/*
 * Copyright (C) 2006 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 com.android.internal.view.menu;


import android.annotation.NonNull;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Parcelable;
import android.util.SparseArray;
import android.view.ActionProvider;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.KeyCharacterMap;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.View;
import android.view.ViewConfiguration;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;

Implementation of the Menu interface for creating a standard menu UI. /**
 * Implementation of the {@link android.view.Menu} interface for creating a
 * standard menu UI.
 */
public class MenuBuilder implements Menu {
    private static final String TAG = "MenuBuilder";

    private static final String PRESENTER_KEY = "android:menu:presenters";
    private static final String ACTION_VIEW_STATES_KEY = "android:menu:actionviewstates";
    private static final String EXPANDED_ACTION_VIEW_ID = "android:menu:expandedactionview";

    private static final int[]  sCategoryToOrder = new int[] {
        1, /* No category */
        4, /* CONTAINER */
        5, /* SYSTEM */
        3, /* SECONDARY */
        2, /* ALTERNATIVE */
        0, /* SELECTED_ALTERNATIVE */
    };

    private final Context mContext;
    private final Resources mResources;

    
Whether the shortcuts should be qwerty-accessible. Use isQwertyMode()
instead of accessing this directly.
/**
     * Whether the shortcuts should be qwerty-accessible. Use isQwertyMode()
     * instead of accessing this directly.
     */
    private boolean mQwertyMode;

    
Whether the shortcuts should be visible on menus. Use isShortcutsVisible()
instead of accessing this directly.
/**
     * Whether the shortcuts should be visible on menus. Use isShortcutsVisible()
     * instead of accessing this directly.
     */ 
    private boolean mShortcutsVisible;
    
    
Callback that will receive the various menu-related events generated by
this class. Use getCallback to get a reference to the callback.
/**
     * Callback that will receive the various menu-related events generated by
     * this class. Use getCallback to get a reference to the callback.
     */
    private Callback mCallback;
    
    
Contains all of the items for this menu /** Contains all of the items for this menu */
    private ArrayList<MenuItemImpl> mItems;

    
Contains only the items that are currently visible. This will be created/refreshed from getVisibleItems() /** Contains only the items that are currently visible.  This will be created/refreshed from
     * {@link #getVisibleItems()} */
    private ArrayList<MenuItemImpl> mVisibleItems;
    
Whether or not the items (or any one item's shown state) has changed since it was last fetched from getVisibleItems() /**
     * Whether or not the items (or any one item's shown state) has changed since it was last
     * fetched from {@link #getVisibleItems()}
     */ 
    private boolean mIsVisibleItemsStale;
    
    
Contains only the items that should appear in the Action Bar, if present.
/**
     * Contains only the items that should appear in the Action Bar, if present.
     */
    private ArrayList<MenuItemImpl> mActionItems;
    
Contains items that should NOT appear in the Action Bar, if present.
/**
     * Contains items that should NOT appear in the Action Bar, if present.
     */
    private ArrayList<MenuItemImpl> mNonActionItems;

    
Whether or not the items (or any one item's action state) has changed since it was
last fetched.
/**
     * Whether or not the items (or any one item's action state) has changed since it was
     * last fetched.
     */
    private boolean mIsActionItemsStale;

    
Default value for how added items should show in the action list.
/**
     * Default value for how added items should show in the action list.
     */
    private int mDefaultShowAsAction = MenuItem.SHOW_AS_ACTION_NEVER;

    
Current use case is Context Menus: As Views populate the context menu, each one has
extra information that should be passed along.  This is the current menu info that
should be set on all items added to this menu.
/**
     * Current use case is Context Menus: As Views populate the context menu, each one has
     * extra information that should be passed along.  This is the current menu info that
     * should be set on all items added to this menu.
     */
    private ContextMenuInfo mCurrentMenuInfo;
    
    
Header title for menu types that have a header (context and submenus) /** Header title for menu types that have a header (context and submenus) */
    CharSequence mHeaderTitle;
    
Header icon for menu types that have a header and support icons (context) /** Header icon for menu types that have a header and support icons (context) */
    Drawable mHeaderIcon;
    
Header custom view for menu types that have a header and support custom views (context) /** Header custom view for menu types that have a header and support custom views (context) */
    View mHeaderView;

    
Contains the state of the View hierarchy for all menu views when the menu
was frozen.
/**
     * Contains the state of the View hierarchy for all menu views when the menu
     * was frozen.
     */
    private SparseArray<Parcelable> mFrozenViewStates;

    
Prevents onItemsChanged from doing its junk, useful for batching commands
that may individually call onItemsChanged.
/**
     * Prevents onItemsChanged from doing its junk, useful for batching commands
     * that may individually call onItemsChanged.
     */
    private boolean mPreventDispatchingItemsChanged = false;
    private boolean mItemsChangedWhileDispatchPrevented = false;
    
    private boolean mOptionalIconsVisible = false;

    private boolean mIsClosing = false;

    private ArrayList<MenuItemImpl> mTempShortcutItemList = new ArrayList<MenuItemImpl>();

    private CopyOnWriteArrayList<WeakReference<MenuPresenter>> mPresenters =
            new CopyOnWriteArrayList<WeakReference<MenuPresenter>>();

    
Currently expanded menu item; must be collapsed when we clear.
/**
     * Currently expanded menu item; must be collapsed when we clear.
     */
    private MenuItemImpl mExpandedItem;

    
Whether group dividers are enabled.
/**
     * Whether group dividers are enabled.
     */
    private boolean mGroupDividerEnabled = false;

    
Called by menu to notify of close and selection changes.
/**
     * Called by menu to notify of close and selection changes.
     */
    public interface Callback {
        
