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1 files changed, 485 insertions, 487 deletions
diff --git a/docs/html/guide/topics/resources/localization.jd b/docs/html/guide/topics/resources/localization.jd index 7288aeb..3bb9ab5 100644 --- a/docs/html/guide/topics/resources/localization.jd +++ b/docs/html/guide/topics/resources/localization.jd @@ -1,487 +1,485 @@ -page.title=Localizing with Resources
-parent.title=Application Resources
-page.tags="localizing","localization","resources", "formats", "l10n"
-parent.link=index.html
-@jd:body
-
-<div id="qv-wrapper">
- <div id="qv">
-
-<h2>Quickview</h2>
-
-<ul>
- <li>Use resource sets to create a localized app.</li>
- <li>Android loads the correct resource set for the user's language and locale.</li>
- <li>If localized resources are not available, Android loads your default resources.</li>
-</ul>
-
-<h2>In this document</h2>
-<ol>
- <li><a href="#resource-switching">Overview: Resource-Switching in Android</a></li>
-<li><a href="#using-framework">Using Resources for Localization</a></li>
-<li><a href="#strategies">Localization Tips</a></li>
-<li><a href="#testing">Testing Localized Applications</a></li>
-</ol>
-
-<h2>See also</h2>
- <ol>
- <li><a href="{@docRoot}distribute/googleplay/publish/localizing.html">Localization Checklist</a></li>
- <li><a href="{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a></li>
- <li><a href="{@docRoot}guide/topics/ui/declaring-layout.html">Layouts</a></li>
- <li><a href="{@docRoot}reference/android/app/Activity.html#ActivityLifecycle">Activity Lifecycle</a></li>
-</ol>
-</div>
-</div>
-
-<p>Android will run on many devices in many regions. To reach the most users,
-your application should handle text, audio files, numbers, currency, and
-graphics in ways appropriate to the locales where your application will be used.
-</p>
-
-<p>This document describes best practices for localizing Android
-applications. The principles apply whether you are developing your application
-using ADT with Eclipse, Ant-based tools, or any other IDE. </p>
-
-<p>You should already have a working knowledge of Java and be familiar with
-Android resource loading, the declaration of user interface elements in XML,
-development considerations such as Activity lifecycle, and general principles of
-internationalization and localization. </p>
-
-<p>It is good practice to use the Android resource framework to separate the
-localized aspects of your application as much as possible from the core Java
-functionality:</p>
-
-<ul>
- <li>You can put most or all of the <em>contents</em> of your application's
-user interface into resource files, as described in this document and in <a
-href="{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a>.</li>
- <li>The <em>behavior</em> of the user interface, on the other hand, is driven
-by your Java code.
- For example, if users input data that needs to be formatted or sorted
-differently depending on locale, then you would use Java to handle the data
-programmatically. This document does not cover how to localize your Java code.
-</li>
-</ul>
-
-<p>For a short guide to localizing strings in your app, see the training lesson, <a
-href="{@docRoot}training/basics/supporting-devices/languages.html">Supporting Different Languages</a>. </p>
-
-
-<h2 id="resource-switching">Overview: Resource-Switching in Android</h2>
-
-<p>Resources are text strings, layouts, sounds, graphics, and any other static
-data that your Android application needs. An application can include multiple
-sets of resources, each customized for a different device configuration. When a
-user runs the application, Android automatically selects and loads the
-resources that best match the device.</p>
-
-<p>(This document focuses on localization and locale. For a complete description
-of resource-switching and all the types of configurations that you can
-specify — screen orientation, touchscreen type, and so on — see <a
-href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">Providing
-Alternative Resources</a>.)</p>
-
-<table border="0" cellspacing="0" cellpadding="0">
- <tr border="0">
- <td width="180" style="border: 0pt none ;"><p class="special-note">
- <strong>When you write your application:</strong>
- <br><br>
- You create a set of default resources, plus alternatives to be used in
- different locales.</p></td>
- <td style="border: 0pt none; padding:0">
- <p style="border:0; padding:0"><img src="../../../images/resources/right-arrow.png" alt="right-arrow"
- width="51" height="17"></p></td>
- <td width="180" style="border: 0pt none ;"><p class="special-note">
- <strong>When a user runs your application:</strong>
- <br><br>The Android system selects which resources to load, based on the
- device's locale.</p></td>
- </tr>
-</table>
-
-<p>When you write your application, you create default and alternative resources
-for your application to use. To create resources, you place files within
-specially named subdirectories of the project's <code>res/</code> directory.
-</p>
-
-
-
-<h3 id="defaults-r-important">Why Default Resources Are Important</h3>
-
-<p>Whenever the application runs in a locale for which you have not provided
-locale-specific text, Android will load the default strings from
-<code>res/values/strings.xml</code>. If this default file is absent, or if it
-is missing a string that your application needs, then your application will not run
-and will show an error.
