CMake provides "hack" for cmake-gui, that allows set options variants
and select then from drop down list. Allows Qt Creator re-use this
solution.
See:
- https://blog.kitware.com/constraining-values-with-comboboxes-in-cmake-cmake-gui/
- http://blog.bethcodes.com/cmake-tips-tricks-drop-down-list
Drop down values can be added to option via:
SET_PROPERTY(CACHE OptionName PROPERTY STRINGS Option1 Option2 Option3)
This solution should not restrict to provide any other value, it
provides only suggestion for user to select one of prdefined values.
Change-Id: I8fc52155775f1e04979db8206bb42363df9359e8
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
