GraphicsWindow embedded to PyQt UI - how to trigger QTimer from main class?

[roman.grz...@gmail.com]

I'd like to embed pyqtgraph window into my GUI which was created in QtDesiger. At first I just created new window and defined everything inside main GUI class (MyApp) and everything is working fine this way.

Now I created a Plotter class for GraphicsWindow, saved it to file pyqtwindow.py, and promoted it in Designer so now when I run my GUI, the window of pyqtgraph is there. 

The rest of GUI stuff is inside MyApp class in GUI.py file. How can I connect signals between these classes? I also have different class in different file for storing the data (dataframes.py, which is defined as dfs in MyApp), how do I read the results from this class inside my Plotter class?

class Plotter(pg.GraphicsWindow):

    def __init__(self, parent=None, **kargs):

        pg.GraphicsWindow.__init__(self, **kargs)

        self.setParent(parent)

        self.plt = self.addPlot(row=1, col=0, title="Plot",

                                    labels={'left': 'Voltage [V]',

                                            'bottom': 'time [s]'})

        self.curve = self.plt.plot(pen='b')

        self.label_cords = pg.LabelItem(justify="right")

        self.addItem(self.label_cords)

        self.proxy = pg.SignalProxy(self.plt.scene().sigMouseMoved, rateLimit=60,

                                    slot=self.mouseMoved)

        self.plot_timer = pg.QtCore.QTimer()

        self.plot_timer.timeout.connect(self.updatePlot)

        

    def startPlot(self):

    self.plot_timer.start(1000) # how can I trigger it from main class MyApp, which has all other signals/slots connected ?

    def stopPlot(self):

    self.plot_timer.stop() # I'd like to stop the trigger the same way (pushing STOP button which is in MyApp class)

    def mouseMoved(self, evt):

        self.mousePoint = self.plt.vb.mapSceneToView(evt[0])

        self.label_cords.setText("<span style='font-size: 8pt; color: white'> x = %0.4f, <span style='color: white'> y = %0.4f</span>"

           % (self.mousePoint.x(), self.mousePoint.y()))

    

    def updatePlot(self):

        self.curve.clear()

        self.curve.setData(dfs.data_dictionary['time'], dfs.data_dictionary['Voltage'])

if __name__ == '__main__':

    w = Plotter()

    w.show()

    QtGui.QApplication.instance().exec_()

[Patrick]

Hi,

I think all this is fairly straightforward. You just need to connect your GUI button signals to your startPlot/stopPlot mothods. From the init of your MyApp class, something like:

self.startButton.clicked.connect(self.plotter.startPlot) # where plotter is a reference to the Plotter window inside your GUI.

For getting the data to the Plotter class, you will need to pass in a reference to your data structure somehow, either in init and/or a method. So:

class Plotter(pg.GraphicsWindow):
    def __init__(self, datasource, parent=None, **kargs):
        # ...
        # self.dfs = datasource
        # ...
   
    # ...

    def setDataSource(self, datasource):
        self.dfs = datasource

    def updatePlot(self):
        # self.curve.clear() # Note, you don't need to clear before doing a setData
        self.curve.setData(self.dfs.data_dictionary['time'], self.dfs.data_dictionary['Voltage'])

Patrick