Connecting QgsCheckableComboBox Qt Signal

Question

I tried to connect Qt signal of QgsCheckableComboBox when checkedItemsChanged.

I tried below:

def showEvent(self, event):
    print("show event")
    self.loadLayersToCombox()
    self.cmbLayers.checkedItemsChanged.connect(self.updateLables)

def loadLayersToCombox(self):
    layers = [x.name() for x in QgsProject().instance().mapLayers().values()]
    self.cmbLayers.clear()
    self.cmbLayers.addItems(layers)

def updateLables(self):
    print("updateLables")
    chkditems = self.cmbLayers.checkedItems()
    self.checkedlayer = [self.getLayer(x) for x in chkditems if self.getLayer(x) is not None]
    for x in self.checkedlayer:
        self.totalvalue = + x.featureCount()
    print(self.totalvalue)
    self.lblCurrentval.setText("0")
    self.lblTotalval.setText(str(self.totalvalue))

def getLayer(self, name):
    try:
        return self.project.mapLayersByName(name)[0]
    except IndexError:
        return None

I am using QGIS 3.14 below

self.cmbLayers.checkedItemsChanged.connect(self.updateLables)

not connecting self.updateLables.

Answer 1

You would need to use a more recent version of QGIS to use the checkedItemsChanged signal. The signal not being emitted was indeed a bug which got fixed rather recently (in this Pull Request). A backport to QGIS LTR 3.16 also seemed to never have happened. I assume you will need at least version 3.20, which was the first release after that PR has been merged.

Answer 2

Use currentTextChanged insted checkedItemsChanged