[PyQt] the mechanism behind qt signal and slot

[Algis Kabaila]

On Monday 20 September 2010 04:03:44 Andreas Pakulat wrote:
> > 
> > That's true, but what happens if the slot does not handle the signal?
> 
> This cannot happen. A signal-slot connection is a direct (or indirect)
> function call. So if you emit a signal _all_ connected slots will be
> executed, always (unless you block signal emission).
> 
> > Why it may not handle it, I have no idea.  May be a programming
> > mistake or whatever.  I seem to recall statement that if the signal is
> > NOT handled, then the signal propagates in the tree up to the root.
> 
> This is the case only for events, for an event the receiver can decide
> to accept it or not. If he doesn't accept it the event-propagation
> mechanism is going to give its parent a chance to handle it until there
> is no parent anymore at which point it'll be thrown away too.
> 
> Andreas

Thank you for the clarification,

Al.

-- 
OldAl
akabaila at pcug.org.au