MenuPopupHelper.java revision 9151103ff20d28e8db2a2cc0386d57b8dad4b5d5 
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.view.KeyEvent;
23import android.view.LayoutInflater;
24import android.view.MenuItem;
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.FrameLayout;
32import android.widget.ListAdapter;
33import android.widget.ListPopupWindow;
34import android.widget.PopupWindow;
35
36import java.util.ArrayList;
37
38/**
39 * Presents a menu as a small, simple popup anchored to another view.
40 * @hide
41 */
42public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.OnKeyListener,
43        ViewTreeObserver.OnGlobalLayoutListener, PopupWindow.OnDismissListener,
44        View.OnAttachStateChangeListener, MenuPresenter {
45    private static final String TAG = "MenuPopupHelper";
46
47    static final int ITEM_LAYOUT = com.android.internal.R.layout.popup_menu_item_layout;
48
49    private Context mContext;
50    private LayoutInflater mInflater;
51    private ListPopupWindow mPopup;
52    private MenuBuilder mMenu;
53    private int mPopupMaxWidth;
54    private View mAnchorView;
55    private boolean mOverflowOnly;
56    private ViewTreeObserver mTreeObserver;
57
58    private MenuAdapter mAdapter;
59
60    private Callback mPresenterCallback;
61
62    boolean mForceShowIcon;
63
64    private ViewGroup mMeasureParent;
65
66    public MenuPopupHelper(Context context, MenuBuilder menu) {
67        this(context, menu, null, false);
68    }
69
70    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView) {
71        this(context, menu, anchorView, false);
72    }
73
74    public MenuPopupHelper(Context context, MenuBuilder menu,
75            View anchorView, boolean overflowOnly) {
76        mContext = context;
77        mInflater = LayoutInflater.from(context);
78        mMenu = menu;
79        mOverflowOnly = overflowOnly;
80
81        final Resources res = context.getResources();
82        mPopupMaxWidth = Math.max(res.getDisplayMetrics().widthPixels / 2,
83                res.getDimensionPixelSize(com.android.internal.R.dimen.config_prefDialogWidth));
84
85        mAnchorView = anchorView;
86
87        menu.addMenuPresenter(this);
88    }
89
90    public void setAnchorView(View anchor) {
91        mAnchorView = anchor;
92    }
93
94    public void setForceShowIcon(boolean forceShow) {
95        mForceShowIcon = forceShow;
96    }
97
98    public void show() {
99        if (!tryShow()) {
100            throw new IllegalStateException("MenuPopupHelper cannot be used without an anchor");
101        }
102    }
103
104    public boolean tryShow() {
105        mPopup = new ListPopupWindow(mContext, null, com.android.internal.R.attr.popupMenuStyle);
106        mPopup.setOnDismissListener(this);
107        mPopup.setOnItemClickListener(this);
108
109        mAdapter = new MenuAdapter(mMenu);
110        mPopup.setAdapter(mAdapter);
111        mPopup.setModal(true);
112
113        View anchor = mAnchorView;
114        if (anchor != null) {
115            final boolean addGlobalListener = mTreeObserver == null;
116            mTreeObserver = anchor.getViewTreeObserver(); // Refresh to latest
117            if (addGlobalListener) mTreeObserver.addOnGlobalLayoutListener(this);
118            anchor.addOnAttachStateChangeListener(this);
119            mPopup.setAnchorView(anchor);
120        } else {
121            return false;
122        }
123
124        mPopup.setContentWidth(Math.min(measureContentWidth(mAdapter), mPopupMaxWidth));
125        mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
126        mPopup.show();
127        mPopup.getListView().setOnKeyListener(this);
128        return true;
129    }
130
131    public void dismiss() {
132        if (isShowing()) {
133            mPopup.dismiss();
134        }
135    }
136
137    public void onDismiss() {
138        mPopup = null;
139        mMenu.close();
140        if (mTreeObserver != null) {
141            if (!mTreeObserver.isAlive()) mTreeObserver = mAnchorView.getViewTreeObserver();
142            mTreeObserver.removeGlobalOnLayoutListener(this);
143            mTreeObserver = null;
144        }
145        mAnchorView.removeOnAttachStateChangeListener(this);
146    }
147
148    public boolean isShowing() {
149        return mPopup != null && mPopup.isShowing();
150    }
151
152    @Override
153    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
154        MenuAdapter adapter = mAdapter;
155        adapter.mAdapterMenu.performItemAction(adapter.getItem(position), 0);
156    }
157
158    public boolean onKey(View v, int keyCode, KeyEvent event) {
159        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
160            dismiss();
161            return true;
162        }
163        return false;
164    }
165
166    private int measureContentWidth(ListAdapter adapter) {
167        // Menus don't tend to be long, so this is more sane than it looks.
