Measurable

A child that has been resolved but not yet laid out.

Created by the framework during layout, where the context needed to lay a child out exists. An instance is only meaningful inside the LayoutFunction call that received it. It has no public members: the scope that call runs in measures it (MeasureScope).

Final, and only Litho creates one: its constructor is internal, so a member added later is not a breaking change. A layout function is tested by rendering a tree that holds its container.