how to get mouse position in - mousemove

Question

I am a new pyqtgraph users,try to "Embedding widgets inside PyQt applications"following the instructions in http://www.pyqtgraph.org/documentation/how_to_use.html. in my example I promote Graphics view to PlotWidget, then save as "test2.ui", also follow the "crosshair/mouse interaction" example,my code:
import sys
import numpy
from PyQt5 import QtCore, QtGui,uic,QtWidgets
from PyQt5.QtWidgets import *
import pyqtgraph as pg
import os
hw,QtBaseClass=uic.loadUiType("test.ui")
def gaussian(A, B, x):
return A * numpy.exp(-(x / (2. * B)) ** 2.)
class MyApp(QtWidgets.QMainWindow, hw):
def __init__(self):
super().__init__()
self.setupUi(self)
winSize=self.size()
self.view.resize(winSize.width(),winSize.height())
x = numpy.linspace(-5., 5., 10000)
y =gaussian(5.,0.2, x)
self.p=self.view.plot(x,y)
proxy = pg.SignalProxy(self.view.scene().sigMouseMoved, rateLimit=60, slot=self.mouseMoved)
self.view.enableAutoRange("xy", True)
def mouseMoved(evt):
print("mouseTest")
mousePoint = self.p.vb.mapSceneToView(evt[0])
label.setText(
"<span style='font-size: 14pt; color: white'> x = %0.2f, <span style='color: white'> y = %0.2f</span>" % (
mousePoint.x(), mousePoint.y()))
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = MyApp()
window.show()
sys.exit(app.exec_())
it seems not get the mouse move event;
after change
proxy = pg.SignalProxy(self.view.scene().sigMouseMoved, rateLimit=60, slot=self.mouseMoved)
to
self.view.scene().sigMouseMoved.connect(self.mouseMoved),
output"MouseTest",but program imediatly crash.
can any one give me some help

Answer 1

Two things:
Re: Crashing
It seems as if you haven't placed a label in the GUI to modify, perhaps your code is seeing this and kicks it back to you. If you're using qtDesigner, it is likely defined as self.label, and in my GUI, I was required to use self.label to reference it.
Re: mouseMoved function
I was just struggling with a similar issue of it not working. I was able to get mine to work by changing the evt[0] to simply evt, something I think they moved to from pyqt4 to pyqt5.
Here's an example of what I was able to get to work:
..........setup code above... IN THE setupUi function:
..........setup code above...
Plotted = self.plot
vLine = pg.InfiniteLine(angle=90, movable=False)
hLine = pg.InfiniteLine(angle=0, movable=False)
Plotted.addItem(vLine, ignoreBounds=True)
Plotted.addItem(hLine, ignoreBounds=True)
Plotted.setMouseTracking(True)
Plotted.scene().sigMouseMoved.connect(self.mouseMoved)
def mouseMoved(self,evt):
pos = evt
if self.plot.sceneBoundingRect().contains(pos):
mousePoint = self.plot.plotItem.vb.mapSceneToView(pos)
self.label.setText("<span style='font-size: 15pt'>X=%0.1f, <span style='color: black'>Y=%0.1f</span>" % (mousePoint.x(),mousePoint.y()))
self.plot.plotItem.vLine.setPos(mousePoint.x())
self.plot.plotItem.hLine.setPos(mousePoint.y()
...the if__name__ =="__main__": function .....
In my case, I did not pass the proxy statement, and instead just went for the sigMouseMoved since it already passes the information the proxy would. I think this was in the example in pyqt5 (and commented out) because it was the change. However, the comment didn't specifically state this.