Custom ExpandableListView: different text colors on parent and children based on parameter

Question

I would like to create a custom ExpandableListView as follows.

I am developing a simple quiz game application.

At the end of the game, I want to show the questions and their answers in an ExpandableListView (each question is a parent, clicking on a question opens its children that are the answers for that question).

Questions and answers have to be in different colors (and in future, possibly different layouts with different images, etc.): RED for wrong answered questions and wrong chosen answers, GREEN for correct answered questions and correct chosen answers, BLACK for wrong answers the user did not choose.

To do that, I created a simple custom class.

public class MyListItem {   
// the text of the item, that can either be a question or an answer
public String text;

// 0 = not chosen and wrong (BLACK)
// 1 = correct (GREEN)
// 2 = wrong (RED)
public int textColor = 0;
}

Then, I created a class for the ExpandableListAdapater

public class MyExpandableListAdapter extends BaseExpandableListAdapter { ... }

which I call from my application class

    [...]
    private HashMap<MyListItem, ArrayList<MyListItem>> listOfGameAnswers;
    listAdapter = new MyExpandableListAdapter(this, listOfGameAnswers);
    [...]

However, I cannot make the MyExpandableListAdapter work (I can provide code if needed).

Is my approach correct or must the MyExpandableListAdapter have in input something like

Map < String, list of something else > ?

Is there a better method to implement it?

P.S.: I referred to this discussion for changing the text color How to change text color in some headers in Expandable List

Thanks a lot

UPDATE: SOLUTION

I accepted the solution below because it is simple and should work well.

Anyway I managed to fix my code as well, as follows:

@Override
public Object getGroup(int groupPosition) {

    ArrayList<MyListItem> myKeyList = new ArrayList<MyListItem>(listOfQuestions.keySet());

    return myKeyList.get(groupPosition);
}


@Override
public Object getChild(int groupPosition, int childPosition) {

    // get KEY
    MyListItem t = (MyListItem) getGroup(groupPosition);

    //get arraylist of my elements from key (which is an element!)
    ArrayList<MyListItem> mylist =  this.listOfQuestions.get(t);

    // return child
    return mylist.get(childPosition);

}

Answer 1

//base class that holds data
public class QuestionWithAnswers {  
  public String question;
  public int rightAnswer = 0;
  List<String> answers = new ArrayList(4);

  public QuestionWithAnswers(String question, int rightAnswer, List<String> answers) {
     this.question = question;
     this.rightAnswer = rightAnswer;
     this.answers.addAll(answers);     
  }

  public QuestionWithAnwsers(String question, int rightAnswer, String answers) {
     this.question = question;
     this.rightAnswer = rightAnswer;
     this.answers.addAll(Arrays.asList(answers));     
  } 
}

Then in your adapter:

public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    final Context context;
    final List<QuestionWithAnswers> data;
    public MyExpandableListAdapter(Context context, List<QuestionWithAnswers> data) {
        this.context = context;
        this.data = data;
    }

    @Override
    public int getGroupCount() {
        return data.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return data.get(groupPosition).answers.size();
    }

    @Override
    public QuestionWithAnswers getGroup(int groupPosition) {
        return data.get(groupPosition);
    }

    @Override
    public String getChild(int groupPosition, int childPosition) {
        return data.get(groupPosition).answers.get(childPosition);
    }

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

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

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

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        //processing views
        return SomeView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        //processing views
        int rightAnswer = data.get(groupPosition).rightAnswer;
        if (childPosition == rightAnswer){
            textViewWithAnswer.setTextColor(Color.GREEN);
        } else {
            textViewWithAnswer.setTextColor(Color.RED);
        }
        return SomeView;
    }

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

implement getGroupView and getChildView methods