Connecting an overloaded PyQT signal using new-style syntax
- by Claudio
I am designing a custom widget which is basically a QGroupBox holding a configurable number of QCheckBox buttons, where each one of them should control a particular bit in a bitmask represented by a QBitArray. In order to do that, I added the QCheckBox instances to a QButtonGroup, with each button given an integer ID:
def populate(self, num_bits, parent = None):
"""
Adds check boxes to the GroupBox according to the bitmask size
"""
self.bitArray.resize(num_bits)
layout = QHBoxLayout()
for i in range(num_bits):
cb = QCheckBox()
cb.setText(QString.number(i))
self.buttonGroup.addButton(cb, i)
layout.addWidget(cb)
self.setLayout(layout)
Then, each time a user would click on a checkbox contained in self.buttonGroup, I'd like self.bitArray to be notified so I can set/unset the corresponding bit in the array. For that I intended to connect QButtonGroup's buttonClicked(int) signal to QBitArray's toggleBit(int) method and, to be as pythonic as possible, I wanted to use new-style signals syntax, so I tried this:
self.buttonGroup.buttonClicked.connect(self.bitArray.toggleBit)
The problem is that buttonClicked is an overloaded signal, so there is also the buttonClicked(QAbstractButton*) signature. In fact, when the program is executing I get this error when I click a check box:
The debugged program raised the exception unhandled TypeError
"QBitArray.toggleBit(int): argument 1 has unexpected type 'QCheckBox'"
which clearly shows the toggleBit method received the buttonClicked(QAbstractButton*) signal instead of the buttonClicked(int) one.
So, the question is, how can we specify, using new-style syntax, that self.buttonGroup emits the buttonClicked(int) signal instead of the default overload - buttonClicked(QAbstractButton*)?