Called when a menu item is selected.
Params:
menu – The menu that is the parent of the item
item – The menu item that is selected
Returns:
whether the menu item selection was handled/**
         * Called when a menu item is selected.
         * @param menu The menu that is the parent of the item
         * @param item The menu item that is selected
         * @return whether the menu item selection was handled
         */
        public boolean onMenuItemSelected(MenuBuilder menu, MenuItem item);
        
        
Called when the mode of the menu changes (for example, from icon to expanded).
Params:
menu – the menu that has changed modes/**
         * Called when the mode of the menu changes (for example, from icon to expanded).
         * 
         * @param menu the menu that has changed modes
         */
        public void onMenuModeChange(MenuBuilder menu);
    }

    
Called by menu items to execute their associated action
/**
     * Called by menu items to execute their associated action
     */
    public interface ItemInvoker {
        public boolean invokeItem(MenuItemImpl item);
    }

    public MenuBuilder(Context context) {
        mContext = context;
        mResources = context.getResources();
        mItems = new ArrayList<MenuItemImpl>();
        
        mVisibleItems = new ArrayList<MenuItemImpl>();
        mIsVisibleItemsStale = true;
        
        mActionItems = new ArrayList<MenuItemImpl>();
        mNonActionItems = new ArrayList<MenuItemImpl>();
        mIsActionItemsStale = true;
        
        setShortcutsVisibleInner(true);
    }
    
    public MenuBuilder setDefaultShowAsAction(int defaultShowAsAction) {
        mDefaultShowAsAction = defaultShowAsAction;
        return this;
    }

    
Add a presenter to this menu. This will only hold a WeakReference; you do not need to explicitly remove a presenter, but you can using removeMenuPresenter(MenuPresenter). 
Params:
presenter – The presenter to add/**
     * Add a presenter to this menu. This will only hold a WeakReference;
     * you do not need to explicitly remove a presenter, but you can using
     * {@link #removeMenuPresenter(MenuPresenter)}.
     *
     * @param presenter The presenter to add
     */
    public void addMenuPresenter(MenuPresenter presenter) {
        addMenuPresenter(presenter, mContext);
    }

    
Add a presenter to this menu that uses an alternate context for inflating menu items. This will only hold a WeakReference; you do not need to explicitly remove a presenter, but you can using removeMenuPresenter(MenuPresenter). 
Params:
presenter – The presenter to add
menuContext – The context used to inflate menu items/**
     * Add a presenter to this menu that uses an alternate context for
     * inflating menu items. This will only hold a WeakReference; you do not
     * need to explicitly remove a presenter, but you can using
     * {@link #removeMenuPresenter(MenuPresenter)}.
     *
     * @param presenter The presenter to add
     * @param menuContext The context used to inflate menu items
     */
    public void addMenuPresenter(MenuPresenter presenter, Context menuContext) {
        mPresenters.add(new WeakReference<MenuPresenter>(presenter));
        presenter.initForMenu(menuContext, this);
        mIsActionItemsStale = true;
    }

    
Remove a presenter from this menu. That presenter will no longer
receive notifications of updates to this menu's data.
Params:
presenter – The presenter to remove/**
     * Remove a presenter from this menu. That presenter will no longer
     * receive notifications of updates to this menu's data.
     *
     * @param presenter The presenter to remove
     */
    public void removeMenuPresenter(MenuPresenter presenter) {
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter item = ref.get();
            if (item == null || item == presenter) {
                mPresenters.remove(ref);
            }
        }
    }
    
    private void dispatchPresenterUpdate(boolean cleared) {
        if (mPresenters.isEmpty()) return;

        stopDispatchingItemsChanged();
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else {
                presenter.updateMenuView(cleared);
            }
        }
        startDispatchingItemsChanged();
    }
    
    private boolean dispatchSubMenuSelected(SubMenuBuilder subMenu,
            MenuPresenter preferredPresenter) {
        if (mPresenters.isEmpty()) return false;

        boolean result = false;

        // Try the preferred presenter first.
        if (preferredPresenter != null) {
            result = preferredPresenter.onSubMenuSelected(subMenu);
        }

        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else if (!result) {
                result = presenter.onSubMenuSelected(subMenu);
            }
        }
        return result;
    }

    private void dispatchSaveInstanceState(Bundle outState) {
        if (mPresenters.isEmpty()) return;

        SparseArray<Parcelable> presenterStates = new SparseArray<Parcelable>();

        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else {
                final int id = presenter.getId();
                if (id > 0) {
                    final Parcelable state = presenter.onSaveInstanceState();
                    if (state != null) {
                        presenterStates.put(id, state);
                    }
                }
            }
        }

        outState.putSparseParcelableArray(PRESENTER_KEY, presenterStates);
    }

    private void dispatchRestoreInstanceState(Bundle state) {
        SparseArray<Parcelable> presenterStates = state.getSparseParcelableArray(PRESENTER_KEY);

        if (presenterStates == null || mPresenters.isEmpty()) return;

