com.actionbarsherlock.internal.view.menu.MenuPopupHelper.java Source code

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/*
50AH-code
=========
    
50 Android Hacks (http://manning.com/sessa/) book source code
    
    
Copyright (c) 2012 Manning
    
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
    
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
    
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
    
    
*/

/*
 * Copyright (C) 2010 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.actionbarsherlock.internal.view.menu;

import java.util.ArrayList;
import android.content.Context;
import android.content.res.Resources;
import android.database.DataSetObserver;
import android.os.Parcelable;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.MeasureSpec;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.FrameLayout;
import android.widget.ListAdapter;
import android.widget.PopupWindow;
import com.actionbarsherlock.R;
import com.actionbarsherlock.internal.view.View_HasStateListenerSupport;
import com.actionbarsherlock.internal.view.View_OnAttachStateChangeListener;
import com.actionbarsherlock.internal.widget.IcsListPopupWindow;
import com.actionbarsherlock.view.MenuItem;

/**
 * Presents a menu as a small, simple popup anchored to another view.
 * @hide
 */
public class MenuPopupHelper
        implements AdapterView.OnItemClickListener, View.OnKeyListener, ViewTreeObserver.OnGlobalLayoutListener,
        PopupWindow.OnDismissListener, View_OnAttachStateChangeListener, MenuPresenter {
    //UNUSED private static final String TAG = "MenuPopupHelper";

    static final int ITEM_LAYOUT = R.layout.abs__popup_menu_item_layout;

    private Context mContext;
    private LayoutInflater mInflater;
    private IcsListPopupWindow mPopup;
    private MenuBuilder mMenu;
    private int mPopupMaxWidth;
    private View mAnchorView;
    private boolean mOverflowOnly;
    private ViewTreeObserver mTreeObserver;

    private MenuAdapter mAdapter;

    private Callback mPresenterCallback;

    boolean mForceShowIcon;

    private ViewGroup mMeasureParent;

    public MenuPopupHelper(Context context, MenuBuilder menu) {
        this(context, menu, null, false);
    }

    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView) {
        this(context, menu, anchorView, false);
    }

    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView, boolean overflowOnly) {
        mContext = context;
        mInflater = LayoutInflater.from(context);
        mMenu = menu;
        mOverflowOnly = overflowOnly;

        final Resources res = context.getResources();
        mPopupMaxWidth = Math.max(res.getDisplayMetrics().widthPixels / 2,
                res.getDimensionPixelSize(R.dimen.abs__config_prefDialogWidth));

        mAnchorView = anchorView;

        menu.addMenuPresenter(this);
    }

    public void setAnchorView(View anchor) {
        mAnchorView = anchor;
    }

    public void setForceShowIcon(boolean forceShow) {
        mForceShowIcon = forceShow;
    }

    public void show() {
        if (!tryShow()) {
            throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
        }
    }

    public boolean tryShow() {
        mPopup = new IcsListPopupWindow(mContext, null, R.attr.popupMenuStyle);
        mPopup.setOnDismissListener(this);
        mPopup.setOnItemClickListener(this);

        mAdapter = new MenuAdapter(mMenu);
        mPopup.setAdapter(mAdapter);
        mPopup.setModal(true);

        View anchor = mAnchorView;
        if (anchor != null) {
            final boolean addGlobalListener = mTreeObserver == null;
            mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest
            if (addGlobalListener)
                mTreeObserver.addOnGlobalLayoutListener(this);
            ((View_HasStateListenerSupport) anchor).addOnAttachStateChangeListener(this);
            mPopup.setAnchorView(anchor);
        } else {
            return false;
        }

        mPopup.setContentWidth(Math.min(measureContentWidth(mAdapter), mPopupMaxWidth));
        mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
        mPopup.show();
        mPopup.getListView().setOnKeyListener(this);
        return true;
    }

    public void dismiss() {
        if (isShowing()) {
            mPopup.dismiss();
        }
    }

    public void onDismiss() {
        mPopup = null;
        mMenu.close();
        if (mTreeObserver != null) {
            if (!mTreeObserver.isAlive())
                mTreeObserver = mAnchorView.getViewTreeObserver();
            mTreeObserver.removeGlobalOnLayoutListener(this);
            mTreeObserver = null;
        }
        ((View_HasStateListenerSupport) mAnchorView).removeOnAttachStateChangeListener(this);
    }

    public boolean isShowing() {
        return mPopup != null && mPopup.isShowing();
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        MenuAdapter adapter = mAdapter;
        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
    }

    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
            dismiss();
            return true;
        }
        return false;
    }

    private int measureContentWidth(ListAdapter adapter) {
        // Menus don't tend to be long, so this is more sane than it looks.
        int width = 0;
        View itemView = null;
        int itemType = 0;
        final int widthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        final int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        final int count = adapter.getCount();
        for (int i = 0; i < count; i++) {
            final int positionType = adapter.getItemViewType(i);
            if (positionType != itemType) {
                itemType = positionType;
                itemView = null;
            }
            if (mMeasureParent == null) {
                mMeasureParent = new FrameLayout(mContext);
            }
            itemView = adapter.getView(i, itemView, mMeasureParent);
            itemView.measure(widthMeasureSpec, heightMeasureSpec);
            width = Math.max(width, itemView.getMeasuredWidth());
        }
        return width;
    }

