| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.view; |
| |
| import android.content.Context; |
| |
| /** |
| * This class is a mediator for accomplishing a given task, for example sharing a file. |
| * It is responsible for creating a view that performs an action that accomplishes the task. |
| * This class also implements other functions such a performing a default action. |
| * <p> |
| * An ActionProvider can be optionally specified for a {@link MenuItem} and in such a |
| * case it will be responsible for creating the action view that appears in the |
| * {@link android.app.ActionBar} as a substitute for the menu item when the item is |
| * displayed as an action item. Also the provider is responsible for performing a |
| * default action if a menu item placed on the overflow menu of the ActionBar is |
| * selected and none of the menu item callbacks has handled the selection. For this |
| * case the provider can also optionally provide a sub-menu for accomplishing the |
| * task at hand. |
| * </p> |
| * <p> |
| * There are two ways for using an action provider for creating and handling of action views: |
| * <ul> |
| * <li> |
| * Setting the action provider on a {@link MenuItem} directly by calling |
| * {@link MenuItem#setActionProvider(ActionProvider)}. |
| * </li> |
| * <li> |
| * Declaring the action provider in the menu XML resource. For example: |
| * <pre> |
| * <code> |
| * <item android:id="@+id/my_menu_item" |
| * android:title="Title" |
| * android:icon="@drawable/my_menu_item_icon" |
| * android:showAsAction="ifRoom" |
| * android:actionProviderClass="foo.bar.SomeActionProvider" /> |
| * </code> |
| * </pre> |
| * </li> |
| * </ul> |
| * </p> |
| * |
| * @see MenuItem#setActionProvider(ActionProvider) |
| * @see MenuItem#getActionProvider() |
| */ |
| public abstract class ActionProvider { |
| private SubUiVisibilityListener mSubUiVisibilityListener; |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param context Context for accessing resources. |
| */ |
| public ActionProvider(Context context) { |
| } |
| |
| /** |
| * Factory method for creating new action views. |
| * |
| * @return A new action view. |
| */ |
| public abstract View onCreateActionView(); |
| |
| /** |
| * Performs an optional default action. |
| * <p> |
| * For the case of an action provider placed in a menu item not shown as an action this |
| * method is invoked if previous callbacks for processing menu selection has handled |
| * the event. |
| * </p> |
| * <p> |
| * A menu item selection is processed in the following order: |
| * <ul> |
| * <li> |
| * Receiving a call to {@link MenuItem.OnMenuItemClickListener#onMenuItemClick |
| * MenuItem.OnMenuItemClickListener.onMenuItemClick}. |
| * </li> |
| * <li> |
| * Receiving a call to {@link android.app.Activity#onOptionsItemSelected(MenuItem) |
| * Activity.onOptionsItemSelected(MenuItem)} |
| * </li> |
| * <li> |
| * Receiving a call to {@link android.app.Fragment#onOptionsItemSelected(MenuItem) |
| * Fragment.onOptionsItemSelected(MenuItem)} |
| * </li> |
| * <li> |
| * Launching the {@link android.content.Intent} set via |
| * {@link MenuItem#setIntent(android.content.Intent) MenuItem.setIntent(android.content.Intent)} |
| * </li> |
| * <li> |
| * Invoking this method. |
| * </li> |
| * </ul> |
| * </p> |
| * <p> |
| * The default implementation does not perform any action and returns false. |
| * </p> |
| */ |
| public boolean onPerformDefaultAction() { |
| return false; |
| } |
| |
| /** |
| * Determines if this ActionProvider has a submenu associated with it. |
| * |
| * <p>Associated submenus will be shown when an action view is not. This |
| * provider instance will receive a call to {@link #onPrepareSubMenu(SubMenu)} |
| * after the call to {@link #onPerformDefaultAction()} and before a submenu is |
| * displayed to the user. |
| * |
| * @return true if the item backed by this provider should have an associated submenu |
| */ |
| public boolean hasSubMenu() { |
| return false; |
| } |
| |
| /** |
| * Called to prepare an associated submenu for the menu item backed by this ActionProvider. |
| * |
| * <p>if {@link #hasSubMenu()} returns true, this method will be called when the |
| * menu item is selected to prepare the submenu for presentation to the user. Apps |
| * may use this to create or alter submenu content right before display. |
| * |
| * @param subMenu Submenu that will be displayed |
| */ |
| public void onPrepareSubMenu(SubMenu subMenu) { |
| } |
| |
| /** |
| * Notify the system that the visibility of an action view's sub-UI such as |
| * an anchored popup has changed. This will affect how other system |
| * visibility notifications occur. |
| * |
| * @hide Pending future API approval |
| */ |
| public void subUiVisibilityChanged(boolean isVisible) { |
| if (mSubUiVisibilityListener != null) { |
| mSubUiVisibilityListener.onSubUiVisibilityChanged(isVisible); |
| } |
| } |
| |
| /** |
| * @hide Internal use only |
| */ |
| public void setSubUiVisibilityListener(SubUiVisibilityListener listener) { |
| mSubUiVisibilityListener = listener; |
| } |
| |
| /** |
| * @hide Internal use only |
| */ |
| public interface SubUiVisibilityListener { |
| public void onSubUiVisibilityChanged(boolean isVisible); |
| } |
| } |