1/*
2 * Copyright (C) 2006 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 android.widget;
18
19import android.view.View;
20import android.view.ViewGroup;
21
22/**
23 * Additional methods that when implemented make an
24 * {@link ExpandableListAdapter} take advantage of the {@link Adapter} view type
25 * mechanism.
26 * <p>
27 * An {@link ExpandableListAdapter} declares it has one view type for its group items
28 * and one view type for its child items. Although adapted for most {@link ExpandableListView}s,
29 * these values should be tuned for heterogeneous {@link ExpandableListView}s.
30 * </p>
31 * Lists that contain different types of group and/or child item views, should use an adapter that
32 * implements this interface. This way, the recycled views that will be provided to
33 * {@link android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup)}
34 * and
35 * {@link android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup)}
36 * will be of the appropriate group or child type, resulting in a more efficient reuse of the
37 * previously created views.
38 */
39public interface HeterogeneousExpandableList {
40    /**
41     * Get the type of group View that will be created by
42     * {@link android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup)}
43     * . for the specified group item.
44     *
45     * @param groupPosition the position of the group for which the type should be returned.
46     * @return An integer representing the type of group View. Two group views should share the same
47     *         type if one can be converted to the other in
48     *         {@link android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup)}
49     *         . Note: Integers must be in the range 0 to {@link #getGroupTypeCount} - 1.
50     *         {@link android.widget.Adapter#IGNORE_ITEM_VIEW_TYPE} can also be returned.
51     * @see android.widget.Adapter#IGNORE_ITEM_VIEW_TYPE
52     * @see #getGroupTypeCount()
53     */
54    int getGroupType(int groupPosition);
55
56    /**
57     * Get the type of child View that will be created by
58     * {@link android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup)}
59     * for the specified child item.
60     *
61     * @param groupPosition the position of the group that the child resides in
62     * @param childPosition the position of the child with respect to other children in the group
63     * @return An integer representing the type of child View. Two child views should share the same
64     *         type if one can be converted to the other in
65     *         {@link android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup)}
66     *         Note: Integers must be in the range 0 to {@link #getChildTypeCount} - 1.
67     *         {@link android.widget.Adapter#IGNORE_ITEM_VIEW_TYPE} can also be returned.
68     * @see android.widget.Adapter#IGNORE_ITEM_VIEW_TYPE
69     * @see #getChildTypeCount()
70     */
71    int getChildType(int groupPosition, int childPosition);
72
73    /**
74     * <p>
75     * Returns the number of types of group Views that will be created by
76     * {@link android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup)}
77     * . Each type represents a set of views that can be converted in
78     * {@link android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup)}
79     * . If the adapter always returns the same type of View for all group items, this method should
80     * return 1.
81     * </p>
82     * This method will only be called when the adapter is set on the {@link AdapterView}.
83     *
84     * @return The number of types of group Views that will be created by this adapter.
85     * @see #getChildTypeCount()
86     * @see #getGroupType(int)
87     */
88    int getGroupTypeCount();
89
90    /**
91     * <p>
92     * Returns the number of types of child Views that will be created by
93     * {@link android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup)}
94     * . Each type represents a set of views that can be converted in
95     * {@link android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup)}
96     * , for any group. If the adapter always returns the same type of View for
97     * all child items, this method should return 1.
98     * </p>
99     * This method will only be called when the adapter is set on the {@link AdapterView}.
100     *
101     * @return The total number of types of child Views that will be created by this adapter.
102     * @see #getGroupTypeCount()
103     * @see #getChildType(int, int)
104     */
105    int getChildTypeCount();
106}
107