/*
 * Copyright (C) 2006 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.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;
import java.util.Map;

An easy adapter to map static data to group and child views defined in an XML
file. You can separately specify the data backing the group as a List of
Maps. Each entry in the ArrayList corresponds to one group in the expandable
list. The Maps contain the data for each row. You also specify an XML file
that defines the views used to display a group, and a mapping from keys in
the Map to specific views. This process is similar for a child, except it is
one-level deeper so the data backing is specified as a List>,
where the first List corresponds to the group of the child, the second List
corresponds to the position of the child within the group, and finally the
Map holds the data for that particular child.
/**
 * An easy adapter to map static data to group and child views defined in an XML
 * file. You can separately specify the data backing the group as a List of
 * Maps. Each entry in the ArrayList corresponds to one group in the expandable
 * list. The Maps contain the data for each row. You also specify an XML file
 * that defines the views used to display a group, and a mapping from keys in
 * the Map to specific views. This process is similar for a child, except it is
 * one-level deeper so the data backing is specified as a List<List<Map>>,
 * where the first List corresponds to the group of the child, the second List
 * corresponds to the position of the child within the group, and finally the
 * Map holds the data for that particular child.
 */
public class SimpleExpandableListAdapter extends BaseExpandableListAdapter {
    private List<? extends Map<String, ?>> mGroupData;
    private int mExpandedGroupLayout;
    private int mCollapsedGroupLayout;
    private String[] mGroupFrom;
    private int[] mGroupTo;

    private List<? extends List<? extends Map<String, ?>>> mChildData;
    private int mChildLayout;
    private int mLastChildLayout;
    private String[] mChildFrom;
    private int[] mChildTo;

    private LayoutInflater mInflater;

    
Constructor
Params:
context – The context where the ExpandableListView associated with this SimpleExpandableListAdapter is running
groupData – A List of Maps. Each entry in the List corresponds to
           one group in the list. The Maps contain the data for each
           group, and should include all the entries specified in
           "groupFrom"
groupFrom – A list of keys that will be fetched from the Map
           associated with each group.
groupTo – The group views that should display column in the
           "groupFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the groupFrom parameter.
groupLayout – resource identifier of a view layout that defines the
           views for a group. The layout file should include at least
           those named views defined in "groupTo"
childData – A List of List of Maps. Each entry in the outer List
           corresponds to a group (index by group position), each entry
           in the inner List corresponds to a child within the group
           (index by child position), and the Map corresponds to the data
           for a child (index by values in the childFrom array). The Map
           contains the data for each child, and should include all the
           entries specified in "childFrom"
childFrom – A list of keys that will be fetched from the Map
           associated with each child.
childTo – The child views that should display column in the
           "childFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the childFrom parameter.
childLayout – resource identifier of a view layout that defines the
           views for a child. The layout file should include at least
           those named views defined in "childTo"/**
     * Constructor
     *
     * @param context The context where the {@link ExpandableListView}
     *            associated with this {@link SimpleExpandableListAdapter} is
     *            running
     * @param groupData A List of Maps. Each entry in the List corresponds to
     *            one group in the list. The Maps contain the data for each
     *            group, and should include all the entries specified in
     *            "groupFrom"
     * @param groupFrom A list of keys that will be fetched from the Map
     *            associated with each group.
     * @param groupTo The group views that should display column in the
     *            "groupFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the groupFrom parameter.
     * @param groupLayout resource identifier of a view layout that defines the
     *            views for a group. The layout file should include at least
     *            those named views defined in "groupTo"
     * @param childData A List of List of Maps. Each entry in the outer List
     *            corresponds to a group (index by group position), each entry
     *            in the inner List corresponds to a child within the group
     *            (index by child position), and the Map corresponds to the data
     *            for a child (index by values in the childFrom array). The Map
     *            contains the data for each child, and should include all the
     *            entries specified in "childFrom"
     * @param childFrom A list of keys that will be fetched from the Map
     *            associated with each child.
     * @param childTo The child views that should display column in the
     *            "childFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the childFrom parameter.
     * @param childLayout resource identifier of a view layout that defines the
     *            views for a child. The layout file should include at least
     *            those named views defined in "childTo"
     */
    public SimpleExpandableListAdapter(Context context,
            List<? extends Map<String, ?>> groupData, int groupLayout,
            String[] groupFrom, int[] groupTo,
            List<? extends List<? extends Map<String, ?>>> childData,
            int childLayout, String[] childFrom, int[] childTo) {
        this(context, groupData, groupLayout, groupLayout, groupFrom, groupTo, childData,
                childLayout, childLayout, childFrom, childTo);
    }

