MenuPopupHelper.java revision 38639b1d75933bfb720db79fce26f09478709614 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.internal.view.menu;
18
19import android.content.Context;
20import android.content.res.Resources;
21import android.util.DisplayMetrics;
22import android.view.KeyEvent;
23import android.view.LayoutInflater;
24import android.view.View;
25import android.view.View.MeasureSpec;
26import android.view.ViewGroup;
27import android.view.ViewTreeObserver;
28import android.widget.AdapterView;
29import android.widget.BaseAdapter;
30import android.widget.ListAdapter;
31import android.widget.ListPopupWindow;
32import android.widget.PopupWindow;
33
34import java.util.ArrayList;
35
36/**
37 * Presents a menu as a small, simple popup anchored to another view.
38 * @hide
39 */
40public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.OnKeyListener,
41        ViewTreeObserver.OnGlobalLayoutListener, PopupWindow.OnDismissListener,
42        View.OnAttachStateChangeListener, MenuPresenter {
43    private static final String TAG = "MenuPopupHelper";
44
45    static final int ITEM_LAYOUT = com.android.internal.R.layout.popup_menu_item_layout;
46
47    private Context mContext;
48    private LayoutInflater mInflater;
49    private ListPopupWindow mPopup;
50    private MenuBuilder mMenu;
51    private int mPopupMaxWidth;
52    private View mAnchorView;
53    private boolean mOverflowOnly;
54    private ViewTreeObserver mTreeObserver;
55
56    private MenuAdapter mAdapter;
57
58    private Callback mPresenterCallback;
59
60    public MenuPopupHelper(Context context, MenuBuilder menu) {
61        this(context, menu, null, false);
62    }
63
64    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView) {
65        this(context, menu, anchorView, false);
66    }
67
68    public MenuPopupHelper(Context context, MenuBuilder menu,
69            View anchorView, boolean overflowOnly) {
70        mContext = context;
71        mInflater = LayoutInflater.from(context);
72        mMenu = menu;
73        mOverflowOnly = overflowOnly;
74
75        final Resources res = context.getResources();
76        mPopupMaxWidth = Math.max(res.getDisplayMetrics().widthPixels / 2,
77                res.getDimensionPixelSize(com.android.internal.R.dimen.config_prefDialogWidth));
78
79        mAnchorView = anchorView;
80
81        menu.addMenuPresenter(this);
82    }
83
84    public void setAnchorView(View anchor) {
85        mAnchorView = anchor;
86    }
87
88    public void show() {
89        if (!tryShow()) {
90            throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
91        }
92    }
93
94    public boolean tryShow() {
95        mPopup = new ListPopupWindow(mContext, null, com.android.internal.R.attr.popupMenuStyle);
96        mPopup.setOnDismissListener(this);
97        mPopup.setOnItemClickListener(this);
98
99        mAdapter = new MenuAdapter(mMenu);
100        mPopup.setAdapter(mAdapter);
101        mPopup.setModal(true);
102
103        View anchor = mAnchorView;
104        if (anchor != null) {
105            final boolean addGlobalListener = mTreeObserver == null;
106            mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest
107            if (addGlobalListener) mTreeObserver.addOnGlobalLayoutListener(this);
108            anchor.addOnAttachStateChangeListener(this);
109            mPopup.setAnchorView(anchor);
110        } else {
111            return false;
112        }
113
114        mPopup.setContentWidth(Math.min(measureContentWidth(mAdapter), mPopupMaxWidth));
115        mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
116        mPopup.show();
117        mPopup.getListView().setOnKeyListener(this);
118        return true;
119    }
120
121    public void dismiss() {
122        if (isShowing()) {
123            mPopup.dismiss();
124        }
125    }
126
127    public void onDismiss() {
128        mPopup = null;
129        if (mTreeObserver != null) {
130            if (!mTreeObserver.isAlive()) mTreeObserver = mAnchorView.getViewTreeObserver();
131            mTreeObserver.removeGlobalOnLayoutListener(this);
132            mTreeObserver = null;
133        }
134        mAnchorView.removeOnAttachStateChangeListener(this);
135    }
136
137    public boolean isShowing() {
138        return mPopup != null && mPopup.isShowing();
139    }
140
141    @Override
142    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
143        MenuAdapter adapter = mAdapter;
144        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
145    }
146
147    public boolean onKey(View v, int keyCode, KeyEvent event) {
148        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
149            dismiss();
150            return true;
151        }
152        return false;
153    }
154
155    private int measureContentWidth(ListAdapter adapter) {
156        // Menus don't tend to be long, so this is more sane than it looks.
