PyQt5 Designer with Custom Slots - python

I'm still trying to figure out PyQt and running into another issue that I've been beating my head over for the last several hours. When I use pyuic5 to convert the .ui file into the .py file, part of the output (in the class Ui_MainWindow) connects signals to slots:
self.browseButton.clicked.connect(MainWindow.browseSlot)
self.importButton.clicked.connect(MainWindow.importSlot)
self.lineEdit.returnPressed.connect(MainWindow.returnPressedSlot)
This is called from the main function:
def main():
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = MainWindowUI()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
Above this, in the same file, I have the following code:
class MainWindowUI(Ui_MainWindow):
def __init__(self):
super().__init__()
self.model = Model()
def setupUi(self, mainWindow):
super().setupUi(mainWindow)
def debugPrint(self, msg):
self.textEdit.append(msg)
def refreshAll(self):
self.lineEdit.setText(self.model.getFileName())
self.textEdit.setText(self.model.getFileContents())
def returnPressedSlot(self):
self.debugPrint('Return key pressed')
def importSlot(self):
self.debugPrint('Import button pressed')
def browseSlot(self):
self.debugPrint('Browse button pressed')
The exact error I'm getting is this:
AttributeError: 'QMainWindow' object has no attribute 'browseSlot'
This actually makes perfect sense, because there's no reason QtWidgets.QMainWindow() should know anything about the custom slots I defined in the MainWindowUI class. So it makes sense that it doesn't work, but I'm confused about what I should be doing differently. This is how every tutorial I've seen sets it up, so clearly I have a fundamental misunderstanding somewhere. Any help in clarifying this issue would be appreciated!
Many thanks in advance.
Edited to add the full code of my Ui_MainWindow class:
# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'test.ui'
#
# Created by: PyQt5 UI code generator 5.11.3
#
# WARNING! All changes made in this file will be lost!
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(798, 593)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
self.gridLayout.setObjectName("gridLayout")
self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
self.tabWidget.setObjectName("tabWidget")
self.tab = QtWidgets.QWidget()
self.tab.setObjectName("tab")
self.verticalLayout = QtWidgets.QVBoxLayout(self.tab)
self.verticalLayout.setObjectName("verticalLayout")
self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
self.horizontalLayout_2.setObjectName("horizontalLayout_2")
self.frame_2 = QtWidgets.QFrame(self.tab)
self.frame_2.setFrameShape(QtWidgets.QFrame.StyledPanel)
self.frame_2.setFrameShadow(QtWidgets.QFrame.Raised)
self.frame_2.setObjectName("frame_2")
self.debugTextBrowser = QtWidgets.QTextBrowser(self.frame_2)
self.debugTextBrowser.setGeometry(QtCore.QRect(10, 10, 351, 461))
self.debugTextBrowser.setObjectName("debugTextBrowser")
self.horizontalLayout_2.addWidget(self.frame_2)
self.frame = QtWidgets.QFrame(self.tab)
self.frame.setFrameShape(QtWidgets.QFrame.StyledPanel)
self.frame.setFrameShadow(QtWidgets.QFrame.Raised)
self.frame.setObjectName("frame")
self.browseButton = QtWidgets.QPushButton(self.frame)
self.browseButton.setGeometry(QtCore.QRect(80, 30, 51, 20))
self.browseButton.setObjectName("browseButton")
self.lineEdit = QtWidgets.QLineEdit(self.frame)
self.lineEdit.setGeometry(QtCore.QRect(80, 10, 281, 20))
self.lineEdit.setObjectName("lineEdit")
self.importButton = QtWidgets.QPushButton(self.frame)
self.importButton.setGeometry(QtCore.QRect(310, 30, 51, 20))
self.importButton.setObjectName("importButton")
self.textEdit = QtWidgets.QTextEdit(self.frame)
self.textEdit.setGeometry(QtCore.QRect(80, 130, 281, 81))
self.textEdit.setObjectName("textEdit")
self.horizontalLayout_2.addWidget(self.frame)
self.verticalLayout.addLayout(self.horizontalLayout_2)
self.setupProgressBar = QtWidgets.QProgressBar(self.tab)
self.setupProgressBar.setProperty("value", 0)
self.setupProgressBar.setTextVisible(False)
self.setupProgressBar.setInvertedAppearance(False)
self.setupProgressBar.setTextDirection(QtWidgets.QProgressBar.TopToBottom)
self.setupProgressBar.setObjectName("setupProgressBar")
self.verticalLayout.addWidget(self.setupProgressBar)
self.tabWidget.addTab(self.tab, "")
self.tab_2 = QtWidgets.QWidget()
self.tab_2.setObjectName("tab_2")
self.tabWidget.addTab(self.tab_2, "")
self.tab_3 = QtWidgets.QWidget()
self.tab_3.setObjectName("tab_3")
self.tabWidget.addTab(self.tab_3, "")
self.tab_4 = QtWidgets.QWidget()
self.tab_4.setObjectName("tab_4")
self.tabWidget.addTab(self.tab_4, "")
self.tab_5 = QtWidgets.QWidget()
self.tab_5.setObjectName("tab_5")
self.tabWidget.addTab(self.tab_5, "")
self.gridLayout.addWidget(self.tabWidget, 0, 0, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 798, 18))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
self.tabWidget.setCurrentIndex(0)
self.browseButton.clicked.connect(MainWindow.browseSlot)
self.importButton.clicked.connect(MainWindow.importSlot)
self.lineEdit.returnPressed.connect(MainWindow.returnPressedSlot)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.browseButton.setText(_translate("MainWindow", "Browse"))
self.importButton.setText(_translate("MainWindow", "Import"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Setup"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Production Forecast"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_3), _translate("MainWindow", "Production Forecast"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_4), _translate("MainWindow", "Page"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_5), _translate("MainWindow", "Page"))

