This is a layout container that manages its subviews by laying them out horizontally or vertically.
Add this view to your view hierarchy, then add subviews (generally buttons, but it works for all views) that you want
laid out. Set the layoutMode
according to whether you want a horizontal layout or a vertical one. Any view that is
not hidden or alpha 0 will be lined up nicely within the container.
MIT. See LICENSE.md.