How to add tabs is Qtabwidget in a new process? - python

I want to add a tab in a new process on button click event and terminate it after sometime.
On Button click a new process is created but tabs are not created.
Please help me regrading this issue!!!
Here is what is tried:
from PyQt4 import Qt, QtCore, QtGui
import sys
import multiprocessing
class createProc(multiprocessing.Process):
def __init__(self,mnWndObj):
super(createProc,self).__init__()
self.Obj = mnWndObj
def run(self):
print "Process is being created!!!"
tab = QtGui.QWidget()
self.Obj.tabwnd.addTab(tab,"tab")
class MainWnd(QtGui.QWidget):
def __init__(self,parent=None):
super(MainWnd,self).__init__(parent)
self.layout = QtGui.QVBoxLayout()
self.tabwnd = QtGui.QTabWidget()
self.webwnd = Qt.QWebView()
self.webwnd.load(QtCore.QUrl("https://www.google.co.in/"))
self.webwnd.show()
self.btn = QtGui.QPushButton("Create Process")
self.layout.addWidget(self.btn)
self.layout.addWidget(self.tabwnd)
self.layout.addWidget(self.webwnd)
self.setLayout(self.layout)
self.btn.clicked.connect(self.crProc)
def crProc(self):
p = createProc(self)
p.start()
print "Process Name",p.name
if __name__=="__main__":
app = Qt.QApplication(sys.argv)
m = MainWnd()
m.show()
app.exec_()

Related

Pyqt5 - how to go back to hided Main Window from Secondary Window?

If I click Back from the second window, the program will just exit. How do I go back to mainwindow in this case? I assume I will need some more code in that clickMethodBack function.
import os
import PyQt5
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QMainWindow, QWidget, QLabel, QPushButton
import time
from PyQt5.QtCore import QSize
class GUI_Window():
def __init__(self):
self.main_window()
return
def main_window(self):
app = PyQt5.QtWidgets.QApplication(sys.argv)
self.MainWindow = MainWindow_()
self.MainWindow.show()
app.exec_()
return
class MainWindow_(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.TestAButton = QPushButton("TestA", self)
self.TestAButton.clicked.connect(self.TestA_clickMethod)
self.TestAButton.move(20, 0)
self.CloseButton = QPushButton("Close", self)
self.CloseButton.clicked.connect(self.Close_clickMethod)
self.CloseButton.move(20, 40)
self.TestingA = TestA_MainWindow()
def TestA_clickMethod(self):
self.TestAButton.setEnabled(False)
time.sleep(0.2)
self.TestingA.show()
self.hide()
try:
if self.TestingA.back == True:
self.show()
except:
None
def Close_clickMethod(self):
self.Test_Choice = 'Exit'
self.close()
class TestA_MainWindow(QWidget):
def __init__(self):
super().__init__()
self.setMinimumSize(QSize(980,700))
self.setWindowTitle("TestA")
self.Back_Button = False
self.closeButton = QPushButton("Close", self)
self.closeButton.clicked.connect(self.clickMethodClose)
self.returnButton = QPushButton("Back", self)
self.returnButton.clicked.connect(self.clickMethodBack)
self.returnButton.move(0,30)
def clickMethodClose(self):
self.Back_Button = False
self.close()
def clickMethodBack(self):
self.returnButton.setEnabled(False)
time.sleep(0.5)
self.back = True
self.close()
# Run if Script
if __name__ == "__main__":
main = GUI_Window() # Initialize GUI
Your code has two very important issues.
you're using a blocking function, time.sleep; Qt, as almost any UI toolkit, is event driven, which means that it has to be able to constantly receive and handle events (coming from the system or after user interaction): when something blocks the event queue, it completely freezes the whole program until that block releases control;
you're checking for the variable too soon: even assuming the sleep would work, you cannot know if the window is closed after that sleep timer has ended;
The solution is to use signals and slots. Since you need to know when the second window has been closed using the "back" button, create a custom signal for the second window that will be emitted whenever the function that is called by the button is closed.
from PyQt5 import QtCore, QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
central = QtWidgets.QWidget()
layout = QtWidgets.QHBoxLayout(central)
self.testButton = QtWidgets.QPushButton('Test A')
self.closeButton = QtWidgets.QPushButton('Close')
layout.addWidget(self.testButton)
layout.addWidget(self.closeButton)
self.setCentralWidget(central)
self.testButton.clicked.connect(self.launchWindow)
self.closeButton.clicked.connect(self.close)
def launchWindow(self):
self.test = TestA_MainWindow()
self.test.backSignal.connect(self.show)
self.hide()
self.test.show()
class TestA_MainWindow(QtWidgets.QWidget):
backSignal = QtCore.pyqtSignal()
def __init__(self):
super().__init__()
layout = QtWidgets.QHBoxLayout(self)
self.closeButton = QtWidgets.QPushButton('Close')
self.backButton = QtWidgets.QPushButton('Back')
layout.addWidget(self.closeButton)
layout.addWidget(self.backButton)
self.closeButton.clicked.connect(self.close)
self.backButton.clicked.connect(self.goBack)
def goBack(self):
self.close()
self.backSignal.emit()
def GUI_Window():
import sys
app = QtWidgets.QApplication(sys.argv)
mainWindow = MainWindow()
mainWindow.show()
sys.exit(app.exec_())
if __name__ == '__main__':
GUI_Window()
Notes:
I removed the GUI_Window class and made a function, as using a class for that is not really useful;
you should always prefer layout managers instead of setting manual geometries;
widgets should not be added to a QMainWindow as direct children, and a central widget should always be used (see the creation and use of central in the example); read more about it in the documentation;
only classes and constants should be capitalized, while variables, attributes and functions should always have names starting with a lowercase letter;

