Develop Reference

How can I change size of circle in pyqt5

How can I change size of circle in first window, using slider from second window. Is there an option to send value from slider to first window and put this value in painter.drawEllipse fuction?
class ThirdWindow(QWidget):
def __init__(self):
super().__init__()
hbox = QHBoxLayout()
sld = QSlider(Qt.Horizontal, self)
sld.setRange(0, 100)
sld.setFocusPolicy(Qt.NoFocus)
sld.setPageStep(5)
sld.valueChanged.connect(self.updateLabel)
self.label = QLabel('0', self)
self.label.setAlignment(Qt.AlignCenter | Qt.AlignVCenter)
self.label.setMinimumWidth(80)
hbox.addWidget(sld)
hbox.addSpacing(15)
hbox.addWidget(self.label)
self.setLayout(hbox)
self.setGeometry(600, 60, 500, 500)
self.setWindowTitle('QSlider')
self.show()
def updateLabel(self, value):
self.label.setText(str(value))
class Window(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.setWindowTitle("Dialogi")
self.w = ThirdWindow()
actionFile = self.menuBar().addMenu("Dialog")
action = actionFile.addAction("Zmień tło")
action1 = actionFile.addAction("Zmień grubość koła")
action1.triggered.connect(self.w.show)
self.setGeometry(100, 60, 300, 300)
self.setStyleSheet("background-color: Green")
def paintEvent(self, event):
painter = QPainter(self)
painter.setPen(QPen(Qt.gray, 8, Qt.SolidLine))
painter.drawEllipse(100, 100, 100, 100)

You can communicate with the parent class (in this case the class where the circle is located i.e. Window by calling self.parentWidget()
so you can call that inside your updateLabel function and pass the value. However to repaint the surface you must have a variable initiated in the main Window
Hence your code should look like-
class Window(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.setWindowTitle("Dialogi")
self.w = ThirdWindow()
actionFile = self.menuBar().addMenu("Dialog")
action = actionFile.addAction("Zmień tło")
action1 = actionFile.addAction("Zmień grubość koła")
action1.triggered.connect(self.w.show)
self.setGeometry(100, 60, 300, 300)
self.setStyleSheet("background-color: Green")
self.radius = 100 #add a variable radius to keep track of the circle radius
def paintEvent(self, event):
painter = QPainter(self)
painter.setPen(QPen(Qt.gray, 8, Qt.SolidLine))
#change function to include radius
painter.drawEllipse(100, 100, self.radius, self.radius)
and in the other widget change the updateLabel function to change the radius and call repaint
class ThirdWindow(QWidget):
def updateLabel(self, value):
self.label.setText(str(value))
self.parentWidget().radius = value
self.parentWidget().repaint()

