[SOLVED] Remove all items from a layout

Remove all items from a layout

I was trying to find something that would take a qt layout and delete everything from it. Just to imagine what the window looks like - I have:

QVBoxLayout
     | ------QHboxLayout
                 |---------QWidget
     | ------QHboxLayout
                 |---------QWidget
            .........

So I need something that I can call recursively to CLEAR AND DELETE all the stuff from my parent QVBoxLayout. I tried things mentioned here (Clear all widgets in a layout in pyqt) but none of them work (no correct answer marked anyway). My code looks like this:

def clearLayout(self, layout):
    for i in range(layout.count()):
        if (type(layout.itemAt(i)) == QtGui.QHBoxLayout):
            print "layout " + str(layout.itemAt(i))
            self.clearLayout(layout.itemAt(i))
        else:
            print "widget" + str(layout.itemAt(i))
            layout.itemAt(i).widget().close()

But it gives an error:

               layout.itemAt(i).widget().close()
            AttributeError: 'NoneType' object has no attribute 'close'

=>EDIT This kinda works (but doesn't if there is any other Layout than HBoxLayout:

def clearLayout(self, layout):
    layouts = []
    for i in range(layout.count()):
        if (type(layout.itemAt(i)) == QtGui.QHBoxLayout):
            print "layout " + str(layout.itemAt(i))
            self.clearLayout(layout.itemAt(i))
            layouts.append(layout.itemAt(i))
        else:
            print "widget" + str(layout.itemAt(i))
            if (type(layout.itemAt(i)) == QtGui.QWidgetItem):
                layout.itemAt(i).widget().close()

Solution

The safest way to clear a layout is to extract the items with its takeAt method, and then explicitly delete any widgets with deleteLater:

def clearLayout(self, layout):
    if isinstance(layout, QLayout):
        while layout.count():
            item = layout.takeAt(0)
            widget = item.widget()
            if widget is not None:
                widget.deleteLater()
            else:
                self.clearLayout(item.layout())

PS: to ensure that everything is deleted immediately, rather than after control returns to the event-loop, see this answer.