Scrollable UI Panel

Right now the only way to create scrollable UI content is to use UIList . But this can only display same-type items and requires a CollectionProperty and an active index property.

Add a new UI element that can define max height and if its contents exceed the limit it will show scrollbar to scroll it. You would fill this element similar like layout.box() with any UI elements you like. Like a UIList it could have a little thingy at bottom to be user resizeable.