how to properly remove qwidgets and update/reload that widget

Trying to remove a qwidget and replace it with another qwidget and then reload the layout the qwidget is a part of
I've already tried the update and removeWidget method, though i could've used it improperly
from PyQt5.Qt import *
import sys
validUser = False
app = None
class App(QMainWindow):
def __init__(self):
super().__init__()
screen = app.primaryScreen().size()
self.title = 'Restaurant Application'
width = screen.width()
height = screen.height()
self.left = 0
self.top = 0
self.width = width
self.height = height
self.setMouseTracking(True)
self.table_widget = MyTableWidget(self)
self.setCentralWidget(self.table_widget)
self.initUI()
self.show()
def initUI(self):
# window
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
# statusbar
self.statusBar().showMessage('Welcome to el restaurante')
def mousePressEvent(self, event):
print('Mouse coords: ( %d : %d )' % (event.x(), event.y()))
class MyTableWidget(QWidget):
def __init__(self, parent):
super(QWidget, self).__init__(parent)
self.layout = QVBoxLayout(self)
# Initialize tab screen
self.tabs = QTabWidget()
self.login = QWidget()
self.menu = QWidget()
self.checkOut = QWidget()
self.tabs.resize(500, 200)
# Add tabs
self.tabs.addTab(self.login, "Login")
self.tabs.addTab(self.menu, "Menu")
self.tabs.addTab(self.checkOut, "Check out")
# Create login tab
self.login.layout = QVBoxLayout(self)
self.menu.layout = QVBoxLayout(self)
# login text
self.loginPrompt = QLabel("Please provide a valid login")
self.loginPrompt.setFixedSize(315,30)
self.loginPromptFont = QFont("Times", 27, QFont.Bold)
self.loginPrompt.setFont(self.loginPromptFont)
self.login.layout.addWidget(self.loginPrompt)
self.login.setLayout(self.login.layout)
# Create textbox
self.loginTextbox = QLineEdit(self)
self.loginTextbox.returnPressed.connect(self.on_click_login)
self.loginTextbox.setFixedSize(170,20)
# Create a button in the window
self.loginButton = QPushButton('Login button', self)
self.loginButton.clicked.connect(self.on_click_login)
self.loginButton.setFixedSize(100,40)
self.login.layout.addWidget(self.loginTextbox,alignment=Qt.AlignCenter)
self.login.layout.addWidget(self.loginButton,alignment=Qt.AlignCenter)
#widget code i use to decide which widget to add
self.menuInvalidUserLogin = QLabel("Please login in to view")
self.menuValidUserLogin = QLabel("Here's the menu")
if(validUser):
self.menu.layout.addWidget(self.menuValidUserLogin)
else:
self.menu.layout.addWidget(self.menuInvalidUserLogin)
self.menu.setLayout(self.menu.layout)
# Add tabs to widget
self.layout.addWidget(self.tabs)
self.setLayout(self.layout)
def on_click_login(self):
global validUser
global app
textboxValue = self.loginTextbox.text()
if(textboxValue.lower() == 'pass'):
validUser=True
#the solutions i have been trying
self.menu.layout.removeWidget(self.menuInvalidUserLogin)
self.layout.removeWidget(self.menuInvalidUserLogin)
self.menu.layout.update()
QMessageBox.question(self, 'Response', "Login successful: Welcome", QMessageBox.Ok,QMessageBox.Ok)
else:
validUser=False
QMessageBox.question(self, 'Response', "Login unsuccessful: EXPLAIN YOURSELF", QMessageBox.Ok,QMessageBox.Ok)
self.loginTextbox.setText("")
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
expected results should be that the old widget is removed, new widget is added and then the layout those widgets are a part of is refreshed

Is this what you were expecting?
Also, is there a specific reason why you are using global variables in your class? It is bad practice, you should make them class members.
from PyQt5 import QtWidgets, QtCore, QtGui
import sys
class App(QtWidgets.QMainWindow):
def __init__(self):
super(App,self).__init__()
app = QtWidgets.QApplication.instance()
screen = app.primaryScreen().size()
self.title = 'Restaurant Application'
width = screen.width()
height = screen.height()
self.left = 0
self.top = 0
self.width = width
self.height = height
self.setMouseTracking(True)
self.table_widget = MyTableWidget(self)
self.setCentralWidget(self.table_widget)
self.initUI()
self.show()
def initUI(self):
# window
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
# statusbar
self.statusBar().showMessage('Welcome to el restaurante')
def mousePressEvent(self, event):
print('Mouse coords: ( %d : %d )' % (event.x(), event.y()))
class MyTableWidget(QtWidgets.QWidget):
def __init__(self, parent):
super(MyTableWidget, self).__init__(parent)
self.layout = QtWidgets.QVBoxLayout()
self.validUser = False
# Initialize tab screen
self.tabs = QtWidgets.QTabWidget()
self.login = QtWidgets.QWidget()
self.menu = QtWidgets.QWidget()
self.checkOut = QtWidgets.QWidget()
self.tabs.resize(500, 200)
# Add tabs
self.tabs.addTab(self.login, "Login")
self.tabs.addTab(self.menu, "Menu")
self.tabs.addTab(self.checkOut, "Check out")
# Create login tab
self.login.layout = QtWidgets.QVBoxLayout()
self.menu.layout = QtWidgets.QVBoxLayout()
# login text
self.loginPrompt = QtWidgets.QLabel("Please provide a valid login")
self.loginPrompt.setFixedSize(315,30)
self.loginPromptFont = QtGui.QFont("Times", 27, QtGui.QFont.Bold)
self.loginPrompt.setFont(self.loginPromptFont)
self.login.layout.addWidget(self.loginPrompt)
self.login.setLayout(self.login.layout)
# Create textbox
self.loginTextbox = QtWidgets.QLineEdit()
self.loginTextbox.returnPressed.connect(self.on_click_login)
self.loginTextbox.setFixedSize(170,20)
# Create a button in the window
self.loginButton = QtWidgets.QPushButton('Login button')
self.loginButton.clicked.connect(self.on_click_login)
self.loginButton.setFixedSize(100,40)
self.login.layout.addWidget(self.loginTextbox,alignment=QtCore.Qt.AlignCenter)
self.login.layout.addWidget(self.loginButton,alignment=QtCore.Qt.AlignCenter)
#widget code i use to decide which widget to add
self.menuInvalidUserLogin = QtWidgets.QLabel("Please login in to view")
self.menuValidUserLogin = QtWidgets.QLabel("Here's the menu")
if(self.validUser):
self.menu.layout.addWidget(self.menuValidUserLogin)
else:
self.menu.layout.addWidget(self.menuInvalidUserLogin)
self.menu.setLayout(self.menu.layout)
# Add tabs to widget
self.layout.addWidget(self.tabs)
self.setLayout(self.layout)
def on_click_login(self):
textboxValue = self.loginTextbox.text()
if(textboxValue.lower() == 'pass'):
self.validUser=True
for i in reversed(range(self.menu.layout.count())):
widgetToRemove = self.menu.layout.itemAt(i).widget()
self.menu.layout.removeWidget(widgetToRemove)
widgetToRemove.deleteLater()
self.menu.layout.addWidget(self.menuValidUserLogin)
QtWidgets.QMessageBox.question(self, 'Response', "Login successful: Welcome", QtWidgets.QMessageBox.Ok,QtWidgets.QMessageBox.Ok)
self.tabs.setCurrentIndex(1)
else:
self.validUser=False
QtWidgets.QMessageBox.question(self, 'Response', "Login unsuccessful: EXPLAIN YOURSELF", QtWidgets.QMessageBox.Ok,QtWidgets.QMessageBox.Ok)
self.loginTextbox.setText("")
def main():
app = QtWidgets.QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())
if __name__ == "__main__":
main()