PyQt recommends in your docs that you should inherit from the appropriate widget, in this case QMainWindow, and use Ui_MainWindow as an interface, it is also recommended that you use the decorator #QtCore.pyqtSlot() since you save resources and avoid having problems with overloaded signals.
class MainWindowUI(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
super().__init__()
self.setupUi(self)
self.model = Model()
def setupUi(self, mainWindow):
super().setupUi(mainWindow)
def debugPrint(self, msg):
self.textEdit.append(msg)
def refreshAll(self):
self.lineEdit.setText(self.model.getFileName())
self.textEdit.setText(self.model.getFileContents())
#QtCore.pyqtSlot()
def returnPressedSlot(self):
self.debugPrint('Return key pressed')
#QtCore.pyqtSlot()
def importSlot(self):
self.debugPrint('Import button pressed')
#QtCore.pyqtSlot()
def browseSlot(self):
self.debugPrint('Browse button pressed')
def main():
app = QtWidgets.QApplication(sys.argv)
w = MainWindowUI()
w.show()
sys.exit(app.exec_())
if __name__ == '__main__': main()

The PyQt 5 Designer generates files with .ui extension. The file contains xml code which can be converted to Python code with the pyuic5 command. The pyuic5 command produces a file with .py extension.
But each time the pyuic5 command is run, it overwrites any changes made to the Python file. To prevent this we need to copy the "main" code in the generated Python file to a separate file and then use this file as our main program file. In this file we can import the Python class generated by the pyuic5 command. We can also add our custom slots in this file
This practice of separating Qt Desginer code from custom code is good Qt programming practice. It has been suggested in Section 3 of the video ebook: "Python GUI Programming Recipes using PyQt5".

