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Calling method from a second class to update QListView data

I have two tabs, Tab1, and Tab2. On Tab2, there is a button that when clicked, calls a method that updates the QListView data in the same tab. This works successfully.
When trying to call the same method from another class, it will not work. Below is a minimum reproducible example.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import (
QDesktopWidget,
QVBoxLayout,
QHBoxLayout,
QPushButton,
)
from PyQt5.QtCore import Qt
class App(QtWidgets.QMainWindow):
def __init__(self):
super().__init__()
self.init_ui()
def init_ui(self):
self.setWindowTitle('App')
self.resize(1200, 800)
self.center()
self.window = MainWindow(self)
self.setCentralWidget(self.window)
self.show()
def center(self):
qr = self.frameGeometry()
cp = QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())
class MainWindow(QtWidgets.QWidget):
def __init__(self, parent):
super(MainWindow, self).__init__(parent)
layout = QVBoxLayout(self)
# Initialize Tabs
tab_holder = QtWidgets.QTabWidget()
tab1 = Home()
tab2 = SecondTab()
tab_holder.addTab(tab1, "Tab1")
tab_holder.addTab(tab2, 'Tab2')
layout.addWidget(tab_holder)
class Home(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Home, self).__init__(parent)
lay = QVBoxLayout(self)
self.btn_login = QPushButton('Login')
self.btn_login.clicked.connect(self.login)
lay.addWidget(self.btn_login)
#QtCore.pyqtSlot()
def login(self):
print('Hello')
SecondTab.load_info()
class SecondTab(QtWidgets.QWidget):
def __init__(self, parent=None):
super(SecondTab, self).__init__(parent)
lay = QVBoxLayout(self)
# Choice Boxes
layout_choice_boxes = QHBoxLayout()
self.list_of_items = QtWidgets.QListView()
self.model_dist = QtGui.QStandardItemModel(self.list_of_items)
layout_choice_boxes.addWidget(self.list_of_items)
# Load data button.
self.loadData = QPushButton('Load Data')
self.loadData.clicked.connect(self.load_info)
# Add all components to main layout.
lay.addLayout(layout_choice_boxes)
lay.addWidget(self.loadData)
#QtCore.pyqtSlot()
def load_info(self):
for member in ['Item 1', 'Item 2', 'Item 3']:
item = QtGui.QStandardItem(member)
item.setCheckable(True)
item.setEditable(False)
check = Qt.Unchecked
item.setCheckState(check)
self.model_dist.appendRow(item)
self.list_of_items.setModel(self.model_dist)
# Press the green button in the gutter to run the script.
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
The error is on the line in the class Home() where I try to call the method from the SecondTab() class: SecondTab.load_info()
The load_info() method uses self in the SecondTab class, so I tried passing in the class directly like this: SecondTab.load_info(SecondTab()), however, it did not work.

This is a problem about the basic OOP issues, you have to interact with the instances (the objects) and not the classes (the abstraction). So the solution is that the connection between the objects "tab1" and "tab2":
class MainWindow(QtWidgets.QWidget):
def __init__(self, parent):
super(MainWindow, self).__init__(parent)
layout = QVBoxLayout(self)
# Initialize Tabs
tab_holder = QtWidgets.QTabWidget()
tab1 = Home()
tab2 = SecondTab()
tab_holder.addTab(tab1, "Tab1")
tab_holder.addTab(tab2, 'Tab2')
layout.addWidget(tab_holder)
tab1.btn_login.clicked.connect(tab2.load_info)
class Home(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Home, self).__init__(parent)
lay = QVBoxLayout(self)
self.btn_login = QPushButton('Login')
lay.addWidget(self.btn_login)