-The example below illustrates what can happen when the default text file is incomplete. </p>
-
-<p><em>Example:</em>
-<p>An application's Java code refers to just two strings, <code>text_a</code> and
- <code>text_b</code>. This application includes a localized resource file
- (<code>res/values-en/strings.xml</code>) that defines <code>text_a</code> and
- <code>text_b</code> in English. This application also includes a default
- resource file (<code>res/values/strings.xml</code>) that includes a
-definition for <code>text_a</code>, but not for <code>text_b</code>:
-<ul>
- <li>This application might compile without a problem. An IDE such as Eclipse
- will not highlight any errors if a resource is missing.</li>
- <li>When this application is launched on a device with locale set to English,
- the application might run without a problem, because
- <code>res/values-en/strings.xml</code> contains both of the needed text
- strings.</li>
- <li>However, <strong>the user will see an error message and a Force Close
- button</strong> when this application is launched on a device set to a
- language other than English. The application will not load.</li>
-</ul>
-
-
-<p>To prevent this situation, make sure that a <code>res/values/strings.xml</code>
- file exists and that it defines every needed string. The situation applies to
- all types of resources, not just strings: You
- need to create a set of default resource files containing all
- the resources that your application calls upon — layouts, drawables,
- animations, etc. For information about testing, see <a href="#test-for-default">
- Testing for Default Resources</a>.</p>
-
-<h2 id="using-framework">Using Resources for Localization</h2>
-
-<h3 id="creating-defaults">How to Create Default Resources</h3>
-
-<p>Put the application's default text in
-a file with the following location and name:</p>
-<p><code> res/values/strings.xml</code> (required directory)</p>
-
-<p>The text strings in <code>res/values/strings.xml</code> should use the
-default language, which is the language that you expect most of your application's users to
-speak. </p>
-
-<p>The default resource set must also include any default drawables and layouts,
- and can include other types of resources such as animations.
-<br>
- <code> res/drawable/</code>(required directory holding at least
- one graphic file, for the application's icon on Google Play)<br>
- <code> res/layout/</code> (required directory holding an XML
- file that defines the default layout)<br>
- <code> res/anim/</code> (required if you have any
- <code>res/anim-<em><qualifiers></em></code> folders)<br>
- <code> res/xml/</code> (required if you have any
- <code>res/xml-<em><qualifiers></em></code> folders)<br>
- <code> res/raw/</code> (required if you have any
- <code>res/raw-<em><qualifiers></em></code> folders)
-</p>
-
-<p class="note"><strong>Tip:</strong> In your code, examine each reference to
- an Android resource. Make sure that a default resource is defined for each
- one. Also make sure that the default string file is complete: A <em>
- localized</em> string file can contain a subset of the strings, but the
- <em>default</em> string file must contain them all.
-</p>
-
-<h3 id="creating-alternatives">How to Create Alternative Resources</h3>
-
-<p>A large part of localizing an application is providing alternative text for
-different languages. In some cases you will also provide alternative graphics,
-sounds, layouts, and other locale-specific resources. </p>
-
-<p>An application can specify many <code>res/<em><qualifiers></em>/</code>
-directories, each with different qualifiers. To create an alternative resource for
-a different locale, you use a qualifier that specifies a language or a
-language-region combination. (The name of a resource directory must conform
-to the naming scheme described in
-<a href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">Providing
-Alternative Resources</a>,
-or else it will not compile.)</p>
-
-<p><em>Example:</em></p>
-
-<p>Suppose that your application's default language is English. Suppose also
-that you want to localize all the text in your application to French, and most
-of the text in your application (everything except the application's title) to
-Japanese. In this case, you could create three alternative <code>strings.xml</code>
-files, each stored in a locale-specific resource directory:</p>
-
-<ol>
- <li><code>res/values/strings.xml</code><br>
- Contains English text for all the strings that the application uses,
-including text for a string named <code>title</code>.</li>
- <li><code>res/values-fr/strings.xml</code><br>
- Contain French text for all the strings, including <code>title</code>.</li>
- <li><code>res/values-ja/strings.xml</code><br>
- Contain Japanese text for all the strings <em>except</em>
-<code>title</code>.<br>
- <code></code></li>
-</ol>
-
-<p>If your Java code refers to <code>R.string.title</code>, here is what will
-happen at runtime:</p>
-
-<ul>
- <li>If the device is set to any language other than French, Android will load
-<code>title</code> from the <code>res/values/strings.xml</code> file.</li>
- <li>If the device is set to French, Android will load <code>title</code> from
-the <code>res/values-fr/strings.xml</code> file.</li>
-</ul>
-
-<p>Notice that if the device is set to Japanese, Android will look for
-<code>title</code> in the <code>res/values-ja/strings.xml</code> file. But
-because no such string is included in that file, Android will fall back to the
-default, and will load <code>title</code> in English from the
-<code>res/values/strings.xml</code> file. </p>
-
-<h3 id="resource-precedence">Which Resources Take Precedence?</h3>
-
-<p> If multiple resource files match a device's configuration, Android follows a
-set of rules in deciding which file to use. Among the qualifiers that can be
-specified in a resource directory name, <strong>locale almost always takes
-precedence</strong>. </p>
-<p><em>Example:</em></p>
-
-<p>Assume that an application includes a default set of graphics and two other