Related

How avoid change tab in QTabWidget | PyQt5

I'm trying to implement a tab with the name "+" in which if I click on it opens a ApplicationModal window for configurate the content in that tab. I want to avoid the change of tab when i click in it until press "Accept" in the ApplicationModal window. How can I block this change? I don't know if I explain me.
This it's de code
tabs.py for the MainWindow
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(628, 504)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
self.tabWidget.setGeometry(QtCore.QRect(36, 34, 541, 396))
self.tabWidget.setObjectName("tabWidget")
self.tab1 = QtWidgets.QWidget()
self.tab1.setObjectName("tab1")
self.tabWidget.addTab(self.tab1, "")
self.tab2 = QtWidgets.QWidget()
self.tab2.setObjectName("tab2")
self.tabWidget.addTab(self.tab2, "")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 628, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
self.tabWidget.setCurrentIndex(0)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab1), _translate("MainWindow", "Tab 1"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab2), _translate("MainWindow", "+"))
win0.py for the ApplicationModal window
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_Win0(object):
def setupUi(self, Win0):
Win0.setObjectName("Win0")
Win0.setWindowModality(QtCore.Qt.ApplicationModal)
Win0.resize(255, 203)
self.centralwidget = QtWidgets.QWidget(Win0)
self.centralwidget.setObjectName("centralwidget")
self.comboBox = QtWidgets.QComboBox(self.centralwidget)
self.comboBox.setGeometry(QtCore.QRect(17, 9, 154, 22))
self.comboBox.setObjectName("comboBox")
self.accpet_button = QtWidgets.QPushButton(self.centralwidget)
self.accpet_button.setGeometry(QtCore.QRect(43, 130, 75, 23))
self.accpet_button.setObjectName("accpet_button")
self.cancel_button = QtWidgets.QPushButton(self.centralwidget)
self.cancel_button.setGeometry(QtCore.QRect(135, 131, 75, 23))
self.cancel_button.setObjectName("cancel_button")
Win0.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(Win0)
self.menubar.setGeometry(QtCore.QRect(0, 0, 255, 21))
self.menubar.setObjectName("menubar")
Win0.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(Win0)
self.statusbar.setObjectName("statusbar")
Win0.setStatusBar(self.statusbar)
self.retranslateUi(Win0)
QtCore.QMetaObject.connectSlotsByName(Win0)
def retranslateUi(self, Win0):
_translate = QtCore.QCoreApplication.translate
Win0.setWindowTitle(_translate("Win0", "New Window"))
self.accpet_button.setText(_translate("Win0", "Accept"))
self.cancel_button.setText(_translate("Win0", "Cancel"))
And the main.py for develop the functionality
from tabs import Ui_MainWindow
from win0 import Ui_Win0
from PyQt5 import QtCore, QtGui, QtWidgets
class Win0(Ui_Win0):
win0 = None
def __init__(self, win):
self.win0 = win
super().__init__()
self.setupUi(self.win0)
class Main(Ui_MainWindow):
win0 = None
win1 = None
def __init__(self, win):
self.win = win
super().__init__()
self.setupUi(self.win)
self.tabWidget.tabBarClicked.connect(self.tabClick)
def tabClick(self, event):
if event == 1:
print("New tab")
self.win1 = QtWidgets.QMainWindow()
new_window = Win0(self.win1)
self.win1.show()
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Main(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
If you want a window that blocks the others until it's closed, you're looking for a modal dialog.
A modal window creates a mode that disables the main window but keeps it visible, with the modal window as a child window in front of it. Users must interact with the modal window before they can return to the parent application. This avoids interrupting the workflow on the main window.
[From the wikipedia article about modal windows]
It is relatively easy to achieve that in Qt, by using a QDialog.
Designer already provides two basic templates with basic Ok/Cancel buttons when you create a new form, so create a new dialog with buttons on right or bottom (this will automatically connect the button box with the dialog's accept/reject slots), add the combobox, save and convert the file with pyuic (in the following example, I exported the file as dialog.py and used the default Ui_Dialog).
Then the implementation is very easy. The important thing is to add the parent argument to the QDialog instance: this ensures that the dialog uses the parent as a reference for the "window modality", so that that parent is blocked until the dialog is closed by accepting or rejecting it (rejection is usually done by clicking on a RejectRole button like Cancel or by closing the dialog in any way, including pressing Esc).
Do note that I changed your approach by using multiple inheritance in order to make things easier (see the guidelines on using Designer about this approach, which is usually the better and most suggested method when using pyuic generated files).
from tabs import Ui_MainWindow
from dialog import Ui_Dialog
from PyQt5 import QtCore, QtGui, QtWidgets
class SelectDialog(QtWidgets.QDialog, Ui_Dialog):
def __init__(self, parent=None):
super().__init__(parent)
self.setupUi(self)
class Main(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
super().__init__()
self.setupUi(self)
self.tabWidget.tabBarClicked.connect(self.tabClick)
def tabClick(self, tab):
if tab == 1:
dialog = SelectDialog(self)
if dialog.exec_():
print(dialog.comboBox.currentIndex())
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
mainWindow = Main()
mainWindow.show()
sys.exit(app.exec_())

