MenuPopupHelper.java revision 42b91bbcdaf64b2f19d0a9ce168964b31a5dc139 
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        mMenu.close();
130        if (mTreeObserver != null) {
131            if (!mTreeObserver.isAlive()) mTreeObserver = mAnchorView.getViewTreeObserver();
132            mTreeObserver.removeGlobalOnLayoutListener(this);
133            mTreeObserver = null;
134        }
135        mAnchorView.removeOnAttachStateChangeListener(this);
136    }
137
138    public boolean isShowing() {
139        return mPopup != null && mPopup.isShowing();
140    }
141
142    @Override
143    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
144        MenuAdapter adapter = mAdapter;
145        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
146    }
147
148    public boolean onKey(View v, int keyCode, KeyEvent event) {
149        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
150            dismiss();
151            return true;
152        }
153        return false;
154    }
155
156    private int measureContentWidth(ListAdapter adapter) {
157        // Menus don't tend to be long, so this is more sane than it looks.
158        int width = 0;
159        View itemView = null;
160        int itemType = 0;
161        final int widthMeasureSpec =
162            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
163        final int heightMeasureSpec =
164            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
165        final int count = adapter.getCount();
166        for (int i = 0; i < count; i++) {
167            final int positionType = adapter.getItemViewType(i);
168            if (positionType != itemType) {
169                itemType = positionType;
170                itemView = null;
171            }
172            itemView = adapter.getView(i, itemView, null);
173            itemView.measure(widthMeasureSpec, heightMeasureSpec);
174            width = Math.max(width, itemView.getMeasuredWidth());
175        }
176        return width;
177    }
178
179    @Override
180    public void onGlobalLayout() {
181        if (isShowing()) {
182            final View anchor = mAnchorView;
183            if (anchor == null || !anchor.isShown()) {
184                dismiss();
185            } else if (isShowing()) {
186                // Recompute window size and position
187                mPopup.show();
188            }
189        }
190    }
191
192    @Override
193    public void onViewAttachedToWindow(View v) {
194    }
195
196    @Override
197    public void onViewDetachedFromWindow(View v) {
198        if (mTreeObserver != null) {
199            if (!mTreeObserver.isAlive()) mTreeObserver = v.getViewTreeObserver();
200            mTreeObserver.removeGlobalOnLayoutListener(this);
201        }
202        v.removeOnAttachStateChangeListener(this);
203    }
204
205    @Override
206    public void initForMenu(Context context, MenuBuilder menu) {
207        // Don't need to do anything; we added as a presenter in the constructor.
208    }
209
210    @Override
211    public MenuView getMenuView(ViewGroup root) {
212        throw new UnsupportedOperationException("MenuPopupHelpers manage their own views");
213    }
214
215    @Override
216    public void updateMenuView(boolean cleared) {
217        if (mAdapter != null) mAdapter.notifyDataSetChanged();
218    }
219
220    @Override
221    public void setCallback(Callback cb) {
222        mPresenterCallback = cb;
223    }
224
225    @Override
226    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
227        if (subMenu.hasVisibleItems()) {
228            MenuPopupHelper subPopup = new MenuPopupHelper(mContext, subMenu, mAnchorView, false);
229            subPopup.setCallback(mPresenterCallback);
230            if (subPopup.tryShow()) {
231                if (mPresenterCallback != null) {
232                    mPresenterCallback.onOpenSubMenu(subMenu);
233                }
234                return true;
235            }
236        }
237        return false;
238    }
239
240    @Override
241    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
242        // Only care about the (sub)menu we're presenting.
243        if (menu != mMenu) return;
244
245        dismiss();
246        if (mPresenterCallback != null) {
247            mPresenterCallback.onCloseMenu(menu, allMenusAreClosing);
248        }
249    }
250
251    @Override
252    public boolean flagActionItems() {
253        return false;
254    }
255
256    public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
257        return false;
258    }
259
260    public boolean collapseItemActionView(MenuBuilder menu, MenuItemImpl item) {
261        return false;
262    }
263
264    private class MenuAdapter extends BaseAdapter {
265        private MenuBuilder mAdapterMenu;
266
267        public MenuAdapter(MenuBuilder menu) {
268            mAdapterMenu = menu;
269        }
270
271        public int getCount() {
272            ArrayList<MenuItemImpl> items = mOverflowOnly ?
273                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
274            return items.size();
275        }
276
277        public MenuItemImpl getItem(int position) {
278            ArrayList<MenuItemImpl> items = mOverflowOnly ?
279                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
280            return items.get(position);
281        }
282
283        public long getItemId(int position) {
284            // Since a menu item's ID is optional, we'll use the position as an
285            // ID for the item in the AdapterView
286            return position;
287        }
288
289        public View getView(int position, View convertView, ViewGroup parent) {
290            if (convertView == null) {
291                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
292            }
293
294            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
295            itemView.initialize(getItem(position), 0);
296            return convertView;
297        }
298    }
299}
300