Displaying real-time data on a 2nd window

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?

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:

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?

Please look at my code above. I have posted the code and where "ct" is used...

JonB

@john_hobbyist

ct = pandas.read_csv('CurrentTown.csv')

We don't know what pandas.read_csv() returns. I would guess some kind of table? So I don't know what you expect to put in a QLineEdit for its "value".

Anyway, if you have qle.textChanged[str].connect(self.onChanged) that means self.onChanged() will be called when qle's text changes. If qle is the QLineEdit you are talking about

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

then that connection is not relevant. If this is what you want, then "when "ct" variable has different value" however that happens just call qle.setText(str(ct)) or whatever you want. Else you mean something different.

john_hobbyist

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

@john_hobbyist
ct = pandas.read_csv('CurrentTown.csv')
We don't know what pandas.read_csv() returns. I would guess some kind of table? So I don't know what you expect to put in a QLineEdit for its "value".

Anyway, if you have qle.textChanged[str].connect(self.onChanged) that means self.onChanged() will be called when qle's text changes. If qle is the QLineEdit you are talking about

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

then that connection is not relevant. If this is what you want, then "when "ct" variable has different value" however that happens just call qle.setText(str(ct)) or whatever you want. Else you mean something different.

 ct = pandas.read_csv('CurrentTown.csv')

holds the name of one town each time I read the .csv. nothing else. It is use in order to pass the name of the town from another class/method and that's it. When I move the cursor of the mouse to another town the .csv stores the other new town (from the other class/method) and I read it with the "ct". I only need to update the town name on the QLineEdit field...