PyQt5 Automatic drawing from input value

I have recently created a widget with Qpaint, which I want to pass value to it, at the same time force the Qpaint Widget to draw from input values. The idea is to define a data value from a Qdialog and pass it to main widget, and pass the value to Qpaint Widget class. I would like to have, when user clicks on the button 'Getting values' a dialog widget would appear and insert some int values, then pass it to main Widget. from there pass value to correct class Paint. Which would draw and display the result. I tried with Qlabel, to assign value first to Qlabel or QlineEdit,
class Button(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Button, self).__init__(parent)
---------
self.value = QtWidgets.QLabel()
--------
Then inside the paint class call the value or text of those. then assign it to Qpaint event. But seems does not work.'
class Paint(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Paint, self).__init__(parent)
self.button = Button()
self.Value = self.button.value
---------
painter.drawRect(100,100,250,250) <----- instead of value 250 having self.Value
The code Main.py
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from datainput import *
class Foo(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Foo, self).__init__(parent)
self.setGeometry(QtCore.QRect(200, 100, 800, 800))
self.button = Button()
self.paint = Paint()
self.lay = QtWidgets.QVBoxLayout()
self.lay.addWidget(self.paint)
self.lay.addWidget(self.button)
self.setLayout(self.lay)
class Paint(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Paint, self).__init__(parent)
self.button = Button()
self.Value = self.button.value
self.setBackgroundRole(QtGui.QPalette.Base)
self.setAutoFillBackground(True)
def paintEvent(self, event):
self.pen = QtGui.QPen()
self.brush = QtGui.QBrush( QtCore.Qt.gray, QtCore.Qt.Dense7Pattern)
painter = QtGui.QPainter(self)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.setPen(self.pen)
painter.setBrush(self.brush)
painter.drawRect(100,100,250,250)
painter.setBrush(QtGui.QBrush())
class Button(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Button, self).__init__(parent)
getbutton = QtWidgets.QPushButton('Getting values')
Alay = QtWidgets.QVBoxLayout(self)
Alay.addWidget(getbutton)
self.value = QtWidgets.QLabel()
getbutton.clicked.connect(self.getbuttonfunc)
def getbuttonfunc(self):
subwindow=Dinput()
subwindow.setWindowModality(QtCore.Qt.ApplicationModal)
if subwindow.exec_() == QtWidgets.QDialog.Accepted:
self._output = subwindow.valueEdit.text()
return self.value.setText(self._output)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = Foo()
w.show()
sys.exit(app.exec_())
Input Qdialog code, datainput.py
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Dinput(QtWidgets.QDialog):
def __init__(self, parent=None):
super(Dinput, self).__init__(parent)
valuelabel = QtWidgets.QLabel('Input: ')
self.valueEdit = QtWidgets.QLineEdit()
buttonBox = QtWidgets.QDialogButtonBox()
buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
buttonBox.accepted.connect(self.accept)
buttonBox.rejected.connect(self.close)
self.Alay = QtWidgets.QHBoxLayout()
self.Alay.addWidget(valuelabel)
self.Alay.addWidget(self.valueEdit)
self.Blay = QtWidgets.QVBoxLayout()
self.Blay.addLayout(self.Alay)
self.Blay.addWidget(buttonBox)
self.setLayout(self.Blay)
def closeEvent(self, event):
super(Dinput, self).closeEvent(event)
def accept(self):
super(Dinput, self).accept()
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = Dinput()
w.show()
sys.exit(app.exec_())
Visualization
I appreciate any help. Thankssss

