How To Show/hide Fab On Scroll Recycler View With Coordinator Parent

I have an activity with coordinator layout.inside activity there is a fragment with Recycler view and float button.how can I show/hide float button when Scroll Recycler view and av

Solution 1:

This code works just fine:

 mRecycler.addOnScrollListener(newRecyclerView.OnScrollListener() {
                @OverridepublicvoidonScrolled(RecyclerView recyclerView, int dx, int dy) {
                    if(dy > 0){
                        mFab.hide();
                    } else{
                        mFab.show();
                    }

                    super.onScrolled(recyclerView, dx, dy);
                }
            });

You cannot do:

app:layout_anchor="@id/listView"app:layout_anchorGravity="bottom|end"

Look here:

There is no support built-in for CoordinatorLayout to work with ListView according to this Google post.

Solution 2:

I modified Leondro's method such that the FAB will hide when there's scrolling and show when the scrolling stops.

scrollListener = newRecyclerView.OnScrollListener() {  
    @OverridepublicvoidonScrollStateChanged(RecyclerView recyclerView, int newState) {
        switch (newState) {
            case RecyclerView.SCROLL_STATE_IDLE:
                fab.show();
                break;
            default:
                fab.hide();
                break;
        }
        super.onScrollStateChanged(recyclerView, newState);
    }
}; 

rv.clearOnScrollListeners();
rv.addOnScrollListener(scrollListener);

Solution 3:

add this to FAB :

app:layout_behavior="@string/hide_bottom_view_on_scroll_behavior"

Solution 4:

Here is working solution:

classHideOnScrollFabBehavior(context: Context?, attrs: AttributeSet?) : FloatingActionButton.Behavior() {

    // changes visibility from GONE to INVISIBLE when fab is hidden because// due to CoordinatorLayout.onStartNestedScroll() implementation// child view's (here, fab) onStartNestedScroll won't be called anymore// because it's visibility is GONEprivateval listener = object : FloatingActionButton.OnVisibilityChangedListener() {
        overridefunonHidden(fab: FloatingActionButton?) {
            fab?.visibility = INVISIBLE
        }
    }

    overridefunonStartNestedScroll(coordinatorLayout: CoordinatorLayout, child: FloatingActionButton, directTargetChild: View, target: View, axes: Int, type: Int): Boolean {
        return axes == ViewCompat.SCROLL_AXIS_VERTICAL // Ensure we react to vertical scrolling
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, axes, type)
    }

    overridefunonNestedScroll(coordinatorLayout: CoordinatorLayout, child: FloatingActionButton, target: View, dxConsumed: Int, dyConsumed: Int, dxUnconsumed: Int, dyUnconsumed: Int, type: Int, consumed: IntArray) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type, consumed)
        if (!target.canScrollVertically(1) && dyConsumed > 0 && child.visibility == VISIBLE) {
            // hide the FAB when scroll view reached its bottom
            child.hide(listener)
        } elseif (dyConsumed < 0 && child.visibility != VISIBLE) {
            // show the FAB on scroll up
            child.show()
        }
    }

}

Solution 5:

Solution in Kotlin

recycler_view = findViewById(R.id.recycler_view)

        recycler_view.addOnScrollListener(object : RecyclerView.OnScrollListener(){
            overridefunonScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                if(dy > 0){
                    fab.hide();
                } else{
                    fab.show();
                }
                super.onScrolled(recyclerView, dx, dy)

            }
        })