On 15/07/12 07:31, Michael Torrie wrote: > On 07/14/2012 11:13 AM, rusi wrote: >> I looked at the second link and find code like this: >> >> app = None if ( not app ): app = QtGui.QApplication([]) >> >> Maybe I'm dense but whats that if doing there? >> >> Frankly I seem to be a bit jinxed with gui stuff. A few days ago >> someone was singing the praises of some new themed tk stuff. I could >> not get the first two lines -- the imports -- to work and then gave >> up > Since you haven't had any experience with gui development then probably > loading ui files isn't the right place to start. First principles > (creating gui widgets from scratch) would be it. > > In any case, the line in question is quite simple. It creates a > QApplication object, which is basically the engine that drives all Qt > applications. Once you call .run() on it, it takes over and handles all > the mouse events and such for you. In fact you do not have any control > over the program's execution from this point on, other than to define > event call-back methods or functions that are called by the widgets when > things happen, like mouse clicks. > > All gui toolkits operate this way. You set up the widgets, then you run > the main engine or main event loop and control never returns to your > main program until something triggers the end (like closing a window or > the quit menu item is pressed). > > Probably a complete working example is what you need to see, that is > documented. I primarily work with Gtk, but I'll whip up a Qt one > tomorrow if I can. Rusi is not the op, and his question is about these lines
app = None if ( not app ): not this one app = QtGui.QApplication([]) which should be written like this app = QtGui.QApplication(sys.argv) -- Vincent V.V. Oqapy <https://launchpad.net/oqapy> . Qarte <https://launchpad.net/qarte> . PaQager <https://launchpad.net/paqager> -- http://mail.python.org/mailman/listinfo/python-list