[PyQt] Treeview with exclusive checkboxes - used to work

[Mads Ipsen]

Hi,

Some time ago I wrote a simple extension to the QStandardItemModel class 
that permits exclusive checkboxes in a treeview, ie. radio button 
behavior.  This no longer works. 

If you check the first item, and then check one of the other, the first 
item it not unchecked. If you then navigate with the keyboard to the 
first item, it then becomes unchecked once you enter it (update/repaint 
not called?).

Strangely enough, for all the other N-1 items, the behavior is 
completely as expected.

Is this a Qt bug?

Minimal example included below:

import sys
from PyQt4 import QtCore, QtGui

class ExclusiveModel(QtGui.QStandardItemModel):
    def __init__(self, parent=None):
        QtGui.QStandardItemModel.__init__(self, parent)

    def setData(self, index, value, role=QtCore.Qt.EditRole):
        # Call base class method
        return_value = QtGui.QStandardItemModel.setData(self, index, 
value, role)

        # Check if all other items must be unchecked
        if role == QtCore.Qt.CheckStateRole:
            changed_item = self.itemFromIndex(index)

            if changed_item.checkState() == QtCore.Qt.Checked:
                for row in range(self.rowCount()):
                    item = self.item(row, 0)
                    if item.text() != changed_item.text():
                        new_value = QtCore.QVariant(QtCore.Qt.Unchecked)
                        new_index = self.indexFromItem(item)
                        QtGui.QStandardItemModel.setData(self, 
new_index, new_value, role)

        return return_value
               
class View(QtGui.QTreeView):
    """
       Class for defining a widget for holding the analysis and 
calculator views.
    """
    def __init__(self, parent=None):
        """
           Constructor.
        """
        # Call base class constructor
        QtGui.QTreeView.__init__(self, parent)

        # model
        self._model = ExclusiveModel()
        for value in ['Why', 'does', 'this', 'not', 'work']:
            item = QtGui.QStandardItem(value)
            item.setCheckable(True)
            self._model.appendRow([item])

        # Add the elements
        self.setModel(self._model)

if __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)

    widget = View()
    widget.show()

    sys.exit(app.exec_())

-- 
+-------------------------------------------------------------+
| Mads Ipsen, Scientific developer                            |
+-------------------------------+-----------------------------+
| QuantumWise A/S               | phone:         +45-29716388 |
| Nørre Søgade 27A              | www:    www.quantumwise.com |
| DK-1370 Copenhagen K, Denmark | email:  mpi at quantumwise.com |
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