I am having problems showing a QWidget window for the user to input some data.
My script has not GUI, but I just want to show this small QWidget window.
I created the window with QtDesigner, and now I am trying to show the QWidget window like this:
from PyQt4 import QtGui
from input_data_window import Ui_Form
class childInputData(QtGui.QWidget ):
def __init__(self, parent=None):
super(childInputData, self).__init__()
self.ui = Ui_Form()
self.ui.setupUi(self)
self.setFocus(True)
self.show()
And then, from my main class, I am doing like that:
class myMainClass():
childWindow = childInputData()
That gave me the error:
QWidget: Must construct a QApplication before a QPaintDevice
So now I am doing, from my main class:
class myMainClass():
app = QtGui.QApplication(sys.argv)
childWindow = childInputData()
Now there is no error, but the window is showed twice and the script does not wait until the data is entered, it just shows the window and continues without waiting.
What is wrong here?
It's perfectly normal that the window is shown and the script goes on: you never told the script to wait for the user to answer. You just told it to show a window.
What you would like is the script to stop until the user is done and the window is closed.
Here's one way to do it:
from PyQt4 import QtGui,QtCore
import sys
class childInputData(QtGui.QWidget):
def __init__(self, parent=None):
super(childInputData, self).__init__()
self.show()
class mainClass():
def __init__(self):
app=QtGui.QApplication(sys.argv)
win=childInputData()
print("this will print even if the window is not closed")
app.exec_()
print("this will be print after the window is closed")
if __name__ == "__main__":
m=mainClass()
The exec() method "Enters the main event loop and waits until exit() is called" (doc):
the script will be blocked on the line app.exec_() until the window is closed.
NB: using sys.exit(app.exec_()) would cause the script to end when the window is closed.
An other way is to use QDialog instead of QWidget. You then replace self.show() by self.exec(), which will block the script
From the doc:
int QDialog::exec()
Shows the dialog as a modal dialog, blocking until the user closes it
Finally, this answer of a related question advocates not to use exec, but to set the window modality with win.setWindowModality(QtCore.Qt.ApplicationModal). However this doesn't work here: it blocks inputs in other windows, but do not block the script.
you dont need the myMainClass...do something like this:
import sys
from PyQt4 import QtGui
from input_data_window import Ui_Form
class childInputData(QtGui.QWidget):
def __init__(self, parent=None):
super(childInputData, self).__init__(parent)
self.ui = Ui_Form()
self.ui.setupUi(self)
self.setFocus(True)
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
win = childInputData()
win.show()
sys.exit(app.exec_())
Related
I have two .py files created from .ui files made in QtDesigner. One is a main window for the program, and the other is a widget that allows users to input information and I'm calling it the "evaluation" widget.
I have a button in the main window called "btn_StartNew", which is meant to open the widget window to allow the user to start a new evaluation. I'm having troubles with opening the main window, and adding the function to the "btn_StartNew" button that opens the "evaluation" widget.
The code I have right now opens both the main window and the evaluation widget in the same window when I run the code:
import sys
from PyQt4 import QtCore, QtGui
from wid_Main import Ui_wid_Main
from wid_Eval_v2 import Ui_wid_Eval
class Win_Eval(QtGui.QWidget):
def __init__(self, parent=None):
super(Win_Eval, self).__init__(parent)
self.ui=Ui_wid_Eval()
self.ui.setupUi(self)
class Win_Main(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Win_Main, self).__init__(parent)
self.ui=Ui_wid_Main()
self.ui.setupUi(self)
#RUN "start new eval" button
self.ui.btn_StartNew.clicked.connect(self.btn_StartNew_click)
self.dialog = Win_Eval(self)
def btn_StartNew_click(self):
self.dialog.show()
def main():
app = QtGui.QApplication(sys.argv)
main = Win_Main()
main.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
Where wid_Main and Ui_wid_Main are the main window file and the main window class, respectively. And wid_Eval_v2 and Ui_wid_Eval are the evaluation widget file and class, respectively.
Any help would be much appreciated!
You must change:
self.dialog = Win_Eval(self)
to
self.dialog = Win_Eval()
I am trying to call another window from a button click in python 2.7 using PyQt4. The code below opens the AddBooking dialog but immediately closes it. Im new to Gui programming, can somebody please tell me what is wrong with my code?
