PyQT: pausing an application for the next event

[Srinath Avadhanula]

Hello,

[Python 2.3 + QT 2.3.0 + PyQT 3.8.0-nc]

I am wondering if QT has something like QWaitForNextEvent() function.
This function would block execution of the application till another key
was pressed and then return the event which occured.

Would like to utlize this in a small application I am building:
I am trying to create vi key-bindings for a simple QMultiLineEdit
control. I created a class which overloads the QMultiLineEdit class
and then re-defined its keyPressEvent() function. If something like
QWaitForNextEvent() were available, I would have done something like the
following:

def MySimpleVi(QMultiLineEdit):
    def keyPressEvent(self, event):
        if event.text() == 'd':
            self.deleteLine(event)

    def deleteLine(self, event):
        count = 0
        movement = None

        nextevent = QWaitForNextEvent()
        while iscount(nextevent):
            count = 10*count + int(nextevent).text
            nextevent = QWaitForNextEvent()

        if ismovement(nextevent):
            movement = nextevent.text()

        range = calculateRange(self.getCursorPosition(), movement, count)
        self.deleteRange(range)

Without a function like QWaitForNextEvent(), I will have to make
deleteLine() somehow remember its state between successive calls. I will
also have to make the keyPressEvent() function remember state between
calls so that it can keep passing events to deleteLine() till
deleteLine() is "done". Such things will get even more complex if I plan
to implement vi commands like "3d3j", which take an optional count
before the command description and then execute the command so many
times.

Any advice/suggestions would be greatly appreciated.

If PyQT does not have something like this, is there some completeley
different way to accomplish something similar? Basically have a function
pause between successive calls and resume from last time but with one of
the local variables corresponding to the function arguments changed?
This sounds a little like generator functions in Python, but I cannot
think of a way to use them here.

I searched the QT-interest mailing list and found this to be of
interest:

http://lists.trolltech.com/qt-interest/2000-10/thread00270-0.html

However, as Mr. Peter Becker says after offering a solution:

	But my last experiences using such techniques taught me: don't use
	such stuff if you can avoid it. You can run in different kinds of
	deadlocks and livelocks -- I even got a reproducable Zombie this way
	(NT showed a running process without task). Plus: to much calling of
	QApplication::processEvents() seems to result in big CPU load.


Thanks,

Srinath