    @Override
    public void onGlobalLayout() {
        if (isShowing()) {
            final View anchor = mAnchorView;
            if (anchor == null || !anchor.isShown()) {
                dismiss();
            } else if (isShowing()) {
                // Recompute window size and position
                mPopup.show();
            }
        }
    }

    @Override
    public void onViewAttachedToWindow(View v) {
    }

    @Override
    public void onViewDetachedFromWindow(View v) {
        if (mTreeObserver != null) {
            if (!mTreeObserver.isAlive())
                mTreeObserver = v.getViewTreeObserver();
            mTreeObserver.removeGlobalOnLayoutListener(this);
        }
        ((View_HasStateListenerSupport) v).removeOnAttachStateChangeListener(this);
    }

    @Override
    public void initForMenu(Context context, MenuBuilder menu) {
        // Don't need to do anything; we added as a presenter in the constructor.
    }

    @Override
    public MenuView getMenuView(ViewGroup root) {
        throw new UnsupportedOperationException("MenuPopupHelpers manage their own views");
    }

    @Override
    public void updateMenuView(boolean cleared) {
        if (mAdapter != null)
            mAdapter.notifyDataSetChanged();
    }

    @Override
    public void setCallback(Callback cb) {
        mPresenterCallback = cb;
    }

    @Override
    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
        if (subMenu.hasVisibleItems()) {
            MenuPopupHelper subPopup = new MenuPopupHelper(mContext, subMenu, mAnchorView, false);
            subPopup.setCallback(mPresenterCallback);

            boolean preserveIconSpacing = false;
            final int count = subMenu.size();
            for (int i = 0; i < count; i++) {
                MenuItem childItem = subMenu.getItem(i);
                if (childItem.isVisible() && childItem.getIcon() != null) {
                    preserveIconSpacing = true;
                    break;
                }
            }
            subPopup.setForceShowIcon(preserveIconSpacing);

            if (subPopup.tryShow()) {
                if (mPresenterCallback != null) {
                    mPresenterCallback.onOpenSubMenu(subMenu);
                }
                return true;
            }
        }
        return false;
    }

    @Override
    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
        // Only care about the (sub)menu we're presenting.
        if (menu != mMenu)
            return;

        dismiss();
        if (mPresenterCallback != null) {
            mPresenterCallback.onCloseMenu(menu, allMenusAreClosing);
        }
    }

    @Override
    public boolean flagActionItems() {
        return false;
    }

    public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
        return false;
    }

    public boolean collapseItemActionView(MenuBuilder menu, MenuItemImpl item) {
        return false;
    }

    @Override
    public int getId() {
        return 0;
    }

    @Override
    public Parcelable onSaveInstanceState() {
        return null;
    }

    @Override
    public void onRestoreInstanceState(Parcelable state) {
    }

    private class MenuAdapter extends BaseAdapter {
        private MenuBuilder mAdapterMenu;
        private int mExpandedIndex = -1;

        public MenuAdapter(MenuBuilder menu) {
            mAdapterMenu = menu;
            registerDataSetObserver(new ExpandedIndexObserver());
            findExpandedIndex();
        }

        public int getCount() {
            ArrayList<MenuItemImpl> items = mOverflowOnly ? mAdapterMenu.getNonActionItems()
                    : mAdapterMenu.getVisibleItems();
            if (mExpandedIndex < 0) {
                return items.size();
            }
            return items.size() - 1;
        }

        public MenuItemImpl getItem(int position) {
            ArrayList<MenuItemImpl> items = mOverflowOnly ? mAdapterMenu.getNonActionItems()
                    : mAdapterMenu.getVisibleItems();
            if (mExpandedIndex >= 0 && position >= mExpandedIndex) {
                position++;
            }
            return items.get(position);
        }

        public long getItemId(int position) {
            // Since a menu item's ID is optional, we'll use the position as an
            // ID for the item in the AdapterView
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            if (convertView == null) {
                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
            }

            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
            if (mForceShowIcon) {
                ((ListMenuItemView) convertView).setForceShowIcon(true);
            }
            itemView.initialize(getItem(position), 0);
            return convertView;
        }

        void findExpandedIndex() {
            final MenuItemImpl expandedItem = mMenu.getExpandedItem();
            if (expandedItem != null) {
                final ArrayList<MenuItemImpl> items = mMenu.getNonActionItems();
                final int count = items.size();
                for (int i = 0; i < count; i++) {
                    final MenuItemImpl item = items.get(i);
                    if (item == expandedItem) {
                        mExpandedIndex = i;
                        return;
                    }
                }
            }
            mExpandedIndex = -1;
        }
    }

    private class ExpandedIndexObserver extends DataSetObserver {
        @Override
        public void onChanged() {
            mAdapter.findExpandedIndex();
        }
    }
}