-sets of graphics, each optimized for a different device setup:</p>
-
-<ul>
- <li><code>res/drawable/</code><br>
- Contains
- default graphics.</li>
- <li><code>res/drawable-small-land-stylus/</code><br>
- Contains graphics optimized for use with a device that expects input from a
- stylus and has a QVGA low-density screen in landscape orientation.</li>
- <li><code>res/drawable-ja/</code> <br>
- Contains graphics optimized for use with Japanese.</li>
-</ul>
-
-<p>If the application runs on a device that is configured to use Japanese,
-Android will load graphics from <code>res/drawable-ja/</code>, even if the
-device happens to be one that expects input from a stylus and has a QVGA
-low-density screen in landscape orientation.</p>
-
-<p class="note"><strong>Exception:</strong> The only qualifiers that take
-precedence over locale in the selection process are MCC and MNC (mobile country
-code and mobile network code). </p>
-
-<p><em>Example:</em></p>
-
-<p>Assume that you have the following situation:</p>
-
-<ul>
- <li>The application code calls for <code>R.string.text_a</code></li>
- <li>Two relevant resource files are available:
- <ul>
- <li><code>res/values-mcc404/strings.xml</code>, which includes
-<code>text_a</code> in the application's default language, in this case
-English.</li>
- <li><code>res/values-hi/strings.xml</code>, which includes
-<code>text_a</code> in Hindi.</li>
- </ul>
- </li>
- <li>The application is running on a device that has the following
-configuration:
- <ul>
- <li>The SIM card is connected to a mobile network in India (MCC 404).</li>
- <li>The language is set to Hindi (<code>hi</code>).</li>
- </ul>
- </li>
-</ul>
-
-<p>Android will load <code>text_a</code> from
-<code>res/values-mcc404/strings.xml</code> (in English), even if the device is
-configured for Hindi. That is because in the resource-selection process, Android
-will prefer an MCC match over a language match. </p>
-
-<p>The selection process is not always as straightforward as these examples
-suggest. Please read <a
-href="{@docRoot}guide/topics/resources/providing-resources.html#BestMatch">How Android Finds
-the Best-matching Resource</a> for a more nuanced description of the
-process. All the qualifiers are described and listed in order of
-precedence in <a
-href="{@docRoot}guide/topics/resources/providing-resources.html#table2">Table 2 of Providing
-Alternative Resources</a>.</p>
-
-<h3 id="referring-to-resources">Referring to Resources in Java</h3>
-
-<p>In your application's Java code, you refer to resources using the syntax
-<code>R.<em>resource_type</em>.<em>resource_name</em></code> or
-<code>android.R.<em>resource_type</em>.<em>resource_name</em></code><em>.</em>
-For more about this, see <a
-href="{@docRoot}guide/topics/resources/accessing-resources.html">Accessing Resources</a>.</p>
-
-<h2 id="checklist">Localization Checklist</h2>
-
-<p>For a complete overview of the process of localizing and distributing an Android application,
-see the <a href="{@docRoot}distribute/googleplay/publish/localizing.html">Localization
-Checklist</a> document.</p>
-
-<h2 id="strategies">Localization Tips</h2>
-
-<h4 id="failing2">Design your application to work in any locale</h4>
-
-<p>You cannot assume anything about the device on which a user will
-run your application. The device might have hardware that you were not
-anticipating, or it might be set to a locale that you did not plan for or that
-you cannot test. Design your application so that it will function normally or fail gracefully no
-matter what device it runs on.</p>
-
-<p class="note"><strong>Important:</strong> Make sure that your application
-includes a full set of default resources.</p> <p>Make sure to include
-<code>res/drawable/</code> and a <code>res/values/</code> folders (without any
-additional modifiers in the folder names) that contain all the images and text
-that your application will need. </p>
-
-<p>If an application is missing even one default resource, it will not run on a
- device that is set to an unsupported locale. For example, the
- <code>res/values/strings.xml</code> default file might lack one string that
- the application needs: When the application runs in an unsupported locale and
- attempts to load <code>res/values/strings.xml</code>, the user will see an
- error message and a Force Close button. An IDE such as Eclipse will not
- highlight this kind of error, and you will not see the problem when you
- test the application on a device or emulator that is set to a supported locale.</p>
-
-<p>For more information, see <a href="#test-for-default">Testing for Default Resources</a>.</p>
-
-<h4>Design a flexible layout</h4>
-
-<p> If you need to rearrange your layout to fit a certain language (for example
-German with its long words), you can create an alternative layout for that
-language (for example <code>res/layout-de/main.xml</code>). However, doing this
-can make your application harder to maintain. It is better to create a single
-layout that is more flexible.</p>
-
-<p>Another typical situation is a language that requires something different in
-its layout. For example, you might have a contact form that should include two
-name fields when the application runs in Japanese, but three name fields when
-the application runs in some other language. You could handle this in either of
-two ways:</p>
-
-<ul>
- <li>Create one layout with a field that you can programmatically enable or
-disable, based on the language, or</li>
- <li>Have the main layout include another layout that includes the changeable
-field. The second layout can have different configurations for different
-languages.</li>
-</ul>
-
-<h4>Avoid creating more resource files and text strings than you need</h4>
-
-<p>You probably do not need to create a locale-specific
-alternative for every resource in your application. For example, the layout
-defined in the <code>res/layout/main.xml</code> file might work in any locale,
-in which case there would be no need to create any alternative layout files.
