how to make cross hair mouse tracker on a PlotWidget() promoted in designer-qt5 - pyqt5

Question

I am trying to make a cross hair on my pyqtgraph interactive plots, which are embedded in a PyQt5 GUI thanks to the designer-qt5. I found a working
code in the pyqtgraph "examples". A simplified WORKING example is posted below. Now I want the same, but the problem seems to be that I promoted a
QGraphicsView() to a pg.PlotWidget in the designer, instead of pg.GraphicsWindow()? The Code does not work for me because my p1 is "pyqtgraph.widgets.PlotWidget.PlotWidget object" while in the example p1 is
"pyqtgraph.graphicsItems.PlotItem.PlotItem.PlotItem object".
So what should I do to make this example work for me?
import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtGui, QtCore
from pyqtgraph.Point import Point
pg.setConfigOption('background', '#ffffff')
pg.setConfigOption('foreground', 'k')
pg.setConfigOptions(antialias=True)
app = QtGui.QApplication([])
win = pg.GraphicsWindow()
win.setWindowTitle('pyqtgraph example: crosshair')
label = pg.LabelItem(justify='right')
win.addItem(label)
p1 = win.addPlot(row=1, col=0)
p1.setAutoVisible(y=True)
#create numpy arrays
#make the numbers large to show that the xrange shows data from 10000 to all the way 0
data1 = 10000 + 15000 * pg.gaussianFilter(np.random.random(size=10000), 10) + 3000 * np.random.random(size=10000)
p1.plot(data1, pen="r")
#cross hair
vLine = pg.InfiniteLine(angle=90, movable=False)
hLine = pg.InfiniteLine(angle=0, movable=False)
p1.addItem(vLine, ignoreBounds=True)
p1.addItem(hLine, ignoreBounds=True)
vb = p1.vb
print(p1)
print(vb)
def mouseMoved(evt):
pos = evt[0] ## using signal proxy turns original arguments into a tuple
if p1.sceneBoundingRect().contains(pos):
mousePoint = vb.mapSceneToView(pos)
index = int(mousePoint.x())
if index > 0 and index < len(data1):
label.setText("<span style='font-size: 12pt'>x=%0.1f, <span style='color: green'>y2=%0.1f</span>" % (mousePoint.x(), data1[index]))
vLine.setPos(mousePoint.x())
hLine.setPos(mousePoint.y())
proxy = pg.SignalProxy(p1.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
#p1.scene().sigMouseMoved.connect(mouseMoved)
## Start Qt event loop unless running in interactive mode or using pyside.
if __name__ == '__main__':
import sys
if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
QtGui.QApplication.instance().exec_()

Answer 1

I am very sorry for the noise!!! I fix it myself!
The important part was:
plot_wg.proxy = proxy
Very simple...
Below is the function, which should work for any PlotWidget:
def cross_hair(self, plot_wg, log=False ):
global fit
################### TETS cross hair ############3
vLine = pg.InfiniteLine(angle=90, movable=False)#, pos=0)
hLine = pg.InfiniteLine(angle=0, movable=False)#, pos=2450000)
plot_wg.addItem(vLine, ignoreBounds=True)
plot_wg.addItem(hLine, ignoreBounds=True)
vb = plot_wg.getViewBox()
label = pg.TextItem()
plot_wg.addItem(label)
def mouseMoved(evt):
pos = evt[0] ## using signal proxy turns original arguments into a tuple
if plot_wg.sceneBoundingRect().contains(pos):
mousePoint = vb.mapSceneToView(pos)
if log == True:
label.setText("x=%0.3f, y1=%0.3f"%(10**mousePoint.x(), mousePoint.y()))
else:
label.setText("x=%0.3f, y1=%0.3f"%(mousePoint.x(), mousePoint.y()))
vLine.setPos(mousePoint.x())
hLine.setPos(mousePoint.y())
#print(mousePoint.x(),mousePoint.y())
plot_wg.getViewBox().setAutoVisible(y=True)
proxy = pg.SignalProxy(plot_wg.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
plot_wg.proxy = proxy
proxy = pg.SignalProxy(plot_wg.scene().sigMouseMoved, rateLimit=60, slot=mouseMoved)
plot_wg.proxy = proxy
################### TETS cross hair ############3