        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else {
                final int id = presenter.getId();
                if (id > 0) {
                    Parcelable parcel = presenterStates.get(id);
                    if (parcel != null) {
                        presenter.onRestoreInstanceState(parcel);
                    }
                }
            }
        }
    }

    public void savePresenterStates(Bundle outState) {
        dispatchSaveInstanceState(outState);
    }

    public void restorePresenterStates(Bundle state) {
        dispatchRestoreInstanceState(state);
    }

    public void saveActionViewStates(Bundle outStates) {
        SparseArray<Parcelable> viewStates = null;

        final int itemCount = size();
        for (int i = 0; i < itemCount; i++) {
            final MenuItem item = getItem(i);
            final View v = item.getActionView();
            if (v != null && v.getId() != View.NO_ID) {
                if (viewStates == null) {
                    viewStates = new SparseArray<Parcelable>();
                }
                v.saveHierarchyState(viewStates);
                if (item.isActionViewExpanded()) {
                    outStates.putInt(EXPANDED_ACTION_VIEW_ID, item.getItemId());
                }
            }
            if (item.hasSubMenu()) {
                final SubMenuBuilder subMenu = (SubMenuBuilder) item.getSubMenu();
                subMenu.saveActionViewStates(outStates);
            }
        }

        if (viewStates != null) {
            outStates.putSparseParcelableArray(getActionViewStatesKey(), viewStates);
        }
    }

    public void restoreActionViewStates(Bundle states) {
        if (states == null) {
            return;
        }

        SparseArray<Parcelable> viewStates = states.getSparseParcelableArray(
                getActionViewStatesKey());

        final int itemCount = size();
        for (int i = 0; i < itemCount; i++) {
            final MenuItem item = getItem(i);
            final View v = item.getActionView();
            if (v != null && v.getId() != View.NO_ID) {
                v.restoreHierarchyState(viewStates);
            }
            if (item.hasSubMenu()) {
                final SubMenuBuilder subMenu = (SubMenuBuilder) item.getSubMenu();
                subMenu.restoreActionViewStates(states);
            }
        }

        final int expandedId = states.getInt(EXPANDED_ACTION_VIEW_ID);
        if (expandedId > 0) {
            MenuItem itemToExpand = findItem(expandedId);
            if (itemToExpand != null) {
                itemToExpand.expandActionView();
            }
        }
    }

    protected String getActionViewStatesKey() {
        return ACTION_VIEW_STATES_KEY;
    }

    public void setCallback(Callback cb) {
        mCallback = cb;
    }
    
    
Adds an item to the menu.  The other add methods funnel to this.
/**
     * Adds an item to the menu.  The other add methods funnel to this.
     */
    private MenuItem addInternal(int group, int id, int categoryOrder, CharSequence title) {
        final int ordering = getOrdering(categoryOrder);
        
        final MenuItemImpl item = createNewMenuItem(group, id, categoryOrder, ordering, title,
                mDefaultShowAsAction);

        if (mCurrentMenuInfo != null) {
            // Pass along the current menu info
            item.setMenuInfo(mCurrentMenuInfo);
        }
        
        mItems.add(findInsertIndex(mItems, ordering), item);
        onItemsChanged(true);
        
        return item;
    }

    // Layoutlib overrides this method to return its custom implementation of MenuItemImpl
    private MenuItemImpl createNewMenuItem(int group, int id, int categoryOrder, int ordering,
            CharSequence title, int defaultShowAsAction) {
        return new MenuItemImpl(this, group, id, categoryOrder, ordering, title,
                defaultShowAsAction);
    }

    public MenuItem add(CharSequence title) {
        return addInternal(0, 0, 0, title);
    }

    public MenuItem add(int titleRes) {
        return addInternal(0, 0, 0, mResources.getString(titleRes));
    }

    public MenuItem add(int group, int id, int categoryOrder, CharSequence title) {
        return addInternal(group, id, categoryOrder, title);
    }

    public MenuItem add(int group, int id, int categoryOrder, int title) {
        return addInternal(group, id, categoryOrder, mResources.getString(title));
    }

    public SubMenu addSubMenu(CharSequence title) {
        return addSubMenu(0, 0, 0, title);
    }

    public SubMenu addSubMenu(int titleRes) {
        return addSubMenu(0, 0, 0, mResources.getString(titleRes));
    }

    public SubMenu addSubMenu(int group, int id, int categoryOrder, CharSequence title) {
        final MenuItemImpl item = (MenuItemImpl) addInternal(group, id, categoryOrder, title);
        final SubMenuBuilder subMenu = new SubMenuBuilder(mContext, this, item);
        item.setSubMenu(subMenu);
        
        return subMenu;
    }

    public SubMenu addSubMenu(int group, int id, int categoryOrder, int title) {
        return addSubMenu(group, id, categoryOrder, mResources.getString(title));
    }

    @Override
    public void setGroupDividerEnabled(boolean groupDividerEnabled) {
        mGroupDividerEnabled = groupDividerEnabled;
    }

    public boolean isGroupDividerEnabled() {
        return mGroupDividerEnabled;
    }

    public int addIntentOptions(int group, int id, int categoryOrder, ComponentName caller,
            Intent[] specifics, Intent intent, int flags, MenuItem[] outSpecificItems) {
        PackageManager pm = mContext.getPackageManager();
        final List<ResolveInfo> lri =
                pm.queryIntentActivityOptions(caller, specifics, intent, 0);
        final int N = lri != null ? lri.size() : 0;

        if ((flags & FLAG_APPEND_TO_GROUP) == 0) {
            removeGroup(group);
        }

        for (int i=0; i<N; i++) {
            final ResolveInfo ri = lri.get(i);
            Intent rintent = new Intent(
                ri.specificIndex < 0 ? intent : specifics[ri.specificIndex]);
            rintent.setComponent(new ComponentName(
                    ri.activityInfo.applicationInfo.packageName,
                    ri.activityInfo.name));
            final MenuItem item = add(group, id, categoryOrder, ri.loadLabel(pm))
                    .setIcon(ri.loadIcon(pm))
                    .setIntent(rintent);
            if (outSpecificItems != null && ri.specificIndex >= 0) {
                outSpecificItems[ri.specificIndex] = item;
            }
        }

        return N;
    }

    public void removeItem(int id) {
        removeItemAtInt(findItemIndex(id), true);
    }

    public void removeGroup(int group) {
        final int i = findGroupIndex(group);

        if (i >= 0) {
            final int maxRemovable = mItems.size() - i;
            int numRemoved = 0;
            while ((numRemoved++ < maxRemovable) && (mItems.get(i).getGroupId() == group)) {
                // Don't force update for each one, this method will do it at the end
                removeItemAtInt(i, false);
            }
            
