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Opening a QDialog and saving last state

I am trying to open a QDialog from a QMainWindow, and after closing the `QDialog, if I need to open it again, it has to open and show the same information that had when I close it.
Here is the code of the QMainWindow:
class A (QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
#I create a QPushButton to open the QDialog
self.axes1 = self.figure_canvas.figure.add_axes ([0.8, 0.01, 0.19, 0.05])
self.button = QPushButton(self.axes1,"Open Dialog")
self.button.on_clicked(self.OpenDialog)
#This is the method to open the QDialog which is in another module
def OpenDialog(self, event):
text = configurePort.ConfigurePort.retrieve_data(self)
print text
What this code does is create a button in my QMainWindow and when I click it, it opens a QDialog, which is created in another module. And this is the code of the QDialog:
class ConfigurePort(QDialog):
def __init__(self, parent = None):
QDialog.__init__(self, parent)
uic.loadUi("configurePort.ui", self)
#I create a button to check active ports and show them
self.connect(self.btn_checkconn, SIGNAL("clicked()"), self.check_ports)
#This method calls another class which opens another QDialog
#and I select the port that I want
def check_ports(self):
self.check_serial = CheckPorts(self)
self.check_serial.exec_()
#After selecting the port, when I close the QDialog of the class named above
#the port´s name appears in the first QDialog
#classmethod
def retrieve_data(cls, parent = None):
dlg = cls(parent)
dlg.exec_()
text = dlg.getPortText()
return text
def closeEvent(self, event):
#Here is where I need to write the code to close the QDialog
#and it does not has to be an event
In the method, closeEvent, I need to write the necessary code, so I can close the window, and using the same button that I use to open it, open it again with the last information that it showed when I closed it.
I have tried to use QSettings but it did not worked (maybe I used it wrong). And I tried the show() and hide() classes of PyQt too, but it did not work. Hope you can help me.
----- EDIT -----
I edited the code of above. and I added some methods for a better understanding. So, i open the QDialog called ConfigurePort and it shows this:
The red circle, surrounds the port´s name. It is shown in a QLabel,and I take this text from the QDialog and then print it when I close the QDialog. I acomplish this thanks to a question I asked before, wich is in this link:
Getting data from child using PyQt
The check_port method shown in the code above, opens another QDialog that works great. With this I can select the ports that I need in my pc. So, this does not matter.
So, after closing the QDialog(and selecting for example "COM3", as you can see in the picture), I need to open it again, and see the same information that was shown before I closed it.
I tried to add this lines, using QSettings :
self.settings = QSettings("MyCompany", "MyApp")
if not self.settings.value("windowsState") == None:
self.restoreState(self.settings.value("windowState"))
But as I said before, I think that I did not use it right, but I hope that I solve this using something simpler.
----- EDIT 2 -----
Thank to the help of #Brendan Abel I have this code:
class ConfigurePort(QDialog):
def __init__(self, parent):
super(ConfigurePort, self).__init__(parent)
uic.loadUi("configurePort.ui", self)
self.myValue = 10
self.restoreSettings()
self.connect(self.btn_checkconn, SIGNAL("clicked()"), self.check_ports)
self.buttonBox.button(QDialogButtonBox.Cancel).clicked.connect(self.close)
self.buttonBox.button(QDialogButtonBox.Ok).clicked.connect(self.closeEvent)
self.iniUi()
def check_ports(self):
pass
def iniUi(self):
pass #I just create some QLabels in here
#classmethod
def retrieve_data(cls, parent = None):
dlg = cls(parent)
dlg.exec_()
text = dlg.getPortText()
return text
def closeEvent(self, event):
self.saveSettings()
super(QDialog,self).closeEvent(event)
def saveSettings(self):
settings = QSettings("MyOrg", "MyApp")
settings.setValue("myValue", self.myValue)
def restoreSettings(self):
settings = QSettings("MyOrg", "MyApp")
self.myValue = settings.value("myValue", self.myValue)
This gives me this error: TypeError: QWidget.closeEvent(QCloseEvent): argument 1 has unexpected type 'bool'
I know that I am missing something, but I can not see it.

