Before 19 R4, making objects focusable but not enterable had to be done through the property list through the form editor under "Entry > Enterable" and "Entry > Focusable". You can programmatically control these options now through the line of code below, which allows an object to be not be enterable, but still focusable:

OBJECT SET ENTERABLE(*; "Input"; obk not enterable)

These new options for the command also allows for controlling the focusability of your object, as compared to the older options (which you can still use) which were just a True/False. Please note that focusability differ between project and binary databases. When enterable is False, an object's focusability depends on the Focusable option in the property list. For a project database, the object is focusable.

To see how to do the same for listbox cells, please check out the link to the Tech Tip below:
https://kb.4d.com/assetid=77038