Remove the QItemDelegate from QTableView - c++

Question

I have the custom item delegate set for one column for QTableView. In some cases I need to remove it (i.e. set default item delegate). But it seems that QT does not allow this. The old delegate is used even after setting the new one.
According to QT documentation for QItemDelegate all handling should be done in the same delegate, but this may bring to performance issues. Is there any way to remove/reset to default the item delegate for QTableView.

Answer 1

I tried it in PyQt5 (sorry, im not able to write C++). I could set the standard itemGelegate to the view and then set a custom itemDelegate to one column. By using the „clicked“-signal i could replace the custom delegate by the standard itemDelegate for this column and vice versa.
This is my code, perhaps it helps:
import sys
from PyQt5 import QtGui, QtCore, QtWidgets
class MyDelegate(QtWidgets.QStyledItemDelegate):
def __init__(self):
QtWidgets.QStyledItemDelegate.__init__(self)
self.AlignmentFlag = QtCore.Qt.AlignHCenter | QtCore.Qt.AlignVCenter
self.abstand = 2
def paint(self, painter, item, index):
rahmen = item.rect.adjusted(self.abstand, self.abstand, -self.abstand, -self.abstand)
eintrag = index.data()
painter.save()
painter.drawText(rahmen,self.AlignmentFlag, eintrag)
painter.restore()
class MyModel(QtCore.QAbstractTableModel):
def __init__(self,):
QtCore.QAbstractTableModel.__init__(self)
self.items = [['a0','a1','a2','a3','a4'],['b0','b1','b2','b3','b4'],['c0','c1','c2','c3','c4']]
def columnCount(self,items):
cc = len(self.items[0])
return cc
def rowCount(self,items):
rc = len(self.items)
return rc
def data(self, index, role=2):
return self.items[index.row()][index.column()]
class MyWidget(QtWidgets.QTableView):
def __init__(self):
QtWidgets.QTableView.__init__(self)
self.setModel(MyModel())
self.setGeometry(200,200,530,120)
self.delegate_1 = MyDelegate()
self.delegate_2 = QtWidgets.QStyledItemDelegate()
self.setItemDelegate(self.delegate_2)
self.setItemDelegateForColumn(0,self.delegate_1)
self.clicked.connect(self.changeDelegate)
def changeDelegate(self,index):
if index.column() == 0:
delegate_new = self.delegate_2 if self.itemDelegateForColumn(index.column()) == self.delegate_1 else self.delegate_1
self.setItemDelegateForColumn(index.column(),delegate_new)
else:
pass
app = QtWidgets.QApplication(sys.argv)
widget = MyWidget()
widget.show()
sys.exit(app.exec_())