Getting value from push button that I can use in a new class/window

I want the first window that opens up to contain 4 push buttons responding to the numbers: 2,3,4,5. Once I have pressed one of these buttons I want the window to close and a new window to open with a label (just so I know it works) and also to use that number as a separate variable as it will select a sheet that I am reading from an excel file.
At the moment I can create the first window with the boxes, and when I press one the new window opens - but I cannot get the selection I made to come across.
Here is as far as I have got so far...
import sys
from PyQt5.QtWidgets import QApplication, QLabel, QPushButton, QHBoxLayout, QGroupBox, QDialog, QVBoxLayout, QMainWindow
# select floor window
class select_floor_window(QDialog):
def __init__(self, parent=None):
super().__init__()
self.title = 'Select floor'
self.left = 10
self.top = 10
self.width = 320
self.height = 100
self.selection_ui()
def selection_ui(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.createHorizontalLayout()
windowLayout = QVBoxLayout()
windowLayout.addWidget(self.horizontalGroupBox)
self.setLayout(windowLayout)
self.show()
def createHorizontalLayout(self):
# box layout
self.horizontalGroupBox = QGroupBox("Which floor are you on?")
layout = QHBoxLayout()
# floor buttons
floor_2_button = QPushButton("2", self)
floor_2_button.clicked.connect(self.on_click2)
layout.addWidget(floor_2_button)
floor_3_button = QPushButton("3", self)
floor_3_button.clicked.connect(self.on_click3)
layout.addWidget(floor_3_button)
floor_4_button = QPushButton("4", self)
floor_4_button.clicked.connect(self.on_click4)
layout.addWidget(floor_4_button)
floor_5_button = QPushButton("5", self)
floor_5_button.clicked.connect(self.on_click5)
layout.addWidget(floor_5_button)
self.horizontalGroupBox.setLayout(layout)
# close this window and load main window
def on_click2(self):
self.floorchoice = 2
self.show_main = main_Window()
self.show_main.show()
self.hide()
print("2")
return floorchoice
def on_click3(self):
self.floorchoice = 3
self.show_main = main_Window()
self.show_main.show()
self.hide()
print("3")
return floorchoice
def on_click4(self):
self.floorchoice = 4
self.show_main = main_Window()
self.show_main.show()
self.hide()
print("4")
return floorchoice
def on_click5(self):
self.floorchoice = 5
self.show_main = main_Window()
self.show_main.show()
self.hide()
print("5")
return floorchoice
# create main window
class main_Window(QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.title = "2ndwindow"
self.top = 100
self.left = 100
self.width = 680
self.height = 500
show_floor_button = QLabel(floorchoice, self)
show_floor_button.move(100,100)
# Close app button
close_app_button = QPushButton("Exit", self)
close_app_button.move(400,400)
close_app_button.setToolTip("Close application")
close_app_button.clicked.connect(self.CloseApp)
self.InitWindow()
# showing window
def InitWindow(self):
self.setWindowTitle(self.title)
self.setGeometry(self.top, self.left, self.width, self.height)
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = select_floor_window()
sys.exit(app.exec_())
Anyway that I try to set up the code, it always says that "name 'floorchoice' is not defined" in the second window, and cannot get it to display the result from the first class.

