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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.widget;
import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;
/**
* An adapter that links a {@link ExpandableListView} with the underlying
* data. The implementation of this interface will provide access
* to the data of the children (categorized by groups), and also instantiate
* {@link View}s for children and groups.
*/
public interface ExpandableListAdapter {
/**
* @see Adapter#registerDataSetObserver(DataSetObserver)
*/
void registerDataSetObserver(DataSetObserver observer);
/**
* @see Adapter#unregisterDataSetObserver(DataSetObserver)
*/
void unregisterDataSetObserver(DataSetObserver observer);
/**
* Gets the number of groups.
*
* @return the number of groups
*/
int getGroupCount();
/**
* Gets the number of children in a specified group.
*
* @param groupPosition the position of the group for which the children
* count should be returned
* @return the children count in the specified group
*/
int getChildrenCount(int groupPosition);
/**
* Gets the data associated with the given group.
*
* @param groupPosition the position of the group
* @return the data child for the specified group
*/
Object getGroup(int groupPosition);
/**
* Gets the data associated with the given child within the given group.
*
* @param groupPosition the position of the group that the child resides in
* @param childPosition the position of the child with respect to other
* children in the group
* @return the data of the child
*/
Object getChild(int groupPosition, int childPosition);
/**
* Gets the ID for the group at the given position. This group ID must be
* unique across groups. The combined ID (see
* {@link #getCombinedGroupId(long)}) must be unique across ALL items
* (groups and all children).
*
* @param groupPosition the position of the group for which the ID is wanted
* @return the ID associated with the group
*/
long getGroupId(int groupPosition);
/**
* Gets the ID for the given child within the given group. This ID must be
* unique across all children within the group. The combined ID (see
* {@link #getCombinedChildId(long, long)}) must be unique across ALL items
* (groups and all children).
*
* @param groupPosition the position of the group that contains the child
* @param childPosition the position of the child within the group for which
* the ID is wanted
* @return the ID associated with the child
*/
long getChildId(int groupPosition, int childPosition);
/**
* Indicates whether the child and group IDs are stable across changes to the
* underlying data.
*
* @return whether or not the same ID always refers to the same object
* @see Adapter#hasStableIds()
*/
boolean hasStableIds();
/**
* Gets a View that displays the given group. This View is only for the
* group--the Views for the group's children will be fetched using
* {@link #getChildView(int, int, boolean, View, ViewGroup)}.
*
* @param groupPosition the position of the group for which the View is
* returned
* @param isExpanded whether the group is expanded or collapsed
* @param convertView the old view to reuse, if possible. You should check
* that this view is non-null and of an appropriate type before
* using. If it is not possible to convert this view to display
* the correct data, this method can create a new view. It is not
* guaranteed that the convertView will have been previously
* created by
* {@link #getGroupView(int, boolean, View, ViewGroup)}.
* @param parent the parent that this view will eventually be attached to
* @return the View corresponding to the group at the specified position
*/
View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent);
/**
* Gets a View that displays the data for the given child within the given
* group.
*
* @param groupPosition the position of the group that contains the child
* @param childPosition the position of the child (for which the View is
* returned) within the group
* @param isLastChild Whether the child is the last child within the group
* @param convertView the old view to reuse, if possible. You should check
* that this view is non-null and of an appropriate type before
* using. If it is not possible to convert this view to display
* the correct data, this method can create a new view. It is not
* guaranteed that the convertView will have been previously
* created by
* {@link #getChildView(int, int, boolean, View, ViewGroup)}.
* @param parent the parent that this view will eventually be attached to
* @return the View corresponding to the child at the specified position
*/
View getChildView(int groupPosition, int childPosition, boolean isLastChild,
View convertView, ViewGroup parent);
/**
* Whether the child at the specified position is selectable.
*
* @param groupPosition the position of the group that contains the child
* @param childPosition the position of the child within the group
* @return whether the child is selectable.
*/
boolean isChildSelectable(int groupPosition, int childPosition);
/**
* @see ListAdapter#areAllItemsEnabled()
*/
boolean areAllItemsEnabled();
/**
* @see ListAdapter#isEmpty()
*/
boolean isEmpty();
/**
* Called when a group is expanded.
*
* @param groupPosition The group being expanded.
*/
void onGroupExpanded(int groupPosition);
/**
* Called when a group is collapsed.
*
* @param groupPosition The group being collapsed.
*/
void onGroupCollapsed(int groupPosition);
/**
* Gets an ID for a child that is unique across any item (either group or
* child) that is in this list. Expandable lists require each item (group or
* child) to have a unique ID among all children and groups in the list.
* This method is responsible for returning that unique ID given a child's
* ID and its group's ID. Furthermore, if {@link #hasStableIds()} is true, the
* returned ID must be stable as well.
*
* @param groupId The ID of the group that contains this child.
* @param childId The ID of the child.
* @return The unique (and possibly stable) ID of the child across all
* groups and children in this list.
*/
long getCombinedChildId(long groupId, long childId);
/**
* Gets an ID for a group that is unique across any item (either group or
* child) that is in this list. Expandable lists require each item (group or
* child) to have a unique ID among all children and groups in the list.
* This method is responsible for returning that unique ID given a group's
* ID. Furthermore, if {@link #hasStableIds()} is true, the returned ID must be
* stable as well.
*
* @param groupId The ID of the group
* @return The unique (and possibly stable) ID of the group across all
* groups and children in this list.
*/
long getCombinedGroupId(long groupId);
}