MenuPopupHelper.java revision 11ed1d6cae9214335c92ac38498a4e6c7d1c8324 
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.os.Parcelable;
22import android.util.DisplayMetrics;
23import android.view.KeyEvent;
24import android.view.LayoutInflater;
25import android.view.View;
26import android.view.View.MeasureSpec;
27import android.view.ViewGroup;
28import android.view.ViewTreeObserver;
29import android.widget.AdapterView;
30import android.widget.BaseAdapter;
31import android.widget.ListAdapter;
32import android.widget.ListPopupWindow;
33import android.widget.PopupWindow;
34
35import java.util.ArrayList;
36
37/**
38 * Presents a menu as a small, simple popup anchored to another view.
39 * @hide
40 */
41public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.OnKeyListener,
42        ViewTreeObserver.OnGlobalLayoutListener, PopupWindow.OnDismissListener,
43        View.OnAttachStateChangeListener, MenuPresenter {
44    private static final String TAG = "MenuPopupHelper";
45
46    static final int ITEM_LAYOUT = com.android.internal.R.layout.popup_menu_item_layout;
47
48    private Context mContext;
49    private LayoutInflater mInflater;
50    private ListPopupWindow mPopup;
51    private MenuBuilder mMenu;
52    private int mPopupMaxWidth;
53    private View mAnchorView;
54    private boolean mOverflowOnly;
55    private ViewTreeObserver mTreeObserver;
56
57    private MenuAdapter mAdapter;
58
59    private Callback mPresenterCallback;
60
61    public MenuPopupHelper(Context context, MenuBuilder menu) {
62        this(context, menu, null, false);
63    }
64
65    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView) {
66        this(context, menu, anchorView, false);
67    }
68
69    public MenuPopupHelper(Context context, MenuBuilder menu,
70            View anchorView, boolean overflowOnly) {
71        mContext = context;
72        mInflater = LayoutInflater.from(context);
73        mMenu = menu;
74        mOverflowOnly = overflowOnly;
75
76        final Resources res = context.getResources();
77        mPopupMaxWidth = Math.max(res.getDisplayMetrics().widthPixels / 2,
78                res.getDimensionPixelSize(com.android.internal.R.dimen.config_prefDialogWidth));
79
80        mAnchorView = anchorView;
81
82        menu.addMenuPresenter(this);
83    }
84
85    public void setAnchorView(View anchor) {
86        mAnchorView = anchor;
87    }
88
89    public void show() {
90        if (!tryShow()) {
91            throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
92        }
93    }
94
95    public boolean tryShow() {
96        mPopup = new ListPopupWindow(mContext, null, com.android.internal.R.attr.popupMenuStyle);
97        mPopup.setOnDismissListener(this);
98        mPopup.setOnItemClickListener(this);
99
100        mAdapter = new MenuAdapter(mMenu);
101        mPopup.setAdapter(mAdapter);
102        mPopup.setModal(true);
103
104        View anchor = mAnchorView;
105        if (anchor != null) {
106            final boolean addGlobalListener = mTreeObserver == null;
107            mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest
108            if (addGlobalListener) mTreeObserver.addOnGlobalLayoutListener(this);
109            anchor.addOnAttachStateChangeListener(this);
110            mPopup.setAnchorView(anchor);
111        } else {
112            return false;
113        }
114
115        mPopup.setContentWidth(Math.min(measureContentWidth(mAdapter), mPopupMaxWidth));
116        mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
117        mPopup.show();
118        mPopup.getListView().setOnKeyListener(this);
119        return true;
120    }
121
122    public void dismiss() {
123        if (isShowing()) {
124            mPopup.dismiss();
125        }
126    }
127
128    public void onDismiss() {
129        mPopup = null;
130        mMenu.close();
131        if (mTreeObserver != null) {
132            if (!mTreeObserver.isAlive()) mTreeObserver = mAnchorView.getViewTreeObserver();
133            mTreeObserver.removeGlobalOnLayoutListener(this);
134            mTreeObserver = null;
135        }
136        mAnchorView.removeOnAttachStateChangeListener(this);
137    }
138
139    public boolean isShowing() {
140        return mPopup != null && mPopup.isShowing();
141    }
142
143    @Override
144    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
145        MenuAdapter adapter = mAdapter;
146        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
147    }
148
149    public boolean onKey(View v, int keyCode, KeyEvent event) {
150        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
151            dismiss();
152            return true;
153        }
154        return false;
155    }
156
157    private int measureContentWidth(ListAdapter adapter) {
158        // Menus don't tend to be long, so this is more sane than it looks.
