I have a pyqt app where I want a dialog to display when I click a menu item. If the dialog loses focus and the menu item is clicked again, it brings the dialog to the front. This is working fine so far.
The problem is that when the dialog is opened and then closed, clicking the menu item doesnt create/display a new dialog. I think I know why, but can't figure out a solution
Heres the code:
from ui import mainWindow, aboutDialog
class ReadingList(QtGui.QMainWindow, mainWindow.Ui_MainWindow):
def __init__(self):
super(self.__class__, self).__init__()
self.setupUi(self)
self.about = None
self.actionAbout.triggered.connect(self.showAbout)
def showAbout(self):
# If the about dialog does not exist, create one
if self.about is None:
self.about = AboutDialog(self)
self.about.show()
# If about dialog exists, bring it to the front
else:
self.about.activateWindow()
self.about.raise_()
class AboutDialog(QtGui.QDialog, aboutDialog.Ui_Dialog):
def __init__(self, parent=None):
super(self.__class__, self).__init__()
self.setupUi(self)
def main():
app = QtGui.QApplication(sys.argv)
readingList = ReadingList()
readingList.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
The problem lies in the fact that when the dialog is created the first time, self.about is no longer None. This is good because the conditional in showAbout() allows me to bring the dialog to the front instead of creating a new one (the else condition)
However, when the dialog is closed, self.about is no longer None due to the previous dialog creation, which means it doesn't create a new one and just jumps to the else condition
How can I make it so that dialogs can be created after the first?
I thought about overriding the closeEvent method in the AboutDialog class but I'm not sure how to get a reference to readingList to send a message back saying the dialog has been closed. Or maybe I'm overthinking it, maybe the return from self.about.show() can be used somehow?
(I know I can probably avoid all of this using modal dialogs but want to try to figure this out)
There are probably several ways to do this, but here's one possibility:
class ReadingList(QtGui.QMainWindow, mainWindow.Ui_MainWindow):
def __init__(self):
super(ReadingList, self).__init__()
self.setupUi(self)
self.actionAbout.triggered.connect(self.showAbout)
self.about = None
def showAbout(self):
if self.about is None:
self.about = AboutDialog(self)
self.about.show()
self.about.finished.connect(
lambda: setattr(self, 'about', None))
else:
self.about.activateWindow()
self.about.raise_()
class AboutDialog(QtGui.QDialog):
def __init__(self, parent=None):
super(AboutDialog, self).__init__(parent)
self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
(NB: you should never use self.__class__ with super as it can lead to an infinite recursion under certain circumstances. Always pass in the subclass as the first argument - unless you're using Python 3, in which case you can omit all the arguments).
Related
i have a main GUI-Window from which i open a new Window (FCT-popup) with a buttonclick:
class MainWindow(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.ui = Ui_MainWindow() # sets ui = to the main window from the ui-file
self.ui.setupUi(self)
[...]
def enter_fct_results(self):
self.FCTpopup = FCT_Window()
self.FCTpopup.show()
In the Window i have a QTable to fill and a button to submit the data and close the window:
class FCT_Window(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.ui = Ui_FCT_Window()
self.ui.setupUi(self)
[...]
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
def on_submit(self): # event when user clicks
fct_nparray = np.zeros((self.ui.tableFCTinputs.rowCount(), self.ui.tableFCTinputs.columnCount()))
for j in range(self.ui.tableFCTinputs.columnCount()):
for i in range(self.ui.tableFCTinputs.rowCount()):
fct_nparray[i, j] = float(self.ui.tableFCTinputs.item(i, j).text())
return fct_nparray, lambda: self.close()
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
The receiving function iin the main window looks like ths:
def store_fct_data(self, data):
self.fct_data = data
Now i just want to understand how i can make either the mainwindow or the pushbutton which opens the 2nd window disabled. Disabling inside enter_fct_results() works, but if i want to enable it again with either store_fct_data or on_submit provides errors like this:
self.ui.pushButton_FCTresults.setEnabled(1)
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
AttributeError: type object 'MainWindow' has no attribute 'ui'
I dont think i have understood it here how to deal with multiple windows and stuff. For example how would i change a the color of a button in the main window by using a button in window2. How do i access the widgets? if i am inside the same Window i do that easily by
self.ui.pushbutton.setText("New Text")
I dont get how to access items and attributes across Windows :( Can you help me?
Access to attributes of another instance
There is a fundamental difference between disabling the button of the second window in enter_fct_results and what you tried in the lambda: in the first case, you're accessing an instance attribute (for instance, self.FCTpopup.ui.pushButton), while in the second you're trying to access a class attribute.
