| /* |
| * 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; |
| import android.util.Log; |
| |
| /** |
| * An ActionProvider defines rich menu interaction in a single component. |
| * ActionProvider can generate action views for use in the action bar, |
| * dynamically populate submenus of a MenuItem, and handle default menu |
| * item invocations. |
| * |
| * <p>An ActionProvider can be optionally specified for a {@link MenuItem} and will be |
| * responsible for creating the action view that appears in the {@link android.app.ActionBar} |
| * in place of a simple button in the bar. When the menu item is presented in a way that |
| * does not allow custom action views, (e.g. in an overflow menu,) the ActionProvider |
| * can perform a default action.</p> |
| * |
| * <p>There are two ways to use an action provider: |
| * <ul> |
| * <li> |
| * Set the action provider on a {@link MenuItem} directly by calling |
| * {@link MenuItem#setActionProvider(ActionProvider)}. |
| * </li> |
| * <li> |
| * Declare the action provider in an XML menu 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 static final String TAG = "ActionProvider"; |
| private SubUiVisibilityListener mSubUiVisibilityListener; |
| private VisibilityListener mVisibilityListener; |
| |
| /** |
| * Creates a new instance. ActionProvider classes should always implement a |
| * constructor that takes a single Context parameter for inflating from menu XML. |
| * |
| * @param context Context for accessing resources. |
| */ |
| public ActionProvider(Context context) { |
| } |
| |
| /** |
| * Factory method called by the Android framework to create new action views. |
| * |
| * <p>This method has been deprecated in favor of {@link #onCreateActionView(MenuItem)}. |
| * Newer apps that wish to support platform versions prior to API 16 should also |
| * implement this method to return a valid action view.</p> |
| * |
| * @return A new action view. |
| * |
| * @deprecated use {@link #onCreateActionView(MenuItem)} |
| */ |
| public abstract View onCreateActionView(); |
| |
| /** |
| * Factory method called by the Android framework to create new action views. |
| * This method returns a new action view for the given MenuItem. |
| * |
| * <p>If your ActionProvider implementation overrides the deprecated no-argument overload |
| * {@link #onCreateActionView()}, overriding this method for devices running API 16 or later |
| * is recommended but optional. The default implementation calls {@link #onCreateActionView()} |
| * for compatibility with applications written for older platform versions.</p> |
| * |
| * @param forItem MenuItem to create the action view for |
| * @return the new action view |
| */ |
| public View onCreateActionView(MenuItem forItem) { |
| return onCreateActionView(); |
| } |
| |
| /** |
| * The result of this method determines whether or not {@link #isVisible()} will be used |
| * by the {@link MenuItem} this ActionProvider is bound to help determine its visibility. |
| * |
| * @return true if this ActionProvider overrides the visibility of the MenuItem |
| * it is bound to, false otherwise. The default implementation returns false. |
| * @see #isVisible() |
| */ |
| public boolean overridesItemVisibility() { |
| return false; |
| } |
| |
| /** |
| * If {@link #overridesItemVisibility()} returns true, the return value of this method |
| * will help determine the visibility of the {@link MenuItem} this ActionProvider is bound to. |
| * |
| * <p>If the MenuItem's visibility is explicitly set to false by the application, |
| * the MenuItem will not be shown, even if this method returns true.</p> |
| * |
| * @return true if the MenuItem this ActionProvider is bound to is visible, false if |
| * it is invisible. The default implementation returns true. |
| */ |
| public boolean isVisible() { |
| return true; |
| } |
| |
| /** |
| * If this ActionProvider is associated with an item in a menu, |
| * refresh the visibility of the item based on {@link #overridesItemVisibility()} and |
| * {@link #isVisible()}. If {@link #overridesItemVisibility()} returns false, this call |
| * will have no effect. |
| */ |
| public void refreshVisibility() { |
| if (mVisibilityListener != null && overridesItemVisibility()) { |
| mVisibilityListener.onActionProviderVisibilityChanged(isVisible()); |
| } |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * Set a listener to be notified when this ActionProvider's overridden visibility changes. |
| * This should only be used by MenuItem implementations. |
| * |
| * @param listener listener to set |
| */ |
| public void setVisibilityListener(VisibilityListener listener) { |
| if (mVisibilityListener != null) { |
| Log.w(TAG, "setVisibilityListener: Setting a new ActionProvider.VisibilityListener " + |
| "when one is already set. Are you reusing this " + getClass().getSimpleName() + |
| " instance while it is still in use somewhere else?"); |
| } |
| mVisibilityListener = listener; |
| } |
| |
| /** |
| * @hide |
| */ |
| public void reset() { |
| mVisibilityListener = null; |
| mSubUiVisibilityListener = null; |
| } |
| |
| /** |
| * @hide Internal use only |
| */ |
| public interface SubUiVisibilityListener { |
| public void onSubUiVisibilityChanged(boolean isVisible); |
| } |
| |
| /** |
| * Listens to changes in visibility as reported by {@link ActionProvider#refreshVisibility()}. |
| * |
| * @see ActionProvider#overridesItemVisibility() |
| * @see ActionProvider#isVisible() |
| */ |
| public interface VisibilityListener { |
| public void onActionProviderVisibilityChanged(boolean isVisible); |
| } |
| } |
