If you want to be notified when the search dialog is activated, override the {@link
|
|
android.app.Activity#onSearchRequested()} method. When the system calls this method, it is an
|
|
indication that your activity has lost input focus to the search dialog, so you can do any
|
|
work appropriate for the event (such as pause
|
|
a game). 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>
|
|
@Override
|
|
public boolean onSearchRequested() {
|
|
pauseSomeStuff();
|
|
return super.onSearchRequested();
|
|
}
|
|
</pre>
|
|
|
|
<p>If the user cancels search by pressing the <em>Back</em> button, the search dialog closes and the
|
|
activity
|
|
regains 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 the <a
|
|
href="{@docRoot}guide/components/activities.html#Lifecycle">Activities</a>
|
|
document). 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 <em>Back</em> button 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 <code>"singleTop"</code>, 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 <code>"singleTop"</code>:
|
|
<pre>
|
|
@Override
|
|
public void onCreate(Bundle savedInstanceState) {
|
|
super.onCreate(savedInstanceState);
|
|
setContentView(R.layout.search);
|
|
handleIntent(getIntent());
|
|
}
|
|
|
|
@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 <code>"singleTop"</code> 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 <code>"singleTop"</code> launch mode in the
|
|
application manifest. For example:</p>
|
|
|
|
<pre>
|
|
<activity android:name=".SearchableActivity"
|
|
<b>android:launchMode="singleTop"</b> >
|
|
<intent-filter>
|
|
<action android:name="android.intent.action.SEARCH" />
|
|
</intent-filter>
|
|
<meta-data android:name="android.app.searchable"
|
|
android:resource="@xml/searchable"/>
|
|
</activity>
|
|
</pre>
|
|
|
|
|
|
|
|
<h3 id="SearchContextData">Passing search context data</h3>
|
|
|
|
<p>In some cases, you can make necessary refinements to the search query inside the searchable
|
|
activity, for every search made. However, if you want to refine your search criteria based on the
|
|
activity from which the user is performing a search, you can provide additional data in the intent
|
|
that the system sends to your searchable activity. You can pass the additional data 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 the {@link
|
|
android.app.Activity#onSearchRequested()} method for the activity from which the user can perform a
|
|
search, create a {@link android.os.Bundle} with the additional data, and call {@link
|
|
android.app.Activity#startSearch startSearch()} to activate the search dialog.
|
|
For example:</p>
|
|
|
|
<pre>
|
|
@Override
|
|
public boolean onSearchRequested() {
|
|
Bundle appData = new Bundle();
|
|
appData.putBoolean(SearchableActivity.JARGON, true);
|
|
startSearch(null, false, appData, false);
|
|
return true;
|
|
}
|
|
</pre>
|
|
|
|
<p>Returning "true" indicates that you have successfully handled this callback event and
|
|
called {@link android.app.Activity#startSearch startSearch()} to activate
|
|
the search dialog. Once the user submits a query, it's delivered to your
|
|
searchable activity along with the data you've added. You can extract the extra data 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(SearchableActivity.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 activate 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="UsingSearchWidget">Using the Search Widget</h2>
|
|
|
|
<div class="figure" style="width:429px;margin:0">
|
|
<img src="{@docRoot}images/ui/actionbar-actionview.png" alt="" />
|
|
<p class="img-caption"><strong>Figure 2.</strong> The {@link
|
|
android.widget.SearchView} widget as an "action view" in the Action Bar.</p>
|
|
</div>
|
|
|
|
<p>The {@link android.widget.SearchView} widget is available in Android 3.0 and higher. If
|
|
you're developing your application for Android 3.0 and have decided to use the search widget, we
|
|
recommend that you insert the search widget as an <a
|
|
href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view in the Action Bar</a>,
|
|
instead of using the search dialog (and instead of placing the search widget in your activity
|
|
layout). For example, figure 2 shows the search widget in the Action Bar.</p>
|
|
|
|
<p>The search widget provides the same functionality as the search dialog. It starts the appropriate
|
|