The self.ui object is created in the __init__ (when the class instance is created), so the instance will have an ui attribute, not the class:
class Test:
def __init__(self):
self.value = True
test = Test()
print(test.value)
>>> True
print(Test.value)
>>> AttributeError: type object 'Test' has no attribute 'value'
Provide a reference
The simple solution is to create a reference of the instance of the first window for the second:
def enter_fct_results(self):
self.FCTpopup = FCT_Window(self)
self.FCTpopup.show()
class FCT_Window(QMainWindow):
def __init__(self, mainWindow):
QMainWindow.__init__(self)
self.mainWindow = mainWindow
self.ui.pushButton_submitFCT.clicked.connect(self.doSomething)
def doSomething(self):
# ...
self.mainWindow.ui.pushButton.setEnabled(True)
Using modal windows (aka, dialogs)
Whenever a window is required for some temporary interaction (data input, document preview, etc), a dialog is preferred: the main benefit of using dialogs is that they are modal to the parent, preventing interaction on that parent until the dialog is closed; another benefit is that (at least on Qt) they also have a blocking event loop within their exec() function, which will only return as soon as the dialog is closed. Both of these aspects also make unnecessary disabling any button in the parent window. Another important reason is that QMainWindow is not intended for this kind of operation, also because it has features that generally unnecessary for that (toolbars, statusbars, menus, etc).
def enter_fct_results(self):
self.FCTpopup = FCT_Window(self)
self.FCTpopup.exec_()
class FCT_Window(QDialog):
def __init__(self, parent):
QMainWindow.__init__(self, parent)
self.ui.pushButton_submitFCT.clicked.connect(self.doSomething)
def doSomething(self):
# ...
self.accept()
The above makes mandatory to recreate the ui in designer using a QDialog (and not a QMainWindow) instead. You can just create a new one and drag&drop widgets from the original one.
i finally found my mistake: It was the place of the signal connection. It has to be right before the 2nd window is opened:
def enter_fct_results(self):
self.FCTpopup = Dialog(self.fct_data)
self.FCTpopup.submitted.connect(self.store_fct_data)
self.FCTpopup.exec_()
With this now i can send the stored data from the mainwindow to the opened window, import into the table, edit it and send it back to the main window on submit.
Guys!
I'm working with QTDesigner and PyQT5, I've created two screens using QTDesi. A Login form and a Main form. I'm trying to call the main screen after the login screen. But it didn't work. I've looked up to many tutorials, but non of them, worked for me.
Here's some code:
To call the Login Screen, I've used this class (On Controller):
class LoginController(QtWidgets.QDialog, Ui_Dialog):
def __init__(self, parent=None):
QtWidgets.QMainWindow.__init__(self, parent=parent)
super().__init__(parent)
self.setupUi(self)
self.txtLogo.setPixmap(QtGui.QPixmap('../gui/img/icons/aperam.png'))
self.action_performed()
def action_performed(self):
self.pushButton.clicked.connect(self.valid_login)
def valid_login(self):
user = self.txtUser.text()
password = self.txtPassword.text()
if model.validate_login(user, password):
self.close()
main = HomeScreen()
Then, to call the Main Screen, I'm using this:
class HomeScreen(Ui_Model):
def __init__(self):
super(HomeScreen, self).__init__()
self.ui = Ui_Model()
self.main = QtWidgets.QMainWindow()
self.login_home_screen()
def login_home_screen(self):
self.ui.setupUi(self.main)
self.main.show()
self.ui.actionNovo.triggered.connect(self.user_screen_show)
self.main.close()
But It didn't work for me. It only shows up a black screen then closes.
The "Start" from the system is this code (Where I call the LoginScreen):
cd = LoginController()
if __name__ == "__main__":
import sys
ui = LoginController()
cd.show()
sys.exit(app.exec_())
Can you help me? I've tried to many tutorials and articles, but both them didn't work. I want to call another form after the login is sucessufuly.
Thanks
There are various problems with your code.
HomeScreen should inherit from QMainWindow too, not only from Ui_Model;
you should avoid mixing QWidget/uic creation styles;
you should not call the base class __init__ if you're also calling super().__init__ afterwards;
you create a HomeScreen instance (main), but then the function returns, which means that that instance will be instantly garbage collected;
two instances of LoginController are being created, but you only need one;
the home screen is shown and closed afterwards, which doesn't make much sense;
there is usually no need to create other functions if you just run them once (I'm referring to action_performed and login_home_screen), especially if they only do small tasks that can be included in the __init__;
The simplest solution for your case is to create a custom signal for the login screen, and connect it to the show function of the home screen window.