from PyQt4 import QtGui
from HomeScreen import Ui_HomeScreen
from AddBooking import Ui_AddBooking
import sys
class HomeScreen(QtGui.QWidget, Ui_HomeScreen):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.setupUi(self)
self.show()
self.Add_Booking_Button.clicked.connect(self.handleButton)
def handleButton(self):
AddBooking2()
class AddBooking2(QtGui.QWidget, Ui_AddBooking):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.setupUi(self)
self.show()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = HomeScreen()
window.show()
sys.exit(app.exec_())
Don't use multi-inheritance and neither call show function inside class initializer. The problem is that the object you are creating with AddBooking2() is a temporal and it's destroyed automatically when the function ends. So you need use some variable to reference that object something like:
addbooking = AddBooking2()
addbooking.show()
Also, since you are working with QtDesigner and pyuic4 tools you can make connections a little bit easier. Said that, your code can be modified:
from PyQt4 import QtGui
from PyQt4.QtCore import pyqtSlot
from HomeScreen import Ui_HomeScreen
from AddBooking import Ui_AddBooking
import sys
class HomeScreen(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.ui = Ui_HomeScreen()
self.ui.setupUi(self)
#pyqtSlot("")
def on_Add_Booking_Button_clicked(self): # The connection is carried by the Ui_* classes generated by pyuic4
addbooking = AddBooking2()
addbooking.show()
class AddBooking2(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.ui = Ui_AddBooking()
self.ui.setupUi(self)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = HomeScreen()
window.show()
sys.exit(app.exec_())
The dialog closes immediately because you are not keeping a reference to it, and so it will get garbage-collected as soon as it goes out of scope.
The simplest way to fix it would be to do something like this:
def handleButton(self):
self.dialog = AddBooking2()
self.dialog.show()
and you can also remove the self.show() lines from AddBooking2.__init__ and HomeScreen.__init__, which are redundant. Other than that, your code looks fine.
I defined a print function using QPrinter and QDialog. However, when I launch the printer dialog and then press cancel, the entire mainwindow goes into not responding mode. I have tried to do QtGui.QPrintDialog.close() but does not work.
Code:
import sys
from PyQt4 import QtCore
from PyQt4 import QtGui
class QButton(QtGui.QWidget):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.button = QtGui.QPushButton('Button', self)
self.name='me'
self.button.clicked.connect(self.calluser)
def calluser(self):
Appli=QtGui.QApplication(sys.argv)
printer= QtGui.QPrinter()
doc=QtGui.QTextDocument("Set local variables in this printing slot." )
dialog = QtGui.QPrintDialog(printer)
dialog.setModal(True)
dialog.setWindowTitle("Print Document" )
if dialog.exec_() == True:
doc.print_(printer)
# dialog.addEnabledOption(QAbstractPrintDialog.PrintSelection)
def demo_QButton():
app = QtGui.QApplication(sys.argv)
tb = QButton()
tb.show()
app.exec_()
if __name__=='__main__':
demo_QButton()
You created a new application in the calluser method. Delete or comment the line:
Appli=QtGui.QApplication(sys.argv)
and try again. I think this time your main window will remain responsive.
I am very new to this and have used the Qt Designer to make a very simple main window ui. The first functionality I want in my project is for a button to open a different window when clicked.
So basically I have the file autoGenUI.py that is generated using pyside-uic which includes
from PySide import QtCore, QtGui
class AutoGeneratedUI(object):
def setupUi(self, MainWindow):
#Auto generated code
def retranslateUi(self, MainWindow):
#Auto generated code
This all works fine of course because the Qt designer made it. I then have my own .py file that is basically my application stuff.
It looks like this:
import sys
from PySide.QtCore import *
from PySide.QtGui import *
from autoGenUI import *
class MyMainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MyMainWindow, self).__init__(parent)
self.ui = AutoGeneratedUI()
self.ui.setupUi(self)
if __name__ == "__main__":
app = QApplication(sys.argv)
myMainWindow = MyMainWindow()
myMainWindow.show()
sys.exit(app.exec_())
My button is called self.pushButton in the auto generated python UI. I would like to design another window and then call that window but for now anything will do. I just don't know where to put the code to make my button do something.
I tried to follow the docs but couldn't get anything to work.
Any help is greatly appreciated.
Thanks
You need to connect the clicked signal of pushButton to a method such as on_button_clicked():
def __init__(self, parent=None):
super(MyMainWindow, self).__init__(parent)
self.ui = AutoGeneratedUI()
self.ui.setupUi(self)
# connect the clicked signal to on_button_clicked() method
self.pushButton.clicked.connect(self.on_button_clicked)
def on_button_clicked(self):
print "button clicked"
# here is the code to open a new window
Please can someone tell me what im doing wrong here with respect to calling pwTxt.text.
#!/usr/bin/python
import sys
from PyQt4 import QtCore, QtGui
from mainwindow import Ui_MainWindow
class MyForm(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
def on_pwExtract_pressed(self):
print self.pwTxt.text
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
myapp = MyForm()
myapp.show()
sys.exit(app.exec_())
The line print self.pwTxt.text fails because it can't find the widget, pwTxt is a QLineEdit defined on the main window. I just made it in QTDesigner and generated python code with pyuic4.
How do I correctly reference other widgets on the same window, in this case I just want to get the text from a QLineEdit named pwTxt when the QPushButton pwExtract is pressed.
Thanks a lot.
Try:
print self.ui.pwTxt.text()