How to filter only active layers in QgsMapLayerComboBox

Question

I'm filtering the layers in a QgsMapLayerComboBox and in addition to filtering according to geometry, I want to remove the layers that are disabled? Is it possible? How do I do it? I'm using the following code to filter according to geometry.

self.CMBNODES.setFilters(QgsMapLayerProxyModel.PointLayer)
self.CMBPIPES.setFilters(QgsMapLayerProxyModel.LineLayer)
self.CMBMDE.setFilters(QgsMapLayerProxyModel.RasterLayer )
self.CMBCURVAS.setFilters(QgsMapLayerProxyModel.NoGeometry)

Answer 1

Use the setExceptedLayerList() method of QgsMapLayerComboBox. You can pass this method a list of layers which want to exclude from being shown in the combo box. You will probably want to run this logic in a method which is also connected to the QgsMapCanvas.layersChanged signal.

Simple example below:

class TestDialog(QDialog):
    def __init__(self):
        super(TestDialog, self).__init__()
        self.canvas = iface.mapCanvas()
        self.setGeometry(300, 300, 500, 200)
        self.mlcb = QgsMapLayerComboBox(self)
        self.layout = QVBoxLayout(self)
        self.layout.addWidget(self.mlcb)
        self.filter_layers()
        self.canvas.layersChanged.connect(self.filter_layers)
        
    def filter_layers(self):
        checked_layers = self.canvas.layers()
        excluded_layers = [l for l in QgsProject.instance().mapLayers().values() if not l in checked_layers]
        self.mlcb.setExceptedLayerList(excluded_layers)
        
dlg = TestDialog()
dlg.show()