Very basic pyqt5 dialog app quits with exit code -1073740791

I tried to design a very basic GUI app that shows the entered height on a dialog, but after I press the ‘OK’ button on the main window, the whole program crashes and the process finishes with this exit code:
Process finished with exit code -1073740791 (0xC0000409)
Here’s the full code for the app, the UI files are below:
import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.uic import *
class My_Dialog(QDialog):
def __init__(self):
super(My_Dialog, self).__init__()
loadUi("dialog.ui", self)
self.mid_label.setText(My_Window.mid_label_nexttext)
class My_Window(QMainWindow):
def __init__(self):
super(My_Window, self).__init__()
loadUi("mainwindow.ui", self)
self.mid_label_nexttext = None
self.height_selecter_spinbox.textChanged.connect(lambda x: self.spin_changed(x))
self.pushButton.clicked.connect(self.onMyPushButtonClick)
def onMyPushButtonClick(self):
dlg = My_Dialog()
if dlg.exec_():
print("Success!")
else:
print("Cancel!")
def spin_changed(self, s):
self.mid_label_nexttext = s
self.update()
def main():
app = QApplication(sys.argv)
window = My_Window()
window.show()
app.exec_()
if __name__ == "__main__":
main()
The main window’s UI:
# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'mainwindow.ui'
#
# Created by: PyQt5 UI code generator 5.15.0
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again. Do not edit this file unless you know what you are doing.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(513, 171)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.pushButton = QtWidgets.QPushButton(self.centralwidget)
self.pushButton.setGeometry(QtCore.QRect(310, 80, 75, 23))
self.pushButton.setObjectName("pushButton")
self.layoutWidget = QtWidgets.QWidget(self.centralwidget)
self.layoutWidget.setGeometry(QtCore.QRect(90, 40, 209, 29))
self.layoutWidget.setObjectName("layoutWidget")
self.layout = QtWidgets.QHBoxLayout(self.layoutWidget)
self.layout.setContentsMargins(0, 0, 0, 0)
self.layout.setObjectName("layout")
self.label_firstpart = QtWidgets.QLabel(self.layoutWidget)
font = QtGui.QFont()
font.setPointSize(15)
self.label_firstpart.setFont(font)
self.label_firstpart.setObjectName("label_firstpart")
self.layout.addWidget(self.label_firstpart)
self.height_selecter_spinbox = QtWidgets.QSpinBox(self.layoutWidget)
font = QtGui.QFont()
font.setPointSize(13)
self.height_selecter_spinbox.setFont(font)
self.height_selecter_spinbox.setMinimum(100)
self.height_selecter_spinbox.setMaximum(250)
self.height_selecter_spinbox.setProperty("value", 175)
self.height_selecter_spinbox.setObjectName("height_selecter_spinbox")
self.layout.addWidget(self.height_selecter_spinbox)
self.label_lastpart = QtWidgets.QLabel(self.layoutWidget)
font = QtGui.QFont()
font.setPointSize(15)
self.label_lastpart.setFont(font)
self.label_lastpart.setObjectName("label_lastpart")
self.layout.addWidget(self.label_lastpart)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 513, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.pushButton.setText(_translate("MainWindow", "OK"))
self.label_firstpart.setText(_translate("MainWindow", "My height is "))
self.label_lastpart.setText(_translate("MainWindow", "cm."))
The dialog’s UI:
# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'dialog.ui'
#
# Created by: PyQt5 UI code generator 5.15.0
#
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again. Do not edit this file unless you know what you are doing.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_Dialog(object):
def setupUi(self, Dialog):
Dialog.setObjectName("Dialog")
Dialog.resize(400, 300)
self.dialog_buttonbox = QtWidgets.QDialogButtonBox(Dialog)
self.dialog_buttonbox.setGeometry(QtCore.QRect(30, 240, 341, 32))
self.dialog_buttonbox.setOrientation(QtCore.Qt.Horizontal)
self.dialog_buttonbox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
self.dialog_buttonbox.setObjectName("dialog_buttonbox")
self.widget = QtWidgets.QWidget(Dialog)
self.widget.setGeometry(QtCore.QRect(80, 90, 151, 41))
self.widget.setObjectName("widget")
self.dialog_layout = QtWidgets.QHBoxLayout(self.widget)
self.dialog_layout.setContentsMargins(0, 0, 0, 0)
self.dialog_layout.setObjectName("dialog_layout")
self.left_label = QtWidgets.QLabel(self.widget)
font = QtGui.QFont()
font.setPointSize(12)
self.left_label.setFont(font)
self.left_label.setObjectName("left_label")
self.dialog_layout.addWidget(self.left_label)
self.mid_label = QtWidgets.QLabel(self.widget)
font = QtGui.QFont()
font.setPointSize(12)
self.mid_label.setFont(font)
self.mid_label.setObjectName("mid_label")
self.dialog_layout.addWidget(self.mid_label)
self.right_label = QtWidgets.QLabel(self.widget)
font = QtGui.QFont()
font.setPointSize(12)
self.right_label.setFont(font)
self.right_label.setObjectName("right_label")
self.dialog_layout.addWidget(self.right_label)
self.retranslateUi(Dialog)
self.dialog_buttonbox.accepted.connect(Dialog.accept)
self.dialog_buttonbox.rejected.connect(Dialog.reject)
QtCore.QMetaObject.connectSlotsByName(Dialog)
def retranslateUi(self, Dialog):
_translate = QtCore.QCoreApplication.translate
Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
self.left_label.setText(_translate("Dialog", "You are"))
self.mid_label.setText(_translate("Dialog", "100"))
self.right_label.setText(_translate("Dialog", "cm tall."))
I would appreciate some help on fixing this error, and on why it occured.
You are trying to access an attribute that does not exist:
self.mid_label.setText(My_Window.mid_label_nexttext)
My_Window is a class, while mid_label_nexttext was assigned to the instance of that class (self is always the reference to the current instance).
If you want to set the text for that label from a "parent" window, you either add an extra argument to the __init__ that allows to get the text, or you set it from the main window.
Use the text as init argument
class My_Dialog(QDialog):
def __init__(self, text):
super(My_Dialog, self).__init__()
loadUi("dialog.ui", self)
# ensure that "text" is a valid string, you can't use setText(None)
if text:
self.mid_label.setText(text)
class My_Window(QMainWindow):
# ...
def onMyPushButtonClick(self):
dlg = My_Dialog(self.mid_label_nexttext)
# ...
Set the text from the parent
class My_Dialog(QDialog):
def __init__(self):
super(My_Dialog, self).__init__()
loadUi("dialog.ui", self)
# NO setText() here!!!
class My_Window(QMainWindow):
# ...
def onMyPushButtonClick(self):
dlg = My_Dialog()
if self.mid_label_nexttext:
dlg.mid_label.setText(self.mid_label_nexttext)
# ...
Note that the first method is usually better, mostly for modularity reasons: let's say that you create that dialog from different classes in different situations, whenever you need to change the object name of the label (or the whole interface structure) you can easily change its reference in the dialog subclass, otherwise you'll need to change every reference in your code.
Note: the call to self.update() is useless; if you want to update the label on the dialog whenever the spinbox value is changed, you need to directly access the label (like in the last example) or use signals. Also, you don't need to use lambda if you're using the same argument parameter, just connect to the function.