            // Notify menu views
            onItemsChanged(true);
        }
    }

    
Remove the item at the given index and optionally forces menu views to
update.
Params:
index – The index of the item to be removed. If this index is
           invalid an exception is thrown.
updateChildrenOnMenuViews – Whether to force update on menu views.
           Please make sure you eventually call this after your batch of
           removals./**
     * Remove the item at the given index and optionally forces menu views to
     * update.
     * 
     * @param index The index of the item to be removed. If this index is
     *            invalid an exception is thrown.
     * @param updateChildrenOnMenuViews Whether to force update on menu views.
     *            Please make sure you eventually call this after your batch of
     *            removals.
     */
    private void removeItemAtInt(int index, boolean updateChildrenOnMenuViews) {
        if ((index < 0) || (index >= mItems.size())) return;

        mItems.remove(index);
        
        if (updateChildrenOnMenuViews) onItemsChanged(true);
    }
    
    public void removeItemAt(int index) {
        removeItemAtInt(index, true);
    }

    public void clearAll() {
        mPreventDispatchingItemsChanged = true;
        clear();
        clearHeader();
        mPresenters.clear();
        mPreventDispatchingItemsChanged = false;
        mItemsChangedWhileDispatchPrevented = false;
        onItemsChanged(true);
    }
    
    public void clear() {
        if (mExpandedItem != null) {
            collapseItemActionView(mExpandedItem);
        }
        mItems.clear();
        
        onItemsChanged(true);
    }

    void setExclusiveItemChecked(MenuItem item) {
        final int group = item.getGroupId();
        
        final int N = mItems.size();
        for (int i = 0; i < N; i++) {
            MenuItemImpl curItem = mItems.get(i);
            if (curItem.getGroupId() == group) {
                if (!curItem.isExclusiveCheckable()) continue;
                if (!curItem.isCheckable()) continue;
                
                // Check the item meant to be checked, uncheck the others (that are in the group)
                curItem.setCheckedInt(curItem == item);
            }
        }
    }
    
    public void setGroupCheckable(int group, boolean checkable, boolean exclusive) {
        final int N = mItems.size();
       
        for (int i = 0; i < N; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.getGroupId() == group) {
                item.setExclusiveCheckable(exclusive);
                item.setCheckable(checkable);
            }
        }
    }

    public void setGroupVisible(int group, boolean visible) {
        final int N = mItems.size();

        // We handle the notification of items being changed ourselves, so we use setVisibleInt rather
        // than setVisible and at the end notify of items being changed
        
        boolean changedAtLeastOneItem = false;
        for (int i = 0; i < N; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.getGroupId() == group) {
                if (item.setVisibleInt(visible)) changedAtLeastOneItem = true;
            }
        }

        if (changedAtLeastOneItem) onItemsChanged(true);
    }

    public void setGroupEnabled(int group, boolean enabled) {
        final int N = mItems.size();

        for (int i = 0; i < N; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.getGroupId() == group) {
                item.setEnabled(enabled);
            }
        }
    }

    public boolean hasVisibleItems() {
        final int size = size();

        for (int i = 0; i < size; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.isVisible()) {
                return true;
            }
        }

        return false;
    }

    public MenuItem findItem(int id) {
        final int size = size();
        for (int i = 0; i < size; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.getItemId() == id) {
                return item;
            } else if (item.hasSubMenu()) {
                MenuItem possibleItem = item.getSubMenu().findItem(id);
                
                if (possibleItem != null) {
                    return possibleItem;
                }
            }
        }
        
        return null;
    }

    public int findItemIndex(int id) {
        final int size = size();

        for (int i = 0; i < size; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.getItemId() == id) {
                return i;
            }
        }

        return -1;
    }

    public int findGroupIndex(int group) {
        return findGroupIndex(group, 0);
    }

    public int findGroupIndex(int group, int start) {
        final int size = size();
        
        if (start < 0) {
            start = 0;
        }
        
        for (int i = start; i < size; i++) {
            final MenuItemImpl item = mItems.get(i);
            
            if (item.getGroupId() == group) {
                return i;
            }
        }

        return -1;
    }
    
    public int size() {
        return mItems.size();
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public MenuItem getItem(int index) {
        return mItems.get(index);
    }

    public boolean isShortcutKey(int keyCode, KeyEvent event) {
        return findItemWithShortcutForKey(keyCode, event) != null;
    }

    public void setQwertyMode(boolean isQwerty) {
        mQwertyMode = isQwerty;

        onItemsChanged(false);
    }

    
Returns the ordering across all items. This will grab the category from
the upper bits, find out how to order the category with respect to other
categories, and combine it with the lower bits.
Params:
categoryOrder – The category order for a particular item (if it has
           not been or/add with a category, the default category is
           assumed).
Returns:
An ordering integer that can be used to order this item across
        all the items (even from other categories)./**
     * Returns the ordering across all items. This will grab the category from
     * the upper bits, find out how to order the category with respect to other
     * categories, and combine it with the lower bits.
     * 
     * @param categoryOrder The category order for a particular item (if it has
     *            not been or/add with a category, the default category is
     *            assumed).
     * @return An ordering integer that can be used to order this item across
     *         all the items (even from other categories).
     */
    private static int getOrdering(int categoryOrder) {
        final int index = (categoryOrder & CATEGORY_MASK) >> CATEGORY_SHIFT;
        
        if (index < 0 || index >= sCategoryToOrder.length) {
            throw new IllegalArgumentException("order does not contain a valid category.");
        }
        
        return (sCategoryToOrder[index] << CATEGORY_SHIFT) | (categoryOrder & USER_MASK);
    }

