PyQt - access data of another interface? - python

I have a python script with 2 classes, each one is a different PyQt interface.
The first one is the main interface, and the second one is a "pop-up interface" - it appears when you click a button in the main interface.
Whenever that pop-up interface is launched via the main interface, i need it to display data coming from the main interface.
How can i do that if they're both in different classes?
For example, main interface:
class MainUI(QtGui.QWidget):
def __init__(self):
super(QtGui.QWidget, self).__init__()
self.myData = "data"
pop-up interface:
class PopUp(QtGui.QDialog):
def __init__(self, parent=None):
super(MyDialog, self).__init__(parent)
# some stuff here
Thanks!

Just pass the data into the constructor for PopUp
class PopUp(QtGui.QDialog):
def __init__(self, data, parent=None):
super(MyDialog, self).__init__(parent)
self.data = data
If this is not feasible due to the design of your project, you can use Signals and Slots to pass the data between classes.

Related

Try to add widgets dinamycally in another thread PyQT5

I have some QDialog with some initial widgets. I try to run a QThread to add others widgets after my api request but I cant.
main.py
class Lobby(QDialog):
signal_api_response = pyqtSignal(dict)
def __init__(self, _token, parent=None):
super().__init__()
self.initUI() # build initial ui
self.mythread= MyThread('arg test')
self.mythread.new_signal.connect(self.response_my_api)
self.mythread.start()
self.showFullScreen()
#pyqtSlot(dict)
def response_worker_mychar(self, response):
print(response)
# build dynamic widget (not creating new widgets here)
self.some_slot = QLabel('zzzzz', self)
self.some_slot.move(10, 10)
self.some_slot.setCursor(Qt.PointingHandCursor)
self.some_slot.setStyleSheet(f"border: 2px solid red;color:white;")
Thread Class
class MyThread(QThread):
new_signal = pyqtSignal(dict)
def __init__(self, token=None, parent=None):
super(QThread, self).__init__(parent)
self.token = token
def run(self):
response = get_blabla_api(self.token)
self.new_signal.emit(response)
QThread is working but it doesn't create new widgets (QLabel, ...). I tried to change an existing widget and it worked, but creating others didn't work.
It doesn't give an error but it doesn't create the widgets.
Note: The function where I create these dynamic widgets after the signal emit works, it just doesn't work using QThread. I'm using QThread because as I make a request in the api, PyQt freezes.

How to get the list of all QPushButton from a specific tab in Python Pyqt5? [duplicate]

I'm using Python3 and PyQt5, make my widgets and windows in Qt Designer. What is more, I do not generate .py files from a .ui. I simply load it using next code:
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
uic.loadUi('UI/Qt/source/MainWindow.ui', self)
So, I wanted to know, how do I bind menu bar actions to functions.
Is there any way I can do something like this?
self.getActionByName("actionTest_Action").connect(self.do_something)
It is not necessary to use findChild when using loadUi since this method adds the object to the attributes of the class using the objectName as a name, for example in this particular case a cleaner code than the other answer is:
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
uic.loadUi('UI/Qt/source/MainWindow.ui', self)
self.actionTest_Action.triggered.connect(self.test)
def test(self):
print("Test")
So, answering my own question..
One way to do this, is to find an action by using FindChild(QAction, "ActionName") function, and then bind a function using connect() function
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
uic.loadUi('UI/Qt/source/MainWindow.ui', self)
action = self.findChild(QAction, "actionTest_Action")
action.triggered.connect(self.test)
def test(self):
print("Test")

