[Qt-interest] processEvents() and reset.

[phil prentice]

Hi Andreas
 Thankyou for your help.

  My application kicks the dialog off as a modal dialog box. So the only means 
of getting input to the application is through the modal dialog box.
I'm not aware of any code in my app that gets executed just by moving the 
mouse into it....unless it is something to do with focus??!!!

  Ok, what my code is trying to do is to talk to some hardware to learn some 
signal data (one network at a time).  There might be up to 10,000 networks.
When the run pushbutton is pushed the slot loops on the networks, one at a 
time and calls an external library function to perform the learn for that 
network.  This works well.  After processing each network in the loop the 
code inside the loop checks a member variable called m_reset.  The reset slot 
invoked from the reset pushbutton sets m_reset to enable the loop to be 
aborted.

  Are you saying that what I should be doing here is to start a thread off 
doing the 10000 or so nets, but the thread would monitor a member variable of 
the dialog. How best should I do this?  Pass the member variable in as an 
address?  Access it via the dialogs parent pointer or can I use signal/slots 
somehow. Which method do you recommend??  Hopefully this should then fix this 
focus problem???

  Thankyou very much for your advice

Phil 
 
On Friday 29 October 2010 17:16, Andreas Pakulat wrote:
> On 29.10.10 16:27:32, phil prentice wrote:
> >   I have a simple dialog. When you click a button on the dialog a slot is
> > called that loops around some code performing an action.  I have another
> > slot that gets called when another button(reset) is pressed on the same
> > dialog.  I use processEvents() within the loop to catch the reset button
> > being pressed. This works absolutely fine if I leave the mouse inside of
> > the dialog.  I can start the loop and reset the loop with no problems. 
> > Its lovely and simple!!!
> >
> >   Unfortunately I have a problem; if I move the mouse outside of the
> > dialog and back in...the reset button no longer responds quite so well. I
> > presume that its got something to do with the focus changing???  But
> > reset is certainly not quick then...in fact sometimes I cant get it to
> > work at all.
> >
> >   Is there a quick fix for this?
>
> Without seeing some code my suggestion is to check for any code that can
> be executed when events are being fired. With your processEvents calling
> you're processing all events in your application. So any code that
> handles events can be executed while you're in your loop. So there might
> be code in your app that gets executed which you don't expect to be on a
> first look.
>
> Its not quite clear why you're calling processEvents, options to avoid
> it are splitting up the work into smaller/shorter pieces and executing
> them in steps with a timer for example. Or move the logic into a
> separate thread so that the normal event loop can continue.
>
> Andreas