159        int width = 0;
160        View itemView = null;
161        int itemType = 0;
162        final int widthMeasureSpec =
163            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
164        final int heightMeasureSpec =
165            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
166        final int count = adapter.getCount();
167        for (int i = 0; i < count; i++) {
168            final int positionType = adapter.getItemViewType(i);
169            if (positionType != itemType) {
170                itemType = positionType;
171                itemView = null;
172            }
173            itemView = adapter.getView(i, itemView, null);
174            itemView.measure(widthMeasureSpec, heightMeasureSpec);
175            width = Math.max(width, itemView.getMeasuredWidth());
176        }
177        return width;
178    }
179
180    @Override
181    public void onGlobalLayout() {
182        if (isShowing()) {
183            final View anchor = mAnchorView;
184            if (anchor == null || !anchor.isShown()) {
185                dismiss();
186            } else if (isShowing()) {
187                // Recompute window size and position
188                mPopup.show();
189            }
190        }
191    }
192
193    @Override
194    public void onViewAttachedToWindow(View v) {
195    }
196
197    @Override
198    public void onViewDetachedFromWindow(View v) {
199        if (mTreeObserver != null) {
200            if (!mTreeObserver.isAlive()) mTreeObserver = v.getViewTreeObserver();
201            mTreeObserver.removeGlobalOnLayoutListener(this);
202        }
203        v.removeOnAttachStateChangeListener(this);
204    }
205
206    @Override
207    public void initForMenu(Context context, MenuBuilder menu) {
208        // Don't need to do anything; we added as a presenter in the constructor.
209    }
210
211    @Override
212    public MenuView getMenuView(ViewGroup root) {
213        throw new UnsupportedOperationException("MenuPopupHelpers manage their own views");
214    }
215
216    @Override
217    public void updateMenuView(boolean cleared) {
218        if (mAdapter != null) mAdapter.notifyDataSetChanged();
219    }
220
221    @Override
222    public void setCallback(Callback cb) {
223        mPresenterCallback = cb;
224    }
225
226    @Override
227    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
228        if (subMenu.hasVisibleItems()) {
229            MenuPopupHelper subPopup = new MenuPopupHelper(mContext, subMenu, mAnchorView, false);
230            subPopup.setCallback(mPresenterCallback);
231            if (subPopup.tryShow()) {
232                if (mPresenterCallback != null) {
233                    mPresenterCallback.onOpenSubMenu(subMenu);
234                }
235                return true;
236            }
237        }
238        return false;
239    }
240
241    @Override
242    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
243        // Only care about the (sub)menu we're presenting.
244        if (menu != mMenu) return;
245
246        dismiss();
247        if (mPresenterCallback != null) {
248            mPresenterCallback.onCloseMenu(menu, allMenusAreClosing);
249        }
250    }
251
252    @Override
253    public boolean flagActionItems() {
254        return false;
255    }
256
257    public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
258        return false;
259    }
260
261    public boolean collapseItemActionView(MenuBuilder menu, MenuItemImpl item) {
262        return false;
263    }
264
265    private class MenuAdapter extends BaseAdapter {
266        private MenuBuilder mAdapterMenu;
267
268        public MenuAdapter(MenuBuilder menu) {
269            mAdapterMenu = menu;
270        }
271
272        public int getCount() {
273            ArrayList<MenuItemImpl> items = mOverflowOnly ?
274                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
275            return items.size();
276        }
277
278        public MenuItemImpl getItem(int position) {
279            ArrayList<MenuItemImpl> items = mOverflowOnly ?
280                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
281            return items.get(position);
282        }
283
284        public long getItemId(int position) {
285            // Since a menu item's ID is optional, we'll use the position as an
286            // ID for the item in the AdapterView
287            return position;
288        }
289
290        public View getView(int position, View convertView, ViewGroup parent) {
291            if (convertView == null) {
292                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
293            }
294
295            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
296            itemView.initialize(getItem(position), 0);
297            return convertView;
298        }
299    }
300
301    @Override
302    public int getId() {
303        return 0;
304    }
305
306    @Override
307    public Parcelable onSaveInstanceState() {
308        return null;
309    }
310
311    @Override
312    public void onRestoreInstanceState(Parcelable state) {
313    }
314}
315