Setting up QStackedWidget properly, signal cannot see function/slot

I am working on developing a GUI with PyQt5. This is my first step into OOP, and I'm trying to teach myself as I go. I'm struggling with understanding when classes inherit methods/attributes etc and what methods they have available -- I guess it is a scope-related question? I have produced a MWE to my GUI below. In total, there will be many more pages and signals/slots.
What I want:
The stack should initialize with the "MainMenu" widget/object showing (left image below). Clicking on "Next Page" button should switch the stack order to put the "OtherPage" widget/object on top (right image below). I am creating each page as a class, thinking this would be a good way to organize my project. Is this good or bad practice?
What happens now:
The GUI works (initializes) if the line nextPg.clicked.connect(self.drawOtherPage()) is commented out, but of course then clicking on the button does nothing. I can switch the initial stack order so that "other" widget is on top of the stack and it shows up fine, so I think that class is also working. When the above line is included in the code, the following error is thrown:
in __init__
nextPg.clicked.connect(self.drawOtherPage())
AttributeError: 'MainMenu' object has no attribute 'drawOtherPage'
What I've tried
I thought that the call to super() was supposed to allow the child class (in this case MainMenu) to inherit the methods from the parent class (RootInit). Therefore, I would think this should make the drawOtherPage method available to the button connect signal. Obviously, the error isa result of the method not being available.
What am I doing wrong? Should I be creating these "page" widgets in methods instead? Do they need to be under the RootInit class or can they live in the top level of the .py file? I'm trying to follow best practices as the project will become pretty large in the end. Fortunately, most of it should be pages with variations based on what buttons were clicked to get there -- I therefore thought classes would be helpful. Please be harsh on the code and my python/PyQt vernacular, trying to learn -- thanks!
import sys, os
from PyQt5.QtWidgets import *
from PyQt5 import QtGui, QtCore
class RootInit(QMainWindow):
# root window
def __init__(self, parent=None):
QMainWindow.__init__(self)
self.root = QWidget()
self.stack = QStackedWidget()
rootLayout = QVBoxLayout()
rootLayout.addWidget(self.stack)
self.root.setLayout(rootLayout)
self.setCentralWidget(self.root)
self.initializeGUI()
def initializeGUI(self):
self.main = MainMenu(self) # build MainMenu (class)
self.other = OtherPage(self) # build OtherPage (class)
self.stack.addWidget(self.main)
self.stack.addWidget(self.other)
def drawMain(self):
self.stack.setCurrentIndex(0)
def drawOtherPage(self):
self.stack.setCurrentIndex(1)
class MainMenu(QWidget):
# class for main menu
def __init__(self, parent=None):
QWidget.__init__(self, parent)
super().__init__()
mainLayout = QGridLayout() # layout for entire main menu
quitBtn = QPushButton("Quit")
quitBtn.clicked.connect(QtCore.QCoreApplication.instance().quit)
nextPg = QPushButton("Next page")
nextPg.clicked.connect(self.drawOtherPage())
mainLayout.addWidget(quitBtn, 0, 0)
mainLayout.addWidget(nextPg, 0, 1)
self.setLayout(mainLayout)
class OtherPage(QWidget):
# class for another menu
def __init__(self, parent=None):
QWidget.__init__(self, parent)
label = QLabel("test label")
layout = QGridLayout() #
layout.addWidget(label, 0, 0)
self.setLayout(layout)
if __name__ == '__main__':
app = QApplication(sys.argv)
root = RootInit()
root.setWindowTitle("Title")
root.show()
sys.exit(app.exec_())
Your code has the following errors:
The variable self refers to the same instance of the class, in your case self refers to an instance of MainMenu, and if we observe MainMenu it does not have any drawOtherPage() method.
Another mistake in your case is to call the parent's constructor twice:
class MainMenu(QWidget):
# class for main menu
def __init__(self, parent=None):
QWidget.__init__(self, parent)
super().__init__()
In the first constructor you are assigning a parent, and in the second, you are not. To clarify in python there are several ways to call the parent's constructor:
QWidget.__init__(self, parent)
super(MainMenu, self).__init__(parent)
super().__init__(parent)
so you should only use one of them.
Another error is that a signal is connected through the name of a function, the function must not be evaluated using parentheses
and for the last use of functions or methods that involve several objects should be done in a place where both objects can access, in your case you can take advantage of what you are going to RootInit as parent of MainMenu: self.main = MainMenu(self), and access the connection to that element through the method parent().
All of the above entails modifying the MainMenu class to the following:
class MainMenu(QWidget):
def __init__(self, parent=None):
QWidget.__init__(self, parent)
mainLayout = QGridLayout() # layout for entire main menu
quitBtn = QPushButton("Quit")
quitBtn.clicked.connect(QtCore.QCoreApplication.instance().quit)
nextPg = QPushButton("Next page")
nextPg.clicked.connect(self.parent().drawOtherPage)
mainLayout.addWidget(quitBtn, 0, 0)
mainLayout.addWidget(nextPg, 0, 1)
self.setLayout(mainLayout)

How to connect to parent SIGNAL in PyQt?