Note that I don't know what user_screen_show does; if it's used to show again the login, you should use a similar system to show the dialog again.
class LoginController(QtWidgets.QDialog, Ui_Dialog):
loginSuccessful = QtCore.pyqtSignal()
def __init__(self, parent=None):
super(LoginController, self).__init__(parent)
self.setupUi(self)
self.txtLogo.setPixmap(QtGui.QPixmap('../gui/img/icons/aperam.png'))
self.pushButton.clicked.connect(self.valid_login)
def valid_login(self):
user = self.txtUser.text()
password = self.txtPassword.text()
if model.validate_login(user, password):
# login is valid, emit the signal
self.loginSuccessful.emit()
self.hide()
class HomeScreen(QtWidgets.QMainWindow, Ui_Model):
newLogin = QtCore.pyqtSignal()
def __init__(self):
super(HomeScreen, self).__init__()
self.setupUi(self)
self.actionNovo.triggered.connect(self.user_screen_show)
def user_screen_show(self):
self.newLogin.emit()
self.hide()
if __name__ == "__main__":
import sys
cd = LoginController()
cd.show()
home = HomeScreen()
cd.loginSuccessful.connect(home.show)
home.newLogin.connect(cd.show)
sys.exit(app.exec_())
How to open a new window after the user clicks a button is described here:
https://stackoverflow.com/a/21414775/1898982
and here:
https://stackoverflow.com/a/13519181/1898982
class Form1(QtGui.QWidget, Ui_Form1):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.setupUi(self)
self.button1.clicked.connect(self.handleButton)
self.window2 = None
def handleButton(self):
if self.window2 is None:
self.window2 = Form2(self)
self.window2.show()
class Form2(QtGui.QWidget, Ui_Form2):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.setupUi(self)
I want to develop a GUI application that consists of several steps. Once the user clicks next, the current window closes and another window opens. Technically I can do this like it is described above: Each window opens a new one. After a few steps this is pretty much nested.
Is there a better way to do this?
I would like to have the control flow in my main. Something like this:
main()
window1 = win2()
window1.show()
wait until button in window1 is clicked, then
window1.close()
window2 = win2()
window2.show()
wait until button in window2 is clicked, then
window1.close()
....
I would recommend to use QWizard or QStackedWidget class to perform this task. You can easily switch between widgets or windows using either of these two classes. Refer to QWizard and QStackedWidget docs.
Qt provides special widget for such cases, which called QWidget. Look at it. It's also available in Qt4.
The idea is to open a child window from parent window menu and when I minimize the parent window, the child window must be minimized also and only one child window can be opened.
I have the solution for minimizing the child when parent is minimized, but I can open child window multiple-times (although the child is already opened) and I would like to disable opening of multiple child windows.
The parent window is MainWindow.py:
class MainWindow(QtGui.QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle('Parent window')
self.flags = QtCore.Qt.Window
self.ControlPanel = Control_panel_window()
self.createActions()
self.createMenus()
def createActions(self):
# window - menu
self.windowShowControlPanelAction = QtGui.QAction(self.tr("&Control panel"), self, statusTip='Control panel')
self.connect(self.windowShowControlPanelAction, QtCore.SIGNAL("triggered()"), self.ShowControlPanel)
def createMenus(self):
# window
self.windowMenu = QtGui.QMenu(self.tr("&Window"), self)
self.windowMenu.addAction(self.windowShowControlPanelAction)
self.menuBar().addMenu(self.windowMenu)
def ShowControlPanel(self):
self.ControlPanel = Control_panel_window(self)
self.ControlPanel.setWindowFlags(QtCore.Qt.Window)
self.ControlPanel.show()
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
win = MainWindow()
win.setContextMenuPolicy(QtCore.Qt.CustomContextMenu)
win.show()
sys.exit(app.exec_())
The child window is ChildWindow.py:
class Control_panel_window(QWidget):
def __init__(self, parent = None):
super(Control_panel_window, self).__init__(parent)
self.setFixedSize(200, 300)
def setWindowFlags(self, flags):
print "flags value in setWindowFlags"
print flags
super(Control_panel_window, self).setWindowFlags(flags)
The problem is: how can I set that only one child window is opened?
