Update UI from fragment

Question

I have a fragment that gets data from a DialogFragment via intent with onActivityResult(...);

I am trying to update the fragment's UI but runOnUiThread does not work.

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    ArrayList<Farm> farms = data.getParcelableArrayListExtra("farms_list");
    float totalArea = 0;
    for(Farm farm : farms) {
        if (farm.isSelected()) {
            Log.d("farm", farm.getName());
            totalArea += farm.getArea();
        }
    }
    final float finalTotalArea = totalArea;
    activity.runOnUiThread(new Runnable() {
        @Override
        public void run() {
            area.setText(String.valueOf(finalTotalArea));
        }
    });
}

The area TextView does not update.

I get the reference to the activity with onAttach() method.

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (!(context instanceof PageFragmentCallbacks)) {
        throw new ClassCastException(
                "Activity must implement PageFragmentCallbacks");
    }

    mCallbacks = (PageFragmentCallbacks) context;
    this.activity = (Activity) context;
}

You should use `getActivity.runOnUiThread(new Runnable() {`. — Jay Rathod, May 12 '16 at 13:25
When you say that runOnUiThread() doesn't work do you mean that it causes error or that it doesn't process anything? — Amesys, May 12 '16 at 13:35
Possible duplicate of http://stackoverflow.com/questions/16425146/runonuithread-in-fragment — Jay Rathod, May 12 '16 at 13:43
I made a check by calling the isAdded method. It returns false — Manos, May 12 '16 at 13:51
Why do you need to use Activity.runOnUIThread(). OnActivityResult is run on the Ui thread already. Btw, is area a TextView of the Activity? — Tin Tran, May 12 '16 at 14:14
no area TextView is at the fragment's layout. Also i tried your approach but still the update is not being rendered — Manos, May 12 '16 at 14:15
use android handler and post your runnable it´s automatically on the main thread http://developer.android.com/reference/android/os/Handler.html — Christian Stengel, May 12 '16 at 14:27

Vladimir Jovanović · Answer 1 · 2016-05-12T13:44:28.677

0

onActivityResult is being called on main thread. More here. For some reason views can't be edited from this method (probably not created or drawn). One trick that you can do is set var boolean updateTextView = false; On onActivityResult set it on true, save data that you got, and than onResume check updateTextView and if true set data to your TextView.

edited May 12 '16 at 13:44

answered May 12 '16 at 13:33

Vladimir Jovanović

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score 0 · Answer 2 · answered May 12 '16 at 13:49

What about trying to wrap it in a proper thread that you launch afterwards?

new Thread() {
            public void run() {
                try {
                   activity.runOnUiThread(new Runnable() {
                       @Override
                       public void run() {
                          area.setText(String.valueOf(finalTotalArea));
                       }
                   });
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }.start();

score 0 · Answer 3 · answered May 12 '16 at 14:11

Seems like your Activity is loosing your Fragment somewhere, what I did in this case was to add a Method to my Callbacks, maybe reattachDialog(DialogFragment dialogFragment) and calling it in onResume of the DialogFragment with reattachDialog(this).

And in your Activity you do this:

@Override
public void reattachFragment(DialogFragment dialogFragment) {
 this.dialogFragment = dialogFragment;
}

Or in Fragment:

@Override
public void reattachFragment(DialogFragment dialogFragment) {
 getActivity().setDialog(dialogFragment);
}

Update UI from fragment

3 Answers3