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 17 package android.widget; 18 19 import android.view.View; 20 import 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 */ 39 public 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