    
Returns:
whether the menu shortcuts are in qwerty mode or not/**
     * @return whether the menu shortcuts are in qwerty mode or not
     */
    boolean isQwertyMode() {
        return mQwertyMode;
    }

    
Sets whether the shortcuts should be visible on menus.  Devices without hardware
key input will never make shortcuts visible even if this method is passed 'true'.
Params:
shortcutsVisible – Whether shortcuts should be visible (if true and a
           menu item does not have a shortcut defined, that item will
           still NOT show a shortcut)/**
     * Sets whether the shortcuts should be visible on menus.  Devices without hardware
     * key input will never make shortcuts visible even if this method is passed 'true'.
     * 
     * @param shortcutsVisible Whether shortcuts should be visible (if true and a
     *            menu item does not have a shortcut defined, that item will
     *            still NOT show a shortcut)
     */
    public void setShortcutsVisible(boolean shortcutsVisible) {
        if (mShortcutsVisible == shortcutsVisible) return;

        setShortcutsVisibleInner(shortcutsVisible);
        onItemsChanged(false);
    }

    private void setShortcutsVisibleInner(boolean shortcutsVisible) {
        mShortcutsVisible = shortcutsVisible
                && mResources.getConfiguration().keyboard != Configuration.KEYBOARD_NOKEYS
                && ViewConfiguration.get(mContext).shouldShowMenuShortcutsWhenKeyboardPresent();
    }

    
Returns:
Whether shortcuts should be visible on menus./**
     * @return Whether shortcuts should be visible on menus.
     */
    public boolean isShortcutsVisible() {
        return mShortcutsVisible;
    }
    
    Resources getResources() {
        return mResources;
    }
    
    public Context getContext() {
        return mContext;
    }
    
    boolean dispatchMenuItemSelected(MenuBuilder menu, MenuItem item) {
        return mCallback != null && mCallback.onMenuItemSelected(menu, item);
    }

    
Dispatch a mode change event to this menu's callback.
/**
     * Dispatch a mode change event to this menu's callback.
     */
    public void changeMenuMode() {
        if (mCallback != null) {
            mCallback.onMenuModeChange(this);
        }
    }

    private static int findInsertIndex(ArrayList<MenuItemImpl> items, int ordering) {
        for (int i = items.size() - 1; i >= 0; i--) {
            MenuItemImpl item = items.get(i);
            if (item.getOrdering() <= ordering) {
                return i + 1;
            }
        }
        
        return 0;
    }
    
    public boolean performShortcut(int keyCode, KeyEvent event, int flags) {
        final MenuItemImpl item = findItemWithShortcutForKey(keyCode, event);

        boolean handled = false;
        
        if (item != null) {
            handled = performItemAction(item, flags);
        }
        
        if ((flags & FLAG_ALWAYS_PERFORM_CLOSE) != 0) {
            close(true /* closeAllMenus */);
        }
        
        return handled;
    }

    /*
     * This function will return all the menu and sub-menu items that can
     * be directly (the shortcut directly corresponds) and indirectly
     * (the ALT-enabled char corresponds to the shortcut) associated
     * with the keyCode.
     */
    void findItemsWithShortcutForKey(List<MenuItemImpl> items, int keyCode, KeyEvent event) {
        final boolean qwerty = isQwertyMode();
        final int modifierState = event.getModifiers();
        final KeyCharacterMap.KeyData possibleChars = new KeyCharacterMap.KeyData();
        // Get the chars associated with the keyCode (i.e using any chording combo)
        final boolean isKeyCodeMapped = event.getKeyData(possibleChars);
        // The delete key is not mapped to '\b' so we treat it specially
        if (!isKeyCodeMapped && (keyCode != KeyEvent.KEYCODE_DEL)) {
            return;
        }

        // Look for an item whose shortcut is this key.
        final int N = mItems.size();
        for (int i = 0; i < N; i++) {
            MenuItemImpl item = mItems.get(i);
            if (item.hasSubMenu()) {
                ((MenuBuilder)item.getSubMenu()).findItemsWithShortcutForKey(items, keyCode, event);
            }
            final char shortcutChar =
                    qwerty ? item.getAlphabeticShortcut() : item.getNumericShortcut();
            final int shortcutModifiers =
                    qwerty ? item.getAlphabeticModifiers() : item.getNumericModifiers();
            final boolean isModifiersExactMatch = (modifierState & SUPPORTED_MODIFIERS_MASK)
                    == (shortcutModifiers & SUPPORTED_MODIFIERS_MASK);
            if (isModifiersExactMatch && (shortcutChar != 0) &&
                  (shortcutChar == possibleChars.meta[0]
                      || shortcutChar == possibleChars.meta[2]
                      || (qwerty && shortcutChar == '\b' &&
                          keyCode == KeyEvent.KEYCODE_DEL)) &&
                  item.isEnabled()) {
                items.add(item);
            }
        }
    }