Problems using method in subclass dialog window to affect main window

I'm trying to create a GUI program using PyQT5. I'm new to programming and Python so if I'm explaining things in the wrong way please correct me.
I have a main window that will contain multiple QLineEdit widgets and corresponding "Clear" buttons to clear the user entered data. The main window also contains "Edit" buttons to dispay specific dialog boxes where the data can also be edited. My example has a "User ID" QLineEdit widget/text box, "Clear" and "Edit" push buttons.
The dialog box that appears when "Edit' is clicked has it's own "Clear" button. If the Clear button in the dialog window is clicked, both the QLineEdit widget in the dialog and main window should be cleared.
Problem: When I inherit the main window class from the dialog class the method, clearUserID(), used to clear the User ID field fails to be invoked.
When I do not inherit from the main window class the clearUserID method works and I am able to clear the dialog QLineEdit (UserIDWin_UserID_lnedt) but not the corresponding widget on the main window (UserID_lnedt). All of the code I've tried to clear the main window QLineEdit widget using the dialog "Clear" button caused my program to crash.
Would somebody please help me to better understand the logic behind these principles and how to get my code working? Thank you.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(820, 611)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
self.tabWidget.setGeometry(QtCore.QRect(0, 0, 801, 551))
self.tabWidget.setObjectName("tabWidget")
self.MainTab = QtWidgets.QWidget()
self.MainTab.setObjectName("MainTab")
self.UserID_Edit_pb = QtWidgets.QPushButton(self.MainTab)
self.UserID_Edit_pb.setGeometry(QtCore.QRect(210, 10, 31, 23))
self.UserID_Edit_pb.setObjectName("UserID_Edit_pb")
self.UserID_Edit_pb.clicked.connect(self.openUserIDWin)
self.UserID_Clear_pb_2 = QtWidgets.QPushButton(self.MainTab)
self.UserID_Clear_pb_2.setGeometry(QtCore.QRect(170, 9, 41, 23))
self.UserID_Clear_pb_2.setObjectName("UserID_Clear_pb_2")
self.UserID_le = QtWidgets.QLineEdit(self.MainTab)
self.label = QtWidgets.QLabel(self.MainTab)
self.label.setGeometry(QtCore.QRect(10, 10, 47, 13))
self.UserID_le.setGeometry(QtCore.QRect(50, 10, 113, 20))
self.UserID_le.setObjectName("UserID_le")
self.tabWidget.addTab(self.MainTab, "")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 820, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
self.tabWidget.setCurrentIndex(0)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
self.UserID_Clear_pb_2.clicked.connect(self.UserID_le.clear)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.UserID_Edit_pb.setText(_translate("MainWindow", "Edit"))
self.UserID_Clear_pb_2.setText(_translate("MainWindow", "Clear"))
self.label.setText(_translate("MainWindow", "User ID"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.MainTab), _translate("MainWindow", "Tab"))
def openUserIDWin(self):
UserID_value = self.UserID_le.text()
UserIDWin = QtWidgets.QDialog()
ui = Ui_UserIDWin(UserID_value)
ui.setupUi(UserIDWin)
UserIDWin.exec_();
class Ui_UserIDWin(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, userID):
print("The User ID is:" + userID)
self.userID = userID
def setupUi(self, UserIDWin):
UserIDWin.setObjectName("UserIDWin")
UserIDWin.resize(400, 124)
self.UserIDWin_UserID_lnedt = QtWidgets.QLineEdit(UserIDWin)
self.UserIDWin_UserID_lnedt.setText(self.userID)
self.UserIDWin_UserID_lnedt.setGeometry(QtCore.QRect(20, 50, 113, 20))
self.UserIDWin_UserID_lnedt.setObjectName("UserIDWin_UserID_lnedt")
self.UserIDWin_UserID_lbl = QtWidgets.QLabel(UserIDWin)
self.UserIDWin_UserID_lbl.setGeometry(QtCore.QRect(20, 30, 47, 13))
self.UserIDWin_UserID_lbl.setObjectName("UserIDWin_UserID_lbl")
self.UserIDWin_UserIDClear_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_UserIDClear_pushb.setGeometry(QtCore.QRect(140, 50, 41, 23))
self.UserIDWin_UserIDClear_pushb.setObjectName("UserIDWin_UserIDClear_pushb")
self.UserIDWin_Cancel_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_Cancel_pushb.setGeometry(QtCore.QRect(110, 80, 75, 23))
self.UserIDWin_Cancel_pushb.setObjectName("UserIDWin_Cancel_pushb")
self.UserIDWin_Next_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_Next_pushb.setGeometry(QtCore.QRect(190, 80, 75, 23))
self.UserIDWin_Next_pushb.setObjectName("UserIDWin_Next_pushb")
self.retranslateUi(UserIDWin)
QtCore.QMetaObject.connectSlotsByName(UserIDWin)
#If I do not inherit from "QtWidgets.QMainWindow, Ui_MainWindow" the code below works and invokes clearUserId(). However, I then am having problems using SetText on the main window UserId_le text box and the program crashes.
self.UserIDWin_UserIDClear_pushb.clicked.connect(self.clearUserID)
def retranslateUi(self, UserIDWin):
_translate = QtCore.QCoreApplication.translate
UserIDWin.setWindowTitle(_translate("UserIDWin", "Dialog"))
self.UserIDWin_UserID_lbl.setText(_translate("UserIDWin", "User ID"))
self.UserIDWin_UserIDClear_pushb.setText(_translate("UserIDWin", "Clear"))
self.UserIDWin_Cancel_pushb.setText(_translate("UserIDWin", "Cancel"))
self.UserIDWin_Next_pushb.setText(_translate("UserIDWin", "Next"))
