Mastering Signals and Slots in Python Desktop Applications -

python signal slot   Dan python slot machine

A slot is a Python callable If a signal is connected to a slot then the slot is called when the signal is emitted If a signal isn't connected then nothing

Slots A slot is a callable that can receive a signal and respond to it To respond to events, you connect signals to slots When you connect a signal to a slot So our event loop never churns the Python interpreter and so our signal delivered to the Python slot mechanism disconnects the signalslots of the object

tinysoft - slots to emit Qt signals from Python is not yet implemented but PythonQt allows to just emit a signal by calling it like a normal slot  You'll need to do two things before building the signalslot connection: Verify that activeLayer() is in fact returning a QgsMapLayer