    /*
     * We want to return the menu item associated with the key, but if there is no
     * ambiguity (i.e. there is only one menu item corresponding to the key) we want
     * to return it even if it's not an exact match; this allow the user to
     * _not_ use the ALT key for example, making the use of shortcuts slightly more
     * user-friendly. An example is on the G1, '!' and '1' are on the same key, and
     * in Gmail, Menu+1 will trigger Menu+! (the actual shortcut).
     *
     * On the other hand, if two (or more) shortcuts corresponds to the same key,
     * we have to only return the exact match.
     */
    MenuItemImpl findItemWithShortcutForKey(int keyCode, KeyEvent event) {
        // Get all items that can be associated directly or indirectly with the keyCode
        ArrayList<MenuItemImpl> items = mTempShortcutItemList;
        items.clear();
        findItemsWithShortcutForKey(items, keyCode, event);

        if (items.isEmpty()) {
            return null;
        }

        final int metaState = event.getMetaState();
        final KeyCharacterMap.KeyData possibleChars = new KeyCharacterMap.KeyData();
        // Get the chars associated with the keyCode (i.e using any chording combo)
        event.getKeyData(possibleChars);

        // If we have only one element, we can safely returns it
        final int size = items.size();
        if (size == 1) {
            return items.get(0);
        }

        final boolean qwerty = isQwertyMode();
        // If we found more than one item associated with the key,
        // we have to return the exact match
        for (int i = 0; i < size; i++) {
            final MenuItemImpl item = items.get(i);
            final char shortcutChar = qwerty ? item.getAlphabeticShortcut() :
                    item.getNumericShortcut();
            if ((shortcutChar == possibleChars.meta[0] &&
                    (metaState & KeyEvent.META_ALT_ON) == 0)
                || (shortcutChar == possibleChars.meta[2] &&
                    (metaState & KeyEvent.META_ALT_ON) != 0)
                || (qwerty && shortcutChar == '\b' &&
                    keyCode == KeyEvent.KEYCODE_DEL)) {
                return item;
            }
        }
        return null;
    }

    public boolean performIdentifierAction(int id, int flags) {
        // Look for an item whose identifier is the id.
        return performItemAction(findItem(id), flags);           
    }

    public boolean performItemAction(MenuItem item, int flags) {
        return performItemAction(item, null, flags);
    }

    public boolean performItemAction(MenuItem item, MenuPresenter preferredPresenter, int flags) {
        MenuItemImpl itemImpl = (MenuItemImpl) item;
        
        if (itemImpl == null || !itemImpl.isEnabled()) {
            return false;
        }

        boolean invoked = itemImpl.invoke();

        final ActionProvider provider = item.getActionProvider();
        final boolean providerHasSubMenu = provider != null && provider.hasSubMenu();
        if (itemImpl.hasCollapsibleActionView()) {
            invoked |= itemImpl.expandActionView();
            if (invoked) {
                close(true /* closeAllMenus */);
            }
        } else if (itemImpl.hasSubMenu() || providerHasSubMenu) {
            if (!itemImpl.hasSubMenu()) {
                itemImpl.setSubMenu(new SubMenuBuilder(getContext(), this, itemImpl));
            }

            final SubMenuBuilder subMenu = (SubMenuBuilder) itemImpl.getSubMenu();
            if (providerHasSubMenu) {
                provider.onPrepareSubMenu(subMenu);
            }
            invoked |= dispatchSubMenuSelected(subMenu, preferredPresenter);
            if (!invoked) {
                close(true /* closeAllMenus */);
            }
        } else {
            if ((flags & FLAG_PERFORM_NO_CLOSE) == 0) {
                close(true /* closeAllMenus */);
            }
        }
        
        return invoked;
    }
    
    
Closes the menu.
Params:
closeAllMenus – true if all displayed menus and submenus should be completely closed (as when a menu item is selected) or false if only this menu should be closed/**
     * Closes the menu.
     *
     * @param closeAllMenus {@code true} if all displayed menus and submenus
     *                      should be completely closed (as when a menu item is
     *                      selected) or {@code false} if only this menu should
     *                      be closed
     */
    public final void close(boolean closeAllMenus) {
        if (mIsClosing) return;

        mIsClosing = true;
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else {
                presenter.onCloseMenu(this, closeAllMenus);
            }
        }
        mIsClosing = false;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void close() {
        close(true /* closeAllMenus */);
    }

    
Called when an item is added or removed.
Params:
structureChanged – true if the menu structure changed,
                        false if only item properties changed.
                        (Visibility is a structural property since it affects layout.)/**
     * Called when an item is added or removed.
     * 
     * @param structureChanged true if the menu structure changed,
     *                         false if only item properties changed.
     *                         (Visibility is a structural property since it affects layout.)
     */
    public void onItemsChanged(boolean structureChanged) {
        if (!mPreventDispatchingItemsChanged) {
            if (structureChanged) {
                mIsVisibleItemsStale = true;
                mIsActionItemsStale = true;
            }

            dispatchPresenterUpdate(structureChanged);
        } else {
            mItemsChangedWhileDispatchPrevented = true;
        }
    }

    
Stop dispatching item changed events to presenters until startDispatchingItemsChanged() is called. Useful when many menu operations are going to be performed as a batch. /**
     * Stop dispatching item changed events to presenters until
     * {@link #startDispatchingItemsChanged()} is called. Useful when
     * many menu operations are going to be performed as a batch.
     */
    public void stopDispatchingItemsChanged() {
        if (!mPreventDispatchingItemsChanged) {
            mPreventDispatchingItemsChanged = true;
            mItemsChangedWhileDispatchPrevented = false;
        }
    }

    public void startDispatchingItemsChanged() {
        mPreventDispatchingItemsChanged = false;

        if (mItemsChangedWhileDispatchPrevented) {
            mItemsChangedWhileDispatchPrevented = false;
            onItemsChanged(true);
        }
    }