157        int width = 0;
158        View itemView = null;
159        int itemType = 0;
160        final int widthMeasureSpec =
161            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
162        final int heightMeasureSpec =
163            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
164        final int count = adapter.getCount();
165        for (int i = 0; i < count; i++) {
166            final int positionType = adapter.getItemViewType(i);
167            if (positionType != itemType) {
168                itemType = positionType;
169                itemView = null;
170            }
171            itemView = adapter.getView(i, itemView, null);
172            itemView.measure(widthMeasureSpec, heightMeasureSpec);
173            width = Math.max(width, itemView.getMeasuredWidth());
174        }
175        return width;
176    }
177
178    @Override
179    public void onGlobalLayout() {
180        if (isShowing()) {
181            final View anchor = mAnchorView;
182            if (anchor == null || !anchor.isShown()) {
183                dismiss();
184            } else if (isShowing()) {
185                // Recompute window size and position
186                mPopup.show();
187            }
188        }
189    }
190
191    @Override
192    public void onViewAttachedToWindow(View v) {
193    }
194
195    @Override
196    public void onViewDetachedFromWindow(View v) {
197        if (mTreeObserver != null) {
198            if (!mTreeObserver.isAlive()) mTreeObserver = v.getViewTreeObserver();
199            mTreeObserver.removeGlobalOnLayoutListener(this);
200        }
201        v.removeOnAttachStateChangeListener(this);
202    }
203
204    @Override
205    public void initForMenu(Context context, MenuBuilder menu) {
206        // Don't need to do anything; we added as a presenter in the constructor.
207    }
208
209    @Override
210    public MenuView getMenuView(ViewGroup root) {
211        throw new UnsupportedOperationException("MenuPopupHelpers manage their own views");
212    }
213
214    @Override
215    public void updateMenuView(boolean cleared) {
216        if (mAdapter != null) mAdapter.notifyDataSetChanged();
217    }
218
219    @Override
220    public void setCallback(Callback cb) {
221        mPresenterCallback = cb;
222    }
223
224    @Override
225    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
226        if (subMenu.hasVisibleItems()) {
227            MenuPopupHelper subPopup = new MenuPopupHelper(mContext, subMenu, mAnchorView, false);
228            subPopup.setCallback(mPresenterCallback);
229            if (subPopup.tryShow()) {
230                if (mPresenterCallback != null) {
231                    mPresenterCallback.onOpenSubMenu(subMenu);
232                }
233                return true;
234            }
235        }
236        return false;
237    }
238
239    @Override
240    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
241        // Only care about the (sub)menu we're presenting.
242        if (menu != mMenu) return;
243
244        dismiss();
245        if (mPresenterCallback != null) {
246            mPresenterCallback.onCloseMenu(menu, allMenusAreClosing);
247        }
248    }
249
250    @Override
251    public boolean flagActionItems() {
252        return false;
253    }
254
255    public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
256        return false;
257    }
258
259    public boolean collapseItemActionView(MenuBuilder menu, MenuItemImpl item) {
260        return false;
261    }
262
263    private class MenuAdapter extends BaseAdapter {
264        private MenuBuilder mAdapterMenu;
265
266        public MenuAdapter(MenuBuilder menu) {
267            mAdapterMenu = menu;
268        }
269
270        public int getCount() {
271            ArrayList<MenuItemImpl> items = mOverflowOnly ?
272                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
273            return items.size();
274        }
275
276        public MenuItemImpl getItem(int position) {
277            ArrayList<MenuItemImpl> items = mOverflowOnly ?
278                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
279            return items.get(position);
280        }
281
282        public long getItemId(int position) {
283            // Since a menu item's ID is optional, we'll use the position as an
284            // ID for the item in the AdapterView
285            return position;
286        }
287
288        public View getView(int position, View convertView, ViewGroup parent) {
289            if (convertView == null) {
290                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
291            }
292
293            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
294            itemView.initialize(getItem(position), 0);
295            return convertView;
296        }
297    }
298}
299