Don't collapse Toolbar when RecyclerView fits the screen

Question

I\'ve made an app using Android Design Library, with a Toolbar and TabLayout.
Actually 2 tabs are present, both with 2 RecyclerView, that automati

Answer 1

I guess it's the best solution. You need to define your custom AppBarLayout behavior:

class CustomScrollingViewBehavior : AppBarLayout.Behavior {

    constructor() : super()
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)

    var shouldScroll = true

    override fun onStartNestedScroll(coordinatorLayout: CoordinatorLayout, child: AppBarLayout, directTargetChild: View, target: View, axes: Int, type: Int): Boolean {
        return shouldScroll && when (target) {
            is NestedScrollView, is ScrollView, is RecyclerView -> {
                return target.canScrollVertically(1) || target.canScrollVertically(-1)
            }
            else -> super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, axes, type)
        }
    }
}

And then you just need to use it in your layout as attribute of AppBarLayout:

...

 

...

That's it.

Note: custom behavior also supports fully disabling of the scrolling - you just need to set shouldScroll flag to false

customScrollingViewBehavior.shouldScroll = false