I have found stuff online suggesting that PyQt5 widgets are not thread safe.
And other Stackoverflow answers suggest creating a class that only fits their problem. I tried using _thread module in Python 3 which works for everything except PyQt.
app = QApplication([])
Ui_MainWindow, QtBaseClass = uic.loadUiType("UI/action_tab.ui") #specify the location of your .ui file
class MyApp(QMainWindow):
def __init__(self):
super(MyApp, self).__init__()
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
self.threadPool = QThreadPool()
self.ui.queryBox.returnPressed.connect(self.load_response)
def start_loader(self):
self.loading_animate = QMovie('IMAGES/GIFS/load_resp.gif')
self.loading_animate.setScaledSize(QSize(400, 300))
self.ui.loader.setMovie(self.loading_animate)
self.loading_animate.setSpeed(200)
self.ui.loader.show()
self.loading_animate.start()
def stop_loader(self):
self.ui.loader.hide()
self.loading_animate.stop()
def get_response(self):
plain_text, speech = get_Wresponse(self.ui.queryBox.displayText())
self.stop_loader()
self.ui.textDisplay.setText(plain_text)
if speech == '':
say("Here you GO!")
else:
say(speech)
def load_response(self):
self.start_loader()
_thread.start_new_thread(self.get_response, ())
#self.get_response()
if __name__ == '__main__':
window = MyApp()
window.setWindowFlags(Qt.FramelessWindowHint)
window.show()
sys.exit(app.exec())
Error in above code follows,
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QTextDocument(0x19fe090b8c0), parent's thread is QThread(0x19fde197fb0), current thread is QThread(0x19fe3a0a5f0)
Do you think you can save me?
Please Do !
Thanks in Advance!!
You do not have to update the GUI from an external thread. There are several options like signals, QMetaObject::invokeMethod(...), QEvent and QTimer::singleShot(0, ...) with pyqtSlot.
Using the last method the solution is as follows:
from functools import partial
from PyQt5.QtCore import pyqtSlot
class MyApp(QMainWindow):
# ...
#pyqtSlot()
def stop_loader(self):
self.ui.loader.hide()
self.loading_animate.stop()
def get_response(self, text):
plain_text, speech = get_Wresponse(text)
QtCore.QTimer.singleShot(0, self.stop_loader)
wrapper = partial(self.ui.textDisplay.setText, plain_text)
QtCore.QTimer.singleShot(0, wrapper)
if speech == '':
say("Here you GO!")
else:
say(speech)
def load_response(self):
self.start_loader()
text = self.ui.queryBox.displayText()
_thread.start_new_thread(self.get_response, (text,))
Related
import sys
from PySide2.QtCore import QFile
from PySide2.QtWidgets import QApplication, QMainWindow
from PySide2.QtUiTools import QUiLoader
class MyMainWindow(QMainWindow):
def __init__(self):
super().__init__()
loader = QUiLoader()
self.ui = loader.load("mainWindow.ui", self)
self.ui.pushButton_call_dialog.clicked.connect(self.call_dialog)
self.ui.close()
self.ui.show()
def call_dialog(self):
loader = QUiLoader()
self.dialog = loader.load("dialog.ui")
self.dialog.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
window = MyMainWindow()
window.show
sys.exit(app.exec_())
Hi everyone,
any idea why the second (dialog) window closes the entire application?
Of course, it is not a crash since i'm getting a message saying:
Process finished with exit code 0
Thanks for your help
You could handle your QDialog on a separate class, and then make them interact only, the structure might change a bit, but you can see if it's a viable answer:
import sys
from PySide2.QtWidgets import *
class MyWindow(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
button = QPushButton("Dialog")
button.clicked.connect(self.open_dialog)
self.setCentralWidget(button)
def open_dialog(self):
dialog = MyDialog()
dialog.show()
dialog.exec_()
class MyDialog(QDialog):
def __init__(self):
QDialog.__init__(self)
button = QPushButton("Close")
button.clicked.connect(self.close_dialog)
layout = QHBoxLayout()
layout.addWidget(button)
self.setLayout(layout)
def close_dialog(self):
self.close()
if __name__ == "__main__":
app = QApplication()
m = MyWindow()
m.show()
sys.exit(app.exec_())
Just notice that you should include the setUp step on each class.
Hope it helps.
To put the dialog into a separate class didn't work for either.
Every time the Dialog.close() event was called, it closes the whole application.
What worked for me, was to use hide() instead
I would like to call a function after the GUI displays. If I run function in init it prevents gui from displaying until after it is completed.
class MyApp(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
QtWidgets.QMainWindow.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
self.function() #waits for this to finish until gui displayed
def function(self):
self.guiBox.setValue(initData)
#inits stuff, takes 5 seconds
The function initializes a piece of equipment via serial port... It takes s few seconds, and it takes gui attributes and updates gui display boxes.
