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| author | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:45 -0800 |
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| committer | The Android Open Source Project <initial-contribution@android.com> | 2009-03-03 18:28:45 -0800 |
| commit | d83a98f4ce9cfa908f5c54bbd70f03eec07e7553 (patch) | |
| tree | 4b825dc642cb6eb9a060e54bf8d69288fbee4904 /docs/html/guide/topics/ui/layout-objects.jd | |
| parent | 076357b8567458d4b6dfdcf839ef751634cd2bfb (diff) | |
| download | frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.zip frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.tar.gz frameworks_base-d83a98f4ce9cfa908f5c54bbd70f03eec07e7553.tar.bz2 | |
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diff --git a/docs/html/guide/topics/ui/layout-objects.jd b/docs/html/guide/topics/ui/layout-objects.jd deleted file mode 100644 index cf85fd6..0000000 --- a/docs/html/guide/topics/ui/layout-objects.jd +++ /dev/null @@ -1,305 +0,0 @@ -page.title=Common Layout Objects -parent.title=User Interface -parent.link=index.html -@jd:body - -<div id="qv-wrapper"> -<div id="qv"> - <h2>In this document</h2> - <ol> - <li><a href="#framelayout">FrameLayout</a></li> - <li><a href="#linearlayout">LinearLayout</a></li> - <li><a href="#tablelayout">TableLayout</a></li> - <li><a href="#absolutelayout">AbsoluteLayout</a></li> - <li><a href="#relativelayout">RelativeLayout</a></li> - <li><a href="#viewgroupsummary">Summary of Important View Groups</a></li> - </ol> -</div> -</div> - -<p>This section describes some of the more common types of layout objects -to use in your applications. Like all layouts, they are subclasses of {@link android.view.ViewGroup ViewGroup}.</p> - -<p>Also see the <a href="{@docRoot}guide/tutorials/views/index.html">Hello Views</a> tutorials for -some guidance on using more Android View layouts.</p> - -<h2 id="framelayout">FrameLayout</h2> -<p>{@link android.widget.FrameLayout FrameLayout} is the simplest type of layout -object. It's basically a blank space on your screen that you can -later fill with a single object — for example, a picture that you'll swap in and out. -All child elements of the FrameLayout are pinned to the top left corner of the screen; you cannot -specify a different location for a child view. Subsequent child views will simply be drawn over previous ones, -partially or totally obscuring them (unless the newer object is transparent). -</p> - - -<h2 id="linearlayout">LinearLayout</h2> -<p>{@link android.widget.LinearLayout LinearLayout} aligns all children in a -single direction — vertically or horizontally, depending on how you -define the <code>orientation</code> attribute. All children are -stacked one after the other, so a vertical list will only have one child per -row, no matter how wide they are, and a horizontal list will only be one row -high (the height of the tallest child, plus padding). A {@link -android.widget.LinearLayout LinearLayout} respects <em>margin</em>s between children -and the <em>gravity</em> (right, center, or left alignment) of each child. </p> - -<p>{@link android.widget.LinearLayout LinearLayout} also supports assigning a -<em>weight</em> to individual children. This attribute assigns an "importance" value to a view, -and allows it to expand to fill any remaining space in the parent view. -Child views can specify an integer weight value, and then any remaining space in the view group is -assigned to children in the proportion of their declared weight. Default -weight is zero. For example, if there are three text boxes and two of -them declare a weight of 1, while the other is given no weight (0), the third text box without weight -will not grow and will only occupy the area required by its content. -The other two will expand equally to fill the space remaining after all three boxes are measured. -If the third box is then given a weight of 2 (instead of 0), then it is now declared -"more important" than both the others, so it gets half the total remaining space, while the first two -share the rest equally.</p> - -<div class="sidebox"> -<p><strong>Tip</strong>: To create a proportionate size -layout on the screen, create a container view group object with the -<code>layout_width</code> and <code>layout_height</code> attributes set to <var>fill_parent</var>; assign -the children <code>height</code> or <code>width</code> to <code>0</code> (zero); then assign relative -<code>weight</code> values -to each child, depending on what proportion of the screen each should -have.