datainput is irrelevant, your task is only to obtain a number so for space question I will not use it and instead I will use QInputDialog::getInt(). Going to the problem, the strategy in these cases where the value can be obtained at any time is to notify the change to the other view through a signal, in the slot that receives the value is to update a variable that stores the value and call update so that it calls when necessary to paintEvent, and in the paintEvent use the variable that stores the value.
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
class Foo(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Foo, self).__init__(parent)
self.setGeometry(QtCore.QRect(200, 100, 800, 800))
self.button = Button()
self.paint = Paint()
self.button.valueChanged.connect(self.paint.set_size_square)
self.lay = QtWidgets.QVBoxLayout(self)
self.lay.addWidget(self.paint)
self.lay.addWidget(self.button)
class Paint(QtWidgets.QWidget):
def __init__(self, parent=None):
super(Paint, self).__init__(parent)
self.setBackgroundRole(QtGui.QPalette.Base)
self.setAutoFillBackground(True)
self._size_square = 250
#QtCore.pyqtSlot(int)
def set_size_square(self, v):
self._size_square = v
self.update()
def paintEvent(self, event):
pen = QtGui.QPen()
brush = QtGui.QBrush( QtCore.Qt.gray, QtCore.Qt.Dense7Pattern)
painter = QtGui.QPainter(self)
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.setPen(pen)
painter.setBrush(brush)
r = QtCore.QRect(QtCore.QPoint(100, 100), self._size_square*QtCore.QSize(1, 1))
painter.drawRect(r)
class Button(QtWidgets.QWidget):
valueChanged = QtCore.pyqtSignal(int)
def __init__(self, parent=None):
super(Button, self).__init__(parent)
getbutton = QtWidgets.QPushButton('Getting values')
Alay = QtWidgets.QVBoxLayout(self)
Alay.addWidget(getbutton)
self.value = QtWidgets.QLabel()
getbutton.clicked.connect(self.getbuttonfunc)
#QtCore.pyqtSlot()
def getbuttonfunc(self):
number, ok = QtWidgets.QInputDialog.getInt(self, self.tr("Set Number"),
self.tr("Input:"), 1, 1)
if ok:
self.valueChanged.emit(number)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = Foo()
w.show()
sys.exit(app.exec_())

giving index to QLineEdit

i want to give index for QLineEdit's.
i have this code.
from PyQt4 import QtGui, QtCore
import sys
class Main(QtGui.QMainWindow):
def __init__(self, parent = None):
super(Main, self).__init__(parent)
# main button
self.addButton = QtGui.QPushButton('button to add other widgets')
self.addButton.clicked.connect(self.addWidget)
self.savebutton = QtGui.QPushButton('Save')
# scroll area widget contents - layout
self.scrollLayout = QtGui.QFormLayout()
# scroll area widget contents
self.scrollWidget = QtGui.QWidget()
self.scrollWidget.setLayout(self.scrollLayout)
# scroll area
self.scrollArea = QtGui.QScrollArea()
self.scrollArea.setWidgetResizable(True)
self.scrollArea.setWidget(self.scrollWidget)
# main layout
self.mainLayout = QtGui.QVBoxLayout()
# add all main to the main vLayout
self.mainLayout.addWidget(self.addButton)
self.mainLayout.addWidget(self.scrollArea)
self.mainLayout.addWidget(self.savebutton)
# central widget
self.centralWidget = QtGui.QWidget()
self.centralWidget.setLayout(self.mainLayout)
# set central widget
self.setCentralWidget(self.centralWidget)
def addWidget(self):
self.scrollLayout.addRow(Test())
class Test(QtGui.QWidget):
def __init__( self, parent=None):
super(Test, self).__init__(parent)
self.kod = QtGui.QLineEdit()
layout = QtGui.QHBoxLayout()
layout.addWidget(self.kod)
self.setLayout(layout)
app = QtGui.QApplication(sys.argv)
myWidget = Main()
myWidget.show()
app.exec_()
when i clicked save button, savebutton sends just last QLineEdit widget.
image is here
like in this photo, i want self.kod[0].text()="aaaa" self.kod1="bbbb" self.kod[2]="cccc" and it just will go like this. kod[x] this x number will increase automatically, while i click add widgetbutton. or it can be like this: kod1,kod2,kod3, kodx. it doesnt matter, i want to just differ from eacht other and take text from them.

You can set a list in Main class, like this ['aaa', 'bbb', 'ccc'],
and set a var = 0.
class Main(QtGui.QMainWindow):
def __init__(self, parent = None):
super(Main, self).__init__(parent)
#
self.lineText = ['aaa', 'bbb', 'ccc']
self.var = 0
...
def addWidget(self):
self.scrollLayout.addRow(Test(self, self.var))
self.var += 1
Then give Test class an arg,
class Test(QtGui.QWidget):
def __init__( self, parent=None, count):
super(Test, self).__init__(parent)
#
self.parent = parent
self.kod = QtGui.QLineEdit()
#
self.kod.setText(self.parent.lineText[count])
---
class Main(QtGui.QMainWindow):
def __init__(self, parent = None):
super(Main, self).__init__(parent)
self.kod = []
...
def addWidget(self):
temp = Test()
self.kod.append(temp)
self.scrollLayout.addRow(temp)
and print(self.kod)
[<__main__.Test object at 0x00000000032EEC18>, <__main__.Test object at 0x00000000032EEDC8>, <__main__.Test object at 0x00000000032EEF78>]

