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 package com.android.contacts.common.list;
17 
18 import android.content.Context;
19 import android.view.View;
20 import android.view.ViewGroup;
21 
22 import com.android.common.widget.CompositeCursorAdapter;
23 
24 /**
25  * A subclass of {@link CompositeCursorAdapter} that manages pinned partition headers.
26  */
27 public abstract class PinnedHeaderListAdapter extends CompositeCursorAdapter
28         implements PinnedHeaderListView.PinnedHeaderAdapter {
29 
30     public static final int PARTITION_HEADER_TYPE = 0;
31 
32     private boolean mPinnedPartitionHeadersEnabled;
33     private boolean mHeaderVisibility[];
34 
PinnedHeaderListAdapter(Context context)35     public PinnedHeaderListAdapter(Context context) {
36         super(context);
37     }
38 
PinnedHeaderListAdapter(Context context, int initialCapacity)39     public PinnedHeaderListAdapter(Context context, int initialCapacity) {
40         super(context, initialCapacity);
41     }
42 
getPinnedPartitionHeadersEnabled()43     public boolean getPinnedPartitionHeadersEnabled() {
44         return mPinnedPartitionHeadersEnabled;
45     }
46 
setPinnedPartitionHeadersEnabled(boolean flag)47     public void setPinnedPartitionHeadersEnabled(boolean flag) {
48         this.mPinnedPartitionHeadersEnabled = flag;
49     }
50 
51     @Override
getPinnedHeaderCount()52     public int getPinnedHeaderCount() {
53         if (mPinnedPartitionHeadersEnabled) {
54             return getPartitionCount();
55         } else {
56             return 0;
57         }
58     }
59 
isPinnedPartitionHeaderVisible(int partition)60     protected boolean isPinnedPartitionHeaderVisible(int partition) {
61         return getPinnedPartitionHeadersEnabled() && hasHeader(partition)
62                 && !isPartitionEmpty(partition);
63     }
64 
65     /**
66      * The default implementation creates the same type of view as a normal
67      * partition header.
68      */
69     @Override
getPinnedHeaderView(int partition, View convertView, ViewGroup parent)70     public View getPinnedHeaderView(int partition, View convertView, ViewGroup parent) {
71         if (hasHeader(partition)) {
72             View view = null;
73             if (convertView != null) {
74                 Integer headerType = (Integer)convertView.getTag();
75                 if (headerType != null && headerType == PARTITION_HEADER_TYPE) {
76                     view = convertView;
77                 }
78             }
79             if (view == null) {
80                 view = newHeaderView(getContext(), partition, null, parent);
81                 view.setTag(PARTITION_HEADER_TYPE);
82                 view.setFocusable(false);
83                 view.setEnabled(false);
84             }
85             bindHeaderView(view, partition, getCursor(partition));
86             view.setLayoutDirection(parent.getLayoutDirection());
87             return view;
88         } else {
89             return null;
90         }
91     }
92 
93     @Override
configurePinnedHeaders(PinnedHeaderListView listView)94     public void configurePinnedHeaders(PinnedHeaderListView listView) {
95         if (!getPinnedPartitionHeadersEnabled()) {
96             return;
97         }
98 
99         int size = getPartitionCount();
100 
101         // Cache visibility bits, because we will need them several times later on
102         if (mHeaderVisibility == null || mHeaderVisibility.length != size) {
103             mHeaderVisibility = new boolean[size];
104         }
105         for (int i = 0; i < size; i++) {
106             boolean visible = isPinnedPartitionHeaderVisible(i);
107             mHeaderVisibility[i] = visible;
108             if (!visible) {
109                 listView.setHeaderInvisible(i, true);
110             }
111         }
112 
113         int headerViewsCount = listView.getHeaderViewsCount();
114 
115         // Starting at the top, find and pin headers for partitions preceding the visible one(s)
116         int maxTopHeader = -1;
117         int topHeaderHeight = 0;
118         for (int i = 0; i < size; i++) {
119             if (mHeaderVisibility[i]) {
120                 int position = listView.getPositionAt(topHeaderHeight) - headerViewsCount;
121                 int partition = getPartitionForPosition(position);
122                 if (i > partition) {
123                     break;
124                 }
125 
126                 listView.setHeaderPinnedAtTop(i, topHeaderHeight, false);
127                 topHeaderHeight += listView.getPinnedHeaderHeight(i);
128                 maxTopHeader = i;
129             }
130         }
131 
132         // Starting at the bottom, find and pin headers for partitions following the visible one(s)
133         int maxBottomHeader = size;
134         int bottomHeaderHeight = 0;
135         int listHeight = listView.getHeight();
136         for (int i = size; --i > maxTopHeader;) {
137             if (mHeaderVisibility[i]) {
138                 int position = listView.getPositionAt(listHeight - bottomHeaderHeight)
139                         - headerViewsCount;
140                 if (position < 0) {
141                     break;
142                 }
143 
144                 int partition = getPartitionForPosition(position - 1);
145                 if (partition == -1 || i <= partition) {
146                     break;
147                 }
148 
149                 int height = listView.getPinnedHeaderHeight(i);
150                 bottomHeaderHeight += height;
151 
152                 listView.setHeaderPinnedAtBottom(i, listHeight - bottomHeaderHeight, false);
153                 maxBottomHeader = i;
154             }
155         }
156 
157         // Headers in between the top-pinned and bottom-pinned should be hidden
158         for (int i = maxTopHeader + 1; i < maxBottomHeader; i++) {
159             if (mHeaderVisibility[i]) {
160                 listView.setHeaderInvisible(i, isPartitionEmpty(i));
161             }
162         }
163     }
164 
165     @Override
getScrollPositionForHeader(int viewIndex)166     public int getScrollPositionForHeader(int viewIndex) {
167         return getPositionForPartition(viewIndex);
168     }
169 }
170