</p> -</div> - -<p>The following two forms represent a {@link android.widget.LinearLayout LinearLayout} with a set of elements: a -button, some labels and text boxes. The text boxes have their width set to <var>fill_parent</var>; other -elements are set to <var>wrap_content</var>. The gravity, by default, is left. -The difference between the two versions of the form is that the form -on the left has weight values unset (0 by default), while the form on the right has -the comments text box weight set to 1. If the Name textbox had also been set -to 1, the Name and Comments text boxes would be the same height. </p> - -<img src="{@docRoot}images/linearlayout.png" alt="" /> - -<p>Within a horizontal {@link android.widget.LinearLayout LinearLayout}, items are aligned by the position of -their text base line (the first line of the first list element — topmost or -leftmost — is considered the reference line). This is so that people scanning -elements in a form shouldn't have to jump up and down to read element text in -neighboring elements. This can be turned off by setting -<code>android:baselineAligned="false"</code> in the layout XML. </p> - -<p>To view other sample code, see the -<a href="{@docRoot}guide/tutorials/views/hello-linearlayout.html">Hello LinearLayout</a> tutorial.</p> - - -<h2 id="tablelayout">TableLayout</h2> -<p>{@link android.widget.TableLayout} positions its children into rows - and columns. TableLayout containers do not display border lines for their rows, columns, - or cells. The table will have as many columns as the row with the most cells. A table can leave -cells empty, but cells cannot span columns, as they can in HTML.</p> -<p>{@link android.widget.TableRow} objects are the child views of a TableLayout -(each TableRow defines a single row in the table). -Each row has zero or more cells, each of which is defined by any kind of other View. So, the cells of a row may be -composed of a variety of View objects, like ImageView or TextView objects. -A cell may also be a ViewGroup object (for example, you can nest another TableLayout as a cell).</p> -<p>The following sample layout has two rows and two cells in each. The accompanying screenshot shows the -result, with cell borders displayed as dotted lines (added for visual effect). </p> - -<table class="columns"> - <tr> - <td> - <pre> -<?xml version="1.0" encoding="utf-8"?> -<TableLayout xmlns:android="http://schemas.android.com/apk/res/android" - android:layout_width="fill_parent" - android:layout_height="fill_parent" - android:stretchColumns="1"> - <TableRow> - <TextView - android:text="@string/table_layout_4_open" - android:padding="3dip" /> - <TextView - android:text="@string/table_layout_4_open_shortcut" - android:gravity="right" - android:padding="3dip" /> - </TableRow> - - <TableRow> - <TextView - android:text="@string/table_layout_4_save" - android:padding="3dip" /> - <TextView - android:text="@string/table_layout_4_save_shortcut" - android:gravity="right" - android:padding="3dip" /> - </TableRow> -</TableLayout> -</pre></td> - <td><img src="{@docRoot}images/table_layout.png" alt="" style="margin:0" /></td> - </tr> -</table> - -<p>Columns can be hidden, marked to stretch and fill the available screen space, - or can be marked as shrinkable to force the column to shrink until the table - fits the screen. See the {@link android.widget.TableLayout TableLayout reference} -documentation for more details. </p> - -<p>To view sample code, see the <a href="{@docRoot}guide/tutorials/views/hello-tablelayout.html">Hello -TableLayout</a> tutorial.</p> - - -<h2 id="absolutelayout">AbsoluteLayout</h2> -<p>{@link android.widget.AbsoluteLayout} enables child views to specify - their own exact x/y coordinates on the screen. Coordinates <em>(0,0)</em> is the upper left - corner, and values increase as you move down and to the right. Margins are not - supported, and overlapping elements are allowed (although not recommended). We - generally recommend against using AbsoluteLayout unless you have good reasons - to use it, because it is fairly rigid and does not adjust to different types of - displays. </p> - - -<h2 id="relativelayout">RelativeLayout</h2> -<p>{@link android.widget.RelativeLayout} lets child views specify their - position relative to the parent view or to each other (specified by ID). So you can - align two elements by right border, or make one below another, centered in - the screen, centered left, and so on. Elements are rendered in the order given, so if the first element - is centered in the screen, other elements aligning themselves to that element - will be aligned relative to screen center. Also, because of this ordering, if using XML to specify this layout, - the element that you will reference (in order to position other view objects) must be listed in the XML -file before you refer to it from the other views via its reference ID. </p> -<p>The example below shows an XML file and the resulting screen in the UI. -Note that the attributes that refer to relative elements (e.g., <var>layout_toLeft</var>) -refer to the ID using the syntax of a relative resource -(<var>@id/<em>id</em></var>). </p> - -<table class="columns"> - <tr> - <td> - <pre> -<?xml version="1.0" encoding="utf-8"?