since header regions can possibly overlap, accommodate by getting main regions visible rect first. Reviewers: sergey, brecht Maniphest Tasks: T62190 Differential Revision: https://developer.blender.org/D4449
since header regions can possibly overlap, accommodate by getting main regions visible rect first. Reviewers: sergey, brecht Maniphest Tasks: T62190 Differential Revision: https://developer.blender.org/D4449