activity when the user executes a search, and it can provide search suggestions and perform voice
|
|
search.</p>
|
|
|
|
<p class="note"><strong>Note:</strong> When you use the search widget as an action view, you
|
|
still might need to support using the search dialog, for cases in which the search widget does
|
|
not fit in the Action Bar. See the following section about <a href="#UsingBoth">Using both
|
|
the widget and the dialog</a>.</p>
|
|
|
|
|
|
<h3 id="ConfiguringWidget">Configuring the search widget</h3>
|
|
|
|
<p>After you've created a <a href="#SearchableConfiguration">searchable configuration</a> and a <a
|
|
href="#SearchableActivity">searchable activity</a>, as discussed above, you need to enable assisted
|
|
search for each {@link android.widget.SearchView}. You can do so by calling {@link
|
|
android.widget.SearchView#setSearchableInfo setSearchableInfo()} and passing it the {@link
|
|
android.app.SearchableInfo} object that represents your searchable configuration.</p>
|
|
|
|
<p>You can get a reference to the {@link android.app.SearchableInfo} by calling {@link
|
|
android.app.SearchManager#getSearchableInfo getSearchableInfo()} on {@link
|
|
android.app.SearchManager}.</p>
|
|
|
|
<p>For example, if you're using a {@link android.widget.SearchView} as an action view in the <a
|
|
href="{@docRoot}guide/topics/ui/actionbar.html">Action Bar</a>, you should enable the widget
|
|
during the {@link android.app.Activity#onCreateOptionsMenu onCreateOptionsMenu()} callback:</p>
|
|
|
|
<pre>
|
|
@Override
|
|
public boolean onCreateOptionsMenu(Menu menu) {
|
|
// Inflate the options menu from XML
|
|
MenuInflater inflater = getMenuInflater();
|
|
inflater.inflate(R.menu.options_menu, menu);
|
|
|
|
// Get the SearchView and set the searchable configuration
|
|
SearchManager searchManager = (SearchManager) {@link android.app.Activity#getSystemService getSystemService}(Context.SEARCH_SERVICE);
|
|
SearchView searchView = (SearchView) menu.findItem(R.id.menu_search).getActionView();
|
|
// Assumes current activity is the searchable activity
|
|
searchView.setSearchableInfo(searchManager.getSearchableInfo({@link android.app.Activity#getComponentName()}));
|
|
searchView.setIconifiedByDefault(false); // Do not iconify the widget; expand it by default
|
|
|
|
return true;
|
|
}
|
|
</pre>
|
|
|
|
<p>That's all you need. The search widget is now configured and the system will deliver search
|
|
queries to your searchable activity. You can also enable <a href="#SearchSuggestions">search
|
|
suggestions</a> for the search widget.</p>
|
|
|
|
<p class="note"><strong>Note:</strong> If you want to handle all user input yourself, you can do so
|
|
with some callback methods and event listeners. For more information, see the reference
|
|
documentation for {@link android.widget.SearchView} and its nested interfaces for the
|
|
appropriate event listeners.</p>
|
|
|
|
<p>For more information about action views in the Action Bar, read the <a
|
|
href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">Action Bar</a> developer guide (which
|
|
includes sample code for adding a search widget as an action view).</p>
|
|
|
|
|
|
<h3 id="WidgetFeatures">Other search widget features</h3>
|
|
|
|
<p>The {@link android.widget.SearchView} widget allows for a few additional features you might
|
|
want:</p>
|
|
|
|
<dl>
|
|
<dt>A submit button</dt>
|
|
<dd>By default, there's no button to submit a search query, so the user must press the
|
|
"Return" key on the keyboard to initiate a search. You can add a "submit" button by calling
|
|
{@link android.widget.SearchView#setSubmitButtonEnabled setSubmitButtonEnabled(true)}.</dd>
|
|
<dt>Query refinement for search suggestions</dt>
|
|
<dd>When you've enabled search suggestions, you usually expect users to simply select a
|
|
suggestion, but they might also want to refine the suggested search query. You can add a button
|
|
alongside each suggestion that inserts the suggestion in the search box for refinement by the
|
|
user, by calling {@link android.widget.SearchView#setQueryRefinementEnabled
|
|
setQueryRefinementEnabled(true)}.</dd>
|
|
<dt>The ability to toggle the search box visibility</dt>
|
|
<dd>By default, the search widget is "iconified," meaning that it is represented only by a
|
|
search icon (a magnifying glass), and expands to show the search box when the user touches it.
