How to deactivate a UI element in an add-on? In an add-on I would like to have a property adjustable via its UI element, but when I have a second elements enabled I want my first element to be disabled : only show the information without being editable. It there a way to make a UI element read-only ? (grayed out / disabled / visible but un-editable).
Try:

col = layout.column()
col.enabled = False
# Use col.prop, col.operator, etc. Everything you add to this column will be faded


col.active is also possible, it will grey out the column but the props will still be editable (this is probably not something you want)