diff options
Diffstat (limited to 'docs/html/guide/topics/resources/layout-resource.jd')
| -rw-r--r-- | docs/html/guide/topics/resources/layout-resource.jd | 81 |
1 files changed, 66 insertions, 15 deletions
diff --git a/docs/html/guide/topics/resources/layout-resource.jd b/docs/html/guide/topics/resources/layout-resource.jd index 0688a18..111851c 100644 --- a/docs/html/guide/topics/resources/layout-resource.jd +++ b/docs/html/guide/topics/resources/layout-resource.jd @@ -35,12 +35,12 @@ In XML: <code>@[<em>package</em>:]layout/<em>filename</em></code> <pre class="stx"> <?xml version="1.0" encoding="utf-8"?> <<a href="#viewgroup-element"><em>ViewGroup</em></a> xmlns:android="http://schemas.android.com/apk/res/android" - android:id="@+id/<em>name</em>" + android:id="@[+][<em>package</em>:]id/<em>resource_name</em>" android:layout_height=["<em>dimension</em>" | "fill_parent" | "wrap_content"] android:layout_width=["<em>dimension</em>" | "fill_parent" | "wrap_content"] [<em>ViewGroup-specific attributes</em>] > <<a href="#view-element"><em>View</em></a> - android:id="@+id/<em>name</em>" + android:id="@[+][<em>package</em>:]id/<em>resource_name</em>" android:layout_height=["<em>dimension</em>" | "fill_parent" | "wrap_content"] android:layout_width=["<em>dimension</em>" | "fill_parent" | "wrap_content"] [<em>View-specific attributes</em>] > @@ -49,10 +49,12 @@ In XML: <code>@[<em>package</em>:]layout/<em>filename</em></code> <<a href="#viewgroup-element"><em>ViewGroup</em></a> > <<a href="#view-element"><em>View</em></a> /> </<em>ViewGroup</em>> + <<a href="#include-element">include</a> layout="@layout/<i>layout_resource</i>"/> </<em>ViewGroup</em>> </pre> <p class="note"><strong>Note:</strong> The root element can be either a -{@link android.view.ViewGroup} or a {@link android.view.View}, but there must be only +{@link android.view.ViewGroup}, a {@link android.view.View}, or a <a +href="#merge-element">{@code <merge>}</a> element, but there must be only one root element and it must contain the {@code xmlns:android} attribute with the {@code android} namespace as shown.</p> </dd> @@ -74,10 +76,9 @@ namespace as shown.</p> <p class="caps">attributes:</p> <dl class="atn-list"> <dt><code>android:id</code></dt> - <dd><em>Resource name</em>. A unique resource name for the element, which you can -use to obtain a reference to the {@link android.view.ViewGroup} from your application. - The value takes the form: <code>"@+id/<em>name</em>"</code>. See more about the - <a href="#idvalue">value for {@code android:id}</a> below. + <dd><em>Resource ID</em>. A unique resource name for the element, which you can +use to obtain a reference to the {@link android.view.ViewGroup} from your application. See more +about the <a href="#idvalue">value for {@code android:id}</a> below. </dd> <dt><code>android:layout_height</code></dt> <dd><em>Dimension or keyword</em>. <strong>Required</strong>. The height for the group, as a @@ -107,10 +108,9 @@ attributes</a>).</p> <p class="caps">attributes:</p> <dl class="atn-list"> <dt><code>android:id</code></dt> - <dd><em>Resource name</em>. A unique resource name for the element, which you can use to - obtain a reference to the {@link android.view.View} from your application. - The value takes the form: <code>"@+id/<em>name</em>"</code>. See more about the - <a href="#idvalue">value for {@code android:id}</a> below. + <dd><em>Resource ID</em>. A unique resource name for the element, which you can use to + obtain a reference to the {@link android.view.View} from your application. See more about +the <a href="#idvalue">value for {@code android:id}</a> below. </dd> <dt><code>android:layout_height</code></dt> <dd><em>Dimension or keyword</em>. <strong>Required</strong>. The height for the element, as @@ -137,20 +137,71 @@ or {@code "wrap_content"}). See the <a href="#layoutvalues">valid values</a> bel which gives it's parent initial focus on the screen. You can have only one of these elements per file.</dd> + <dt id="include-element"><code><include></code></dt> + <dd>Includes a layout file into this layout. + <p class="caps">attributes:</p> + <dl class="atn-list"> + <dt><code>layout</code></dt> + <dd><em>Layout resource</em>. <strong>Required</strong>. Reference to a layout +resource.</dd> + <dt><code>android:id</code></dt> + <dd><em>Resource ID</em>. Overrides the ID given to the root view in the included layout. + </dd> + <dt><code>android:layout_height</code></dt> + <dd><em>Dimension or keyword</em>. Overrides the height given to the root view in the +included layout. + </dd> + <dt><code>android:layout_width</code></dt> + <dd><em>Dimension or keyword</em>. Overrides the width given to the root view in the +included layout. + </dd> + </dl> + <p>You can include any other layout attributes in the <code><include></code> that are +supported by the root element in the included layout and they will override those defined in the +root element.</p> + + <p>Another way to include a layout is to use {@link android.view.ViewStub}. It is a lightweight +View that consumes no layout space until you explicitly inflate it, at which point, it includes a +layout file defined by its {@code android:layout} attribute. For more information about using {@link +android.view.ViewStub}, read <a href="{@docRoot}resources/articles/layout-tricks-stubs.html">Layout +Tricks: ViewStubs</a>.</p> + </dd> + + <dt id="merge-element"><code><merge></code></dt> + <dd>An alternative root element that is not drawn in the layout hierarchy. Using this as the +root element is useful when you know that this layout will be placed into a layout +that already contains the appropriate parent View to contain the children of the +<code><merge></code> element. This is particularly useful when you plan to include this layout +in another layout file using <a href="#include-element"><code><include></code></a> and +this layout doesn't require a different {@link android.view.ViewGroup} container. For more +information about merging layouts, read <a +href="{@docRoot}resources/articles/layout-tricks-merging.html">Layout +Tricks: Merging</a>.</dd> + </dl> + + <h4 id="idvalue">Value for <code>android:id</code></h4> -<p>For the ID value, you should use this syntax form: <code>"@+id/<em>name</em>"</code>. The plus symbol, -{@code +}, indicates that this is a new resource ID and the aapt tool will create -a new resource number to the {@code R.java} class, if it doesn't already exist. For example:</p> +<p>For the ID value, you should usually use this syntax form: <code>"@+id/<em>name</em>"</code>. The +plus symbol, {@code +}, indicates that this is a new resource ID and the <code>aapt</code> tool will +create a new resource integer in the {@code R.java} class, if it doesn't already exist. For +example:</p> <pre> <TextView android:id="@+id/nameTextbox"/> </pre> -<p>You can then refer to it this way in Java:</p> +<p>The <code>nameTextbox</code> name is now a resource ID attached to this element. You can then +refer to the {@link android.widget.TextView} to which the ID is associated in Java:</p> <pre> findViewById(R.id.nameTextbox); </pre> +<p>This code returns the {@link android.widget.TextView} object.</p> + +<p>However, if you have already defined an <a +href="{@docRoot}guide/topics/resources/drawable-resource.html#Id">ID resource</a> (and it is not +already used), then you can apply that ID to a {@link android.view.View} element by excluding the +plus symbol in the <code>android:id</code> value.</p> <h4 id="layoutvalues">Value for <code>android:layout_height</code> and <code>android:layout_width</code>:</h4> |