I launch my dialog fragment using
FragmentTransaction ft =
getFragmentManager().beginTransaction();
MyDialogFragment dialog = new MyDialogFragment()
dialog.
simply check if it's null
if(prev == null)
//There is no active fragment with tag "dialog"
else
//There is an active fragment with tag "dialog" and "prev" variable holds a reference to it.
Alternatively, you could check the activity the fragment prev
is currently associated with, however, make sure you ask that after you make sure it's not null or you'll get a NullPointerException. Like this:
if(prev == null)
//There is no active fragment with tag "dialog"
else
if(prev.getActivity() != this) //additional check
//There is a fragment with tag "dialog", but it is not active (shown) which means it was found on device's back stack.
else
//There is an active fragment with tag "dialog"
if (dialogFragment != null
&& dialogFragment.getDialog() != null
&& dialogFragment.getDialog().isShowing()
&& !dialogFragment.isRemoving()) {
//dialog is showing so do something
} else {
//dialog is not showing
}
I added this to be inside my custom dialog fragment, so I don't have to worry about any logic on the outside. Override the show()
and onDismiss()
methods, with a boolean shown
field:
private static boolean shown = false;
@Override
public void show(FragmentManager manager, String tag) {
if (shown) return;
super.show(manager, tag);
shown = true;
}
@Override
public void onDismiss(DialogInterface dialog) {
shown = false;
super.onDismiss(dialog);
}
If you want to check whether it is shown or not, you can create a getter for the shown
boolean.
Kotlin style:
private fun showDialog(dialogFragment: DialogFragment, tag: String) {
supportFragmentManager.findFragmentByTag(tag).let { fragment ->
fragment ?: let {
supportFragmentManager.beginTransaction().let { transition ->
dialogFragment.show(transition, tag)
}
}
}
}