Using result from DialogFragment to update database via Gridview OnItemClickListener

Question

I have a Gridview with some times, which are pulled from a database. The Gridview is populated with Textviews (which show the times), which are tagged with the necessary information (ROW ID etc) to make changes to that time in the database. I have set an OnItemClickListener for the Gridview, which will load a TimePickerDialog via a DialogFragment.

        // When items on the grid are pressed:
    gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v,
                                int position, long id) {
            String type = (String) (v.getTag(R.id.VIEW_TAG_TIMEENTRY_TYPE));
            String direction = (String) (v.getTag(R.id.VIEW_TAG_TIMEENTRY_DIRECTION));
            long row_id = (long) v.getTag(R.id.VIEW_TAG_TIMEENTRY_ID);

            // If entry doesn't exist
            if (row_id < 0) {
                DialogFragment dialogFragment = new TimePickerFragment();

                // Tell the dialogFragment what to do when set......

                dialogFragment.show(getSupportFragmentManager(), "timePicker");


            }
        }
    });

The TimePickerFragment class is as follows:

public class TimePickerFragment extends DialogFragment
    implements TimePickerDialog.OnTimeSetListener {


@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    // Use the current time as the default values for the picker
    final Calendar c = Calendar.getInstance();
    int hour = c.get(Calendar.HOUR_OF_DAY);
    int minute = c.get(Calendar.MINUTE);

    // Create a new instance of TimePickerDialog and return it
    return new TimePickerDialog(getActivity(), this, hour, minute,
            DateFormat.is24HourFormat(getActivity()));
}

public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
    // Do something with the time chosen by the user

}

In most of the examples I've seen, they just do something simple in the onTimeSet function, like update a specific textview. However I want the action taken to be a database add or update to the row corresponding to the textview that was clicked.

In C++ I would probably have passed a function that calls the update method in the ContentProvider as an argument to the constructor of this class, but I don't know the equivalent design pattern for Java.

One answer has mentioned an 'interface' might be the way to go, but I'm not sure how to implement this. (Results from a DialogFragment to an ActivityFragment)

Another answer mentioned using the setTargetFragment method, but the calling class is an activity in this case, so I can't do it. (Receive result from DialogFragment)

How should I best solve this design requirement? I've been wracking my android-app newbie brain quite a while.

Many thanks

Melvin Mauricio · Accepted Answer · 2015-07-25T07:47:14.853

0

can you try this...

1 . On you TimePickerFragment..

declare this

public TimeListener listener;

public static abstract class TimeListener {
    public abstract void onTime(); // add parameters if you like
}

on your on onTimeSet

public void onTimeSet(TimePicker view, int hourOfDay, int minute) {

    if(listener!=null)
         listener.onTime();

}

Instantiate your dialog fragment something like this

TimePickerFragment tm = new TimePickerFragment();

tm.listener = new TimePickerFragment.TimeListener(){
```
 @Override
 public void onTime(){

     //do something here

 }
```
}

edited Jul 25 '15 at 07:47

answered Jul 25 '15 at 06:43

Melvin Mauricio

387
1
6

OK, however it says not to declare a non-empty constructor for DialogFragment, I think something to do with the create and destroy process. It says to use setArguments and getArguments functions instead, but the getArguments function does not have a getInterface method. – Jul 25 '15 at 07:20

Using result from DialogFragment to update database via Gridview OnItemClickListener

1 Answers1