onNestedScroll called only once

Question

I have a class

public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
    public ScrollAwareFABBehavior(Context context, AttributeSet attrs         


        

Answer 1

Do not set the visibility of FAB to GONE in child.hide() - use INVISIBLE instead. From 25.1.0, the scroll events are not passed on to views whose visibility is GONE

Answer 2

@Override
public void onNestedScroll(@NonNull CoordinatorLayout coordinatorLayout, @NonNull FloatingActionButton child, @NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
    super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
    if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
        child.hide(new FloatingActionButton.OnVisibilityChangedListener() {
            @Override
            public void onHidden(FloatingActionButton fab) {
                super.onHidden(fab);
                fab.setVisibility(View.INVISIBLE);
            }
        });
    } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
        child.show();
    }
}

Answer 3

I solved the problem changing the visibility from GONE to INVISIBLE with the following code.

 @Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
                           View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
    super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed,
            dyUnconsumed);

    if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
        child.hide(new FloatingActionButton.OnVisibilityChangedListener() {
            @Override
            public void onShown(FloatingActionButton fab) {
                super.onShown(fab);
            }

            @Override
            public void onHidden(FloatingActionButton fab) {
                super.onHidden(fab);
                fab.setVisibility(View.INVISIBLE);
            }
        });
    } else if (dyConsumed <= 0 && child.getVisibility() != View.VISIBLE) {
        child.show();
    }
}

Answer 4

I have just answered to absolutely the same problem in another post, check it.

Speaking shortly, use the following:

compile 'com.android.support:design:25.0.1'

Answer 5

For me i replace child.hide() with ((View)child).setVisibility(View.INVISIBLE).