-</p>
-
-<p>Also, you might not need to create alternative text for every
-string. For example, assume the following:</p>
-
-<ul>
- <li>Your application's default language is American
-English. Every string that the application uses is defined, using American
-English spellings, in <code>res/values/strings.xml</code>. </li>
-
- <li>For a few important phrases, you want to provide
-British English spelling. You want these alternative strings to be used when your
-application runs on a device in the United Kingdom. </li>
-</ul>
-
-<p>To do this, you could create a small file called
-<code>res/values-en-rGB/strings.xml</code> that includes only the strings that
-should be different when the application runs in the U.K. For all the rest of
-the strings, the application will fall back to the defaults and use what is
-defined in <code>res/values/strings.xml</code>.</p>
-
-<h4>Use the Android Context object for manual locale lookup</h4>
-
-<p>You can look up the locale using the {@link android.content.Context} object
-that Android makes available:</p>
-
-<pre>String locale = context.getResources().getConfiguration().locale.getDisplayName();</pre>
-
-<h2 id="testing">Testing Localized Applications</h2>
-
-<h3 id="device">Testing on a Device</h3>
-<p>Keep in mind that the device you are testing may be significantly different from
- the devices available to consumers in other geographies. The locales available
- on your device may differ from those available on other devices. Also, the
- resolution and density of the device screen may differ, which could affect
- the display of strings and drawables in your UI.</p>
-
-<p>To change the locale on a device, use the Settings application (Home >
-Menu > Settings > Locale & text > Select locale). </p>
-
-<h3 id="emulator">Testing on an Emulator</h3>
-
-<p>For details about using the emulator, see See <a
-href="{@docRoot}tools/help/emulator.html">Android Emulator</a>.</p>
-<h4>Creating and using a custom locale</h4>
-
-<p>A "custom" locale is a language/region combination that the Android
-system image does not explicitly support. (For a list of supported locales in
-Android platforms see the Version Notes in the <a
-href="{@docRoot}sdk/index.html">SDK</a> tab). You can test
-how your application will run in a custom locale by creating a custom locale in
-the emulator. There are two ways to do this:</p>
-
-<ul>
- <li>Use the Custom Locale application, which is accessible from the
-Application tab. (After you create a custom locale, switch to it by
-pressing and holding the locale name.)</li>
- <li>Change to a custom locale from the adb shell, as described below.</li>
-</ul>
-
-<p>When you set the emulator to a locale that is not available in the Android
-system image, the system itself will display in its default language. Your
-application, however, should localize properly.</p>
-
-<h4>Changing the emulator locale from the adb shell</h4>
-
-<p>To change the locale in the emulator by using the adb shell. </p>
-
-<ol>
- <li>Pick the locale you want to test and determine its language and region codes, for
-example <code>fr</code> for French and <code>CA</code> for Canada.<br>
- </li>
- <li>Launch an emulator.</li>
- <li>From a command-line shell on the host computer, run the following
-command:<br>
- <code>adb shell</code><br>
- or if you have a device attached, specify that you want the emulator by adding
-the <code>-e</code> option:<br>
- <code>adb -e shell</code></li>
- <li>At the adb shell prompt (<code>#</code>), run this command: <br>
- <code>setprop persist.sys.language [<em>language code</em>];setprop
-persist.sys.country [<em>country code</em>];stop;sleep 5;start <br>
- </code>Replace bracketed sections with the appropriate codes from Step
-1.</li>
-</ol>
-
-<p>For instance, to test in Canadian French:</p>
-
-<p><code>setprop persist.sys.language fr;setprop persist.sys.country
-CA;stop;sleep 5;start </code></p>
-
-<p>This will cause the emulator to restart. (It will look like a full reboot,
-but it is not.) Once the Home screen appears again, re-launch your application (for
-example, click the Run icon in Eclipse), and the application will launch with
-the new locale. </p>
-
-<h3 id="test-for-default">Testing for Default Resources</h3>
-<p>Here's how to test whether an application includes every string resource that it needs: </p>
-<ol><li>Set the emulator or device to a language that your application does not
- support. For example, if the application has French strings in
- <code>res/values-fr/</code> but does not have any Spanish strings in
- <code>res/values-es/</code>, then set the emulator's locale to Spanish.
