How to show cursor coordinate in pyqtgraph embedded in pyqt5?

Question

I'm following this tutorial. Here is a simple minimal pyqtgrapth embedded in pyqt5. How can I enable pyqtgraph to show cursor coordinate on canvas?

from PyQt5 import QtWidgets
from pyqtgraph import PlotWidget, plot
import pyqtgraph as pg
import sys  

class MainWindow(QtWidgets.QMainWindow):

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.graphWidget = pg.PlotWidget()
        self.setCentralWidget(self.graphWidget)

        hour = [1,2,3,4,5,6,7,8,9,10]
        temperature = [30,32,34,32,33,31,29,32,35,45]

        self.graphWidget.plot(hour, temperature)

def main():
    app = QtWidgets.QApplication(sys.argv)
    main = MainWindow()
    main.show()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()

Answer 1

Try it:

import sys
from PyQt5 import QtWidgets
from pyqtgraph import PlotWidget, plot
import pyqtgraph as pg
  

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)

        self.graphWidget = pg.PlotWidget()
        self.setCentralWidget(self.graphWidget)

        hour = [1,2,3,4,5,6,7,8,9,10]
        temperature = [30,32,34,32,33,31,29,32,35,45]

        self.graphWidget.plot(hour, temperature)
        
# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
        self.label = pg.TextItem(text="Abscissa: {} \nOrdinate: {}".format(0, 0))
        self.graphWidget.addItem(self.label)
        
        self.setMouseTracking(True)
        self.graphWidget.scene().sigMouseMoved.connect(self.onMouseMoved)
        
    def onMouseMoved(self, evt):
        if self.graphWidget.plotItem.vb.mapSceneToView(evt):
            point =self.graphWidget.plotItem.vb.mapSceneToView(evt)
            self.label.setHtml(
                "<p style='color:white'>Abscissa： {0} <br> Ordinate: {1}</p>".\
                format(point.x(), point.y()))
# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


def main():
    app = QtWidgets.QApplication(sys.argv)
    main = MainWindow()
    main.show()
    sys.exit(app.exec_())

if __name__ == '__main__':
    main()