Remove all items from a layout

Question

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
          


        

Answer 1

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

Answer 2

The problem with your code is QLayout.itemAt() returns a QLayoutItem, QWidgetItem or QSpacerItem depending on the item at that position. So the condition:

type(layout.itemAt(i)) == QtGui.QHBoxLayout

will never be True and you will be trying to do .widget() for a QLayoutItem and that returns None. Thus the error you get. Another thing is, you need to loop backwards. Because removing things from the beginning will shift items and change the order of items.

You need to write your function like this:

def clearLayout(self, layout):
    for i in reversed(range(layout.count())):
        item = layout.itemAt(i)

        if isinstance(item, QtGui.QWidgetItem):
            print "widget" + str(item)
            item.widget().close()
            # or
            # item.widget().setParent(None)
        elif isinstance(item, QtGui.QSpacerItem):
            print "spacer " + str(item)
            # no need to do extra stuff
        else:
            print "layout " + str(item)
            self.clearLayout(item.layout())

        # remove the item from layout
        layout.removeItem(item)