- (You can use the Custom Locale application to set the emulator to an
- unsupported locale.)</li>
- <li>Run the application.</li>
-<li>If the application shows an error message and a Force Close button, it might
- be looking for a string that is not available. Make sure that your
- <code>res/values/strings.xml</code> file includes a definition for
- every string that the application uses.</li>
-</ol>
-</p>
-
-<p>If the test is successful, repeat it for other types of
- configurations. For example, if the application has a layout file called
- <code>res/layout-land/main.xml</code> but does not contain a file called
- <code>res/layout-port/main.xml</code>, then set the emulator or device to
- portrait orientation and see if the application will run.
-
-
-
+page.title=Localizing with Resources +parent.title=Application Resources +page.tags=localizing,localization,resources,formats,l10n +parent.link=index.html +@jd:body + +<div id="qv-wrapper"> + <div id="qv"> + +<h2>Quickview</h2> + +<ul> + <li>Use resource sets to create a localized app.</li> + <li>Android loads the correct resource set for the user's language and locale.</li> + <li>If localized resources are not available, Android loads your default resources.</li> +</ul> + +<h2>In this document</h2> +<ol> + <li><a href="#resource-switching">Overview: Resource-Switching in Android</a></li> +<li><a href="#using-framework">Using Resources for Localization</a></li> +<li><a href="#strategies">Localization Tips</a></li> +<li><a href="#testing">Testing Localized Applications</a></li> +</ol> + +<h2>See also</h2> + <ol> + <li><a href="{@docRoot}distribute/googleplay/publish/localizing.html">Localization Checklist</a></li> + <li><a href="{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a></li> + <li><a href="{@docRoot}guide/topics/ui/declaring-layout.html">Layouts</a></li> + <li><a href="{@docRoot}reference/android/app/Activity.html#ActivityLifecycle">Activity Lifecycle</a></li> +</ol> +</div> +</div> + +<p>Android will run on many devices in many regions. To reach the most users, +your application should handle text, audio files, numbers, currency, and +graphics in ways appropriate to the locales where your application will be used. +</p> + +<p>This document describes best practices for localizing Android +applications. The principles apply whether you are developing your application +using ADT with Eclipse, Ant-based tools, or any other IDE. </p> + +<p>You should already have a working knowledge of Java and be familiar with +Android resource loading, the declaration of user interface elements in XML, +development considerations such as Activity lifecycle, and general principles of +internationalization and localization. </p> + +<p>It is good practice to use the Android resource framework to separate the +localized aspects of your application as much as possible from the core Java +functionality:</p> + +<ul> + <li>You can put most or all of the <em>contents</em> of your application's +user interface into resource files, as described in this document and in <a +href="{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a>.</li> + <li>The <em>behavior</em> of the user interface, on the other hand, is driven +by your Java code. + For example, if users input data that needs to be formatted or sorted +differently depending on locale, then you would use Java to handle the data +programmatically. This document does not cover how to localize your Java code. +</li> +</ul> + +<p>For a short guide to localizing strings in your app, see the training lesson, <a +href="{@docRoot}training/basics/supporting-devices/languages.html">Supporting Different Languages</a>. </p> + + +<h2 id="resource-switching">Overview: Resource-Switching in Android</h2> + +<p>Resources are text strings, layouts, sounds, graphics, and any other static +data that your Android application needs. An application can include multiple +sets of resources, each customized for a different device configuration. When a +user runs the application, Android automatically selects and loads the +resources that best match the device.</p> + +<p>(This document focuses on localization and locale. For a complete description +of resource-switching and all the types of configurations that you can +specify — screen orientation, touchscreen type, and so on — see <a +href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">Providing +Alternative Resources</a>.)</p> + +<table border="0" cellspacing="0" cellpadding="0"> + <tr border="0"> + <td width="180" style="border: 0pt none ;"><p class="special-note"> + <strong>When you write your application:</strong> + <br><br> + You create a set of default resources, plus alternatives to be used in + different locales.</p></td> + <td style="border: 0pt none; padding:0"> + <p style="border:0; padding:0"><img src="../../../images/resources/right-arrow.png" alt="right-arrow" + width="51" height="17"></p></td> + <td width="180" style="border: 0pt none ;"><p class="special-note"> + <strong>When a user runs your application:</strong> + <br><br>The Android system selects which resources to load, based on the + device's locale.