|
|
As shown above, you can show the search box by default, by calling {@link
|
|
android.widget.SearchView#setIconifiedByDefault setIconifiedByDefault(false)}. You can also
|
|
toggle the search widget appearance by calling {@link android.widget.SearchView#setIconified
|
|
setIconified()}.</dd>
|
|
</dl>
|
|
|
|
<p>There are several other APIs in the {@link android.widget.SearchView} class that allow you to
|
|
customize the search widget. However, most of them are used only when you handle all
|
|
user input yourself, instead of using the Android system to deliver search queries and display
|
|
search suggestions.</p>
|
|
|
|
|
|
<h3 id="UsingBoth">Using both the widget and the dialog</h3>
|
|
|
|
<p>If you insert the search widget in the Action Bar as an <a
|
|
href="{@docRoot}guide/topics/ui/actionbar.html#ActionView">action view</a>, and you enable it to
|
|
appear in the Action Bar "if there is room" (by setting {@code
|
|
android:showAsAction="ifRoom"}), then there is a chance that the search widget will not appear
|
|
as an action view, but the menu item will appear in the overflow menu. For example, when your
|
|
application runs on a smaller screen, there might not be enough room in the Action Bar to display
|
|
the search widget along with other action items or navigation elements, so the menu item will
|
|
instead appear in the overflow menu. When placed in the overflow menu, the item works like an
|
|
ordinary menu item and does not display the action view (the search widget).</p>
|
|
|
|
<p>To handle this situation, the menu item to which you've attached the search widget should
|
|
activate the search dialog when the user selects it from the overflow menu. In order for it to do
|
|
so, you must implement {@link android.app.Activity#onOptionsItemSelected onOptionsItemSelected()} to
|
|
handle the "Search" menu item and open the search dialog by calling {@link
|
|
android.app.Activity#onSearchRequested onSearchRequested()}.</p>
|
|
|
|
<p>For more information about how items in the Action Bar work and how to handle this situation, see
|
|
the <a href="{@docRoot}guide/topics/ui/actionbar.html">Action
|
|
Bar</a> developer guide.</p>
|
|
|
|
<p>Also see the <a
|
|
href="{@docRoot}resources/samples/SearchableDictionary/src/com/example/android/searchabledict/SearchableDictionary.html"
|
|
>Searchable Dictionary</a> for an example implementation using
|
|
both the dialog and the widget.</p>
|
|
|
|
|
|
|
|
<h2 id="VoiceSearch">Adding Voice Search</h2>
|
|
|
|
<p>You can add voice search functionality to your search dialog or widget by adding the {@code
|
|
android:voiceSearchMode} attribute to your searchable configuration. This adds a voice search
|
|
button 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>
|
|
<?xml version="1.0" encoding="utf-8"?>
|
|
<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> >
|
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</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>
|
|
|
|
|
|
|
|
<h2 id="SearchSuggestions">Adding Search Suggestions</h2>
|
|
|
|
<div class="figure" style="width:250px;margin:0">
|
|
<img src="{@docRoot}images/search/search-suggest-custom.png" alt="" height="417" />
|
|
<p class="img-caption"><strong>Figure 3.</strong> Screenshot of a search dialog with custom
|
|
search suggestions.</p>
|
|
</div>
|
|
|
|
<p>Both the search dialog and the search widget can provide search suggestions as the user
|
|
types, with assistance from the Android system. The system manages the list of suggestions and
|
|
handles the event when the user selects a suggestion.</p>
|
|
|
|
<p>You can provide two kinds of search suggestions:</p>
|
|
|
|
<dl>
|
|
<dt>Recent query search suggestions</dt>
|
|
<dd>These suggestions are simply words that the user previously used as search queries in
|
|
your application.
|
|
<p>See <a href="adding-recent-query-suggestions.html">Adding Recent Query
|
|
Suggestions</a>.</p></dd>
|
|
<dt>Custom search suggestions</dt>
|
|
<dd>These are search suggestions that you provide from your own data source, to help users
|
|
immediately select the correct spelling or item they are searching for. Figure 3 shows an
|
|
example of custom suggestions for a dictionary application—the user can select a suggestion
|
|
to instantly go to the definition.
|
|
<p>See <a href="adding-custom-suggestions.html">Adding Custom
|
|
Suggestions</a></p></dd>
|
|
</dl>
|
|
|