core/java/com/android/internal/view/menu/ActionMenuPresenter.java

/*
 * 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 com.android.internal.view.menu;

import com.android.internal.view.menu.ActionMenuView.ActionMenuChildView;

import android.content.Context;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.util.SparseBooleanArray;
import android.view.MenuItem;
import android.view.SoundEffectConstants;
import android.view.View;
import android.view.View.MeasureSpec;
import android.view.ViewGroup;
import android.widget.ImageButton;

import java.util.ArrayList;

/**
 * MenuPresenter for building action menus as seen in the action bar and action modes.
 */
public class ActionMenuPresenter extends BaseMenuPresenter {
    private static final String TAG = "ActionMenuPresenter";

    private View mOverflowButton;
    private boolean mReserveOverflow;
    private int mWidthLimit;
    private int mActionItemWidthLimit;
    private int mMaxItems;
    private boolean mStrictWidthLimit;

    // Group IDs that have been added as actions - used temporarily, allocated here for reuse.
    private final SparseBooleanArray mActionButtonGroups = new SparseBooleanArray();

    private View mScrapActionButtonView;

    private OverflowPopup mOverflowPopup;
    private ActionButtonSubmenu mActionButtonPopup;

    private OpenOverflowRunnable mPostedOpenRunnable;

    public ActionMenuPresenter() {
        super(com.android.internal.R.layout.action_menu_layout,
                com.android.internal.R.layout.action_menu_item_layout);
    }

    @Override
    public void initForMenu(Context context, MenuBuilder menu) {
        super.initForMenu(context, menu);

        final Resources res = context.getResources();
        final int screen = res.getConfiguration().screenLayout;
        // TODO Use the no-buttons specifier instead here
        mReserveOverflow = (screen & Configuration.SCREENLAYOUT_SIZE_MASK) ==
                Configuration.SCREENLAYOUT_SIZE_XLARGE;
        mWidthLimit = res.getDisplayMetrics().widthPixels / 2;

        // Measure for initial configuration
        mMaxItems = res.getInteger(com.android.internal.R.integer.max_action_buttons);

        int width = mWidthLimit;
        if (mReserveOverflow) {
            if (mOverflowButton == null) {
                mOverflowButton = new OverflowMenuButton(mContext);
                final int spec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
                mOverflowButton.measure(spec, spec);
            }
            width -= mOverflowButton.getMeasuredWidth();
        } else {
            mOverflowButton = null;
        }

        mActionItemWidthLimit = width;

        // Drop a scrap view as it may no longer reflect the proper context/config.
        mScrapActionButtonView = null;
    }

    public void setWidthLimit(int width, boolean strict) {
        if (mReserveOverflow) {
            width -= mOverflowButton.getMeasuredWidth();
        }
        mActionItemWidthLimit = width;
        mStrictWidthLimit = strict;
    }

    public void setItemLimit(int itemCount) {
        mMaxItems = itemCount;
    }

    @Override
    public MenuView getMenuView(ViewGroup root) {
        MenuView result = super.getMenuView(root);
        ((ActionMenuView) result).setPresenter(this);
        return result;
    }

    @Override
    public View getItemView(MenuItemImpl item, View convertView, ViewGroup parent) {
        final View actionView = item.getActionView();
        return actionView != null ? actionView : super.getItemView(item, convertView, parent);
    }

    @Override
    public void bindItemView(MenuItemImpl item, MenuView.ItemView itemView) {
        itemView.initialize(item, 0);
        ((ActionMenuItemView) itemView).setItemInvoker((ActionMenuView) mMenuView);
    }

    @Override
    public boolean shouldIncludeItem(int childIndex, MenuItemImpl item) {
        return item.isActionButton();
    }

    @Override
    public void updateMenuView(boolean cleared) {
        super.updateMenuView(cleared);

        if (mReserveOverflow && mMenu.getNonActionItems().size() > 0) {
            if (mOverflowButton == null) {
                mOverflowButton = new OverflowMenuButton(mContext);
                mOverflowButton.setLayoutParams(
                        ((ActionMenuView) mMenuView).generateOverflowButtonLayoutParams());
            }
            ViewGroup parent = (ViewGroup) mOverflowButton.getParent();
            if (parent != mMenuView) {
                if (parent != null) {
                    parent.removeView(mOverflowButton);
                }
                ((ViewGroup) mMenuView).addView(mOverflowButton);
            }
        } else if (mOverflowButton != null && mOverflowButton.getParent() == mMenuView) {
            ((ViewGroup) mMenuView).removeView(mOverflowButton);
        }
    }