</p></td> + </tr> +</table> + +<p>When you write your application, you create default and alternative resources +for your application to use. To create resources, you place files within +specially named subdirectories of the project's <code>res/</code> directory. +</p> + + + +<h3 id="defaults-r-important">Why Default Resources Are Important</h3> + +<p>Whenever the application runs in a locale for which you have not provided +locale-specific text, Android will load the default strings from +<code>res/values/strings.xml</code>. If this default file is absent, or if it +is missing a string that your application needs, then your application will not run +and will show an error. +The example below illustrates what can happen when the default text file is incomplete. </p> + +<p><em>Example:</em> +<p>An application's Java code refers to just two strings, <code>text_a</code> and + <code>text_b</code>. This application includes a localized resource file + (<code>res/values-en/strings.xml</code>) that defines <code>text_a</code> and + <code>text_b</code> in English. This application also includes a default + resource file (<code>res/values/strings.xml</code>) that includes a +definition for <code>text_a</code>, but not for <code>text_b</code>: +<ul> + <li>This application might compile without a problem. An IDE such as Eclipse + will not highlight any errors if a resource is missing.</li> + <li>When this application is launched on a device with locale set to English, + the application might run without a problem, because + <code>res/values-en/strings.xml</code> contains both of the needed text + strings.</li> + <li>However, <strong>the user will see an error message and a Force Close + button</strong> when this application is launched on a device set to a + language other than English. The application will not load.</li> +</ul> + + +<p>To prevent this situation, make sure that a <code>res/values/strings.xml</code> + file exists and that it defines every needed string. The situation applies to + all types of resources, not just strings: You + need to create a set of default resource files containing all + the resources that your application calls upon — layouts, drawables, + animations, etc. For information about testing, see <a href="#test-for-default"> + Testing for Default Resources</a>.</p> + +<h2 id="using-framework">Using Resources for Localization</h2> + +<h3 id="creating-defaults">How to Create Default Resources</h3> + +<p>Put the application's default text in +a file with the following location and name:</p> +<p><code> res/values/strings.xml</code> (required directory)</p> + +<p>The text strings in <code>res/values/strings.xml</code> should use the +default language, which is the language that you expect most of your application's users to +speak. </p> + +<p>The default resource set must also include any default drawables and layouts, + and can include other types of resources such as animations. +<br> + <code> res/drawable/</code>(required directory holding at least + one graphic file, for the application's icon on Google Play)<br> + <code> res/layout/</code> (required directory holding an XML + file that defines the default layout)<br> + <code> res/anim/</code> (required if you have any + <code>res/anim-<em><qualifiers></em></code> folders)<br> + <code> res/xml/</code> (required if you have any + <code>res/xml-<em><qualifiers></em></code> folders)<br> + <code> res/raw/</code> (required if you have any + <code>res/raw-<em><qualifiers></em></code> folders) +</p> + +<p class="note"><strong>Tip:</strong> In your code, examine each reference to + an Android resource. Make sure that a default resource is defined for each + one. Also make sure that the default string file is complete: A <em> + localized</em> string file can contain a subset of the strings, but the + <em>default</em> string file must contain them all. +</p> + +<h3 id="creating-alternatives">How to Create Alternative Resources</h3> + +<p>A large part of localizing an application is providing alternative text for +different languages. In some cases you will also provide alternative graphics, +sounds, layouts, and other locale-specific resources. </p> + +<p>An application can specify many <code>res/<em><qualifiers></em>/</code> +directories, each with different qualifiers. To create an alternative resource for +a different locale, you use a qualifier that specifies a language or a +language-region combination. (The name of a resource directory must conform +to the naming scheme described in +<a href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">Providing +Alternative Resources</a>, +or else it will not compile.)</p> + +<p><em>Example:</em></p> + +<p>Suppose that your application's default language is English. Suppose also +that you want to localize all the text in your application to French, and most +of the text in your application (everything except the application's title) to +Japanese. In this case, you could create three alternative <code>strings.xml</code> +files, each stored in a locale-specific resource directory:</p> + +<ol> + <li><code>res/values/strings.xml</code><br> + Contains English text for all the strings that the application uses, +including text for a string named <code>title</code>.</li> + <li><code>res/values-fr/strings.xml</code><br> + Contain French text for all the strings, including <code>title</code>.</li> + <li><code>res/values-ja/strings.xml</code><br> + Contain Japanese text for all the strings <em>except</em> +<code>title</code>.<br> + <code></code></li> +</ol> + +<p>If your Java code refers to <code>R.string.title</code>, here is what will +happen at runtime:</p> + +<ul> + <li>If the device is set to any language other than French, Android will load +<code>title</code> from the <code>res/values/strings.xml</code> file.</li> + <li>If the device is set to French, Android will load <code>title</code> from +the <code>res/values-fr/strings.xml</code> file.</li> +</ul> + +<p>Notice that if the device is set to Japanese, Android will look for +<code>title</code> in the <code>res/values-ja/strings.xml</code> file. But +because no such string is included in that file, Android will fall back to the +default, and will load <code>title</code> in English from the +<code>res/values/strings.xml</code> file. </p> + +<h3 id="resource-precedence">Which Resources Take Precedence?