168        int width = 0;
169        View itemView = null;
170        int itemType = 0;
171        final int widthMeasureSpec =
172            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
173        final int heightMeasureSpec =
174            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
175        final int count = adapter.getCount();
176        for (int i = 0; i < count; i++) {
177            final int positionType = adapter.getItemViewType(i);
178            if (positionType != itemType) {
179                itemType = positionType;
180                itemView = null;
181            }
182            if (mMeasureParent == null) {
183                mMeasureParent = new FrameLayout(mContext);
184            }
185            itemView = adapter.getView(i, itemView, mMeasureParent);
186            itemView.measure(widthMeasureSpec, heightMeasureSpec);
187            width = Math.max(width, itemView.getMeasuredWidth());
188        }
189        return width;
190    }
191
192    @Override
193    public void onGlobalLayout() {
194        if (isShowing()) {
195            final View anchor = mAnchorView;
196            if (anchor == null || !anchor.isShown()) {
197                dismiss();
198            } else if (isShowing()) {
199                // Recompute window size and position
200                mPopup.show();
201            }
202        }
203    }
204
205    @Override
206    public void onViewAttachedToWindow(View v) {
207    }
208
209    @Override
210    public void onViewDetachedFromWindow(View v) {
211        if (mTreeObserver != null) {
212            if (!mTreeObserver.isAlive()) mTreeObserver = v.getViewTreeObserver();
213            mTreeObserver.removeGlobalOnLayoutListener(this);
214        }
215        v.removeOnAttachStateChangeListener(this);
216    }
217
218    @Override
219    public void initForMenu(Context context, MenuBuilder menu) {
220        // Don't need to do anything; we added as a presenter in the constructor.
221    }
222
223    @Override
224    public MenuView getMenuView(ViewGroup root) {
225        throw new UnsupportedOperationException("MenuPopupHelpers manage their own views");
226    }
227
228    @Override
229    public void updateMenuView(boolean cleared) {
230        if (mAdapter != null) mAdapter.notifyDataSetChanged();
231    }
232
233    @Override
234    public void setCallback(Callback cb) {
235        mPresenterCallback = cb;
236    }
237
238    @Override
239    public boolean onSubMenuSelected(SubMenuBuilder subMenu) {
240        if (subMenu.hasVisibleItems()) {
241            MenuPopupHelper subPopup = new MenuPopupHelper(mContext, subMenu, mAnchorView, false);
242            subPopup.setCallback(mPresenterCallback);
243
244            boolean preserveIconSpacing = false;
245            final int count = subMenu.size();
246            for (int i = 0; i < count; i++) {
247                MenuItem childItem = subMenu.getItem(i);
248                if (childItem.isVisible() && childItem.getIcon() != null) {
249                    preserveIconSpacing = true;
250                    break;
251                }
252            }
253            subPopup.setForceShowIcon(preserveIconSpacing);
254
255            if (subPopup.tryShow()) {
256                if (mPresenterCallback != null) {
257                    mPresenterCallback.onOpenSubMenu(subMenu);
258                }
259                return true;
260            }
261        }
262        return false;
263    }
264
265    @Override
266    public void onCloseMenu(MenuBuilder menu, boolean allMenusAreClosing) {
267        // Only care about the (sub)menu we're presenting.
268        if (menu != mMenu) return;
269
270        dismiss();
271        if (mPresenterCallback != null) {
272            mPresenterCallback.onCloseMenu(menu, allMenusAreClosing);
273        }
274    }
275
276    @Override
277    public boolean flagActionItems() {
278        return false;
279    }
280
281    public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
282        return false;
283    }
284
285    public boolean collapseItemActionView(MenuBuilder menu, MenuItemImpl item) {
286        return false;
287    }
288
289    private class MenuAdapter extends BaseAdapter {
290        private MenuBuilder mAdapterMenu;
291
292        public MenuAdapter(MenuBuilder menu) {
293            mAdapterMenu = menu;
294        }
295
296        public int getCount() {
297            ArrayList<MenuItemImpl> items = mOverflowOnly ?
298                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
299            return items.size();
300        }
301
302        public MenuItemImpl getItem(int position) {
303            ArrayList<MenuItemImpl> items = mOverflowOnly ?
304                    mAdapterMenu.getNonActionItems() : mAdapterMenu.getVisibleItems();
305            return items.get(position);
306        }
307
308        public long getItemId(int position) {
309            // Since a menu item's ID is optional, we'll use the position as an
310            // ID for the item in the AdapterView
311            return position;
312        }
313
314        public View getView(int position, View convertView, ViewGroup parent) {
315            if (convertView == null) {
316                convertView = mInflater.inflate(ITEM_LAYOUT, parent, false);
317            }
318
319            MenuView.ItemView itemView = (MenuView.ItemView) convertView;
320            if (mForceShowIcon) {
321                ((ListMenuItemView) convertView).setForceShowIcon(true);
322            }
323            itemView.initialize(getItem(position), 0);
324            return convertView;
325        }
326    }
327
328    @Override
329    public int getId() {
330        return 0;
331    }
332
333    @Override
334    public Parcelable onSaveInstanceState() {
335        return null;
336    }
337
338    @Override
339    public void onRestoreInstanceState(Parcelable state) {
340    }
341}
342