JSONExpandableListAdapter.java

/***
  Copyright (c) 2012 CommonsWare, LLC
  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.
  
  Covered in detail in the book _The Busy Coder's Guide to Android Development_
    https://commonsware.com/Android
 */

package com.commonsware.android.wc.elv;

import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
import java.util.Iterator;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class JSONExpandableListAdapter extends
    BaseExpandableListAdapter {
  LayoutInflater inflater=null;
  JSONObject model=null;

  JSONExpandableListAdapter(LayoutInflater inflater, JSONObject model) {
    this.inflater=inflater;
    this.model=model;
  }

  @Override
  public int getGroupCount() {
    return(model.length());
  }

  @Override
  public Object getGroup(int groupPosition) {
    @SuppressWarnings("rawtypes")
    Iterator i=model.keys();

    while (groupPosition > 0) {
      i.next();
      groupPosition--;
    }

    return(i.next());
  }

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

  @Override
  public View getGroupView(int groupPosition, boolean isExpanded,
                           View convertView, ViewGroup parent) {
    if (convertView == null) {
      convertView=
          inflater.inflate(android.R.layout.simple_expandable_list_item_1,
                           parent, false);
    }

    TextView tv=
        ((TextView)convertView.findViewById(android.R.id.text1));
    tv.setText(getGroup(groupPosition).toString());

    return(convertView);
  }

  @Override
  public int getChildrenCount(int groupPosition) {
    try {
      JSONArray children=getChildren(groupPosition);

      return(children.length());
    }
    catch (JSONException e) {
      // JSONArray is really annoying
      Log.e(getClass().getSimpleName(), "Exception getting children", e);
    }

    return(0);
  }

  @Override
  public Object getChild(int groupPosition, int childPosition) {
    try {
      JSONArray children=getChildren(groupPosition);

      return(children.get(childPosition));
    }
    catch (JSONException e) {
      // JSONArray is really annoying
      Log.e(getClass().getSimpleName(),
            "Exception getting item from JSON array", e);
    }

    return(null);
  }

  @Override
  public long getChildId(int groupPosition, int childPosition) {
    return(groupPosition * 1024 + childPosition);
  }

  @Override
  public View getChildView(int groupPosition, int childPosition,
                           boolean isLastChild, View convertView,
                           ViewGroup parent) {
    if (convertView == null) {
      convertView=
          inflater.inflate(android.R.layout.simple_list_item_1, parent,
                           false);
    }

    TextView tv=(TextView)convertView;
    tv.setText(getChild(groupPosition, childPosition).toString());

    return(convertView);
  }

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

  @Override
  public boolean hasStableIds() {
    return(true);
  }

  private JSONArray getChildren(int groupPosition) throws JSONException {
    String key=getGroup(groupPosition).toString();

    return(model.getJSONArray(key));
  }
}