def clearUserID(self):
self.UserIDWin_UserID_lnedt.setText('')
# The line below crashes my program if I am able to invoke this method.
#self.Ui_MainWindow.UserID_le.setText('')
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
It seems that they have certain clear concepts about inheritance and good practices but others do not like the following:
PyQt recommends not modifying the code generated by Qt Designer because you probably want to modify the GUI in the future and when using pyuic the initial code is overwritten. Another problem is that beginners do not understand that the class generated by Qt Designer is not a widget but an interface that serves to fill another widget, and consequently can not overwrite the methods of the widgets in addition to other problems.
You only have to modify the object of a class from the object of another class if both have the same scope, in your case when wanting to clean the QLineEdit of the main window from the other window is a dangerous task, instead you should do that logic where both windows have the same scope and that is in the openUserIDWin method.
QLineEdit already has the clear() method that allows to clean, it fulfills the same function as setText("") but the first method is more readable.
Considering the above, the solution is:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(820, 611)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
self.tabWidget.setGeometry(QtCore.QRect(0, 0, 801, 551))
self.tabWidget.setObjectName("tabWidget")
self.MainTab = QtWidgets.QWidget()
self.MainTab.setObjectName("MainTab")
self.UserID_Edit_pb = QtWidgets.QPushButton(self.MainTab)
self.UserID_Edit_pb.setGeometry(QtCore.QRect(210, 10, 31, 23))
self.UserID_Edit_pb.setObjectName("UserID_Edit_pb")
self.UserID_Clear_pb_2 = QtWidgets.QPushButton(self.MainTab)
self.UserID_Clear_pb_2.setGeometry(QtCore.QRect(170, 9, 41, 23))
self.UserID_Clear_pb_2.setObjectName("UserID_Clear_pb_2")
self.UserID_le = QtWidgets.QLineEdit(self.MainTab)
self.label = QtWidgets.QLabel(self.MainTab)
self.label.setGeometry(QtCore.QRect(10, 10, 47, 13))
self.UserID_le.setGeometry(QtCore.QRect(50, 10, 113, 20))
self.UserID_le.setObjectName("UserID_le")
self.tabWidget.addTab(self.MainTab, "")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 820, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
self.tabWidget.setCurrentIndex(0)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.UserID_Edit_pb.setText(_translate("MainWindow", "Edit"))
self.UserID_Clear_pb_2.setText(_translate("MainWindow", "Clear"))
self.label.setText(_translate("MainWindow", "User ID"))
self.tabWidget.setTabText(self.tabWidget.indexOf(self.MainTab), _translate("MainWindow", "Tab"))
class Ui_UserIDWin(object):
def setupUi(self, UserIDWin):
UserIDWin.setObjectName("UserIDWin")
UserIDWin.resize(400, 124)
self.UserIDWin_UserID_lnedt = QtWidgets.QLineEdit(UserIDWin)
self.UserIDWin_UserID_lnedt.setGeometry(QtCore.QRect(20, 50, 113, 20))
self.UserIDWin_UserID_lnedt.setObjectName("UserIDWin_UserID_lnedt")
self.UserIDWin_UserID_lbl = QtWidgets.QLabel(UserIDWin)
self.UserIDWin_UserID_lbl.setGeometry(QtCore.QRect(20, 30, 47, 13))
self.UserIDWin_UserID_lbl.setObjectName("UserIDWin_UserID_lbl")
self.UserIDWin_UserIDClear_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_UserIDClear_pushb.setGeometry(QtCore.QRect(140, 50, 41, 23))
self.UserIDWin_UserIDClear_pushb.setObjectName("UserIDWin_UserIDClear_pushb")
self.UserIDWin_Cancel_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_Cancel_pushb.setGeometry(QtCore.QRect(110, 80, 75, 23))
self.UserIDWin_Cancel_pushb.setObjectName("UserIDWin_Cancel_pushb")
self.UserIDWin_Next_pushb = QtWidgets.QPushButton(UserIDWin)
self.UserIDWin_Next_pushb.setGeometry(QtCore.QRect(190, 80, 75, 23))
self.UserIDWin_Next_pushb.setObjectName("UserIDWin_Next_pushb")
self.retranslateUi(UserIDWin)
QtCore.QMetaObject.connectSlotsByName(UserIDWin)
def retranslateUi(self, UserIDWin):
_translate = QtCore.QCoreApplication.translate
UserIDWin.setWindowTitle(_translate("UserIDWin", "Dialog"))
self.UserIDWin_UserID_lbl.setText(_translate("UserIDWin", "User ID"))
self.UserIDWin_UserIDClear_pushb.setText(_translate("UserIDWin", "Clear"))
self.UserIDWin_Cancel_pushb.setText(_translate("UserIDWin", "Cancel"))
self.UserIDWin_Next_pushb.setText(_translate("UserIDWin", "Next"))
class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setupUi(self)
self.UserID_Edit_pb.clicked.connect(self.openUserIDWin)
self.UserID_Clear_pb_2.clicked.connect(self.UserID_le.clear)
def openUserIDWin(self):
UserID_value = self.UserID_le.text()
w = UserIDWin(UserID_value)
w.UserIDWin_UserIDClear_pushb.clicked.connect(self.UserID_le.clear)
w.exec_()
class UserIDWin(QtWidgets.QDialog, Ui_UserIDWin):
def __init__(self, userID, parent=None):
super(UserIDWin, self).__init__(parent)
self.setupUi(self)
self.userID = userID
self.UserIDWin_UserID_lnedt.setText(self.userID)
self.UserIDWin_UserIDClear_pushb.clicked.connect(self.UserIDWin_UserID_lnedt.clear)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
I recommend you read:
http://pyqt.sourceforge.net/Docs/PyQt5/designer.html
QtDesigner changes will be lost after redesign User Interface

