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Displaying real-time data on a 2nd window

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  • J 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??

    JonBJ Online
    JonBJ Online
    JonB
    wrote on last edited by JonB
    #26

    @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.

    1 Reply Last reply
    3
    • J Offline
      J Offline
      john_hobbyist
      wrote on last edited by john_hobbyist
      #27

      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....

      JonBJ 1 Reply Last reply
      0
      • J 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....

        JonBJ Online
        JonBJ Online
        JonB
        wrote on last edited by JonB
        #28

        @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).
        1 Reply Last reply
        1
        • J Offline
          J Offline
          john_hobbyist
          wrote on last edited by john_hobbyist
          #29
          This post is deleted!
          1 Reply Last reply
          0
          • J Offline
            J Offline
            john_hobbyist
            wrote on last edited by john_hobbyist
            #30

            In order to start from somewhere, after your very useful comments I did a change in the code so that when the ct changes to call the method def onChanged(self, text) which prints "OK". However, this happens only the first time that ct changes value. All the next times it does not print "OK"...What do I miss here???

            1 Reply Last reply
            0
            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #31

              I may sound harsh but: proper architecture.

              I would suggest to start with something really minimal to just learn to use signals and slots properly, how to manage multiple different complex widgets that are only linked together by signals and slots.

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

              1 Reply Last reply
              2
              • J Offline
                J Offline
                john_hobbyist
                wrote on last edited by
                #32

                I am trying! How can I call a method before declaring it?

                1 Reply Last reply
                0
                • SGaistS Offline
                  SGaistS Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on last edited by
                  #33

                  You just don't.

                  As I already suggested: start with Qt's basics.

                  • Single widget with signals and slots within it.
                  • Second widget completely unrelated to the first one
                  • Connect them only after they both properly work independently
                  • While doing that: write unit tests

                  Interested in AI ? www.idiap.ch
                  Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                  1 Reply Last reply
                  2
                  • J Offline
                    J Offline
                    john_hobbyist
                    wrote on last edited by
                    #34

                    @SGaist Thank you, I will try it.

                    Please tell me a reason that the code runs commands such as open/make a widget + QLinedit + QLabels (I checked it with print commands) but I see only the widget (window) and nothing inside... What is wrong?

                    jsulmJ 1 Reply Last reply
                    0
                    • J john_hobbyist

                      @SGaist Thank you, I will try it.

                      Please tell me a reason that the code runs commands such as open/make a widget + QLinedit + QLabels (I checked it with print commands) but I see only the widget (window) and nothing inside... What is wrong?

                      jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #35

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

                      What is wrong?

                      Please show the code, else only guessing is possible!
                      Did you add these widgets to your container widget (main window or whatever)?

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                      1 Reply Last reply
                      1
                      • J Offline
                        J Offline
                        john_hobbyist
                        wrote on last edited by
                        #36

                        I am trying to embed a grid layout to the right side of the mainwidget. Imagine that I have divided the mainwidget area into 2 areas, left and side. I get this error though:

                        File "code.py", line 1643, in __init__
                          mylayout.addWidget(self.imageviewer, 1, 1)
                        TypeError: addWidget(self, QWidget, stretch: int = 0, alignment: Union[Qt.Alignment, Qt.AlignmentFlag] = Qt.Alignment()): argument 3 has unexpected type 'int'
                        

                        What did I do wrong?

                        1 Reply Last reply
                        0
                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #37

                          Are you sure mylayout is a QGridLayout ?

                          Interested in AI ? www.idiap.ch
                          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                          1 Reply Last reply
                          1
                          • J Offline
                            J Offline
                            john_hobbyist
                            wrote on last edited by john_hobbyist
                            #38

                            I have it like this:

                            mylayout = QHBoxLayout()
                            
                            1 Reply Last reply
                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #39

                              So since it's a QHBoxLayout, why are you trying to use it like a grid layout ?

                              The error message tells you exactly the problem you have. If you read the method documentation, you'll see that the second parameter shall be a value from the Alignment enum.

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              1 Reply Last reply
                              1
                              • J Offline
                                J Offline
                                john_hobbyist
                                wrote on last edited by
                                #40
                                This post is deleted!
                                JonBJ 1 Reply Last reply
                                0
                                • J john_hobbyist

                                  This post is deleted!

                                  JonBJ Online
                                  JonBJ Online
                                  JonB
                                  wrote on last edited by JonB
                                  #41

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

                                  mylayout.addWidget(self.imageviewer, 1, 1)

                                  You're not reading @SGaist's replies and understanding/acting on them. Anyway, what do you intend this line to do?

                                  1 Reply Last reply
                                  1
                                  • J Offline
                                    J Offline
                                    john_hobbyist
                                    wrote on last edited by
                                    #42

                                    @SGaist @JonB: You are right!!!! Thanks!

                                    1 Reply Last reply
                                    0
                                    • J Offline
                                      J Offline
                                      john_hobbyist
                                      wrote on last edited by john_hobbyist
                                      #43

                                      I call the above class each time the mouse pointer changes position. The problem is that nothing is shown..but the print commands that I have embed between the below commands work!
                                      Why?
                                      I call it like this:

                                      w = Town()
                                      w.show()
                                      

                                      This is the class that I call

                                      class Town(QWidget):
                                          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
                                              
                                              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.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()
                                              win.update()
                                      jsulmJ 1 Reply Last reply
                                      0
                                      • J john_hobbyist

                                        I call the above class each time the mouse pointer changes position. The problem is that nothing is shown..but the print commands that I have embed between the below commands work!
                                        Why?
                                        I call it like this:

                                        w = Town()
                                        w.show()
                                        

                                        This is the class that I call

                                        class Town(QWidget):
                                            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
                                                
                                                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.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()
                                                win.update()
                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #44

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

                                        I call it like this:

                                        Where?
                                        Please show that part of your code.
                                        Also, why do you create a new QWidget in Town which does not contain anything? Town is already a QWidget.

                                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        J 1 Reply Last reply
                                        1
                                        • jsulmJ jsulm

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

                                          I call it like this:

                                          Where?
                                          Please show that part of your code.
                                          Also, why do you create a new QWidget in Town which does not contain anything? Town is already a QWidget.

                                          J Offline
                                          J Offline
                                          john_hobbyist
                                          wrote on last edited by john_hobbyist
                                          #45

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

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

                                          I call it like this:

                                          Where?
                                          Please show that part of your code.
                                          Also, why do you create a new QWidget in Town which does not contain anything? Town is already a QWidget.

                                          You mean this (?) :

                                          win = QWidget()
                                          . . . 
                                          win.setGeometry(100,100,200,100)
                                          win.setWindowTitle("Test")
                                          win.show()
                                          win.update()
                                          

                                          So, class Town(QWidget): makes a widget before the previous code...(?)

                                          jsulmJ 1 Reply Last reply
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