How to bind method on RadioGroup on checkChanged event with data-binding

Question

I was searching over the internet for how to perform the new cool android data-binding over the RadioGroup and I didn\'t find a single blog post about it.

Answer 1

Often you care more about what was actually checked instead of "something was checked". In such case alternative solution is to ignore RadioGroup and bind all items as below:

where optionA, optionB and optionC are defined in ViewModel like below:

public final ObservableBoolean optionA = new ObservableBoolean();
public final ObservableBoolean optionB = new ObservableBoolean();
public final ObservableBoolean optionC = new ObservableBoolean();

This is usually enough, however if you want to react immediately on click then you can add callBacks and use them like that:

OnPropertyChangedCallback userChoosedA = new OnPropertyChangedCallback() {
    @Override
    public void onPropertyChanged(Observable sender, int propertyId) {
        (...) // basically propertyId can be ignored in such case
    }
};

optionA.addOnPropertyChangedCallback(userChoosedA);

Advantage of such approach is that you don't need to compare and track "id".