Variable inside a spinbox widget to display in the LCD widget at a click of the pushbutton widget

What should I do when I want the variable inside a spinbox widget to display in the LCD widget at a click of the pushbutton widget?
Code form converting .ui to .py. Now I don't know what else to do. please edit as you see fit. :-)
# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'C:\Users\CpE-18\Desktop\mk2.ui'
#
# Created by: PyQt5 UI code generator 5.11.3
#
# WARNING! All changes made in this file will be lost!
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(800, 600)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.spinBox = QtWidgets.QSpinBox(self.centralwidget)
self.spinBox.setGeometry(QtCore.QRect(320, 250, 51, 31))
self.spinBox.setObjectName("spinBox")
self.lcdNumber = QtWidgets.QLCDNumber(self.centralwidget)
self.lcdNumber.setGeometry(QtCore.QRect(270, 110, 141, 101))
self.lcdNumber.setObjectName("lcdNumber")
self.pushButton = QtWidgets.QPushButton(self.centralwidget)
self.pushButton.setGeometry(QtCore.QRect(310, 320, 75, 23))
self.pushButton.setObjectName("pushButton")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.pushButton.setText(_translate("MainWindow", "OK"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
You have to do the following:
Create a function that is called when the button is pressed, for this the clicked signal is used.
Obtain the value of the QSpinBox using the value() method.
Set the value in the QLCDNumber through the display() method.
# ...
class Ui_MainWindow(object):
# ...
class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.setupUi(self)
self.pushButton.clicked.connect(self.on_clicked)
#QtCore.pyqtSlot()
def on_clicked(self):
self.lcdNumber.display(self.spinBox.value())
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())

