Showing hidden ActionButton does not always draw the button circle about ncontrol.controls

[ddklo]

Any clues to what could be causing this? I would be happy to look into it and create a PR, but not sure where to start looking.

[ddklo]

So I looked a little more into this and it seems to be related to using bindings. If IsVisible on the ActionButton is bound to a view model the circle is not redrawn when IsVisible is changed on the view model. If the ActionButton is a child of a layout control (for instance a StackLayout) and IsVisible is bound on the layout control nothing is redrawn when IsVisible is changed in the view model.

We solved it by listening to PropertyChanged on the ActionButton and the parent of the ActionButton and calling Invalidate() on the ActionButton and the NControlView's in the ActionButton when IsVisible is changed.

private void MyActionButton_PropertyChanged(object sender,   System.ComponentModel.PropertyChangedEventArgs e)
{
    if (e.PropertyName != IsVisibleProperty.PropertyName) return;
    Invalidate();
    ButtonElement?.Invalidate();
    ButtonShadowElement?.Invalidate();
}

private Xamarin.Forms.Element parent;
protected override void OnParentSet()
{
    base.OnParentSet();            
    if (parent != null)
        parent.PropertyChanged -= Parent_PropertyChanged;
    parent = Parent;
    parent.PropertyChanged += Parent_PropertyChanged;
}
private void Parent_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
    if (e.PropertyName != IsVisibleProperty.PropertyName) return;
    Invalidate();
    ButtonElement?.Invalidate();
    ButtonShadowElement?.Invalidate();
}