MenuPopupHelper.java revision 8028dd32a4a04154050220dd0693583d5b750330 
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 com.android.internal.view.menu.MenuBuilder.MenuAdapter;
20
21import android.content.Context;
22import android.util.DisplayMetrics;
23import android.view.KeyEvent;
24import android.view.MenuItem;
25import android.view.View;
26import android.view.View.MeasureSpec;
27import android.widget.AdapterView;
28import android.widget.ListPopupWindow;
29
30import java.lang.ref.WeakReference;
31
32/**
33 * @hide
34 */
35public class MenuPopupHelper implements AdapterView.OnItemClickListener, View.OnKeyListener {
36    private static final String TAG = "MenuPopupHelper";
37
38    private Context mContext;
39    private ListPopupWindow mPopup;
40    private MenuBuilder mMenu;
41    private int mPopupMaxWidth;
42    private WeakReference<View> mAnchorView;
43    private boolean mOverflowOnly;
44
45    public MenuPopupHelper(Context context, MenuBuilder menu) {
46        this(context, menu, null, false);
47    }
48
49    public MenuPopupHelper(Context context, MenuBuilder menu, View anchorView) {
50        this(context, menu, anchorView, false);
51    }
52
53    public MenuPopupHelper(Context context, MenuBuilder menu,
54            View anchorView, boolean overflowOnly) {
55        mContext = context;
56        mMenu = menu;
57        mOverflowOnly = overflowOnly;
58
59        final DisplayMetrics metrics = context.getResources().getDisplayMetrics();
60        mPopupMaxWidth = metrics.widthPixels / 2;
61
62        if (anchorView != null) {
63            mAnchorView = new WeakReference<View>(anchorView);
64        }
65    }
66
67    public void show() {
68        // TODO Use a style from the theme here
69        mPopup = new ListPopupWindow(mContext, null, 0,
70                com.android.internal.R.style.Widget_Spinner);
71        mPopup.setOnItemClickListener(this);
72
73        final MenuAdapter adapter = mOverflowOnly ?
74                mMenu.getOverflowMenuAdapter(MenuBuilder.TYPE_POPUP) :
75                mMenu.getMenuAdapter(MenuBuilder.TYPE_POPUP);
76        mPopup.setAdapter(adapter);
77        mPopup.setModal(true);
78
79        if (mMenu instanceof SubMenuBuilder) {
80            SubMenuBuilder subMenu = (SubMenuBuilder) mMenu;
81            final MenuItemImpl itemImpl = (MenuItemImpl) subMenu.getItem();
82            mPopup.setAnchorView(itemImpl.getItemView(MenuBuilder.TYPE_ACTION_BUTTON, null));
83        } else if (mAnchorView != null) {
84            mPopup.setAnchorView(mAnchorView.get());
85        }
86
87        mPopup.setContentWidth(Math.min(measureContentWidth(adapter), mPopupMaxWidth));
88        mPopup.show();
89        mPopup.getListView().setOnKeyListener(this);
90    }
91
92    public void dismiss() {
93        mPopup.dismiss();
94        mPopup = null;
95    }
96
97    public boolean isShowing() {
98        return mPopup != null && mPopup.isShowing();
99    }
100
101    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
102        MenuItem item = null;
103        if (mOverflowOnly) {
104            item = mMenu.getOverflowItem(position);
105        } else {
106            item = mMenu.getItem(position);
107        }
108        mMenu.performItemAction(item, 0);
109        mPopup.dismiss();
110    }
111
112    public boolean onKey(View v, int keyCode, KeyEvent event) {
113        if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_MENU) {
114            dismiss();
115            return true;
116        }
117        return false;
118    }
119
120    private int measureContentWidth(MenuAdapter adapter) {
121        // Menus don't tend to be long, so this is more sane than it looks.
122        int width = 0;
123        View itemView = null;
124        final int widthMeasureSpec =
125            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
126        final int heightMeasureSpec =
127            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
128        final int count = adapter.getCount();
129        for (int i = 0; i < count; i++) {
130            itemView = adapter.getView(i, itemView, null);
131            itemView.measure(widthMeasureSpec, heightMeasureSpec);
132            width = Math.max(width, itemView.getMeasuredWidth());
133        }
134        return width;
135    }
136}
137