> -<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android - android:layout_width="fill_parent" - android:layout_height="wrap_content" - android:background="@drawable/blue" - android:padding="10px" > - - <TextView android:id="@+id/label" - android:layout_width="fill_parent" - android:layout_height="wrap_content" - android:text="Type here:" /> - - <EditText android:id="@+id/entry" - android:layout_width="fill_parent" - android:layout_height="wrap_content" - android:background="@android:drawable/editbox_background" - android:layout_below="@id/label" /> - - <Button android:id="@+id/ok" - android:layout_width="wrap_content" - android:layout_height="wrap_content" - android:layout_below="@id/entry" - android:layout_alignParentRight="true" - android:layout_marginLeft="10px" - android:text="OK" /> - - <Button android:layout_width="wrap_content" - android:layout_height="wrap_content" - android:layout_toLeftOf="@id/ok" - android:layout_alignTop="@id/ok" - android:text="Cancel" /> -</RelativeLayout> -</pre></td> - <td><img src="{@docRoot}images/designing_ui_layout_example.png" alt="" style="margin:0" /></td> - </tr> -</table> - - -<p>Some of these properties are supported directly by - the element, and some are supported by its LayoutParams member (subclass RelativeLayout - for all the elements in this screen, because all elements are children of a RelativeLayout - parent object). The defined RelativeLayout parameters are: <code>width</code>, <code>height</code>, - <code>below</code>, <code>alignTop</code>, <code>toLeft</code>, <code>padding[Bottom|Left|Right|Top]</code>, - and <code>margin[Bottom|Left|Right|Top]</code>. Note that some of these parameters specifically support - relative layout positions — their values must be the ID of the element to which you'd like this view laid relative. - For example, assigning the parameter <code>toLeft="my_button"</code> to a TextView would place the TextView to - the left of the View with the ID <var>my_button</var> (which must be written in the XML <em>before</em> the TextView). </p> - -<p>To view this sample code, see the <a href="{@docRoot}guide/tutorials/views/hello-relativelayout.html">Hello -RelativeLayout</a> tutorial.</p> - - -<h2 id="viewgroupsummary">Summary of Important View Groups</h2> -<p>These objects all hold child UI elements. Some provide their own form of a visible UI, while others - are invisible structures that only manage the layout of their child views. </p> -<table width="100%" border="1"> - <tr> - <th scope="col">Class</th> - <th scope="col">Description</th> - </tr> - <tr> - <td>{@link android.widget.AbsoluteLayout AbsoluteLayout}<br /></td> - <td>Enables you to specify the location of child objects relative to the - parent in exact measurements (for example, pixels). </td> - </tr> - <tr> - <td>{@link android.widget.FrameLayout FrameLayout}</td> - <td>Layout that acts as a view frame to display - a single object. </td> - </tr> - <tr> - <td>{@link android.widget.Gallery Gallery} </td> - <td>A horizontal scrolling display of images, from a bound list. </td> - </tr> - <tr> - <td>{@link android.widget.GridView GridView} </td> - <td>Displays a scrolling grid of m columns and n rows.</td> - </tr> - <tr> - <td>{@link android.widget.LinearLayout LinearLayout} </td> - <td>A layout that organizes its children into a single horizontal or vertical - row. It creates a scrollbar if the length of the window exceeds the length - of the screen. </td> - </tr> - <tr> - <td>{@link android.widget.ListView ListView} </td> - <td>Displays a scrolling single column list. </td> - </tr> - <tr> - <td>{@link android.widget.RelativeLayout RelativeLayout} </td> - <td>Enables you to specify the location of child objects relative to each - other (child A to the left of child B) or to the parent (aligned to the - top of the parent). </td> - </tr> - <tr> - <td>{@link android.widget.ScrollView ScrollView} </td> - <td>A vertically scrolling column of elements. </td> - </tr> - <tr> - <td>{@link android.widget.Spinner Spinner} </td> - <td>Displays a single item at a time from a bound list, inside a one-row - textbox. Rather like a one-row listbox that can scroll either horizontally - or vertically. </td> - </tr> - <tr> - <td>{@link android.view.SurfaceView SurfaceView} </td> - <td>Provides direct access to a dedicated drawing surface. It can hold child - views layered on top of the surface, but is intended for applications - that need to draw pixels, rather than using widgets. </td> - </tr> - <tr> - <td>{@link android.widget.TabHost TabHost} </td> - <td>Provides a tab selection list that monitors clicks and enables the application - to change the screen whenever a tab is clicked. </td> - </tr> - <tr> - <td>{@link android.widget.TableLayout TableLayout} </td> - <td>A tabular layout with an arbitrary number of rows and columns, each cell - holding the widget of your choice. The rows resize to fit the largest - column. The cell borders are not - visible. </td> - </tr> - <tr> - <td>{@link android.widget.ViewFlipper ViewFlipper} </td> - <td>A list that displays one item at a time, inside a one-row textbox. It - can be set to swap items at timed intervals, like a slide show. </td> - </tr> - <tr> - <td>{@link android.widget.ViewSwitcher ViewSwitcher} </td> - <td>Same as ViewFlipper. </td> - </tr> -</table> |
