diff options
Diffstat (limited to 'docs/html/guide/topics/manifest/supports-screens-element.jd')
| -rw-r--r-- | docs/html/guide/topics/manifest/supports-screens-element.jd | 138 |
1 files changed, 108 insertions, 30 deletions
diff --git a/docs/html/guide/topics/manifest/supports-screens-element.jd b/docs/html/guide/topics/manifest/supports-screens-element.jd index ee99a37..605a2bb 100644 --- a/docs/html/guide/topics/manifest/supports-screens-element.jd +++ b/docs/html/guide/topics/manifest/supports-screens-element.jd @@ -8,12 +8,15 @@ parent.link=manifest-intro.html <dt>syntax:</dt> <dd> <pre class="stx"> -<supports-screens android:<a href="#resizeable">resizeable</a>=["true" | "false"] - android:<a href="#small">smallScreens</a>=["true" | "false"] - android:<a href="#normal">normalScreens</a>=["true" | "false"] - android:<a href="#large">largeScreens</a>=["true" | "false"] +<supports-screens android:<a href="#requiresSmallest">requiresSmallestWidthDp</a>="<em>integer</em>" + android:<a href="#compatibleWidth">compatibleWidthLimitDp</a>="<em>integer</em>" + android:<a href="#largestWidth">largestWidthLimitDp</a>="<em>integer</em>" + android:<a href="#resizeable">resizeable</a>=["true"| "false"] + android:<a href="#small">smallScreens</a>=["true" | "false"] + android:<a href="#normal">normalScreens</a>=["true" | "false"] + android:<a href="#large">largeScreens</a>=["true" | "false"] android:<a href="#xlarge">xlargeScreens</a>=["true" | "false"] - android:<a href="#any">anyDensity</a>=["true" | "false"] /> + android:<a href="#any">anyDensity</a>=["true" | "false"] /> </pre> </dd> @@ -21,36 +24,37 @@ parent.link=manifest-intro.html <dd><code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code></dd> <dt>description:</dt> -<dd>Lets you specify the screen dimensions the -application supports. By default, a modern application (using API Level 4 or higher) supports all -screen sizes; older applications are assumed to support only the "normal" screen size. Screen -size is determined as the available pixels to an application after density scaling has been -applied. (Note that screen size is a separate axis from screen density.) - -<p>An application "supports" a given screen size if it fills the entire screen and works as -expected. By default, the system will resize your application to fill the screen, if you have set +<dd>Lets you specify the screen sizes your application supports and enable screen +compatibility mode for screens larger than what your application supports. By default, a modern +application (using API Level 4 or higher) supports all screen sizes; older applications are assumed +to support only the "normal" screen size. Screen size is determined by the number of pixels on the +screen after the system accounts for screen density scaling. + +<p>An application "supports" a given screen size if it resizes properly to fill the entire screen. +By default, the system resizes your application UI to fill the screen if you have set either <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min">{@code minSdkVersion}</a> or <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">{@code -targetSdkVersion}</a> to {@code "4"} or higher. Resizing works well for most applications and -you don't have to do any extra work to make your application work on larger screens.</p> +targetSdkVersion}</a> to {@code "4"} or higher. Normal resizing works well for most applications and +you don't have to do any extra work to make your application work on screens larger than a +handset device.</p> -<p>In addition to allowing the system to resize your application, you can add additional support -for different screen sizes by providing <a +<p>In addition to allowing the system to resize your application to fit the current screen, you can +optimize your UI for different screen sizes by providing <a href="{@docRoot}guide/topics/resources/providing-resources.html#AlternativeResources">alternative layout resources</a> for different sizes. For instance, you might want to modify the layout of an activity when it is on a tablet or similar device that has an <em>xlarge</em> screen.</p> -<p>If your application does not support <em>large</em> or <em>xlarge</em> screens, then you should -declare that it is not resizeable by setting <a href="#resizeable">{@code android:resizeable}</a> to -{@code "false"}, so that the system will not resize your application on larger screens.</p> - -<p>If your application does not support <em>small</em> screens, then -there isn't much the system can do to make the application work well on a smaller screen, so -external services (such as Android Market) should not allow users to install the application on such -screens.</p> - - -<p>For more information, see +<p>However, if your application does not work well when resized to fit different screen sizes, +you can use the attributes of the {@code <supports-screens>} element to control whether +your application should be distributed to smaller screens or have its UI scaled up to fit larger +screens using the system's screen compatibility mode. When you have not designed for larger screen +sizes and the normal resizing does not achieve the appropriate results, <em>screen compatibility +mode</em> will scale your UI by emulating a <em>normal</em> size screen and then zooming in on it so +that it fills the entire screen—thus achieving the same layout as a normal handset device on +the large screen (but this usually causes pixelation and blurring of your UI).</p> + +<p>For more information about how to properly support different screen sizes so that you can avoid +using screen compatibility mode, read <a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a>.</p> @@ -59,6 +63,74 @@ screens.</p> <dd> <dl class="attr"> + <dt id="requiresSmallest">{@code android:requiresSmallestWidthDp}</dt> + <dd>This attribute specifies the minimum "smallest screen width" with which your +application is compatible. In order for a device to be considered compatible with your +application, the shortest side of the available screen space must be equal to or greater than this +value. +<p>The width against which your value is compared takes into account screen decorations and system +UI. For example, if the device has some persistent UI elements on the left or right edge of the +display, the system declares the device's available width as one that is smaller than the actual +screen size, accounting for these UI elements because those are screen pixels not available for your +UI. Thus, the value you use should be the actual smallest width required by your layout.</p> +<p>If your application properly resizes for smaller screen sizes (down to the +<em>small</em> size or a minimum width of 320dp), you do +not need to use this attribute. Otherwise, you should use a value for this attribute that +matches the smallest value used by your application for the <a +href="{@docRoot}guide/topics/resources/providing-resources.html#SmallestScreenWidthQualifier"> +smallest screen width qualifier</a> ({@code sw<N>dp}).