    @Override
    public boolean filterLeftoverView(ViewGroup parent, int childIndex) {
        if (parent.getChildAt(childIndex) == mOverflowButton) return false;
        return super.filterLeftoverView(parent, childIndex);
    }

    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
        if (!subMenu.hasVisibleItems()) return false;

        SubMenuBuilder topSubMenu = subMenu;
        while (topSubMenu.getParentMenu() != mMenu) {
            topSubMenu = (SubMenuBuilder) topSubMenu.getParentMenu();
        }
        View anchor = findViewForItem(topSubMenu.getItem());
        if (anchor == null) return false;

        mActionButtonPopup = new ActionButtonSubmenu(mContext, subMenu);
        mActionButtonPopup.setAnchorView(anchor);
        mActionButtonPopup.show();
        super.onSubMenuSelected(subMenu);
        return true;
    }

    private View findViewForItem(MenuItem item) {
        final ViewGroup parent = (ViewGroup) mMenuView;
        if (parent == null) return null;

        final int count = parent.getChildCount();
        for (int i = 0; i < count; i++) {
            final View child = parent.getChildAt(i);
            if (child instanceof MenuView.ItemView &&
                    ((MenuView.ItemView) child).getItemData() == item) {
                return child;
            }
        }
        return null;
    }

    /**
     * Display the overflow menu if one is present.
     * @return true if the overflow menu was shown, false otherwise.
     */
    public boolean showOverflowMenu() {
        if (mReserveOverflow && !isOverflowMenuShowing() && mMenuView != null &&
                mPostedOpenRunnable == null) {
            OverflowPopup popup = new OverflowPopup(mContext, mMenu, mOverflowButton, true);
            mPostedOpenRunnable = new OpenOverflowRunnable(popup);
            // Post this for later; we might still need a layout for the anchor to be right.
            ((View) mMenuView).post(mPostedOpenRunnable);

            // ActionMenuPresenter uses null as a callback argument here
            // to indicate overflow is opening.
            super.onSubMenuSelected(null);

            return true;
        }
        return false;
    }

    /**
     * Hide the overflow menu if it is currently showing.
     *
     * @return true if the overflow menu was hidden, false otherwise.
     */
    public boolean hideOverflowMenu() {
        if (mPostedOpenRunnable != null && mMenuView != null) {
            ((View) mMenuView).removeCallbacks(mPostedOpenRunnable);
            return true;
        }

        MenuPopupHelper popup = mOverflowPopup;
        if (popup != null) {
            popup.dismiss();
            return true;
        }
        return false;
    }

    /**
     * Dismiss all popup menus - overflow and submenus.
     * @return true if popups were dismissed, false otherwise. (This can be because none were open.)
     */
    public boolean dismissPopupMenus() {
        boolean result = hideOverflowMenu();
        result |= hideSubMenus();
        return result;
    }

    /**
     * Dismiss all submenu popups.
     *
     * @return true if popups were dismissed, false otherwise. (This can be because none were open.)
     */
    public boolean hideSubMenus() {
        if (mActionButtonPopup != null) {
            mActionButtonPopup.dismiss();
            return true;
        }
        return false;
    }

    /**
     * @return true if the overflow menu is currently showing
     */
    public boolean isOverflowMenuShowing() {
        return mOverflowPopup != null && mOverflowPopup.isShowing();
    }

    /**
     * @return true if space has been reserved in the action menu for an overflow item.
     */
    public boolean isOverflowReserved() {
        return mReserveOverflow;
    }

    public boolean flagActionItems() {
        final ArrayList<MenuItemImpl> visibleItems = mMenu.getVisibleItems();
        final int itemsSize = visibleItems.size();
        int maxActions = mMaxItems;
        int widthLimit = mActionItemWidthLimit;
        final int querySpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        final ViewGroup parent = (ViewGroup) mMenuView;

        int requiredItems = 0;
        int requestedItems = 0;
        int firstActionWidth = 0;
        boolean hasOverflow = false;
        for (int i = 0; i < itemsSize; i++) {
            MenuItemImpl item = visibleItems.get(i);
            if (item.requiresActionButton()) {
                requiredItems++;
            } else if (item.requestsActionButton()) {
                requestedItems++;
            } else {
                hasOverflow = true;
            }
        }

        // Reserve a spot for the overflow item if needed.
        if (mReserveOverflow &&
                (hasOverflow || requiredItems + requestedItems > maxActions)) {
            maxActions--;
        }
        maxActions -= requiredItems;

        final SparseBooleanArray seenGroups = mActionButtonGroups;
        seenGroups.clear();