There are a couple ways you could persist this data Generally, to persist data across sessions, you use QSettings and load the data in the __init__ and save it in the closeEvent method
Generally it looks something like this. This also assumes your using the v2 version of the QVariant api; otherwise, the results returned from QSettings.value is going to be a QVariant and you'll need to cast it to the appropriate python type. If you're using a recent version of PyQt then you should be on v2, but if not you can force it by sticking this at the top of your file
import sip
sip.setapi('QVariant', 2)
sip.setapi('QString', 2)
class MyDialog(QDialog):
def __init__(self, parent):
super(MyDialog, self).__init__(parent)
self.myvalue = 10
self.restoreSettings()
def closeEvent(self, event):
self.saveSettings()
super(MyDialog, self).closeEvent(event)
def saveSettings(self):
settings = QSettings('myorg', 'myapp')
settings.setValue('myvalue', self.myvalue)
def restoreSettings(self):
settings = QSettings('myorg', 'myapp')
self.myvalue = settings.value('myvalue', self.myvalue)
EDIT:
The error in your code is caused by this:
self.buttonBox.button(QDialogButtonBox.Ok).clicked.connect(self.closeEvent)
You shouldn't be calling or connecting to closeEvent directly. Instead, you should connect to .close or .accept
self.buttonBox.button(QDialogButtonBox.Ok).clicked.connect(self.accept)

You need to instantiate the ConfigurePort class then the self.configurePortDialog object should keep consistent. You will need to make sure if you have the user enter data that a cancel does not store the data and that an "ok" stores the data, but I not sure what you are putting in your dialog.
class A (QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
#I create a QPushButton to open the QDialog
self.button = QPushButton("Open Dialog")
self.button.on_clicked(self.OpenDialog)
self.configurePortDialog = configurePort.ConfigurePort(parent=self)
self.configurePortDialog.accepted.connect(self.get_data)
#This is the method to open the QDialog which is in another module
def OpenDialog(self, event):
self.configurePortDialog.show()
#QtCore.Slot()
def get_data(self)
text = self.configurePortDialog.retrieve_data()
print text

Click event is sent immediately after I start application (PySide and Python)

I have an application with a button for which the clicked signal is connected to a slot that opens a QFileDialog. I want to manipulate the state of the button (sender) within the slot depending on the actions taken by the user in the QFileDialog.
However, with the code I have presently, my application do not starts correctly. It starts immediately with QFileDialogOpen and I do not understand why. When I comment the line that connect the button's clicked signal to the slot, the application starts normally though.
How can I correctly pass the button as an argument when I want to connect a clicked signal of a button to a slot? Here is a MCWE of my problem:
from PySide import QtGui
import sys
class MyApplication(QtGui.QWidget):
def __init__(self, parent=None):
super(MyApplication, self).__init__(parent)
self.fileButton = QtGui.QPushButton('Select File')
self.fileButton.clicked.connect(self.select_file(self.fileButton))
layout = QtGui.QGridLayout()
layout.addWidget(self.fileButton)
self.setLayout(layout)
def select_file(self, button):
file_name = QtGui.QFileDialog.getOpenFileName()
if str(file_name[0]) is not "":
button.setEnabled(True)
else:
button.setDisabled(True)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
w = MyApplication()
w.show()
sys.exit(app.exec_())

You don't bind an actual function call using PySide signals/slots, you bind a function, method, or function-like object using PySide's signals/slots.
You have:
self.fileButton.clicked.connect(self.select_file(self.fileButton))
This tells Qt to bind the click event to something that is returned from the self.select_file function call, which presumably has no __call__ attribute and is called immediately (causing the opening of the QFileDialog)
What you want is the following:
from functools import partial
self.fileButton.clicked.connect(partial(self.select_file, self.fileButton))
This creates a callable, frozen function-like object with arguments for Qt to call.
This is comparable to saying:
self.fileButton.clicked.connect(self.select_file)
Rather than saying:
self.fileButton.clicked.connect(self.select_file())

Python program works, but it shows an error. Why?