</h3> + +<p> If multiple resource files match a device's configuration, Android follows a +set of rules in deciding which file to use. Among the qualifiers that can be +specified in a resource directory name, <strong>locale almost always takes +precedence</strong>. </p> +<p><em>Example:</em></p> + +<p>Assume that an application includes a default set of graphics and two other +sets of graphics, each optimized for a different device setup:</p> + +<ul> + <li><code>res/drawable/</code><br> + Contains + default graphics.</li> + <li><code>res/drawable-small-land-stylus/</code><br> + Contains graphics optimized for use with a device that expects input from a + stylus and has a QVGA low-density screen in landscape orientation.</li> + <li><code>res/drawable-ja/</code> <br> + Contains graphics optimized for use with Japanese.</li> +</ul> + +<p>If the application runs on a device that is configured to use Japanese, +Android will load graphics from <code>res/drawable-ja/</code>, even if the +device happens to be one that expects input from a stylus and has a QVGA +low-density screen in landscape orientation.</p> + +<p class="note"><strong>Exception:</strong> The only qualifiers that take +precedence over locale in the selection process are MCC and MNC (mobile country +code and mobile network code). </p> + +<p><em>Example:</em></p> + +<p>Assume that you have the following situation:</p> + +<ul> + <li>The application code calls for <code>R.string.text_a</code></li> + <li>Two relevant resource files are available: + <ul> + <li><code>res/values-mcc404/strings.xml</code>, which includes +<code>text_a</code> in the application's default language, in this case +English.</li> + <li><code>res/values-hi/strings.xml</code>, which includes +<code>text_a</code> in Hindi.</li> + </ul> + </li> + <li>The application is running on a device that has the following +configuration: + <ul> + <li>The SIM card is connected to a mobile network in India (MCC 404).</li> + <li>The language is set to Hindi (<code>hi</code>).</li> + </ul> + </li> +</ul> + +<p>Android will load <code>text_a</code> from +<code>res/values-mcc404/strings.xml</code> (in English), even if the device is +configured for Hindi. That is because in the resource-selection process, Android +will prefer an MCC match over a language match. </p> + +<p>The selection process is not always as straightforward as these examples +suggest. Please read <a +href="{@docRoot}guide/topics/resources/providing-resources.html#BestMatch">How Android Finds +the Best-matching Resource</a> for a more nuanced description of the +process. All the qualifiers are described and listed in order of +precedence in <a +href="{@docRoot}guide/topics/resources/providing-resources.html#table2">Table 2 of Providing +Alternative Resources</a>.</p> + +<h3 id="referring-to-resources">Referring to Resources in Java</h3> + +<p>In your application's Java code, you refer to resources using the syntax +<code>R.<em>resource_type</em>.<em>resource_name</em></code> or +<code>android.R.<em>resource_type</em>.<em>resource_name</em></code><em>.</em> +For more about this, see <a +href="{@docRoot}guide/topics/resources/accessing-resources.html">Accessing Resources</a>.</p> + +<h2 id="checklist">Localization Checklist</h2> + +<p>For a complete overview of the process of localizing and distributing an Android application, +see the <a href="{@docRoot}distribute/googleplay/publish/localizing.html">Localization +Checklist</a> document.</p> + +<h2 id="strategies">Localization Tips</h2> + +<h4 id="failing2">Design your application to work in any locale</h4> + +<p>You cannot assume anything about the device on which a user will +run your application. The device might have hardware that you were not +anticipating, or it might be set to a locale that you did not plan for or that +you cannot test. Design your application so that it will function normally or fail gracefully no +matter what device it runs on.</p> + +<p class="note"><strong>Important:</strong> Make sure that your application +includes a full set of default resources.</p> <p>Make sure to include +<code>res/drawable/</code> and a <code>res/values/</code> folders (without any +additional modifiers in the folder names) that contain all the images and text +that your application will need. </p> + +<p>If an application is missing even one default resource, it will not run on a + device that is set to an unsupported locale. For example, the + <code>res/values/strings.xml</code> default file might lack one string that + the application needs: When the application runs in an unsupported locale and + attempts to load <code>res/values/strings.xml</code>, the user will see an + error message and a Force Close button. An IDE such as Eclipse will not + highlight this kind of error, and you will not see the problem when you + test the application on a device or emulator that is set to a supported locale.</p> + +<p>For more information, see <a href="#test-for-default">Testing for Default Resources</a>.</p> + +<h4>Design a flexible layout</h4> + +<p> If you need to rearrange your layout to fit a certain language (for example +German with its long words), you can create an alternative layout for that +language (for example <code>res/layout-de/main.xml</code>). However, doing this +can make your application harder to maintain. It is better to create a single +layout that is more flexible.</p> + +<p>Another typical situation is a language that requires something different in +its layout. For example, you might have a contact form that should include two +name fields when the application runs in Japanese, but three name fields when +the application runs in some other language. You could handle this in either of +two ways:</p> + +<ul> + <li>Create one layout with a field that you can programmatically enable or +disable, based on the language, or</li> + <li>Have the main layout include another layout that includes the changeable +field. The second layout can have different configurations for different +languages.