    
Constructor
Params:
context – The context where the ExpandableListView associated with this SimpleExpandableListAdapter is running
groupData – A List of Maps. Each entry in the List corresponds to
           one group in the list. The Maps contain the data for each
           group, and should include all the entries specified in
           "groupFrom"
groupFrom – A list of keys that will be fetched from the Map
           associated with each group.
groupTo – The group views that should display column in the
           "groupFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the groupFrom parameter.
expandedGroupLayout – resource identifier of a view layout that
           defines the views for an expanded group. The layout file
           should include at least those named views defined in "groupTo"
collapsedGroupLayout – resource identifier of a view layout that
           defines the views for a collapsed group. The layout file
           should include at least those named views defined in "groupTo"
childData – A List of List of Maps. Each entry in the outer List
           corresponds to a group (index by group position), each entry
           in the inner List corresponds to a child within the group
           (index by child position), and the Map corresponds to the data
           for a child (index by values in the childFrom array). The Map
           contains the data for each child, and should include all the
           entries specified in "childFrom"
childFrom – A list of keys that will be fetched from the Map
           associated with each child.
childTo – The child views that should display column in the
           "childFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the childFrom parameter.
childLayout – resource identifier of a view layout that defines the
           views for a child. The layout file should include at least
           those named views defined in "childTo"/**
     * Constructor
     *
     * @param context The context where the {@link ExpandableListView}
     *            associated with this {@link SimpleExpandableListAdapter} is
     *            running
     * @param groupData A List of Maps. Each entry in the List corresponds to
     *            one group in the list. The Maps contain the data for each
     *            group, and should include all the entries specified in
     *            "groupFrom"
     * @param groupFrom A list of keys that will be fetched from the Map
     *            associated with each group.
     * @param groupTo The group views that should display column in the
     *            "groupFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the groupFrom parameter.
     * @param expandedGroupLayout resource identifier of a view layout that
     *            defines the views for an expanded group. The layout file
     *            should include at least those named views defined in "groupTo"
     * @param collapsedGroupLayout resource identifier of a view layout that
     *            defines the views for a collapsed group. The layout file
     *            should include at least those named views defined in "groupTo"
     * @param childData A List of List of Maps. Each entry in the outer List
     *            corresponds to a group (index by group position), each entry
     *            in the inner List corresponds to a child within the group
     *            (index by child position), and the Map corresponds to the data
     *            for a child (index by values in the childFrom array). The Map
     *            contains the data for each child, and should include all the
     *            entries specified in "childFrom"
     * @param childFrom A list of keys that will be fetched from the Map
     *            associated with each child.
     * @param childTo The child views that should display column in the
     *            "childFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the childFrom parameter.
     * @param childLayout resource identifier of a view layout that defines the
     *            views for a child. The layout file should include at least
     *            those named views defined in "childTo"
     */
    public SimpleExpandableListAdapter(Context context,
            List<? extends Map<String, ?>> groupData, int expandedGroupLayout,
            int collapsedGroupLayout, String[] groupFrom, int[] groupTo,
            List<? extends List<? extends Map<String, ?>>> childData,
            int childLayout, String[] childFrom, int[] childTo) {
        this(context, groupData, expandedGroupLayout, collapsedGroupLayout,
                groupFrom, groupTo, childData, childLayout, childLayout,
                childFrom, childTo);
    }