I am new in programming and I have done my research on this website and others, but I can't find anything helpful for my problem. I am writing a Python program with several PyQt windows opening when different buttons are pressed. This is my program:
import sys, os,
from PyQt4 import QtCore, QtGui, uic
Ui_IntroWindow = uic.loadUiType('introduction.ui')[0]
Ui_ElmWindow = uic.loadUiType('elm.ui')[0]
Ui_ClueWindow = uic.loadUiType('pistaelm.ui') [0]
Ui_ButtonWindow = uic.loadUiType('firtsguibutton.ui')[0]
class IntroWindow(QtGui.QMainWindow, Ui_IntroWindow):
def __init__ (self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.continuar.clicked.connect(self.continuar_clicked)
def continuar_clicked(self):
window = ElmWindow(self)
window.show()
window.exec_()
self.close()
class ElmWindow(QtGui.QMainWindow, Ui_ElmWindow):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
self.bpista.clicked.connect(self.pista)
self.bcontinuar.clicked.connect(self.continuar)
def pista(self):
pistaelm = ClueWindow(self)
pistaelm.show()
pistaelm.exec_()
def continuar(self):
elemento = str(self.elemento.text())
main = ButtonWindow(self)
if elemento == 'cobalto':
main.show()
main.exec_()
self.close()
class ClueWindow(QtGui.QMainWindow, Ui_ClueWindow):
def __init__ (self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
class ButtonWindow(QtGui.QMainWindow, Ui_ButtonWindow):
def __init__(self, parent = None):
QtGui.QMainWindow.__init__(self, parent)
self.setupUi(self)
app = QtGui.QApplication(sys.argv)
myWindow = IntroWindow()
myWindow.show()
app.exec_()
I have several sub windows created, for example in:
def continuar_clicked(self):
window = ElmWindow(self)
window.show()
window.exec_()
self.close()
If i don't write
window.exec_()
the window will open, but the buttons won't work. But when i write it I get an error:
Traceback (most recent call last):
File "C:\Users\Work\Desktop\Project\project.py", line 19, in continuar_clicked
window.exec_()
AttributeError: 'ElmWindow' object has no attribute 'exec_'
How can I stop the error?

Objects derived from QMainWindow do not have a method exec_(). This is why you see the exception.
The reason this exception is modifying the behaviour of your program is because when an exception is raised, the rest of the slot currently being executed is not run. So your continuar_clicked method runs until it hits the line with the missing method, and stops.
This points to the fact that not calling self.close() in continuar_clicked keeps your GUI working. Calling self.close() is apparently breaking the program.
SO what does this mean? Well it points to a bad object hierarchy. You are spawning new windows, that are children of an existing window, and then closing the parent window. Quite possibly the parent window is being deleted, depending on whether the Qt.WA_DeleteOnClose attribute is set to true for your windows.
So I would suggest redesigning your program. Perhaps have a parent window that is always open, or write a window managing class which handles the creation/closing of all windows (eg a window object calls a method from your window managing object to close the current window and open a new window).
Ultimately how you structure your code will be up to you as it is difficult to gauge the details of your program from a minimal example

How to call a QWidget from another QWidget in PyQt

I am developping an application with PyQt based on a QWidget. I put my whole app inside a class (named "Example"). Inside this app, I have a button which calls to another QWidget window (named "Report Widget") I designed on QtDesigner and opens it.
The problem is that I don't know how to do this. Here is the method I use (which comes from something I found on internet).
On my main class "Example", a method defines the Button calling for the "Report Widget" :
ReportBtn = QtGui.QPushButton("Generate report")
ReportBtn.clicked.connect(self.ShowReportWidget)
The second line calls the ShowReportWidget method of the Example (main) class :
def ShowReportWidget(self):
self.f = QtGui.QWidget()
self.ReportWidget = ReportWidget(self.f)
self.ReportWidget.show()
This method calls the class ReportWidget, which is a class from the Example (main) class :
class ReportWidget(QtGui.QWidget):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self)
self.ui = rw.Ui_ReportWidget()
self.ui.setupUi(parent)
and finally, this class refers to an outer class (Ui_ReportWidget), contained in another separate Python file (the one generated from the QtDesigner .ui file), which I import as rw in the beginning of my script.
The problem is that with this method, when I click on the Report Widget button, a new window pops but is empty. The content of the Ui_ReportWidget class is not loaded.
I hope my question is clear enough.
Thanks

