1/*
2 * Copyright (C) 2016 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 */
16package com.android.internal.widget;
17
18import android.annotation.IdRes;
19import android.content.Context;
20import android.util.AttributeSet;
21import android.view.View;
22import android.view.ViewGroup;
23import android.widget.AdapterView;
24import android.widget.ListAdapter;
25import android.widget.ListView;
26import android.widget.HeaderViewListAdapter;
27
28import java.util.ArrayList;
29import java.util.function.Predicate;
30
31public class WatchHeaderListView extends ListView {
32    private View mTopPanel;
33
34    public WatchHeaderListView(Context context, AttributeSet attrs) {
35        super(context, attrs);
36    }
37
38    public WatchHeaderListView(Context context, AttributeSet attrs, int defStyleAttr) {
39        super(context, attrs, defStyleAttr);
40    }
41
42    public WatchHeaderListView(
43            Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
44        super(context, attrs, defStyleAttr, defStyleRes);
45    }
46
47    @Override
48    protected HeaderViewListAdapter wrapHeaderListAdapterInternal(
49            ArrayList<ListView.FixedViewInfo> headerViewInfos,
50            ArrayList<ListView.FixedViewInfo> footerViewInfos,
51            ListAdapter adapter) {
52        return new WatchHeaderListAdapter(headerViewInfos, footerViewInfos, adapter);
53    }
54
55    @Override
56    public void addView(View child, ViewGroup.LayoutParams params) {
57        if (mTopPanel == null) {
58            setTopPanel(child);
59        } else {
60            throw new IllegalStateException("WatchHeaderListView can host only one header");
61        }
62    }
63
64    public void setTopPanel(View v) {
65        mTopPanel = v;
66        wrapAdapterIfNecessary();
67    }
68
69    @Override
70    public void setAdapter(ListAdapter adapter) {
71        super.setAdapter(adapter);
72        wrapAdapterIfNecessary();
73    }
74
75    @Override
76    protected View findViewTraversal(@IdRes int id) {
77        View v = super.findViewTraversal(id);
78        if (v == null && mTopPanel != null && !mTopPanel.isRootNamespace()) {
79            return mTopPanel.findViewById(id);
80        }
81        return v;
82    }
83
84    @Override
85    protected View findViewWithTagTraversal(Object tag) {
86        View v = super.findViewWithTagTraversal(tag);
87        if (v == null && mTopPanel != null && !mTopPanel.isRootNamespace()) {
88            return mTopPanel.findViewWithTag(tag);
89        }
90        return v;
91    }
92
93    @Override
94    protected <T extends View> T findViewByPredicateTraversal(
95            Predicate<View> predicate, View childToSkip) {
96        View v = super.findViewByPredicateTraversal(predicate, childToSkip);
97        if (v == null && mTopPanel != null && mTopPanel != childToSkip
98                && !mTopPanel.isRootNamespace()) {
99            return (T) mTopPanel.findViewByPredicate(predicate);
100        }
101        return (T) v;
102    }
103
104    @Override
105    public int getHeaderViewsCount() {
106        return mTopPanel == null ? super.getHeaderViewsCount()
107                : super.getHeaderViewsCount() + (mTopPanel.getVisibility() == GONE ? 0 : 1);
108    }
109
110    private void wrapAdapterIfNecessary() {
111        ListAdapter adapter = getAdapter();
112        if (adapter != null && mTopPanel != null) {
113            if (!(adapter instanceof WatchHeaderListAdapter)) {
114                wrapHeaderListAdapterInternal();
115            }
116
117            ((WatchHeaderListAdapter) getAdapter()).setTopPanel(mTopPanel);
118            dispatchDataSetObserverOnChangedInternal();
119        }
120    }
121
122    private static class WatchHeaderListAdapter extends HeaderViewListAdapter {
123        private View mTopPanel;
124
125        public WatchHeaderListAdapter(
126                ArrayList<ListView.FixedViewInfo> headerViewInfos,
127                ArrayList<ListView.FixedViewInfo> footerViewInfos,
128                ListAdapter adapter) {
129            super(headerViewInfos, footerViewInfos, adapter);
130        }
131
132        public void setTopPanel(View v) {
133            mTopPanel = v;
134        }
135
136        private int getTopPanelCount() {
137            return (mTopPanel == null || mTopPanel.getVisibility() == GONE) ? 0 : 1;
138        }
139
140        @Override
141        public int getCount() {
142            return super.getCount() + getTopPanelCount();
143        }
144
145        @Override
146        public boolean areAllItemsEnabled() {
147            return getTopPanelCount() == 0 && super.areAllItemsEnabled();
148        }
149
150        @Override
151        public boolean isEnabled(int position) {
152            int topPanelCount = getTopPanelCount();
153            return position < topPanelCount ? false : super.isEnabled(position - topPanelCount);
154        }
155
156        @Override
157        public Object getItem(int position) {
158            int topPanelCount = getTopPanelCount();
159            return position < topPanelCount ? null : super.getItem(position - topPanelCount);
160        }
161
162        @Override
163        public long getItemId(int position) {
164            int numHeaders = getHeadersCount() + getTopPanelCount();
165            if (getWrappedAdapter() != null && position >= numHeaders) {
166                int adjPosition = position - numHeaders;
167                int adapterCount = getWrappedAdapter().getCount();
168                if (adjPosition < adapterCount) {
169                    return getWrappedAdapter().getItemId(adjPosition);
170                }
171            }
172            return -1;
173        }
174
175        @Override
176        public View getView(int position, View convertView, ViewGroup parent) {
177            int topPanelCount = getTopPanelCount();
178            return position < topPanelCount
179                    ? mTopPanel : super.getView(position - topPanelCount, convertView, parent);
180        }
181
182        @Override
183        public int getItemViewType(int position) {
184            int numHeaders = getHeadersCount() + getTopPanelCount();
185            if (getWrappedAdapter() != null && position >= numHeaders) {
186                int adjPosition = position - numHeaders;
187                int adapterCount = getWrappedAdapter().getCount();
188                if (adjPosition < adapterCount) {
189                    return getWrappedAdapter().getItemViewType(adjPosition);
190                }
191            }
192
193            return AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER;
194        }
195    }
196}
197