</p> + +<p>For example, a typical handset screen has a minimum width of 320dp, a 7" tablet has a minimum +width of 600dp, and a 10" tablet has a minimum width of 720dp. If the smallest available screen +width on a device is less than the value you supply here, then the application is considered +incompatible with that +device. External services such as Android Market use this to determine whether a device +is compatible with your application and prevent incompatible devices from installing it.</p> +<p>Beginning with Android 3.2 (API level 13), using this attribute is the preferred way to +specify the minimum screen size your application requires, instead of using the other attributes +for small, normal, large, and xlarge screens. The advantage of using this attribute is that you +have more control over exactly how much screen space your application needs at a minimum in order +to properly display its UI, rather than relying on the generalized size groups.</p> +<p>This attribute has no default value. If this attribute is not specified, then any of the old +<code><a href="#small">smallScreens</a></code>, <code><a href="#normal">normalScreens</a></code>, +<code><a href="#large">largeScreens</a></code>, or <code><a href="#xlarge">xlargeScreens</a></code> +attributes are used instead to determine the smallest screen required.</p> + <p>This attribute was introduced in API level 13.</p> + </dd> + + <dt id="compatibleWidth">{@code android:compatibleWidthLimitDp}</dt> + <dd>This attribute allows you to enable screen compatibility mode as a user-optional feature by +specifying the maximum "smallest screen width" for which your application is designed. If the value +you supply here is less than the shortest side of the available screen space, users can still +install your application, but are offered to run it in screen compatibility mode. By default, screen +compatibility mode is disabled and your layout is resized to fit the screen as usual, but a +button is available in the system bar that allows the user to toggle screen compatibility mode on +and off. + <p>If your application is compatible with all screen sizes and its layout properly resizes, you do +not need to use this attribute.</p> + <p class="note"><strong>Note:</strong> Currently, screen compatibility mode only emulates handset +screens with a 320dp width, so screen compatibility mode is not applied if your value for {@code +android:compatibleWidthLimitDp} is larger than 320.</p> + <p>This attribute was introduced in API level 13.</p> + </dd> + + <dt id="largestWidth">{@code android:largestWidthLimitDp}</dt> + <dd>This attribute allows you to force enable screen compatibility mode by specifying the maximum +"smallest screen width" for which your application is designed. If the value you supply here is less +than the shortest side of the available screen space, the application runs in screen +compatibility mode with no way for the user to disable it. + <p>If your application is compatible with all screen sizes and its layout properly resizes, you do +not need to use this attribute. Otherwise, you should first consider using the <a +href="#compatibleWidth">{@code android:compatibleWidthLimitDp}</a> attribute. You should use the +{@code android:largestWidthLimitDp} attribute only when your application is functionally broken when +resized for larger screens and screen compatibility mode is the only way that users should use +your application.</p> + <p class="note"><strong>Note:</strong> Currently, screen compatibility mode only emulates handset +screens with a 320dp width, so screen compatibility mode is not applied if your value for {@code +android:largestWidthLimitDp} is larger than 320.</p> + <p>This attribute was introduced in API level 13.</p> + </dd> + <dt><a name="resizeable"></a>{@code android:resizeable}</dt> <dd>Indicates whether the application is resizeable for different screen sizes. This attribute is true, by default, if you have set either <a @@ -75,6 +147,7 @@ when resized.</p> application does not work well on larger screens, follow the guide to <a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a> to enable additional screen support.</p> + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> @@ -91,6 +164,7 @@ href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">{@code targe {@code "4"} or higher, the default value for this is {@code "true"}, any value less than {@code "4"} results in this set to {@code "false"}. + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> <dt><a name="normal"></a>{@code android:normalScreens}</dt> @@ -99,12 +173,13 @@ the default value for this is {@code "true"}, any value less than {@code "4"} re screen, but WQVGA low density and WVGA high density are also considered to be normal. This attribute is "true" by default, and applications currently should leave it that way. + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> <dt><a name="large"></a>{@code android:largeScreens}</dt> <dd>Indicates whether the application supports larger screen form-factors. A large screen is defined as a screen that is significantly larger - than a "normal" phone screen, and thus might require some special care + than a "normal" handset screen, and thus might require some special care on the application's part to make good use of it, though it may rely on resizing by the system to fill the screen. If the application has set either <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min">{@code minSdkVersion}</a> or <a @@ -112,6 +187,7 @@ href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">{@code targe {@code "4"} or higher, the default value for this is {@code "true"}, any value less than {@code "4"} results in this set to {@code "false"}. + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> <dt><a name="xlarge"></a>{@code android:xlargeScreens}</dt> @@ -125,7 +201,8 @@ href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">{@code targe {@code "4"} or higher, the default value for this is {@code "true"}, any value less than {@code "4"} results in this set to {@code "false"}. - <p>This attribute was introduced in API Level 9.</p> + <p>This attribute was introduced in API level 9.</p> + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> <dt><a name="any"></a>{@code android:anyDensity}</dt> @@ -142,6 +219,7 @@ the default value for this is {@code "true"}. Otherwise, it is {@code "false"}. down application assets by a factor of 0.75 (low dpi screens) or scale them up by a factor of 1.5 (high dpi screens), when you don't provide alternative resources for a specifc screen density. The screen density is expressed as dots-per-inch (dpi).</p> + <p><strong>This attribute is deprecated</strong> as of API level 13.</p> </dd> |