How to control QProgressBar with Signal

Pushing the button starts 100 rounds cycle. With QLabel.setText() we update self.label from inside of scope of clicked() function.
Aside from updating self.label we would like to update the progressbar as well.
But since progressbar is a local variable we can't update it from inside of onClick() function.
import time
class ProgressBar(QtGui.QProgressBar):
def __init__(self, parent=None, total=20):
super(ProgressBar, self).__init__(parent=parent)
self.setMinimum(1)
self.setMaximum(105)
self.setTextVisible(True)
def set_to_value(self, value):
self.setValue(value)
QtGui.qApp.processEvents()
def closeEvent(self, event):
self._active=False
class Dialog(QtGui.QDialog):
def __init__(self):
super(QtGui.QDialog,self).__init__()
layout = QtGui.QVBoxLayout()
self.setLayout(layout)
self.label = QtGui.QLabel('idle...')
layout.addWidget(self.label)
progressbar = ProgressBar(self)
layout.addWidget(progressbar)
button = QtGui.QPushButton('Process')
button.clicked.connect(self.onClick)
layout.addWidget(button)
def onClick(self):
for i in range(101):
message = '...processing %s of 100'%i
self.label.setText(message)
QtGui.qApp.processEvents()
time.sleep(1)
if __name__ == '__main__':
app = QtGui.QApplication([])
dialog = Dialog()
dialog.resize(300, 100)
dialog.show()
app.exec_()

Declare the progress bar as:
self.progressbar = ProgressBar(self)

The code declares a local progressbar object connected to a custom 'customSignal` using:
QtCore.QObject.connect(self, QtCore.SIGNAL("customSignal(int)"), progressbar, QtCore.SLOT("setValue(int)"))
with four arguments passed to QtCore.QObject.connect().
The first argument self is the object that will be emitting the signal. Since the function that will do the "sleep-every-second-processing" is declared under the main Dialog instance we pass self here.
The second argument is the name of the signal itself: 'customSignal'.
The progressbar object is used as third and its method setValue as fourth last argument.
class ProgressBar(QtGui.QProgressBar):
def __init__(self, parent=None):
super(ProgressBar, self).__init__(parent=parent)
class Dialog(QtGui.QDialog):
def __init__(self):
super(QtGui.QDialog,self).__init__()
layout = QtGui.QVBoxLayout()
self.setLayout(layout)
self.label = QtGui.QLabel('idle...')
layout.addWidget(self.label)
progressbar = ProgressBar(self)
QtCore.QObject.connect(self, QtCore.SIGNAL("customSignal(int)"), progressbar, QtCore.SLOT("setValue(int)"))
layout.addWidget(progressbar)
button = QtGui.QPushButton('Process')
button.clicked.connect(self.clicked)
layout.addWidget(button)
def clicked(self):
for value in range(101):
message = '...processing %s of 100'%value
self.label.setText(message)
self.emit(QtCore.SIGNAL("customSignal(int)"), value)
QtGui.qApp.processEvents()
time.sleep(1)
if __name__ == '__main__':
app = QtGui.QApplication([])
dialog = Dialog()
dialog.resize(300, 100)
dialog.show()
app.exec_()
--------------------
Here is variation of the same solution except linking to the progressbar method.
import time
class ProgressBar(QtGui.QProgressBar):
def __init__(self, parent=None):
super(ProgressBar, self).__init__(parent=parent)
def set_to_value(self, value):
self.setValue(value)
QtGui.qApp.processEvents()
return True
def closeEvent(self, event):
self._active=False
class Dialog(QtGui.QDialog):
def __init__(self):
QtGui.QDialog.__init__(self, parent=None)
layout = QtGui.QVBoxLayout()
self.setLayout(layout)
self.label = QtGui.QLabel('idle...')
layout.addWidget(self.label)
progressbar = ProgressBar(self)
QtCore.QObject.connect(self, QtCore.SIGNAL("customSignal(int)"), progressbar.set_to_value )
layout.addWidget(progressbar)
button = QtGui.QPushButton('Process')
button.clicked.connect(self.clicked)
layout.addWidget(button)
def clicked(self):
for value in range(101):
message = '...processing %s of 100'%value
self.label.setText(message)
self.emit(QtCore.SIGNAL("customSignal(int)"), value)
QtGui.qApp.processEvents()
time.sleep(1)
if __name__ == '__main__':
app = QtGui.QApplication([])
dialog = Dialog()
dialog.resize(300, 100)
dialog.show()
app.exec_()
======================
This code now links a custom signal to a function referred as Slot in Qt.
from PySide import QtCore, QtGui
import time
class ProgressBar(QtGui.QProgressBar):
def __init__(self, parent=None):
super(ProgressBar, self).__init__(parent=parent)
#QtCore.Slot(int)
def set_to_value(self, value):
self.setValue(value)
QtGui.qApp.processEvents()
return True
def closeEvent(self, event):
self._active=False
class Dialog(QtGui.QDialog):
def __init__(self):
QtGui.QDialog.__init__(self, parent=None)
layout = QtGui.QVBoxLayout()
self.setLayout(layout)
self.label = QtGui.QLabel('idle...')
layout.addWidget(self.label)
progressbar = ProgressBar(self)
# QtCore.QObject.connect(self, QtCore.SIGNAL("customSignal(int)"), progressbar.set_to_value )
QtCore.QObject.connect(self, QtCore.SIGNAL("customSignal(int)"), progressbar, QtCore.SLOT("set_to_value(int)"))
layout.addWidget(progressbar)
button = QtGui.QPushButton('Process')
button.clicked.connect(self.clicked)
layout.addWidget(button)
def clicked(self):
for value in range(101):
message = '...processing %s of 100'%value
self.label.setText(message)
self.emit(QtCore.SIGNAL("customSignal(int)"), value)
QtGui.qApp.processEvents()
time.sleep(1)
if __name__ == '__main__':
dialog = Dialog()
dialog.resize(300, 100)
dialog.show()

