Android: ListView position and DatePicker

Question

I have onItemClickListener for the ListView that opens DatePicker dialog when an item is clicked:

list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        showDatePickerDialog(view);
    }
});

public void showDatePickerDialog(View v) {
    DialogFragment newFragment = new DatePickerFragment();
    newFragment.show(getFragmentManager(), "datePicker");
}

After date in DatePicker gets set, I have onDateSet method which I want to use to update database and set date for item that was clicked in ListView:

public void onDateSet(DatePicker view, int year, int month, int day) {
    ...
    dataSource.updateDate(adapter.getItemId(position), month + "/" + day + "/" + year);
    ...
} 

How can I pass ListView position of the item that was clicked to onDateSet so that my database helper knows which record to update?

---

EDIT: Here's the DatePickerFragment class:

public static class DatePickerFragment extends DialogFragment
        implements DatePickerDialog.OnDateSetListener {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        // Use the current date as the default date in the picker
        final Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        // Create a new instance of DatePickerDialog and return it
        return new DatePickerDialog(getActivity(), this, year, month, day);
    }

    public void onDateSet(DatePicker view, int year, int month, int day) {
        ...
        dataSource.updateDate(adapter.getItemId(position), month + "/" + day + "/" + year);
        ...
    }
}

Thanks!

Answer 1

Send the position to DatePickerFragment - I guess this is a class of your own. Send this parameter through arguments (as this is a best practice to protect your code in fragment recreations):

public class DatePickerFragment extends Fragment {

    private DatePickerListener datePickerListener;
    private int listPosition = -1;
    private static final String POSITION_ARG_KEY = "POSITION_ARG_KEY";

    public static DatePickerFragment newInstance(int position) {
        DatePickerFragment fragment = new DatePickerFragment();
        Bundle args = new Bundle();
        args.putInt(POSITION_ARG_KEY, position);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Bundle args = getArguments();
        if (args != null) {
            listPosition = args.getInt(POSITION_ARG_KEY);
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        if (activity instanceof DatePickerListener) {
            datePickerListener = (DatePickerListener) activity;
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        datePickerListener = null;
    }

    public void methodThatCallsActivity() {
        if(datePickerListener) {
            datePickerListener.onDateSet(datePicker, year, month, day, this.listPosition);
        }
    }

    // / the rest of the code

    public static interface DatePickerListener {
        public void onDateSet(DatePicker view, int year, int month, int day, int listPosition);
    }
}

Then in the activity that displays the fragment, (it must implement DatePickerListener):

A. send the list position:

public void showDatePickerDialog(int listPosition) {
    DialogFragment newFragment = DatePickerFragment.newInstance(listPosition);
    newFragment.show(getFragmentManager(), "datePicker");
}

B. call this method from list item click:

list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        showDatePickerDialog(position);
    }
});

C. You have the list position in onDateSet implementation:

public void onDateSet(DatePicker view, int year, int month, int day, int listPosition) {
    // your relevant code
}

To brief: send the list position through arguments and parameters from listview to fragment and from there to parent activity.