Add single shot timer 1 ms and after call function
class MyApp(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
QtWidgets.QMainWindow.__init__(self)
Ui_MainWindow.__init__(self)
self.setupUi(self)
QTimer.singleShot(1,self.function) #waits for this to finish until gui displayed
def function(self):
self.guiBox.setValue(initData)
#inits stuff, takes 5 seconds
Time-consuming tasks are blocking, and this goes against the natural way of working on the GUI, an option is to use qApp.processEvents(), for example:
def function(self):
self.guiBox.setValue(initData)
code1
QtWidgets.qApp.processEvents()
code2
QtWidgets.qApp.processEvents()
...
I would recommend QThreads, especially if you are performing a ton of other actions in your "function." This example isn't the only way to thread in PyQt, but thought an example where you are able to pass data back and forth between the thread and the main gui would be best.
import os
import sys
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QWidget
from PyQt5.QtCore import QUrl, QEventLoop, QThread, QObject, pyqtSlot, pyqtSignal
from PyQt5.QtWebEngineWidgets import QWebEngineView
class time_consuming_function(QObject):
def __init__(self, widget):
super(time_consuming_function, self).__init__()
self.widget = widget
self.run_trigger.connect(self.run)
run_trigger = pyqtSignal(int, int)
#pyqtSlot(int, int)
def run(self, int1, int2):
print("In Time Consuming Function")
for i in range(100000000):
i*i
print("Finished with Time Consuming Function")
self.widget.someTrigger.emit([1, 2, 3])
class WebPage(QWebEngineView):
def __init__(self):
QWebEngineView.__init__(self)
self.load(QUrl("https://www.google.com"))
self.loadFinished.connect(self._on_load_finished)
self.someTrigger.connect(self.gui_response)
self.thread = QThread()
self.thread.start()
self.consume = time_consuming_function(self)
self.consume.moveToThread(self.thread)
self.consume.run_trigger.emit(1,1)
someTrigger = pyqtSignal(list)
def _on_load_finished(self):
print("Finished Loading")
def gui_response(self, data):
print("Responding to GUI: ", str(data))
if __name__ == "__main__":
app = QApplication(sys.argv)
web = WebPage()
web.show()
sys.exit(app.exec_())
I'd say the easiest way without using thread and related would be to verify if the last event of showing up the window was executed and then call your method.
You'd have something like that:
import sys
from PyQt5.QtCore import QEvent
from PyQt5.QtWidgets import QApplication
from PyQt5.QtWidgets import QMainWindow
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.setFixedSize(500, 500)
self.move(300, 50)
def print_1_bi(self):
for i in range(10**9): print(i)
def event(self, event):
if event.type() == QEvent.InputMethodQuery:
self.print_1_bi()
return super(MainWindow, self).event(event)
if __name__ == "__main__":
app = QApplication(sys.argv)
mw = MainWindow()
mw.show()
sys.exit(app.exec_())
Note: Remember that even though the UI already showed up your application will be waiting your method to finish, if it's a problem you'll have to use process like the guys told you to in the other answers.
i'm trying to create an client server application in python. When the server closes i wish the gui of the client wich is on a separate thread to close, but the application crushes with Xlib error: bad implementation... I've searched and seems to be from accessing GUI interface from other thread. What should I do?python gui access from other thread
this might help you..
from PyQt4 import QtGui as gui
from PyQt4 import QtCore as core
import sys
import time
class ServerThread(core.QThread):
def __init__(self, parent=None):
core.QThread.__init__(self)
def start_server(self):
for i in range(1,6):
time.sleep(1)
self.emit(core.SIGNAL("dosomething(QString)"), str(i))
def run(self):
self.start_server()
class MainApp(gui.QWidget):
def __init__(self, parent=None):
super(MainApp,self).__init__(parent)
self.label = gui.QLabel("hello world!!")
layout = gui.QHBoxLayout(self)
layout.addWidget(self.label)
self.thread = ServerThread()
self.thread.start()
self.connect(self.thread, core.SIGNAL("dosomething(QString)"), self.doing)
def doing(self, i):
self.label.setText(i)
if i == "5":
self.destroy(self, destroyWindow =True, destroySubWindows = True)
sys.exit()
app = gui.QApplication(sys.argv)
form = MainApp()
form.show()
app.exec_()
I'm trying to create a client-server application, and when the server closes I wish that client GUI to close, which is running on another thread. I wish to access the GUI and close but I get X error:
Bad implementation(...).