Qt and python - how to refer to another class

I have main window which contains scene and button in widget from where I need to call scene:
import sys
from PySide.QtCore import *
from PySide.QtGui import *
class Widget(QWidget):
def __init__(self, scene):
super(Widget, self).__init__()
self.refreshButton = QPushButton("Refresh", self)
self.refreshButton.clicked.connect(self.Refresh)
# THIS ACTION SHOULD PROCEED ARGUMENTS
# TO FUNCION "Refresh"
layout = QHBoxLayout()
layout.addWidget(self.refreshButton)
self.setLayout(layout)
self.show()
def Refresh(self, scene):
mainWinScene = scene
print "On Refresh! - ", mainWinScene.items()
class MainScene(QGraphicsScene):
def __init__(self):
super(MainScene, self).__init__()
class MainWindow(QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.scene = MainScene()
self.scene.setSceneRect(0,0,200,100)
self.scene.addLine(20,10,150,80)
self.view = QGraphicsView()
self.view.setScene(self.scene)
drawRectAct = QAction('&Add Rectangle', self)
drawRectAct.triggered.connect(self.drawRect)
shapeInspectorAct = QAction('&Show Inspector', self)
shapeInspectorAct.triggered.connect(self.showInspector)
menubar = self.menuBar()
fileMenu = menubar.addMenu('&Shapes')
fileMenu.addAction(drawRectAct)
fileMenu.addAction(shapeInspectorAct)
self.setCentralWidget(self.view)
def drawRect(self):
self.scene.addRect(50,50,20,30)
def showInspector(self):
self.I = Widget(self.scene)
if __name__ == '__main__':
app = QApplication(sys.argv)
main = MainWindow()
main.show()
sys.exit(app.exec_())
How to proceed "scene" argument with action - to "Refresh" function?

You can pass a scene in Widget's constructor:
class Widget(QWidget):
def __init__(self, scene):
...
self.scene = scene
...
def Refresh(self):
print "On Refresh! - ", self.scene.items()
class MainWindow(QMainWindow):
...
def showInspector(self):
self.I = Widget(self.scene)
...