[PyQt] trap ESC in mapper editing

[Mario Daniel Carugno]

I'm isolating my problem with mapper.
When i setup a mapper, the ESC key reverts changes in the edited widgets.
That's ok, but i need to trap that situation. I need to do more than
revert changes
when i press ESC.
For instance, before going into editing mode i disable some buttons.
When i press ESC, i'm not in editing mode anymore, so i need to enable
that buttons back.
How i detect the moment when i press ESC in a mapper form ?

Thanks