    
Called by MenuItemImpl when its visible flag is changed. 
Params:
item – The item that has gone through a visibility change./**
     * Called by {@link MenuItemImpl} when its visible flag is changed.
     * @param item The item that has gone through a visibility change.
     */
    void onItemVisibleChanged(MenuItemImpl item) {
        // Notify of items being changed
        mIsVisibleItemsStale = true;
        onItemsChanged(true);
    }
    
    
Called by MenuItemImpl when its action request status is changed. 
Params:
item – The item that has gone through a change in action request status./**
     * Called by {@link MenuItemImpl} when its action request status is changed.
     * @param item The item that has gone through a change in action request status.
     */
    void onItemActionRequestChanged(MenuItemImpl item) {
        // Notify of items being changed
        mIsActionItemsStale = true;
        onItemsChanged(true);
    }

    @NonNull
    public ArrayList<MenuItemImpl> getVisibleItems() {
        if (!mIsVisibleItemsStale) return mVisibleItems;

        // Refresh the visible items
        mVisibleItems.clear();

        final int itemsSize = mItems.size(); 
        MenuItemImpl item;
        for (int i = 0; i < itemsSize; i++) {
            item = mItems.get(i);
            if (item.isVisible()) mVisibleItems.add(item);
        }

        mIsVisibleItemsStale = false;
        mIsActionItemsStale = true;

        return mVisibleItems;
    }

    
This method determines which menu items get to be 'action items' that will appear
in an action bar and which items should be 'overflow items' in a secondary menu.
The rules are as follows:
Items are considered for inclusion in the order specified within the menu.
There is a limit of mMaxActionItems as a total count, optionally including the overflow
menu button itself. This is a soft limit; if an item shares a group ID with an item
previously included as an action item, the new item will stay with its group and become
an action item itself even if it breaks the max item count limit. This is done to
limit the conceptual complexity of the items presented within an action bar. Only a few
unrelated concepts should be presented to the user in this space, and groups are treated
as a single concept.
There is also a hard limit of consumed measurable space: mActionWidthLimit. This
limit may be broken by a single item that exceeds the remaining space, but no further
items may be added. If an item that is part of a group cannot fit within the remaining
measured width, the entire group will be demoted to overflow. This is done to ensure room
for navigation and other affordances in the action bar as well as reduce general UI clutter.
The space freed by demoting a full group cannot be consumed by future menu items.
Once items begin to overflow, all future items become overflow items as well. This is
to avoid inadvertent reordering that may break the app's intended design.
/**
     * This method determines which menu items get to be 'action items' that will appear
     * in an action bar and which items should be 'overflow items' in a secondary menu.
     * The rules are as follows:
     *
     * <p>Items are considered for inclusion in the order specified within the menu.
     * There is a limit of mMaxActionItems as a total count, optionally including the overflow
     * menu button itself. This is a soft limit; if an item shares a group ID with an item
     * previously included as an action item, the new item will stay with its group and become
     * an action item itself even if it breaks the max item count limit. This is done to
     * limit the conceptual complexity of the items presented within an action bar. Only a few
     * unrelated concepts should be presented to the user in this space, and groups are treated
     * as a single concept.
     *
     * <p>There is also a hard limit of consumed measurable space: mActionWidthLimit. This
     * limit may be broken by a single item that exceeds the remaining space, but no further
     * items may be added. If an item that is part of a group cannot fit within the remaining
     * measured width, the entire group will be demoted to overflow. This is done to ensure room
     * for navigation and other affordances in the action bar as well as reduce general UI clutter.
     *
     * <p>The space freed by demoting a full group cannot be consumed by future menu items.
     * Once items begin to overflow, all future items become overflow items as well. This is
     * to avoid inadvertent reordering that may break the app's intended design.
     */
    public void flagActionItems() {
        // Important side effect: if getVisibleItems is stale it may refresh,
        // which can affect action items staleness.
        final ArrayList<MenuItemImpl> visibleItems = getVisibleItems();

        if (!mIsActionItemsStale) {
            return;
        }

        // Presenters flag action items as needed.
        boolean flagged = false;
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else {
                flagged |= presenter.flagActionItems();
            }
        }

        if (flagged) {
            mActionItems.clear();
            mNonActionItems.clear();
            final int itemsSize = visibleItems.size();
            for (int i = 0; i < itemsSize; i++) {
                MenuItemImpl item = visibleItems.get(i);
                if (item.isActionButton()) {
                    mActionItems.add(item);
                } else {
                    mNonActionItems.add(item);
                }
            }
        } else {
            // Nobody flagged anything, everything is a non-action item.
            // (This happens during a first pass with no action-item presenters.)
            mActionItems.clear();
            mNonActionItems.clear();
            mNonActionItems.addAll(getVisibleItems());
        }
        mIsActionItemsStale = false;
    }
    
    public ArrayList<MenuItemImpl> getActionItems() {
        flagActionItems();
        return mActionItems;
    }
    
    public ArrayList<MenuItemImpl> getNonActionItems() {
        flagActionItems();
        return mNonActionItems;
    }

    public void clearHeader() {
        mHeaderIcon = null;
        mHeaderTitle = null;
        mHeaderView = null;
        
        onItemsChanged(false);
    }
    
    private void setHeaderInternal(final int titleRes, final CharSequence title, final int iconRes,
            final Drawable icon, final View view) {
        final Resources r = getResources();

        if (view != null) {
            mHeaderView = view;
            
