Displaying real-time data on a 2nd window

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...

JonB

@john_hobbyist

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.

Show the code you use to connect the mouse move signal or event in the first window to the slot in the second window.

If you say everything works when you output the town name on the terminal (print() maybe?), and now want to display it on a QTextEdit instead, then as I already said all you have to do is call the line edit's setText().

john_hobbyist

class Town(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()
        
    def initUI(self):
        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
        
        win = QWidget()
        grid=QGridLayout()
       
        import pandas
        ct = pandas.read_csv('CurrentTown.csv')
        town = QLabel("town:")
        town.setStyleSheet("border: 1px solid black; background-color: yellow")  
        grid.addWidget(town, 1,1)
        textEdit_1 = QLineEdit(ct)
        textEdit_1.textChanged[str].connect(self.onChanged)
        textEdit_1.setReadOnly(True)
        grid.addWidget(textEdit_1,1,2)

        
        import os
        os.remove('CurrentTown.csv')
    
        self.setLayout(grid)
        win.setGeometry(100,100,200,100)
        win.setWindowTitle("Test")
        win.show()
        
    def onChanged(self, text):
         self.textEdit_1.setText(str(ct))

Any ideas??

JonB

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

textEdit_1.textChanged[str].connect(self.onChanged)

I already said. You think you want to connect QLineEdit.textChanged signal to do something. That is when something changes the text. But you don't have anything changing the text. You need a signal for when the file content changes to connect to a slot to change the text in the line edit.

You claimed you had it working printing on terminal fine, but I don't see that.

Conceptually the code you have to read the file must be in a method called when the text in the file is changed. You have all this code in the constructor of the Town widget, which cannot be right.

There is no connection at all between your textEdit_1 = QLineEdit(ct) and the self.textEdit_1.setText(str(ct)) you use later. Please review local versus member variables in Python.

You don't want to have any self.textEdit_1 in class Town as the line edit you want to address is not on the Town widget, it is on the win widget.

Start by creating a separate Python module and class for your second window. Put the code to read the file and set the line edit text there. Then in this Town module create an instance of that class and show it. In Town you will have some connection like:

self.signalForFileDataChanged.connect(self.otherWindow.onFileDataChanged)

where the second window's onFileDataChanged() reads the new text from the file and sets its line edit.

When you have that working you may see that you could have the Town.signalForFileDataChanged() signal send a parameter of the new town name to the OtherWindow.onFileDataChanged() slot for it to show. Then you can ditch having them communicate via the content of an external file.

john_hobbyist

I have another method that I want to call from another class. I have this code:

class Two(CentralWindow):
    def do_something(self, checked):
    . . .

I want to call the do_something method from initUI(self) ??
I have tried google search solutions, but they show to call a method outside a class/method. I need to call the do_something method from inside initUI(self) method....

JonB

@john_hobbyist
Fundamental Python. Nothing special about initUI(self).

From within class Two: self.do_something(checked).
From outside class Two: class_two_instance.do_something(checked).