[PyKDE] Newbie question on QWidget.focusOutEvent

[Hans-Peter Jansen]

Hi Volker,

Am Montag, 26. September 2005 12:36 schrieb Volker Lenhardt:
>
> I tried installing the event filter in the dialog itself without a
> special Combo class: no effect at all.

This version works as expected for me:


#!/usr/bin/env python
#
# focusouttest.py
#

import sys
from qt import *
try:
    from qtpe import QPEApplication as QApplication
except:
    pass

class Dlg(QDialog):
     def __init__(self):
        QDialog.__init__(self, None, None, True, 1)
        self.setCaption("FocusOut Test")
        self.playerList=["", "Pete", "Volker"]
        self.wCmbList=[]

        self.layout=QVBoxLayout(self)
        self.placeEdit=QLineEdit(self)
        self.layout.addWidget(self.placeEdit)

        for i in range(4):
            cmb=QComboBox(True, self)
            cmb.setDuplicatesEnabled(False)
            cmb.lineEdit().installEventFilter(self)

            for p in self.playerList:
                cmb.insertItem(p)
            self.wCmbList.append(cmb)
            self.layout.addWidget(cmb)
        
     def eventFilter(self, o, e):
        if e and o:
            if e.type()==QEvent.FocusOut:
                for cmb in self.wCmbList:
                    if o==cmb.lineEdit():
                        print "bingo"
                        #QMessageBox.information(self, "Info", "Bingo")
        return False

if __name__=="__main__":
     app=QApplication(sys.argv)
     QObject.connect(app, SIGNAL('lastWindowClosed()'), app, SLOT('quit()'))
     win = Dlg() 
     app.setMainWidget(win)
     win.show()
     app.exec_loop()

> And with the special class there is no difference whether installing
> the filter in the dialog or in the Combo class. It get double message
> boxes and segmentation fault.

Notes:
 - I removed the Combo class, but it would be pretty straight forward to
   transform..
 - You need to install the eventFilter on the lineEdit() in this case, and 
   I admit, event filtering on Qt container widgets involves a bit of voodoo
   (but at least it should be consistent across platforms, which is _the_ 
   horror other toolkits often suffer from..).
 - If you use focus event impacting GUI functions inthe event handler, don't 
   wonder about multiple focus events. 
 - The QComboBox duplicatesEnabled property has the wrong default IMHO.

I've no idea, where your segfault came from, but it could be a reentrancy 
problem in QPE. If you cannot use print, how about using a log file, or do
something focus agnostic or handle the mess..

Pete