[Qt-interest] Maintaining a map of QProcesses

[Wm. G. Urquhart]

Wm. G. Urquhart wrote:
> Hi,
> 
> I have an application that I want to use to launch other processes from 
> based on the user's actions. These processes will be an instance of the 
> same application but with different parameters passed to them. For 
> example "Notepad.exe" "text1.txt" and "Notepad.exe" "text2.txt".
> 
> At present I'm keeping the * of the process in a map along with an ID as 
> the key but ideally, what I'd like to be able to do is when any of the 
> processes state changes I would like to be notified of this so I can 
> clean up my UI and perform housekeeping on the map. I know there is a 
> stateChange slot but how to tie this all together and knowing which 
> process raised it is where I'm confused.
> 
> I'd really appreciate your thoughts on this.

While working on a solution I have a class derived from QObject and in 
the classes constructor I want to connect the various signals from the 
QProcess to their slots.

However, connect(...) returns false when I try this even though IFAICT 
it should work. On page 311 of the C++ GUI Programming with Qt4 book 
they are doing something similar only using QDialog.

if (!connect(m_Process, SIGNAL(stateChanged(QProcess::ProcessState)), 
this, SLOT(processDone(QProcess::ProcessState))))
     {
         ::QMessageBox::critical(0, "Oops", "Unable to connect slot!") ;
     }

I have tried using QProcess as both a pointer and reference, but neither 
work. Does anyone have any idea to what or where I'm going wrong?

-- 
William