How to connect a QgsMaptool with a widget pushButton

Question

I've write this QgsMaptool above and it works great in python console

imports...

class obsCreator(QgsMapToolEmitPoint):

    def __init__(self, iface):
        self.iface = iface
        self.canvas = QgsMapCanvas()
        QgsMapTool.__init__(self, self.canvas)
        QgsMapToolEmitPoint.__init__(self, self.canvas)
        self.layer = self.canvas.currentLayer()
        self.x = float
        self.y = float

    def canvasPressEvent(self, event):
        point = self.toLayerCoordinates(self.canvas.mouseLastXY())
        self.x = point[0]
        self.y = point[1]

    def canvasReleaseEvent(self, event):
        feats = []
        pr = self.layer.dataProvider()
        fields = self.layer.fields()
        fet = QgsFeature
        geom = QgsGeometry().fromPointXY(QgsPointXY(self.x, self.y))
        fet.setgeometry(geom)
        feats.append(fet)
        fet.setAttributes([1, 'test'])

        if event.button() == Qt.RightButton:
            self.canvas.unsetMapTool(self)
        else:
            pr.addFeatures(feats)
            self.layer.triggerRepaint()
        pr.addFeatures(feats)
        self.layer.triggerRepaint()

but, I want to connect it with a pushButton in my dockwidget:

    def run(self):
        if not self.pluginIsActive:
            self.pluginIsActive = True

            if self.dockwidget == None:
                self.dockwidget = revEnvDockWidget()

            self.dockwidget.closingPlugin.connect(self.onClosePlugin)

            # show the dockwidget
            self.iface.addDockWidget(Qt.RightDockWidgetArea, self.dockwidget)
            self.dockwidget.show()

            # Clear comboBox (useful so we don't create duplicate items in list)
            self.dockwidget.obsComboBox.clear()

            # Add all items in list to comboBox
            self.dockwidget.obsComboBox.addItems(Handler.obsListCombo(self))

            canvas_clicked = obsCreator(iface.mapCanvas())
            self.dockwidget.hookPushButton.clicked.connect(iface.mapCanvas().setMapTool(canvas_clicked))

and I get this error:

WARNING    Traceback (most recent call last):
              File "E:\_Code\QGIS\rev_env\rev_env.py", line 268, in run
              self.dockwidget.hookPushButton.clicked.connect(iface.mapCanvas().setMapTool(canvas_clicked))
             TypeError: argument 1 has unexpected type 'NoneType'

I`ve based my code in this question: How to get co ordinates of points on mouse click in PyQGIS. Am I missing somethig?

Answer 1

Based on @BenW comment I use a lambda function to pass a dockwidget parameter and it works perfectly.

 def run(self):
        if not self.pluginIsActive:
            self.pluginIsActive = True

            if self.dockwidget == None:
                self.dockwidget = revEnvDockWidget()

            self.dockwidget.closingPlugin.connect(self.onClosePlugin)

            # show the dockwidget
            self.iface.addDockWidget(Qt.RightDockWidgetArea, self.dockwidget)
            self.dockwidget.show()

            # Clear comboBox (useful so we don't create duplicate items in list)
            self.dockwidget.obsComboBox.clear()

            # Add all items in list to comboBox
            self.dockwidget.obsComboBox.addItems(Handler.obsListCombo(self))

            self.canvas_clicked = HookCreator(self.iface.mapCanvas(), self.dockwidget)
            self.dockwidget.hookPushButton.clicked.connect(lambda: self.iface.mapCanvas().setMapTool(self.canvas_clicked))