New overriden and generated QLineEdit class will not be placed on the MainWindow as expected

Mohsen Owzar mohsen.owzar at
Fri Oct 8 03:03:00 EDT 2021

Hi all
Some days ago, I send a question to this community about a clickable QLineEdit.
After getting the Hint to use QMouseEvent, I've written the program which is working almost good but with a small or perhaps big ugliness and that is:
Below is the imgur link to the screenshots of my program after clicking the buttons in sequence:
As you will see in the code blow, I override the QlineEdit widget and define a new class " CustomLineEdit " to generate a "clicked" signal, when the user pressed with mouse on this field.
I use this "CustomLineEdit" class and place it on the MainWindow with the desired "layout".
I couldn't figure out, why this widget is placed not in the MainWindow, but outside this window, as you can see in the top picture of the attached screenshots.
When I take the line 12 ( from the code, the generated class will not appear.
The problem here is that at the beginning, the MainWindow with a LineEdit field should appear at the program start.
Then, after clicking on this field, the keypad should come up outside the MainWindow.
Could anyone see, where my mistake is?
Thanks for any help.
Here is the code:
import sys
from PyQt5.QtWidgets import (QApplication, QLineEdit, QPushButton, QMainWindow,
                             QVBoxLayout, QHBoxLayout, QGridLayout, QWidget)
from PyQt5.QtCore import pyqtSignal, pyqtSlot

class CustomLineEdit(QLineEdit):
    clicked = pyqtSignal()

    def __init__(self):

    def mousePressEvent(self, QMouseEvent):

class MainWindow(QMainWindow):
    def __init__( self, parent=None ):

        self.title = 'Window 1'
        self.left = 700 = 300
        self.width = 200
        self.height = 200

    def initUI(self):

        self.keypad_window = Keypad_Window(self)

        hbox = QHBoxLayout()

        self.cle = CustomLineEdit()
        self.cle.setFixedSize(220, 60)
        self.cle.setStyleSheet("color: red;"
                               "background-color: yellow;"
                               "font-family: Arial;"
                               "font-weight: Bold;"
                               "font-size: 30pt")


        self.setGeometry(self.left,, self.width, self.height)

    def show_keypad_window(self):

    def close(self):
        super(MainWindow, self).close()

    def update_label(self, txt):

class Keypad_Window(QWidget):
    def __init__(self, parent=None):
        self.parent = parent

        self.setGeometry(1200, 500, 230, 400)

        vbox = QVBoxLayout()
        self.display = QLineEdit()
        self.display.setFixedSize(220, 60)
        self.display.setStyleSheet("color: Blue; "
                                   "background-color: lightgreen;"
                                   "font-family: Arial;"
                                   "font-weight: Bold;"
                                   "font-size: 18pt")

        """Create the buttons."""
        self.buttons = {}
        self.gridlay = QGridLayout()

        self.button_name = [['7', '8', '9'],
                            ['4', '5', '6'],
                            ['1', '2', '3'],
                            ['C', '0', '>']]

        self.command_name = [['7', '8', '9'],
                             ['4', '5', '6'],
                             ['1', '2', '3'],
                             ['delete', '0', 'accept']]

        for i in range(4):
            for j in range(3):
                text = self.button_name[i][j]

                # keep a reference to the buttons
                self.buttons[i, j] = QPushButton()
                self.buttons[i, j].setText(text)
                self.buttons[i, j].setObjectName(text)
                self.buttons[i, j].setFixedSize(70, 70)
                if i == 3:
                    if j == 0:
                        self.buttons[i, j].setToolTip('Each click deletes\na digit to the left')

                    if j == 2:
                        self.buttons[i, j].setToolTip('The whole displayed\nvalue will be taken!')

                self.buttons[i, j].clicked.connect(self.call_button_fun(i, j, self.command_name))

                # add to the GridLayout
                self.gridlay.addWidget(self.buttons[i, j], i, j)
                self.buttons[i, j].setStyleSheet("color: blue; "
                                                 "background-color: cyan;"
                                                 "font-family: Arial;"
                                                 "font-weight: Bold;"
                                                 "font-size: 20pt")

    def call_button_fun(self, i, j, command_name):
        def button_fun():
            if command_name[i][j] == self.button_name[i][j]:
                displayed_text = self.display.text()
                self.new_text = displayed_text + self.button_name[i][j]

            if command_name[i][j] == 'accept':
                print('>-key pressed!')

            if command_name[i][j] == 'delete':
                print('C-key pressed!')

        return button_fun

if __name__ == "__main__":
    app = QApplication(sys.argv)
    mainwindow = MainWindow()

    # Exception abfangen, wenn sie nicht behandelt wurde
    sys._excepthook = sys.excepthook

    def exception_hook(exctype, value, traceback):
        print(exctype, value, traceback)
        sys._excepthook(exctype, value, traceback)

    sys.excepthook = exception_hook


More information about the Python-list mailing list