CODEWITHSUNDEEP
androidandroid-fragments
tpdi
tpdi

Reputation: 35151

Android DialogFragment: can I re-use, or must I new up another?

I want to pop up a timepicker and a datepicker, more than once in an Activity.

It's not clear to me whether I should make one instance of each, and show them as needed, or if I should make new instances each time I need to pop a dialog up.

And I'm very confused by findFragmentByTag/findFragmentById. It seems that the fragment is only found if it's currently displayed?

But if it's not found and I make a new Fragment and show it with the same tag, I get an IllegalStateException. How can I recover a fragment in onCreate?

Currently, I'm doing this:

FragmentManager fm = getSupportFragmentManager();

if (savedInstanceState == null) {
    timePicker = new RadialTimePickerDialog();
    datePicker = new CalendarDatePickerDialog();
    fm.beginTransaction().add(timePicker, FRAGMENT_TIME_PICKER)
        .add(datePicker, FRAGMENT_DATE_PICKER).commit();
} else {
    timePicker = (RadialTimePickerDialog)  
        fm.findFragmentByTag(MedicationCollapsePanel.FRAGMENT_TIME_PICKER);
    datePicker = (CalendarDatePickerDialog) 
        fm.findFragmentByTag(MedicationCollapsePanel.FRAGMENT_DATE_PICKER);
}

As I mentioned, this fails to actually find the fragments, and almost as bad, it displays them immediately when the Activity starts, which I don't want.

Thanks.

Upvotes: 1

Views: 634

Answers (1)

NameSpace
NameSpace

Reputation: 10177

I assume these classes are the ones by the same name from gitHub that pop up at the top of a google search.

They extend dialogFragments.

DialogFragments take care of removing themselves with the fragment manager when they are dismissed. You can see the source code as well as get this decription, from the link below:

Dismiss():

Dismiss the fragment and its dialog. If the fragment was added to the back stack, all back stack state up to and including this entry will be popped. Otherwise, a new transaction will be committed to remove the fragment.

http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.0.1_r1/android/app/DialogFragment.java#DialogFragment.onDismiss%28android.content.DialogInterface%29

Hence, they are not reusable after being dismissed since they will unattach themselves automatically by calling the underlying context and getting the fragment manager themselves. Rather create a new instance, and show them, or you can try overriding their default behavior. You can try either changing what they do after being dismissed, or prevent them from being dismissed in the first place (e.g. hiding them).

Upvotes: 1

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