How can I resolve this problem?
what you can do is emit a custom signal when the first thread goes down..
from PyQt4 import QtGui as gui
from PyQt4 import QtCore as core
import sys
import time
class ServerThread(core.QThread):
def __init__(self, parent=None):
core.QThread.__init__(self)
def start_server(self):
for i in range(1,6):
time.sleep(1)
self.emit(core.SIGNAL("dosomething(QString)"), str(i))
def run(self):
self.start_server()
class MainApp(gui.QWidget):
def __init__(self, parent=None):
super(MainApp,self).__init__(parent)
self.label = gui.QLabel("hello world!!")
layout = gui.QHBoxLayout(self)
layout.addWidget(self.label)
self.thread = ServerThread()
self.thread.start()
self.connect(self.thread, core.SIGNAL("dosomething(QString)"), self.doing)
def doing(self, i):
self.label.setText(i)
if i == "5":
self.destroy(self, destroyWindow =True, destroySubWindows = True)
sys.exit()
app = gui.QApplication(sys.argv)
form = MainApp()
form.show()
app.exec_()
Why doesn't the following example work?
from PyQt4 import QtGui
import sys
class TestView(QtGui.QWidget):
def __init__(self):
super(TestView, self).__init__()
self.initUI()
def initUI(self):
self.btn = QtGui.QPushButton('Button', self)
self.btn.resize(self.btn.sizeHint())
self.btn.move(50, 50)
class TestViewController():
def __init__(self, view):
view.btn.clicked.connect(self.buttonClicked)
view.show()
def buttonClicked(self):
print 'clicked'
def main():
app = QtGui.QApplication(sys.argv)
view = TestView()
TestViewController(view)
app.exec_()
if __name__ == '__main__':
main()
The example is supposed to represent an MVC structure (like the one in Figure 4 -- without the Model) where the controller (TestViewController) receives a reference to the view (TestView) and connects the clicked signal from the view's button view.btn to its function self.buttonClicked.
I'm sure the line view.btn.clicked.connect(self.buttonClicked) is executed but, apparently, it has no effect. Does anyone knows how to solve that?
Update (awful solution):
In the example, if I replace the line
view.btn.clicked.connect(self.buttonClicked)
with
view.clicked = self.clicked
view.btn.clicked.connect(view.clicked)
it works. I'm still not happy with that.
The reason it is not working is because the controller class is being garbage collected before you can ever click anything for it.
When you set view.clicked = self.clicked, what you're actually doing is making one of the objects from the controller persist on the view object so it never gets cleaned up - which isn't really the solution.
If you store your controller to a variable, it will protect it from collection.
So if you change your code above to read:
ctrl = TestViewController(view)
You'll be all set.
That being said - what exactly you are trying to do here, I am not sure...it seems you're trying to setup an MVC system for Qt - but Qt already has a pretty good system for that using the Qt Designer to separate the interface components into UI (view/template) files from controller logic (QWidget subclasses). Again, I don't know what you are trying to do and this may be a dumb down version of it, but I'd recommend making it all one class like so:
from PyQt4 import QtGui
import sys
class TestView(QtGui.QWidget):
def __init__(self):
super(TestView, self).__init__()
self.initUI()
def initUI(self):
self.btn = QtGui.QPushButton('Button', self)
self.btn.resize(self.btn.sizeHint())
self.btn.move(50, 50)
self.btn.clicked.connect(self.buttonClicked)
def buttonClicked(self):
print 'clicked'
def main():
app = QtGui.QApplication(sys.argv)
view = TestView()
view.show()
app.exec_()
if __name__ == '__main__':
main()
Edit: Clarifying the MVC of Qt
So this above example doesn't actually load the ui dynamically and create a controller/view separation. Its a bit hard to show on here. Best to work through some Qt/Designer based examples/tutorials - I have one here http://bitesofcode.blogspot.com/2011/10/introduction-to-designer.html but many can be found online.
The short answer is, your loadUi method can be replace with a PyQt4.uic dynamic load (and there are a number of different ways to set that up) such that your code ultimately reads something like this:
from PyQt4 import QtGui
import PyQt4.uic
import sys
class TestController(QtGui.QWidget):
def __init__(self):
super(TestController, self).__init__()
# load view
uifile = '/path/to/some/widget.ui'
PyQt4.uic.loadUi(uifile, self)
# create connections (assuming there is a widget called 'btn' that is loaded)
self.btn.clicked.connect(self.buttonClicked)
def buttonClicked(self):
print 'clicked'
def main():
app = QtGui.QApplication(sys.argv)
view = TestController()
view.show()
app.exec_()
if __name__ == '__main__':
main()
Edit 2: Storing UI references
If it is easier to visualize this concept, you Can also store a reference to the generated UI object:
from PyQt4 import QtGui
import PyQt4.uic
import sys
class TestController(QtGui.QWidget):
def __init__(self):
super(TestController, self).__init__()
# load a view from an external template
uifile = '/path/to/some/widget.ui'
self.ui = PyQt4.uic.loadUi(uifile, self)
# create connections (assuming there is a widget called 'btn' that is loaded)
self.ui.btn.clicked.connect(self.buttonClicked)
def buttonClicked(self):
print 'clicked'
def main():
app = QtGui.QApplication(sys.argv)
view = TestController()
view.show()
app.exec_()
if __name__ == '__main__':
main()