Qt - remove all widgets from layout?

Question

This doesn\'t seem easy. Basically, I add QPushButtons through a function to a layout, and when the function executes, I want to clear the layout first (removi

Answer 1

Layout management page in Qt's help states:

The layout will automatically reparent the widgets (using QWidget::setParent()) so that they are children of the widget on which the layout is installed.

My conclusion: Widgets need to be destroyed manually or by destroying the parent WIDGET, not layout

Widgets in a layout are children of the widget on which the layout is installed, not of the layout itself. Widgets can only have other widgets as parent, not layouts.

My conclusion: Same as above

To @Muelner for "contradiction" "The ownership of item is transferred to the layout, and it's the layout's responsibility to delete it." - this doesn't mean WIDGET, but ITEM that is reparented to the layout and will be deleted later by the layout. Widgets are still children of the widget the layout is installed on, and they need to be removed either manually or by deleting the whole parent widget.

If one really needs to remove all widgets and items from a layout, leaving it completely empty, he needs to make a recursive function like this:

// shallowly tested, seems to work, but apply the logic

void clearLayout(QLayout* layout, bool deleteWidgets = true)
{
    while (QLayoutItem* item = layout->takeAt(0))
    {
        if (deleteWidgets)
        {
            if (QWidget* widget = item->widget())
                widget->deleteLater();
        }
        if (QLayout* childLayout = item->layout())
            clearLayout(childLayout, deleteWidgets);
        delete item;
    }
}