[PyQt] findChildren: setting visibility problems

[Chris Wood]

I've found that where I have a QLabel as a child of my QWidget, and a
QLabel which is a child of a QGroupBox which is a child of my QWidget, and
I toggle the visibility of all the children of the QWidget via the click
action of a button:

def toggleVis(self):
  self.results = findChildren((QLabel,QGroupBox))
  print self.results
  for w in self.results:
    w.setVisible(not w.isVisible())

After hiding the objects initially, and clicking the button again, the
QLabel which is a child of the QGroupBox does not reappear, but all 3
objects are listed when self.results is printed (full code at end of
email).  I expected this to work, since findChildren is recursive.
However, it *does* work if I reverse the list (for w in
reverse(self.results)).  I get the same behaviour on both Unix (Fedora 20)
and Windows 7. Is this documented? Perhaps a different way round this would
be to specify names (I could probably use some regex to ensure I capture
the objects I want), but wanted to make sure I hadn't missed something
obvious from the docs first...

Cheers,
Chris

------

import sys
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):

    def __init__(self):
        super(Example, self).__init__()
        vbox = QtGui.QVBoxLayout()
        gb = QtGui.QGroupBox()

        button = QtGui.QPushButton("Hide")
        button.clicked.connect(self.toggle)

        vbox.addWidget(button)

        lbl = QtGui.QLabel("Test Label")
        vbox.addWidget(lbl)

        gbLayout = QtGui.QFormLayout()
        lbl1 = QtGui.QLabel("Hello", gb)
        gbLayout.addWidget(lbl1)

        le1 = QtGui.QLineEdit(gb)
        gbLayout.addWidget(le1)

        gb.setLayout(gbLayout)
        vbox.addWidget(gb)

        gb.setTitle("Test")
        self.setLayout(vbox)

        self.show()

    def toggle(self):

       self.l = self.findChildren((QtGui.QGroupBox, QtGui.QLabel))
       print self.l
       for i in self.l:
         i.setVisible(not i.isVisible())

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())
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