python - Checkboxes in a Combobox using PyQt

Question

I need to implement a drop down list that contains CheckBoxes, much like having the entries in a ComboBox being CheckBoxes. But QComboBox doesn't accept QCheckBox as its member and I couldn't find any alternate solution. I found an implementation in C++ on the Qt Wiki, but don't know how to port it to python.

Answer 1

Use the Combobox item model, since items support checkBoxes you just need to mark the item to be checkable by the user, and set an initial checkState to make the checkBox appear (it does only show if there is a valid state)

item.setFlags(QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled)
item.setCheckState(QtCore.Qt.Unchecked)  # causes checkBox to show

Here is a minimal subclass example:

from PyQt5 import QtGui, QtCore, QtWidgets
import sys, os

# subclass
class CheckableComboBox(QtWidgets.QComboBox):
    # once there is a checkState set, it is rendered
    # here we assume default Unchecked
    def addItem(self, item):
        super(CheckableComboBox, self).addItem(item)
        item = self.model().item(self.count()-1,0)
        item.setFlags(QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled)
        item.setCheckState(QtCore.Qt.Unchecked)

    def itemChecked(self, index):
        item = self.model().item(i,0)
        return item.checkState() == QtCore.Qt.Checked

# the basic main()
app = QtWidgets.QApplication(sys.argv)
dialog = QtWidgets.QMainWindow()
mainWidget = QtWidgets.QWidget()
dialog.setCentralWidget(mainWidget)
ComboBox = CheckableComboBox(mainWidget)
for i in range(6):
    ComboBox.addItem("Combobox Item " + str(i))

dialog.show()
sys.exit(app.exec_())