Displaying real-time data on a 2nd window

john_hobbyist

So the idea is that I have a window where I display a map of a country. Through a button I open another new window (auxiliary to the 1st window, I mean both windows exist after the opening of the 2nd window) where it should display some data. Everytime I move the mouse pointer (on the map) to different places, the second window should update the values and show new data, which does not happen. In order to check that the code works, I also print the data (that should be displayed and updated in real-time on the second window) on the terminal which work just fine! What I am missing here?

In C++ I think this a volatile variable problem. But in python I have no idea! Is this a thread problem? Any ideas? (I work on PyQt5)

JonB

@john_hobbyist
It should be perfectly doable. You will have to show some code.

But in python I have no idea! Is this a thread problem?

Hopefully you are not using threads anyway? If you do, again show relevant code.

john_hobbyist

The 2nd window that displays the names of the towns (from where the pointer points on the 1st map) keeps only the 1st town I pointed. When I change position to the mouse pointer, it does not refresh the name on the 2nd window. I use a .csv file in order to pass data from the 1st window (class) to the 2nd window (class). Can you guide me? What should I check?

SGaist

Hi,

Did you check that the signal arrives ?
What are you using to show the information ?
How do you do it ?

JonB

@john_hobbyist said in Displaying real-time data on a 2nd window:

I use a .csv file in order to pass data from the 1st window (class) to the 2nd window (class).

Please first answer @SGaist's questions. But if you are using a file somehow to pass data between two windows rather than a signal that is likely not a good idea.

john_hobbyist

@SGaist said in Displaying real-time data on a 2nd window:

Hi,

Did you check that the signal arrives ?
What are you using to show the information ?
How do you do it ?

How I check them? With "print" commands do you mean?
QLineEdit (on the 2nd window)
I have a .csv with coordinates and the towns' name, when I change coordinates (by moving the mouse pointer) the name of the town on the 2nd window should change/refresh.

What I see now, is that If I close the 2nd window and open a new one (2nd window again), the town's name is refreshed. But I cannot continuously refresh the 2nd window, the text inside the QLineEdit should be updated only... Do I miss something here?

SGaist

Yes, print is one option.

Please show us the code you are using.

john_hobbyist

From google search I found this: https://stackoverflow.com/questions/14630863/changing-text-in-qlineedit-of-qt-application-in-real-time and this: https://pythonpyqt.com/qtimer/

So, how I attach Qtimer to a QLineEdit and update the text it has inside?

JonB

@john_hobbyist said in Displaying real-time data on a 2nd window:

So, how I attach Qtimer to a QLineEdit and update the text it has inside?

Since both of your links, especially the first, show you, what is the question?

john_hobbyist

@JonB said in Displaying real-time data on a 2nd window:

@john_hobbyist said in Displaying real-time data on a 2nd window:

So, how I attach Qtimer to a QLineEdit and update the text it has inside?

Since both of your links, especially the first, show you, what is the question?

It is in C++...

SGaist

Indeed but that code is not really hard to translate to Python.

john_hobbyist

    def __init__(self):
        super().__init__()
        import sys
        from PyQt5.QtWidgets import QWidget,QPushButton,QApplication,QListWidget,QGridLayout,QLabel
        from PyQt5.QtCore import QTimer,QDateTime
        from PyQt5 import QtWidgets
        from PyQt5.QtWidgets import QApplication, QMainWindow
        from PyQt5 import QtCore
        
        timer = QtCore.QTimer()
        timer.timeout.connect(self.ShowText)
        timer.start(1000)
        
    def ShowText(self):
        import pandas
        win = QWidget()   
        grid=QGridLayout()   
        ct = pandas.read_csv('CurrentTown.csv')   
        town = QLabel("town:")   
        town.setStyleSheet("border: 1px solid black; background-color: yellow")   
        grid.addWidget(town , 1,1)   
        self.textEdit_1 = QLineEdit(ct)   
        self.textEdit_1.setReadOnly(True)   
        grid.addWidget(self.textEdit_1,1,2)   
               
        import os
        os.remove('CurrentTown.csv')   
        self.setLayout(grid)   
        win.setGeometry(100,100,200,100)   
        win.setWindowTitle("Test")   
        win.show()

It does not display even a static text...and obviously it does not update anything on the textboxes, any ideas why?

SGaist

That code does not define a widget nor anything within it so it's pretty hard to tell you what's wrong.

john_hobbyist

I updated it again...Any ideas???

SGaist

Why are you recreating the whole widget each time ?
Why are you deleting the data file each time as well ?

john_hobbyist

@SGaist I put

win = QWidget()   
grid=QGridLayout()

inside

def __init__(self):

again the same thing! One widget without any even a QLabel, QLineEdit, no data, nothing...

I use the .csv in order to pass and get value from another method from another class.

Any ideas?

SGaist

Your code is incomplete so it's not possible to answer.
However one thing is sure: creating and deleting a file to communicate between two classes in the same application is not the correct solution.

If you want more help provide a minimal runnable script that shows what you are trying to do.

john_hobbyist

How do I make this command:

qle.textChanged[str].connect(self.onChanged)

(source: https://zetcode.com/pyqt/qlineedit/)

change the text in QLineEdit when "ct" variable has different value. "ct" variable is in my code...

SGaist

@SGaist said in Displaying real-time data on a 2nd window:

If you want more help provide a minimal runnable script that shows what you are trying to do.

JonB

@john_hobbyist said in Displaying real-time data on a 2nd window:

change the text in QLineEdit when "ct" variable has different value. "ct" variable is in my code...

You ask about a piece of code which has no "ct variable" used in it. How do you think anybody can answer this?