fragmentStatePagerAdapter correct data but incorrect adapter on my Fragment

Question

I have a ListFragment to show a list of data based on a specific day. This day is passed as an argument from the getItem() function of my fragmentStatePagerAdapter.

    public Fragment getItem(int position) {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.DAY_OF_YEAR, -(mNumDays - (position + 1)));

        return MyFragment.initNewInstance(calendar.getTimeInMillis(), 
                                          position, 
                                          mNumDays);
    }

I also have a LoaderManager to load the data when a change on my database is issued.

On the onCreate() function of my ListFragment I get the day and on onCreateLoader I query the database based on that specific day.

public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    this.mDateToShow = getArguments() != null ? getArguments().getString("date") : "";
}

public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
    String sameDay =  ChronomasterDatabaseHelper.KEY_DATE_TIME +"='"+ mDateToShow +"'";

    return new CursorLoader(getActivity(), uri, null, sameDay, null, null);
}

On onLoadFinished() fucntion I start a new thread to get the data and update the ArrayList of my BaseAdapter which is responsible of showing the data in a specific form.

public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
    if ((cursor == null) || (cursor.isClosed())) {
        return;
    }
    try {
        new UpdateDataHelper(cursor).executeOnExecutor();
    }catch (RejectedExecutionException rejectedExecutionException){
        Log.d(LOGTAG,"Task to update data was rejected");
    }
}

And on the thread:

protected void onPostExecute(ArrayList<Application> result) {
    mAdapter.setData(result);
    super.onPostExecute(result);
}

However, from debugging I can see that the data showed to the device are correct(correct data on correct date) but the actual data are incorrect!

What I mean by that?

When I swipe to the page the data queried are of the next day's data (the specific day is actually the next day), and my BaseAdapter has next's day's data. I know that the fragmentStatePagerAdapter by default, not only the visible fragment is loaded, but also the next one and previous one.

How Can I resolve this issue?

When I click on an item on the screen(onListItemClick) I get index Out Of Bounds Exception because my BaseAdapter's ArrayList has the next day's data.

@Override
public void onListItemClick(ListView listView, View view, int pos, long id)
{
    appClicked(mAdapter.getItem(pos - 1));
}

Do you have your ListFragment and Details Fragments within the same viewpager? — ILovemyPoncho, Jun 19 '14 at 15:43
I mean, when you click an item of the list, you show extra data in a fragment. — ILovemyPoncho, Jun 19 '14 at 15:52
Yes, my viewPager has one ListFragment and I change the content base on the day. — Andreas Lymbouras, Jun 19 '14 at 16:03
ok, but you need to post the relevant code; your asynctask, the activity/fragment containing the viewpager... — ILovemyPoncho, Jun 19 '14 at 16:29
the position parm of method onListItemClick is already zero based why are you subtracting one from it? — danny117, Jun 20 '14 at 11:11
What is your problem exactly? The Exception thrown? Or that your data is wrong? Please specify your problem clearly. danny117 already told you that your `onListItemClick()` implementation is wrong, did that fix your problem? — einschnaehkeee, Jun 25 '14 at 12:09
The data showed are correct, my adapter is wrong. danny117 is wrong, my `onListItemClick()` is correct. — Andreas Lymbouras, Jun 26 '14 at 00:06

score 0 · Answer 1 · answered Jun 25 '14 at 16:45

0

An option you could use that's a workaround is to have just that page load with mViewPager.setOffscreenPageLimit(0);

That way the data that is being loaded up is for the current page. The drawback would be that it wouldn't look quite as smooth because each fragment would be loaded only when it is current fragment.

answered Jun 25 '14 at 16:45

user3331142

1,222
1
11
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Yes, but the user experience will be awful. Swapping would be slow. – Andreas Lymbouras Jun 26 '14 at 00:09

Andreas Lymbouras · Accepted Answer · 2014-06-27T08:48:17.493

The solution was to have a private ArrayList on my Fragment and add the data there.

private ArrayList<Application> mResults = new ArrayList<>();

Then on my thread add the data on my field (Not creating new ArrayList each time):

mResults.add(new Application(data1,data2,data3));
mAdapter.setData(mResults,totalDuration,totalTimes);

and onListItemClick

public void onListItemClick(ListView listView, View view, int pos, long id)
{
    appClicked(mResults.get(pos - 1));
}

fragmentStatePagerAdapter correct data but incorrect adapter on my Fragment

2 Answers2