SetupUi takes an Qwidget as input , while the init() function should take the calling QObject as the parent.
def ShowReportWidget(self):
self.f = QtGui.QWidget()
self.ReportWidget = ReportWidget(self)
self.ReportWidget.setupUi(self.f)
self.f.exec_()
class ReportWidget(QtGui.QWidget):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self,parent)
def setupUi(self,Widget):
self.ui = rw.Ui_ReportWidget()
self.ui.setupUi(Widget)

Open a second window in PyQt

I'm trying to use pyqt to show a custom QDialog window when a button on a QMainWindow is clicked. I keep getting the following error:
$ python main.py
DEBUG: Launch edit window
Traceback (most recent call last):
File "/home/james/Dropbox/Database/qt/ui_med.py", line 23, in launchEditWindow
dialog = Ui_Dialog(c)
File "/home/james/Dropbox/Database/qt/ui_edit.py", line 15, in __init__
QtGui.QDialog.__init__(self)
TypeError: descriptor '__init__' requires a 'sip.simplewrapper' object but received a 'Ui_Dialog'
I've gone over several online tutorials, but most of them stop just short of showing how to use a non built-in dialog window. I generated the code for both the main window and the dialog using pyuic4. What I think should be the relevant code is below. What am I missing here?
class Ui_Dialog(object):
def __init__(self, dbConnection):
QtGui.QDialog.__init__(self)
global c
c = dbConnection
class Ui_MainWindow(object):
def __init__(self, dbConnection):
global c
c = dbConnection
def launchEditWindow(self):
print "DEBUG: Launch edit window"
dialog = QtGui.QDialog()
dialogui = Ui_Dialog(c)
dialogui = setupUi(dialog)
dialogui.show()
class StartQT4(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
conn = sqlite3.connect('meds.sqlite')
c = conn.cursor()
self.ui = Ui_MainWindow(c)
self.ui.setupUi(self)
def main():
app = QtGui.QApplication(sys.argv)
program = StartQT4()
program.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
Bonus question: since it looks like you can't pass arguments in pyqt function callbacks, is setting something which would otherwise be passed as an argument (the poorly named "c") to be global the best way to get information into those functions?

I've done like this in the past, and i can tell it works.
assuming your button is called "Button"
class Main(QtGui.QMainWindow):
''' some stuff '''
def on_Button_clicked(self, checked=None):
if checked==None: return
dialog = QDialog()
dialog.ui = Ui_MyDialog()
dialog.ui.setupUi(dialog)
dialog.setAttribute(QtCore.Qt.WA_DeleteOnClose)
dialog.exec_()
This works for my application, and I believe it should work with yours as well. hope it'll help, it should be pretty straight forward to do the few changes needed to apply it to your case.
have a good day everybody.

Ui_Dialog should inherent from QtGui.QDialog, not object.
class Ui_Dialog(QtGui.QDialog):
def __init__(self, dbConnection):
QtGui.QDialog.__init__(self)
global c
c = dbConnection

class StartQT4(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
Why QtGui.QWidget.__init___ ???
Use insted:
class StartQT4(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent)
You must call __init__ methon from base class (name in parenthesis '()')
QDialog have two useful routins:
exec_()
show()
First wait for closing dialog and then you can access any field form dialog. Second show dialog but don't wait, so to work properly you must set some slot/signals connections to respond for dialog actions.
eg. for exec_():
class Dialog(QDialog):
def __init__(self, parent):
QDialog.__init__(parent)
line_edit = QLineEdit()
...
dialog = Dialog()
if dialog.exec_(): # here dialog will be shown and main script will wait for its closing (with no errors)
data = dialog.line_edit.text()
Small tip: can you change your ui classes into widgets (with layouts). And perhaps problem is that your __init__ should be __init__(self, parent=None, dbConnection)
Because when you create new widget in existing one PyQt may try to set it as children of existing one. (So change all init to have additional parent param (must be on second position)).