</li> +</ul> + +<h4>Avoid creating more resource files and text strings than you need</h4> + +<p>You probably do not need to create a locale-specific +alternative for every resource in your application. For example, the layout +defined in the <code>res/layout/main.xml</code> file might work in any locale, +in which case there would be no need to create any alternative layout files. +</p> + +<p>Also, you might not need to create alternative text for every +string. For example, assume the following:</p> + +<ul> + <li>Your application's default language is American +English. Every string that the application uses is defined, using American +English spellings, in <code>res/values/strings.xml</code>. </li> + + <li>For a few important phrases, you want to provide +British English spelling. You want these alternative strings to be used when your +application runs on a device in the United Kingdom. </li> +</ul> + +<p>To do this, you could create a small file called +<code>res/values-en-rGB/strings.xml</code> that includes only the strings that +should be different when the application runs in the U.K. For all the rest of +the strings, the application will fall back to the defaults and use what is +defined in <code>res/values/strings.xml</code>.</p> + +<h4>Use the Android Context object for manual locale lookup</h4> + +<p>You can look up the locale using the {@link android.content.Context} object +that Android makes available:</p> + +<pre>String locale = context.getResources().getConfiguration().locale.getDisplayName();</pre> + +<h2 id="testing">Testing Localized Applications</h2> + +<h3 id="device">Testing on a Device</h3> +<p>Keep in mind that the device you are testing may be significantly different from + the devices available to consumers in other geographies. The locales available + on your device may differ from those available on other devices. Also, the + resolution and density of the device screen may differ, which could affect + the display of strings and drawables in your UI.</p> + +<p>To change the locale on a device, use the Settings application (Home > +Menu > Settings > Locale & text > Select locale). </p> + +<h3 id="emulator">Testing on an Emulator</h3> + +<p>For details about using the emulator, see See <a +href="{@docRoot}tools/help/emulator.html">Android Emulator</a>.</p> +<h4>Creating and using a custom locale</h4> + +<p>A "custom" locale is a language/region combination that the Android +system image does not explicitly support. (For a list of supported locales in +Android platforms see the Version Notes in the <a +href="{@docRoot}sdk/index.html">SDK</a> tab). You can test +how your application will run in a custom locale by creating a custom locale in +the emulator. There are two ways to do this:</p> + +<ul> + <li>Use the Custom Locale application, which is accessible from the +Application tab. (After you create a custom locale, switch to it by +pressing and holding the locale name.)</li> + <li>Change to a custom locale from the adb shell, as described below.</li> +</ul> + +<p>When you set the emulator to a locale that is not available in the Android +system image, the system itself will display in its default language. Your +application, however, should localize properly.</p> + +<h4>Changing the emulator locale from the adb shell</h4> + +<p>To change the locale in the emulator by using the adb shell. </p> + +<ol> + <li>Pick the locale you want to test and determine its language and region codes, for +example <code>fr</code> for French and <code>CA</code> for Canada.<br> + </li> + <li>Launch an emulator.</li> + <li>From a command-line shell on the host computer, run the following +command:<br> + <code>adb shell</code><br> + or if you have a device attached, specify that you want the emulator by adding +the <code>-e</code> option:<br> + <code>adb -e shell</code></li> + <li>At the adb shell prompt (<code>#</code>), run this command: <br> + <code>setprop persist.sys.language [<em>language code</em>];setprop +persist.sys.country [<em>country code</em>];stop;sleep 5;start <br> + </code>Replace bracketed sections with the appropriate codes from Step +1.</li> +</ol> + +<p>For instance, to test in Canadian French:</p> + +<p><code>setprop persist.sys.language fr;setprop persist.sys.country +CA;stop;sleep 5;start </code></p> + +<p>This will cause the emulator to restart. (It will look like a full reboot, +but it is not.) Once the Home screen appears again, re-launch your application (for +example, click the Run icon in Eclipse), and the application will launch with +the new locale. </p> + +<h3 id="test-for-default">Testing for Default Resources</h3> +<p>Here's how to test whether an application includes every string resource that it needs: </p> +<ol><li>Set the emulator or device to a language that your application does not + support. For example, if the application has French strings in + <code>res/values-fr/</code> but does not have any Spanish strings in + <code>res/values-es/</code>, then set the emulator's locale to Spanish. + (You can use the Custom Locale application to set the emulator to an + unsupported locale.)</li> + <li>Run the application.</li> +<li>If the application shows an error message and a Force Close button, it might + be looking for a string that is not available. Make sure that your + <code>res/values/strings.xml</code> file includes a definition for + every string that the application uses.</li> +</ol> +</p> + +<p>If the test is successful, repeat it for other types of + configurations. For example, if the application has a layout file called + <code>res/layout-land/main.xml</code> but does not contain a file called + <code>res/layout-port/main.xml</code>, then set the emulator or device to + portrait orientation and see if the application will run. + |