AttributeError: 'MyMainWindow' object has no attribute 'pushButton'

Trying to proceed click button event in my code but got some issue.
AttributeError: 'MyMainWindow' object has no attribute 'pushButton'
Seems, like clicked event can`t find pushbutton from my subclass. Probably i did some mistakes in syntax, so really waiting for your help guys. Sorry if the question very banal, pyQt5 is simply new for me, trying to figure out in all of this.
Here is my files.
ui_main.py
# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file '1.ui'
#
# Created by: PyQt5 UI code generator 5.7.1
#
# WARNING! All changes made in this file will be lost!
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(349, 131)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
self.gridLayout.setObjectName("gridLayout")
self.formLayout = QtWidgets.QFormLayout()
self.formLayout.setObjectName("formLayout")
self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)
self.lineEdit.setAlignment(QtCore.Qt.AlignHCenter|QtCore.Qt.AlignTop)
self.lineEdit.setObjectName("lineEdit")
self.formLayout.setWidget(1, QtWidgets.QFormLayout.SpanningRole, self.lineEdit)
self.label = QtWidgets.QLabel(self.centralwidget)
self.label.setAlignment(QtCore.Qt.AlignCenter)
self.label.setObjectName("label")
self.formLayout.setWidget(0, QtWidgets.QFormLayout.SpanningRole, self.label)
self.gridLayout.addLayout(self.formLayout, 0, 0, 1, 1)
self.horizontalLayout = QtWidgets.QHBoxLayout()
self.horizontalLayout.setObjectName("horizontalLayout")
self.pushButton = QtWidgets.QPushButton(self.centralwidget)
self.pushButton.setObjectName("pushButton")
self.horizontalLayout.addWidget(self.pushButton)
self.pushButton_2 = QtWidgets.QPushButton(self.centralwidget)
self.pushButton_2.setObjectName("pushButton_2")
self.horizontalLayout.addWidget(self.pushButton_2)
self.gridLayout.addLayout(self.horizontalLayout, 1, 0, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 349, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.label.setText(_translate("MainWindow", "TextLabel"))
self.pushButton.setText(_translate("MainWindow", "PushButton"))
self.pushButton_2.setText(_translate("MainWindow", "PushButton"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
py_main.py
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow, qApp
from PyQt5.QtCore import Qt, QEvent, QObject
from ui_main import Ui_MainWindow
class MyMainWindow(QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(MyMainWindow, self).__init__(parent)
qApp.installEventFilter(self)
self.pushButton.clicked.connect(self.clickButton()) #here is where the issue is occurs
self.show()
self.setupUi(self)
def eventFilter(self, obj, event):
if event.type() == QEvent.KeyPress:
if event.key() == Qt.Key_Escape:
self.close()
return super(MyMainWindow, self).eventFilter(obj, event)
def clickButton(self):
sender = self.sender()
self.statusbar().showMessage(sender.text() + ' was pressed')
if __name__ == '__main__':
app = QApplication(sys.argv)
win = MyMainWindow()
test = TestClass()
sys.exit(app.exec_())
Waiting forward for your help!
In your code there are 3 errors:
You must call the setupUI function first since the button is created here and then connect that button to the slot.
When the button is connected to the slot you just have to pass the slot name without parenthesis.
Change statusbar() to statusBar().
Code:
# ...
class MyMainWindow(QMainWindow, Ui_MainWindow):
def __init__(self, parent=None):
super(MyMainWindow, self).__init__(parent)
qApp.installEventFilter(self)
self.setupUi(self)
self.pushButton.clicked.connect(self.clickButton)
self.show()
# ...
def clickButton(self):
sender = self.sender()
self.statusBar().showMessage(sender.text() + ' was pressed')
# ...
it work for me
call the setupUI function first
self.setupUi(self)
self.pushButton.clicked.connect(self.click_button)
tag QDialog and Ui_Dialog
main.py
MyMainWindow(QDialog, Ui_Dialog):
mainGui.py
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
Dialog = QtWidgets.QDialog()
ui = Ui_Dialog()
ui.setupUi(Dialog)
Dialog.show()
sys.exit(app.exec_())
OUTPUT:
SOLVED: AttributeError Main object has no attribute pushButton

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