I have a MainWindow that looks like this:
def __init__(self, parent = None):
QMainWindow.__init__(self, parent)
self.setupUi(self)
self.showMaximized()
menu=mainMenu.MainMenu()
classification=classificationMain.ClassificationMain()
self.stackedWidget.addWidget(menu)
self.stackedWidget.addWidget(classification)
self.stackedWidget.setCurrentWidget(menu)
self.stackedWidget.showFullScreen()
#connections
menu.pushButton.clicked.connect(self.showClassification)
classification.backButton.clicked.connect(self.showMainWindow)
def showClassification(self ):
self.stackedWidget.setCurrentIndex(3)
def showMainWindow(self):
self.stackedWidget.setCurrentIndex(2)
The MainWindows waits for signal from the rest of the dialogs. Now, the Classification dialog has another StackedWidget in it, since it works as a main window for an important part of the application. It looks like:
class ClassificationMain(QDialog, Ui_Dialog):
def __init__(self, parent = None):
QDialog.__init__(self, parent)
self.setupUi(self)
choose=choosePatient.ChoosePatient()
self.stackedWidget.addWidget(choose)
self.stackedWidget.setCurrentWidget(choose)
Now, I want to reload the data inside ChoosePatient every time the button "Show Classification" from MainMenu is clicked, but now the data is loaded only once in the line classification=classificationMain.ClassificationMain() of MainWindow.
I was thinking I had to connect a slot inside ChoosePatient with the click of "Show Classification" button inside MainMenu, but I would need an instance of MainMenu, which is not possible.
How can a method of ChoosePatient can be execute every time the button in the "parent" window is clicked? (also, please tell me if this is not the right way to work with pyqt windows)
You need to save references to your composed widgets, and also to expose some public methods to the parents:
class ClassificationMain(QDialog, Ui_Dialog):
def __init__(self, parent = None):
QDialog.__init__(self, parent)
self.setupUi(self)
self.chooseWidget=choosePatient.ChoosePatient()
self.stackedWidget.addWidget(self.chooseWidget)
self.stackedWidget.setCurrentWidget(self.chooseWidget)
def reloadPatients(self):
# whatever your operation should be on the ChoosePatient
self.chooseWidget.reload()
# MAIN WINDOW
def __init__(self, parent = None):
...
self.classification=classificationMain.ClassificationMain()
self.stackedWidget.addWidget(self.classification)
...
#connections
menu.pushButton.clicked.connect(self.showClassification)
def showClassification(self ):
self.stackedWidget.setCurrentIndex(3)
self.classification.reloadPatients()
You could also just skip the reloadPatients method and connect to the ChoosePatient directly if you want:
def showClassification(self ):
self.stackedWidget.setCurrentIndex(3)
self.classification.chooseWidget.reload()
My personal opinion is to make your custom classes wrap up the internal functionality nicely so that you only need to interface with it over the custom class, and not dig into its internals. That way you can change how it works inside without breaking the main window.

PyQt4 custom widget (uic loaded) added to layout is invisible

I've created a custom widget in pyqt4 that I've worked on and tested and now am ready to load it into my main window. Since it doesn't show up in designer, I need to manually add it to my main window manually.
My widget uses uic to load the ui file instead of converting it to a py file (it's been quicker less hassle so far) so it looks something like this:
class widgetWindow(QtGui.QWidget):
def __init__(self, parent = None):
super(widgetWindow, self).__init__(parent)
self.ui = uic.loadUi("widget.ui")
#everything else
now in my main class (example for brevity) I create the layout, add the widget to the layout and then add it to the main widget
class main(QtGui.QMainWindow):
def __init__(self, parent = None):
super(main, self).__init__(parent)
self.ui = uic.loadUi("testWindow.ui")
mainlayout = QtGui.QVBoxLayout()
window = widgetWindow(self)
mainlayout.addWidget(window)
centerWidget = QtGui.QWidget()
centerWidget.setLayout(mainlayout)
self.ui.setCentralWidget(centerWidget)
There are no errors thrown, and it will make space for the widget, but it simply won't show anything.
adding in the line window.ui.show() will just pop open a new window overtop the space that it should be occupying on the main window. What am I missing?
Doing some more research into the uic loader, there are two ways to load a ui file. The way I'm using it in the question is one way, the other way is with the uic.loadUiType(). This creates both the base class and the form class to be inherited by the class object instead of just the QtGui.QWidget class object.
widgetForm, baseClass= uic.loadUiType("addTilesWidget.ui")
class windowTest(baseClass, widgetForm):
def __init__(self, parent = None):
super(windowTest, self).__init__(parent)
self.setupUi(self)
This way, the widget can be loaded into another form as expected. As for exactly why, I haven't found that answer yet.
Some more info on the different setup types: http://bitesofcode.blogspot.com/2011/10/comparison-of-loading-techniques.html
Try to add the parent argument into the loadUi statements:
self.ui = uic.loadUi("widget.ui",parent)
self.ui = uic.loadUi("testWindow.ui",self)
And try the following line at the end of your main class.
self.setCentralWidget(centerWidget)
You need to specify that 'centerWidget' is the central widget of the main window.
i.e your code for class main should be have a line like:
self.setCentralWidget(centerWidget)
class main(QMainWindow):
def __init__(self, parent = None):
super(main, self).__init__(parent)
....
self.setCentralWidget(centerWidget)

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