Detect when button/control is focused in Inno Setup

Question

I need to fire an event (for example updating a label) when a control (button) is focused.

Is there any trick doing this in Inno Setup?

Answer 1

This is difficult to implement due to a lack of OnEnter event in Inno Setup API (there are 3rd party Inno Setup clones that do have this functionality, not that I recommend using them).

The only solution, I know, is to periodically monitor the active control. For an example, see:
Prevent button from receiving focus in Inno Setup