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diff --git a/docs/html/design/patterns/selection.jd b/docs/html/design/patterns/selection.jd new file mode 100644 index 0000000..e3ee90e --- /dev/null +++ b/docs/html/design/patterns/selection.jd @@ -0,0 +1,100 @@ +page.title=Selection +@jd:body + +<p>Android 3.0 introduced the <em>long press</em> gesture—that is, a touch that's held in the same +position for a moment—as the global gesture to select data. This affects the way you should +handle multi-select and contextual actions in your apps.</p> + +<div class="vspace size-1"> </div> + +<div class="layout-content-row"> + <div class="layout-content-col span-6"> + +<h4>What has changed?</h4> +<p>In previous versions of Android, the long press gesture was universally used to display contextual +actions for a given data item in a contextual menu.</p> +<p>This pattern changed with Android 3.0. The long press gesture is now used to select data, combining +contextual actions and selection management functions for selected data into a new element called +the contextual action bar (CAB).</p> + + </div> + <div class="layout-content-col span-7"> + + <img src="{@docRoot}design/media/selection_context_menu.png"> + <div class="figure-caption"> + Traditional use of the long press gesture to show contextual menus. + </div> + + </div> +</div> + +<h4>Using the contextual action bar (CAB)</h4> +<p>The selection CAB is a temporary action bar that overlays your app's current action bar while data +is selected. It appears after the user long presses on a selectable data item.</p> + +<img src="{@docRoot}design/media/selection_cab_big.png"> + +<div class="vspace size-1"> </div> + +<div class="layout-content-row"> + <div class="layout-content-col span-6"> + +<p>From here the user can:</p> +<ul> +<li>Select additional data items by touching them.</li> +<li>Trigger an action from the CAB that applies to all highlighted data items. The CAB then + automatically dismisses itself.</li> +<li>Dismiss the CAB via the navigation bar's Back button or the CAB's checkmark button. This removes + the CAB along with all selection highlights.</li> +</ul> + + </div> + <div class="layout-content-col span-7"> + + <img src="{@docRoot}design/media/selection_cab_example.png"> + + </div> +</div> + +<div class="layout-content-row"> + <div class="layout-content-col span-6"> + +<h4>Selecting CAB actions</h4> +<p>You can decide which actions and elements appear in the CAB. Use the guidelines in the <a href="actionbar.html">Action Bar +pattern</a> to decide which items to surface at the top level and which to move to the +action overflow.</p> +<h4>Dynamically adjust CAB actions</h4> +<p>In most cases you need to adjust the actions in the CAB dynamically as the user adds more items to +the selection. Actions that apply to a single selected data item don't necessarily apply to multiple +selected data items of the same kind.</p> + + </div> + <div class="layout-content-col span-7"> + + <img src="{@docRoot}design/media/selection_adjusting_actions.png"> + <div class="figure-caption"> + Adjusting actions in the CAB as additional items are selected. + </div> + + </div> +</div> + +<h2 id="checklist">Checklist</h2> + +<ul> +<li> +<p>Whenever your app supports the selection of multiple data items, make use of the contextual action + bar (CAB).</p> +</li> +<li> +<p>Reserve the long press gesture for selection exclusively. Don't use it to display traditional + contextual menus.</p> +</li> +<li> +<p>If you don't support multi-selection within a list, long press should do nothing.</p> +</li> +<li> +<p>Plan the actions you want to display inside of a CAB in the same way you would plan the actions + inside your app's action bar.</p> +</li> +</ul> |