How to print test output to a label in pyqt gui

what I am trying to do with a python script: Use a pytest test method to print a text line to a label in the pyqt GUI.
When running the main python file, the GUI starts and a click on the "test" button runs the test without blocking the GUI (see full code example below). But I have no clue how to proceed now.
Code:
import sys
import pytest
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QWidget
class Window(QtWidgets.QMainWindow):
signal_start_background_job = QtCore.pyqtSignal()
def __init__(self):
super(Window, self).__init__()
layout = QVBoxLayout()
self.button = QtWidgets.QPushButton("test", self)
self.label = QtWidgets.QLabel("console output")
layout.addWidget(self.button)
layout.addWidget(self.label)
widget = QWidget()
widget.setLayout(layout)
self.setCentralWidget(widget)
self.worker = WorkerObject()
self.thread = QtCore.QThread()
self.worker.moveToThread(self.thread)
self.signal_start_background_job.connect(self.worker.background_job)
self.button.clicked.connect(self.start_background_job)
def start_background_job(self):
self.thread.start()
self.signal_start_background_job.emit()
class WorkerObject(QtCore.QObject):
#QtCore.pyqtSlot()
def background_job(self):
pytest.main(["-s", "-k test_something"])
if __name__ == "__main__":
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
def test_something():
print("unit test some stuff")
assert 0 == 0
Instead of using pytest directly you could use QProcess to launch it and then capture the output:
import os
import sys
from PyQt5 import QtWidgets, QtCore
from PyQt5.QtWidgets import QApplication, QVBoxLayout, QWidget
CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))
class Window(QtWidgets.QMainWindow):
def __init__(self):
super(Window, self).__init__()
self.button = QtWidgets.QPushButton("test", self)
self.label = QtWidgets.QLabel("console output")
self.textedit = QtWidgets.QTextEdit(readOnly=True)
widget = QWidget()
layout = QVBoxLayout(widget)
layout.addWidget(self.button)
layout.addWidget(self.label)
layout.addWidget(self.textedit)
self.setCentralWidget(widget)
self.process = QtCore.QProcess()
self.process.setProgram(sys.executable)
self.process.readyReadStandardError.connect(self.on_readyReadStandardError)
self.process.readyReadStandardOutput.connect(self.on_readyReadStandardOutput)
self.button.clicked.connect(self.on_clicked)
#QtCore.pyqtSlot()
def on_clicked(self):
self.process.setWorkingDirectory(CURRENT_DIR)
self.process.setArguments(["-m", "pytest", "-s", "-k", "test_something"])
self.process.start()
#QtCore.pyqtSlot()
def on_readyReadStandardError(self):
err = self.process.readAllStandardError().data().decode()
self.textedit.append(err)
#QtCore.pyqtSlot()
def on_readyReadStandardOutput(self):
out = self.process.readAllStandardOutput().data().decode()
self.textedit.append(out)
if __name__ == "__main__":
app = QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())
I'm thinking you need to check out sys.stdout, and route that to an io object that you can route to the label in your widget. Then I would set a timer and every 0.1 seconds or so set the text of your label to that object. Alternatively you can implement a widget that grabs the stdout text in qt, example here: https://stackoverflow.com/a/1220002/6615517 I haven't tried it but the other answers to that question should help. You'll probably want to clear the label on each test to prevent it from getting too long.