    
Constructor
Params:
context – The context where the ExpandableListView associated with this SimpleExpandableListAdapter is running
groupData – A List of Maps. Each entry in the List corresponds to
           one group in the list. The Maps contain the data for each
           group, and should include all the entries specified in
           "groupFrom"
groupFrom – A list of keys that will be fetched from the Map
           associated with each group.
groupTo – The group views that should display column in the
           "groupFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the groupFrom parameter.
expandedGroupLayout – resource identifier of a view layout that
           defines the views for an expanded group. The layout file
           should include at least those named views defined in "groupTo"
collapsedGroupLayout – resource identifier of a view layout that
           defines the views for a collapsed group. The layout file
           should include at least those named views defined in "groupTo"
childData – A List of List of Maps. Each entry in the outer List
           corresponds to a group (index by group position), each entry
           in the inner List corresponds to a child within the group
           (index by child position), and the Map corresponds to the data
           for a child (index by values in the childFrom array). The Map
           contains the data for each child, and should include all the
           entries specified in "childFrom"
childFrom – A list of keys that will be fetched from the Map
           associated with each child.
childTo – The child views that should display column in the
           "childFrom" parameter. These should all be TextViews. The
           first N views in this list are given the values of the first N
           columns in the childFrom parameter.
childLayout – resource identifier of a view layout that defines the
           views for a child (unless it is the last child within a group,
           in which case the lastChildLayout is used). The layout file
           should include at least those named views defined in "childTo"
lastChildLayout – resource identifier of a view layout that defines
           the views for the last child within each group. The layout
           file should include at least those named views defined in
           "childTo"/**
     * Constructor
     *
     * @param context The context where the {@link ExpandableListView}
     *            associated with this {@link SimpleExpandableListAdapter} is
     *            running
     * @param groupData A List of Maps. Each entry in the List corresponds to
     *            one group in the list. The Maps contain the data for each
     *            group, and should include all the entries specified in
     *            "groupFrom"
     * @param groupFrom A list of keys that will be fetched from the Map
     *            associated with each group.
     * @param groupTo The group views that should display column in the
     *            "groupFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the groupFrom parameter.
     * @param expandedGroupLayout resource identifier of a view layout that
     *            defines the views for an expanded group. The layout file
     *            should include at least those named views defined in "groupTo"
     * @param collapsedGroupLayout resource identifier of a view layout that
     *            defines the views for a collapsed group. The layout file
     *            should include at least those named views defined in "groupTo"
     * @param childData A List of List of Maps. Each entry in the outer List
     *            corresponds to a group (index by group position), each entry
     *            in the inner List corresponds to a child within the group
     *            (index by child position), and the Map corresponds to the data
     *            for a child (index by values in the childFrom array). The Map
     *            contains the data for each child, and should include all the
     *            entries specified in "childFrom"
     * @param childFrom A list of keys that will be fetched from the Map
     *            associated with each child.
     * @param childTo The child views that should display column in the
     *            "childFrom" parameter. These should all be TextViews. The
     *            first N views in this list are given the values of the first N
     *            columns in the childFrom parameter.
     * @param childLayout resource identifier of a view layout that defines the
     *            views for a child (unless it is the last child within a group,
     *            in which case the lastChildLayout is used). The layout file
     *            should include at least those named views defined in "childTo"
     * @param lastChildLayout resource identifier of a view layout that defines
     *            the views for the last child within each group. The layout
     *            file should include at least those named views defined in
     *            "childTo"
     */
    public SimpleExpandableListAdapter(Context context,
            List<? extends Map<String, ?>> groupData, int expandedGroupLayout,
            int collapsedGroupLayout, String[] groupFrom, int[] groupTo,
            List<? extends List<? extends Map<String, ?>>> childData,
            int childLayout, int lastChildLayout, String[] childFrom,
            int[] childTo) {
        mGroupData = groupData;
        mExpandedGroupLayout = expandedGroupLayout;
        mCollapsedGroupLayout = collapsedGroupLayout;
        mGroupFrom = groupFrom;
        mGroupTo = groupTo;

        mChildData = childData;
        mChildLayout = childLayout;
        mLastChildLayout = lastChildLayout;
        mChildFrom = childFrom;
        mChildTo = childTo;

        mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    public Object getChild(int groupPosition, int childPosition) {
        return mChildData.get(groupPosition).get(childPosition);
    }

    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
            View convertView, ViewGroup parent) {
        View v;
        if (convertView == null) {
            v = newChildView(isLastChild, parent);
        } else {
            v = convertView;
        }
        bindView(v, mChildData.get(groupPosition).get(childPosition), mChildFrom, mChildTo);
        return v;
    }

    
Instantiates a new View for a child.
Params:
isLastChild – Whether the child is the last child within its group.
parent – The eventual parent of this new View.
Returns:
A new child View/**
     * Instantiates a new View for a child.
     * @param isLastChild Whether the child is the last child within its group.
     * @param parent The eventual parent of this new View.
     * @return A new child View
     */
    public View newChildView(boolean isLastChild, ViewGroup parent) {
        return mInflater.inflate((isLastChild) ? mLastChildLayout : mChildLayout, parent, false);
    }

    private void bindView(View view, Map<String, ?> data, String[] from, int[] to) {
        int len = to.length;

        for (int i = 0; i < len; i++) {
            TextView v = (TextView)view.findViewById(to[i]);
            if (v != null) {
                v.setText((String)data.get(from[i]));
            }
        }
    }

    public int getChildrenCount(int groupPosition) {
        return mChildData.get(groupPosition).size();
    }

    public Object getGroup(int groupPosition) {
        return mGroupData.get(groupPosition);
    }

    public int getGroupCount() {
        return mGroupData.size();
    }

    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
            ViewGroup parent) {
        View v;
        if (convertView == null) {
            v = newGroupView(isExpanded, parent);
        } else {
            v = convertView;
        }
        bindView(v, mGroupData.get(groupPosition), mGroupFrom, mGroupTo);
        return v;
    }

    
Instantiates a new View for a group.
Params:
isExpanded – Whether the group is currently expanded.
parent – The eventual parent of this new View.
Returns:
A new group View/**
     * Instantiates a new View for a group.
     * @param isExpanded Whether the group is currently expanded.
     * @param parent The eventual parent of this new View.
     * @return A new group View
     */
    public View newGroupView(boolean isExpanded, ViewGroup parent) {
        return mInflater.inflate((isExpanded) ? mExpandedGroupLayout : mCollapsedGroupLayout,
                parent, false);
    }

    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }

    public boolean hasStableIds() {
        return true;
    }

}