        // Flag as many more requested items as will fit.
        for (int i = 0; i < itemsSize; i++) {
            MenuItemImpl item = visibleItems.get(i);

            if (item.requiresActionButton()) {
                View v = item.getActionView();
                if (v == null) {
                    v = getItemView(item, mScrapActionButtonView, parent);
                    if (mScrapActionButtonView == null) {
                        mScrapActionButtonView = v;
                    }
                }
                v.measure(querySpec, querySpec);
                final int measuredWidth = v.getMeasuredWidth();
                widthLimit -= measuredWidth;
                if (firstActionWidth == 0) {
                    firstActionWidth = measuredWidth;
                }
                final int groupId = item.getGroupId();
                if (groupId != 0) {
                    seenGroups.put(groupId, true);
                }
            } else if (item.requestsActionButton()) {
                // Items in a group with other items that already have an action slot
                // can break the max actions rule, but not the width limit.
                final int groupId = item.getGroupId();
                final boolean inGroup = seenGroups.get(groupId);
                boolean isAction = (maxActions > 0 || inGroup) && widthLimit > 0;
                maxActions--;

                if (isAction) {
                    View v = item.getActionView();
                    if (v == null) {
                        v = getItemView(item, mScrapActionButtonView, parent);
                        if (mScrapActionButtonView == null) {
                            mScrapActionButtonView = v;
                        }
                    }
                    v.measure(querySpec, querySpec);
                    final int measuredWidth = v.getMeasuredWidth();
                    widthLimit -= measuredWidth;
                    if (firstActionWidth == 0) {
                        firstActionWidth = measuredWidth;
                    }

                    if (mStrictWidthLimit) {
                        isAction = widthLimit >= 0;
                    } else {
                        // Did this push the entire first item past the limit?
                        isAction = widthLimit + firstActionWidth > 0;
                    }
                }

                if (isAction && groupId != 0) {
                    seenGroups.put(groupId, true);
                } else if (inGroup) {
                    // We broke the width limit. Demote the whole group, they all overflow now.
                    seenGroups.put(groupId, false);
                    for (int j = 0; j < i; j++) {
                        MenuItemImpl areYouMyGroupie = visibleItems.get(j);
                        if (areYouMyGroupie.getGroupId() == groupId) {
                            areYouMyGroupie.setIsActionButton(false);
                        }
                    }
                }

                item.setIsActionButton(isAction);
            }
        }
        return true;
    }

    @Override
    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
        dismissPopupMenus();
        super.onCloseMenu(menu, allMenusAreClosing);
    }

    private class OverflowMenuButton extends ImageButton implements ActionMenuChildView {
        public OverflowMenuButton(Context context) {
            super(context, null, com.android.internal.R.attr.actionOverflowButtonStyle);

            setClickable(true);
            setFocusable(true);
            setVisibility(VISIBLE);
            setEnabled(true);
        }

        @Override
        public boolean performClick() {
            if (super.performClick()) {
                return true;
            }

            playSoundEffect(SoundEffectConstants.CLICK);
            showOverflowMenu();
            return true;
        }

        public boolean needsDividerBefore() {
            return true;
        }

        public boolean needsDividerAfter() {
            return false;
        }
    }

    private class OverflowPopup extends MenuPopupHelper {
        public OverflowPopup(Context context, MenuBuilder menu, View anchorView,
                boolean overflowOnly) {
            super(context, menu, anchorView, overflowOnly);
        }

        @Override
        public void onDismiss() {
            super.onDismiss();
            mMenu.close();
            mOverflowPopup = null;
        }
    }

    private class ActionButtonSubmenu extends MenuPopupHelper {
        private SubMenuBuilder mSubMenu;

        public ActionButtonSubmenu(Context context, SubMenuBuilder subMenu) {
            super(context, subMenu);
            mSubMenu = subMenu;

            MenuItemImpl item = (MenuItemImpl) subMenu.getItem();
            if (!item.isActionButton()) {
                // Give a reasonable anchor to nested submenus.
                setAnchorView(mOverflowButton == null ? (View) mMenuView : mOverflowButton);
            }
        }

        @Override
        public void onDismiss() {
            super.onDismiss();
            mSubMenu.close();
            mActionButtonPopup = null;
        }
    }

    private class OpenOverflowRunnable implements Runnable {
        private OverflowPopup mPopup;

        public OpenOverflowRunnable(OverflowPopup popup) {
            mPopup = popup;
        }

        public void run() {
            mMenu.changeMenuMode();
            if (mPopup.tryShow()) {
                mOverflowPopup = mPopup;
                mPostedOpenRunnable = null;
            }
        }
    }
}