PyQT GUI Freeze with Infinite Loop in QThread

I'm new to PyQT and QThread. My PyQT program has a button which trigger a continuous writing/reading of the serial port every second.
Problem: When the button is clicked and the looping starts, the GUI freezes up. Am I using QThread wrongly?
import sys
from PyQt4.QtGui import *
from PyQt4 import QtCore
import serial
import time
from TemperatureReader import TemperatureReader # my module to talk to serial hardware
class Screen(QMainWindow):
def __init__(self):
super(Screen, self).__init__()
self.initTemperatureReader()
self.initUI()
def initTemperatureReader(self):
ser = serial.Serial(port='COM9', baudrate=115200, timeout=5)
self.temperatureReader = TemperatureReader(ser)
def initUI(self):
startReadingTCsBtn = QPushButton('Start Reading')
startReadingTCsBtn.clicked.connect(self.startReadingTCsThread)
startReadingTCsBtn.show()
directControlBoxLayout = QVBoxLayout()
directControlBoxLayout.addWidget(startReadingTCsBtn)
self.mainFrame = QWidget()
mainLayout = QVBoxLayout()
mainLayout.addWidget(directControlGroupBox)
self.mainFrame.setLayout(mainLayout)
self.setCentralWidget(self.mainFrame)
self.setGeometry(300,300,400,150)
self.show()
def startReadingTCsThread(self):
self.tcReaderThread = TCReaderThread(self.temperatureReader)
self.tcReaderThread.temperatures.connect(self.onTemperatureDataReady)
self.tcReaderThread.start()
def onTemperatureDataReady(self, data):
print data
class TCReaderThread(QtCore.QThread):
temperatures = QtCore.pyqtSignal(object)
def __init__(self, temperatureReader):
QtCore.QThread.__init__(self)
self.temperatureReader = temperatureReader
def run(self):
while True:
resultString = self.temperatureReader.getTemperature() # returns a strng
self.temperatures.emit(resultString)
time.sleep(1)
def main():
app = QApplication(sys.argv)
screen = Screen()
app.exec_()
if __name__ == '__main__':
main()

Error with thread in pyqt4

I have the problem. I made the thread and from there I want to open the new window. But it does not work.
import sys
from grab import Grab
from PyQt4 import QtGui, QtCore
class Requests(QtCore.QThread):
def __init__(self, parent=None):
QtCore.QThread.__init__(self, parent)
def run(self):
# here some comands
self.emit(QtCore.SIGNAL("mysignal(QString)"), 'open')
class window(QtGui.QWidget):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self, parent)
self.setGeometry(100, 100, 500, 200)
self.setWindowTitle('Window')
self.label = QtGui.QLabel(u'Hello')
self.Layout = QtGui.QVBoxLayout()
self.Layout.addWidget(self.label)
self.setLayout(self.Layout)
self.c = Requests()
self.c.start()
self.connect(self.c, QtCore.SIGNAL("mysignal(QString)"), self.open_window, QtCore.Qt.QueuedConnection)
def open_window(self):
print 'open modal window'
modal_w = popup_window()
modal_w.show()
app = QtGui.QApplication(sys.argv)
main = window()
main.show()
sys.exit(app.exec_())
It is not show new window. Where is the error?
You need to connect the signal before the thread starts, and hence before the signal is emitted. If you want to show a dialog when the worker thread completes, just use the finished signal:
class Requests(QtCore.QThread):
def run(self):
# do some work...
print 'work finished'
...
self.c = Requests()
self.c.finished.connect(self.open_window)
self.c.start()
You also need to keep a reference to the dialog when opening it in the slot:
def open_window(self):
print 'open modal window'
self.modal_w = popup_window()
self.modal_w.show()

Python PyQt QWebView load site in clicked tab

I need your help!
The situation: I have different tabs and in one tab ["Support"-Tab] I want to use the QWebView Widget.
But the site should first load when I click on this tab:
main.py
import sys
from PyQt4 import QtCore, QtGui, QtWebKit
from tab-file import Support
class Widget(QtGui.QWidget):
def __init__(self, parent=None):
super(Widget, self).__init__(parent)
self.createTabs()
widgetLayout = QtGui.QVBoxLayout()
widgetLayout.addWidget(self.tabs)
self.setLayout(widgetLayout)
self.setWindowTitle("Tabs")
self.resize(400,400)
def createTabs(self):
self.tabs = QtGui.QTabWidget()
support = Support()
tab1 = QtGui.QWidget()
tab2 = support
self.tabs.addTab(tab1,"tab1")
self.tabs.addTab(tab2,"SUPPORT")
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
w = Widget()
w.show()
sys.exit(app.exec_())
I load the "Support"-Tab from this file:
tab-file.py
import sys
from PyQt4 import QtGui, QtCore, QtWebKit
class Support(QtGui.QWidget):
def __init__(self, parent=None):
super(Support, self).__init__(parent)
self.supportTab()
def supportTab(self):
view = QtWebKit.QWebView()
url = "http://www.google.com"
view.load(QtCore.QUrl(url))
vbox = QtGui.QVBoxLayout()
vbox.addWidget(view)
self.setLayout(vbox)
Can you please tell me how I can solve this?
Thanks in advance.
in main.py:
make the tab2 addressable, and add code to listen to tab change event:
#...
self.tab2 = support
self.tabs.addTab(tab1,"tab1")
self.tabs.addTab(self.tab2,"SUPPORT")
#
self.tabs.currentChanged.connect(self.load_on_show)
Then add the action
def load_on_show(self):
idx = self.tabs.currentIndex()
if idx == 1:
url = "http://www.google.com"
print url
self.tab2.load_url(url)
At last, in tab_file.py [i can't use a dash, have to use an underscore!]:
Make view addressable, again (self.view) and add code
def load_url(self, url):
self.view. load(QtCore.QUrl(url))
Does this help?

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