There is a useful medium article how to hide the bottom bar when scrolling down. Maybe you can implement this feature to this library. https://medium.com/@nullthemall/bottom-navigation-behavior-388b9b206667#.7ufpfhq3a

@FabianTerhorst @roughike Hi guys, I'm the author of the mentioned behavior and article. I forked the repo and tried to add it to the lib. It wont work because of two things:

First: BottomBar is attached to content view which is FrameLayout not CoordinatorLayout
Second: The content is always above it, not behind it. Which means that it will leave empty (window background color will be visible) space when the BottomBar is hidden.

I assume this is for favoring the SnackBars, but they should be handled by behavior (lol, mine doesnt care about snackbars)

Also the content view should be given a proper padding in order the bottom bar and content view do not overlap. This would be applicable if the BottomBar is not attached directly to the android.R.id.content.

IMHO, the BottomBar should not be added directly to the content view, it should work like any other view.Basically, BottomBar should work as ViewGroup out of the box. This is totally subjective opinion and should not be taken as true.

Possible solution is checking if the child at 0 is CoordinatorLayout and avoid removing it in attach method. I mean overall rearrangement of the views. This needs tremendous efforts to be invested, because we have a unknown number of child inside CoordinatorLayout add padding so the content does not overlap.

What I have tried:

Binding the behavior whenever LayoutParams are added to the BottomBar.

I'm subscribing this issue for any comments.