LiveDataSample | ViewModel DataBinding LiveData RxJava | Reactive Programming library

The Code A is based https://github.com/android/architecture-components-samples/blob/master/LiveDataSample/app/src/main/java/com/android/example/livedatabuilder/LiveDataViewModel.kt

I modified some code.

I think that emit(timeStampToTime(currentTime.value)) will be correct, but the system report error, so I have to use emit(timeStampToTime(currentTime.value?:0))

1: I'm very strange that why val currentTime isn't Nullable and currentTime.value is Nullable .

2: Why does the original code use liveData { emit(timeStampToTime(it)) } instead of liveData { emit(timeStampToTime(it?:0)) }

Code A

I am using LiveData with DataBinding. I used minifyEnabled=true in my release config and used standard proguard rules. Everything works fine in Android 9 and below but however in Android 10(Q) the live data is not calling the observers.

I tried all the different rules based on the answers I found on the Internet, none resolved the issue.

I have a problem with LiveData from new Android Architecture Components. I have used ObservableField before but wanted to try ACC.

When I set up value by MutableLiveData.setValue 4 times in one method in Activity I get only one call onChange, when I use ObservableField instead it works as I expect - it hits callback 4 times.

Why LiveData doesn't hit onChange for every single setValue?

ViewModel: