Here is a demo project which demonstrates multiple issues when having a visible virtual treeview on Lazarus Mac/Cocoa (using fpcupdeluxe "trunk" which includes newest virtual treeview)
I first reported the issue here:
https://bugs.freepascal.org/view.php?id=34002And together with Lazarus developers narrowed it down to be an issue with virtualtreeview and lazarus/cocoa.
The attached demo project demonstrates:
Toolbuttons becoming invisible until clicked
TPageControl tabsheets misdrawn until clicked
TEdit looking very weird with black background until clicked
Some captions/labels etc. are drawn upside down some places
All only when the two virtual treeviews are set to visible in the project.
...
To see all issues simply
run project
doubleclick window title bar (minimizes to dock)
open from mac dock.