            // If using a custom view, then the title and icon aren't used
            mHeaderTitle = null;
            mHeaderIcon = null;
        } else {
            if (titleRes > 0) {
                mHeaderTitle = r.getText(titleRes);
            } else if (title != null) {
                mHeaderTitle = title;
            }
            
            if (iconRes > 0) {
                mHeaderIcon = getContext().getDrawable(iconRes);
            } else if (icon != null) {
                mHeaderIcon = icon;
            }
            
            // If using the title or icon, then a custom view isn't used
            mHeaderView = null;
        }
        
        // Notify of change
        onItemsChanged(false);
    }

    
Sets the header's title. This replaces the header view. Called by the
builder-style methods of subclasses.
Params:
title – The new title.
Returns:
This MenuBuilder so additional setters can be called./**
     * Sets the header's title. This replaces the header view. Called by the
     * builder-style methods of subclasses.
     * 
     * @param title The new title.
     * @return This MenuBuilder so additional setters can be called.
     */
    protected MenuBuilder setHeaderTitleInt(CharSequence title) {
        setHeaderInternal(0, title, 0, null, null);
        return this;
    }
    
    
Sets the header's title. This replaces the header view. Called by the
builder-style methods of subclasses.
Params:
titleRes – The new title (as a resource ID).
Returns:
This MenuBuilder so additional setters can be called./**
     * Sets the header's title. This replaces the header view. Called by the
     * builder-style methods of subclasses.
     * 
     * @param titleRes The new title (as a resource ID).
     * @return This MenuBuilder so additional setters can be called.
     */
    protected MenuBuilder setHeaderTitleInt(int titleRes) {
        setHeaderInternal(titleRes, null, 0, null, null);
        return this;
    }
    
    
Sets the header's icon. This replaces the header view. Called by the
builder-style methods of subclasses.
Params:
icon – The new icon.
Returns:
This MenuBuilder so additional setters can be called./**
     * Sets the header's icon. This replaces the header view. Called by the
     * builder-style methods of subclasses.
     * 
     * @param icon The new icon.
     * @return This MenuBuilder so additional setters can be called.
     */
    protected MenuBuilder setHeaderIconInt(Drawable icon) {
        setHeaderInternal(0, null, 0, icon, null);
        return this;
    }
    
    
Sets the header's icon. This replaces the header view. Called by the
builder-style methods of subclasses.
Params:
iconRes – The new icon (as a resource ID).
Returns:
This MenuBuilder so additional setters can be called./**
     * Sets the header's icon. This replaces the header view. Called by the
     * builder-style methods of subclasses.
     * 
     * @param iconRes The new icon (as a resource ID).
     * @return This MenuBuilder so additional setters can be called.
     */
    protected MenuBuilder setHeaderIconInt(int iconRes) {
        setHeaderInternal(0, null, iconRes, null, null);
        return this;
    }
    
    
Sets the header's view. This replaces the title and icon. Called by the
builder-style methods of subclasses.
Params:
view – The new view.
Returns:
This MenuBuilder so additional setters can be called./**
     * Sets the header's view. This replaces the title and icon. Called by the
     * builder-style methods of subclasses.
     * 
     * @param view The new view.
     * @return This MenuBuilder so additional setters can be called.
     */
    protected MenuBuilder setHeaderViewInt(View view) {
        setHeaderInternal(0, null, 0, null, view);
        return this;
    }
    
    public CharSequence getHeaderTitle() {
        return mHeaderTitle;
    }
    
    public Drawable getHeaderIcon() {
        return mHeaderIcon;
    }
    
    public View getHeaderView() {
        return mHeaderView;
    }
    
    
Gets the root menu (if this is a submenu, find its root menu).
Returns:
The root menu./**
     * Gets the root menu (if this is a submenu, find its root menu).
     * @return The root menu.
     */
    public MenuBuilder getRootMenu() {
        return this;
    }
    
    
Sets the current menu info that is set on all items added to this menu
(until this is called again with different menu info, in which case that
one will be added to all subsequent item additions).
Params:
menuInfo – The extra menu information to add./**
     * Sets the current menu info that is set on all items added to this menu
     * (until this is called again with different menu info, in which case that
     * one will be added to all subsequent item additions).
     * 
     * @param menuInfo The extra menu information to add.
     */
    public void setCurrentMenuInfo(ContextMenuInfo menuInfo) {
        mCurrentMenuInfo = menuInfo;
    }

    void setOptionalIconsVisible(boolean visible) {
        mOptionalIconsVisible = visible;
    }
    
    boolean getOptionalIconsVisible() {
        return mOptionalIconsVisible;
    }

    public boolean expandItemActionView(MenuItemImpl item) {
        if (mPresenters.isEmpty()) return false;

        boolean expanded = false;

        stopDispatchingItemsChanged();
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else if ((expanded = presenter.expandItemActionView(this, item))) {
                break;
            }
        }
        startDispatchingItemsChanged();

        if (expanded) {
            mExpandedItem = item;
        }
        return expanded;
    }

    public boolean collapseItemActionView(MenuItemImpl item) {
        if (mPresenters.isEmpty() || mExpandedItem != item) return false;

        boolean collapsed = false;

        stopDispatchingItemsChanged();
        for (WeakReference<MenuPresenter> ref : mPresenters) {
            final MenuPresenter presenter = ref.get();
            if (presenter == null) {
                mPresenters.remove(ref);
            } else if ((collapsed = presenter.collapseItemActionView(this, item))) {
                break;
            }
        }
        startDispatchingItemsChanged();

        if (collapsed) {
            mExpandedItem = null;
        }
        return collapsed;
    }

    public MenuItemImpl getExpandedItem() {
        return mExpandedItem;
    }
}