In your ShowControlPanel function you are creating a new control panel each time the signal is triggered. Since you already have an instance available why don't you use that instead?
class MainWindow(QtGui.QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle('Parent window')
self.flags = QtCore.Qt.Window
self.control_panel = ControlPanelWindow(self)
self.control_panel.setWindowFlags(self.flags)
#...
def create_actions(self):
self.show_control_panel_action = QtGui.QAction(
self.tr("&Control panel"),
self,
statusTip='Control panel'
)
self.show_control_panel_action.triggered.connect(self.show_control_panel)
#...
def show_control_panel(self):
self.control_panel.show()
Some stylistic notes:
Try to follow PEP8 official python coding-style guide. This include using CamelCase for classes, lowercase_with_underscore for almost everything else. In this case, since Qt uses halfCamelCase for methods etc you may use it too for consistency.
Use the new-style signal syntax:
the_object.signal_name.connect(function)
instead of:
self.connect(the_object, QtCore.SIGNAL('signal_name'), function)
not only it reads nicer, but it also provides better debugging information. Using QtCore.SIGNAL you will not receive an error if the signal doesn't exist (e.g. you wrote a typo like trigered() instead of triggered()). The new-style syntax does raise an exception in that case you will be able to correct the mistake earlier, without having to guess why something is not working right and searching the whole codebase for the typo.
Trying to build a user interface using PyQt4. Got a dialog window that pops up, and I want it to do something then close, when 'Ok' is pressed. Unfortunately, I can't seem to get it working - tried all sorts of combinations of Dialog.exec_(), Dialog.close(), self.exec_(), self.close(), emitting an 'accepted' signal to Dialog.accept, etc. So far, nothing has worked, and I'm not quite sure why. Here's the code for it:
Dialog window initialised as such;
def begin_grab(self):
self.GrabIm=qtg.QDialog(self)
self.GrabIm.ui=Ui_Dialog()
self.GrabIm.ui.setupUi(self.GrabIm)
self.GrabIm.show()
Dialog window;
class Ui_Dialog(object):
def setupUi(self, Dialog):
Dialog.setObjectName(_fromUtf8("Dialog"))
...
QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("accepted()")), self.accept)
QtCore.QObject.connect(self.buttonBox, QtCore.SIGNAL(_fromUtf8("rejected()")), Dialog.reject)
QtCore.QMetaObject.connectSlotsByName(Dialog)
def accept(self):
if self.radioButton.isChecked()==True: #assume it is true
#Call continuous grabber
print "Grabbing continuously"
Dialog.exec_() #Close it here
else:
#Call trigger server
print "Grabbing triggered"
self.exec_()
The main thing that keeps happening is either a message saying 'Dialog' is an unknown variable, in the accept() function, or if I use self.exec_() or similar it says exec_() is not a known attribute. If I try doing accept(self, Dialog), and put self.accept(Dialog) in the connect statement, it also crashes.
Any and all help would be appreciated.
You are doing it pretty wrong. You shouldn't modify the Qt Designer generated code (Ui_Dialog). You should subclass QDialog and define the accept there:
class MyDialog(QtGui.QDialog):
def __init__(self, parent=None):
super(MyDialog, self).__init__(parent)
self.ui = Ui_Dialog()
self.ui.setupUi(self)
# use new style signals
self.ui.buttonBox.accepted.connect(self.accept)
self.ui.buttonBox.rejected.connect(self.reject)
def accept(self):
if self.ui.radioButton.isChecked(): # no need to do ==True
#Call continuous grabber
print "Grabbing continuously"
else:
#Call trigger server
print "Grabbing triggered"
super(MyDialog, self).accept() # call the accept method of QDialog.
# super is needed
# since we just override the accept method
Then you initialize it as:
def begin_grab(self):
self.GrabIm=MyDialog(self)
self.GrabIm.exec_() # exec_() for modal dialog
# show() for non-modal dialog
But looking at your code, I wouldn't do it that way. Let the dialog return with accept/reject and then do your conditional stuff in the caller (i.e. Main window):
class MyDialog(QtGui.QDialog):
def __init__(self, parent=None):
super(MyDialog, self).__init__(parent)
self.ui = Ui_Dialog()
self.ui.setupUi(self)
# use new style signals
self.ui.buttonBox.accepted.connect(self.accept)
self.ui.buttonBox.rejected.connect(self.reject)
and the caller code:
def begin_grab(self):
self.GrabIm=MyDialog(self)
if self.GrabIm.exec_(): # this will be True if dialog is 'accept'ed, False otherwise
if self.GrabIm.ui.radioButton.isChecked():
#Call continuous grabber
print "Grabbing continuously"
else:
#Call trigger server
print "Grabbing triggered"
You can re implement closeEvent which will help you to do some process before Dialog exit
def closeEvent(self,event):
print "I am here"
event.accept()