ExpandableListView and checkboxes

Question

I am writing a simple filter in Android and want to use ExpandableListAdapterwith checkboxes.

I have no problem creating a list or checking a checkbox. but I really don’t know how to remember the choice. After closing a group and opening again or when I try to open different group flags, these are changes.

I tried to read about it on the net, but I did not find how to solve my problem.

Here is my code:

public class TasksFilterDialog extends Dialog{

private static final String TAG = "Filter Dialog";
private static final String ChildID = "ChildID";
private static final String GroupID = "GroupID";

private boolean[] statusCheck;

ExpandableListView list;
SimpleExpandableListAdapter listAdapter;

public TasksFilterDialog(Context context) {
    super(context);
    statusCheck = new boolean[Tasks.Status.values().length];
    for(int i=0; i<statusCheck.length; i++)
        statusCheck[i]=true;
}


@Override
protected void onCreate(Bundle savedInstanceState) {
    Log.d(TAG, "Creating dialog");
    this.setContentView(R.layout.tasks_filter);
    list = (ExpandableListView)findViewById(R.id.filter_list);
    setListAdapter();                       // Setting Adapter Values to use on list
    list.setAdapter(listAdapter);           // Setting creating adapter to list
    setOnChildClickListeners();         


    Log.d(TAG, "Creating dialog successfull");
}


private void setListAdapter() {
    Log.d(TAG, "Setting list adapter");
    listAdapter = new SimpleExpandableListAdapter(this.getContext(), 
            getGroups(), 
            R.layout.tasks_filter_groups_layout,  
            new String[] {GroupID}, 
            new int[] {R.id.filter_group_text}, 
            getChilds(), 
            R.layout.tasks_filter_simple_element, 
            new String[] {ChildID}, 
            new int[] {R.id.filter_simple_element_text});

    Log.d(TAG, "Setting list adapter successfull");
}

private List<HashMap<String, String>> getGroups() {
    Log.d(TAG, "Adding groups values");
    List<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
    HashMap<String, String> statusMap = new HashMap<String, String>();
    statusMap.put(GroupID, "Status");
    list.add(statusMap);
    HashMap<String, String> usersMap = new HashMap<String, String>();
    usersMap.put(GroupID, "Users");
    list.add(usersMap);
    Log.d(TAG, "Adding groups values successfull");
    return list;
}

private List<List<HashMap<String, String>>> getChilds() {
    Log.d(TAG, "Adding childs values");
    List<List<HashMap<String, String>>> list = new ArrayList<List<HashMap<String, String>>>();
    List<HashMap<String, String>> secList = new ArrayList<HashMap<String, String>>();
    HashMap<String, String> map;
    Tasks.Status status[] = Tasks.Status.values();
    for(int i=0; i<status.length; i++) {
        Log.d(TAG, "Adding child" + status[i].toString());
        map = new HashMap<String, String>();
        map.put(ChildID, status[i].toString());
        secList.add(map);
    }
    list.add(secList);
    list.add(secList);
    Log.d(TAG, "Adding childs values succesfull");
    return list;
}

private void setOnChildClickListeners() {
    list.setOnChildClickListener(new OnChildClickListener() {

        @Override
        public boolean onChildClick(ExpandableListView list, View v,
                int group, int id, long arg4) {
            CheckBox cb = (CheckBox) v.findViewById(R.id.filter_simple_element_check);
            cb.toggle();
            switch(group){
            case 0:
                if(statusCheck[id])
                    statusCheck[id]=false;
                else
                    statusCheck[id]=true;
                break;
            case 1:
                //TODO After getting Tasks function

            }
            return false;
        }

    });

}

}

Answer 1

It depends on how much you want to design it. Map> will work. The card takes a position and gives you a set of trusted children. To determine if the child is checked or not, call Map.get () in the group, and then see if the set contains the identifier of the child.

, , :

boolean isChecked = yourMap.get(3).contains(2);

checked:

yourMap.get(groupNum).add(childNum);

:

yourMap.get(groupNum).remove(childNum);

, , NPE, , . , , , .