The functions that are invoked do not return anything, plus self.floorchoice is different floorchoice, the first is an attribute of the class and the other is a local variable.
What you have to do is that the class through the constructor or another method get that information.
In the next one I add one more argument to the invocation using functool.partial, then I pass that argument to the constructor of the other window so that I get that information.
I think your main error is caused by not taking into account that each variable, instance, object, etc. has a scope within the application.
import sys
from PyQt5.QtWidgets import QApplication, QLabel, QPushButton, QHBoxLayout, QGroupBox, QDialog, QVBoxLayout, QMainWindow
from functools import partial
# select floor window
class select_floor_window(QDialog):
def __init__(self, parent=None):
super().__init__()
self.title = "Select floor"
self.left = 10
self.top = 10
self.width = 320
self.height = 100
self.selection_ui()
def selection_ui(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.createHorizontalLayout()
windowLayout = QVBoxLayout(self)
windowLayout.addWidget(self.horizontalGroupBox)
def createHorizontalLayout(self):
# box layout
self.horizontalGroupBox = QGroupBox("Which floor are you on?")
layout = QHBoxLayout()
self.horizontalGroupBox.setLayout(layout)
# floor buttons
for option in (2, 3, 4, 5):
button = QPushButton(str(option))
layout.addWidget(button)
wrapper = partial(self.on_click, option)
button.clicked.connect(wrapper)
# close this window and load main window
def on_click(self, option):
self.show_main = main_Window(option)
self.show_main.show()
self.hide()
# create main window
class main_Window(QMainWindow):
def __init__(self, option, parent=None):
super().__init__(parent)
self.title = "2ndwindow"
self.top = 100
self.left = 100
self.width = 680
self.height = 500
show_floor_button = QLabel(str(option), self)
show_floor_button.move(100, 100)
# Close app button
close_app_button = QPushButton("Exit", self)
close_app_button.move(400, 400)
close_app_button.setToolTip("Close application")
close_app_button.clicked.connect(self.close)
self.InitWindow()
# showing window
def InitWindow(self):
self.setWindowTitle(self.title)
self.setGeometry(self.top, self.left, self.width, self.height)
if __name__ == "__main__":
app = QApplication(sys.argv)
ex = select_floor_window()
ex.show()
sys.exit(app.exec_())

failed to open a new window after push button pyqt5

i learning pyqt5 and trying to open a new window by click a button from another window. if there are not input() function it will close the open window immediately, so i put input() to keep the window open. the window will open for long, but then it has stopped working. Can some one help me ? Thank you
import sys
from PyQt5.QtWidgets import QApplication, QPushButton,QMainWindow,QWidget
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
class App1(QWidget):
def __init__(self):
super().__init__()
self.title = 'open window'
self.left = 60
self.top = 60
self.width = 320
self.height = 200
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.show()
m.getch()
input() '''here is the problem'''
class App(QMainWindow):
def __init__(self):
super().__init__()
self.title = 'PyQt5 button - pythonspot.com'
self.left = 200
self.top = 200
self.width = 320
self.height = 200
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
button = QPushButton('PyQt5 button', self)
button.setToolTip('This is an example button')
button.move(100, 70)
button.clicked.connect(self.on_click)
self.show()
#pyqtSlot()
def on_click(self):
app1 = QApplication(sys.argv)
ex1 = App1()
sys.exit(app1.exec_())
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())

You need to save a reference to the window or it will be garbage collected when on_click() finishes executing. The easiest way is to store it in App through the use of self
#pyqtSlot()
def on_click(self):
self.ex1 = App1()

import sys
from PyQt5.QtWidgets import QApplication, QPushButton,QMainWindow,QWidget
from PyQt5.QtGui import QIcon
from PyQt5.QtCore import pyqtSlot
class App1(QWidget):
def __init__(self):
super().__init__()
self.title = 'open window'
self.left = 60
self.top = 60
self.width = 320
self.height = 200
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
self.show()
input()
class App(QMainWindow):
def __init__(self):
super().__init__()
self.title = 'PyQt5 button - pythonspot.com'
self.left = 200
self.top = 200
self.width = 320
self.height = 200
self.initUI()
def initUI(self):
self.setWindowTitle(self.title)
self.setGeometry(self.left, self.top, self.width, self.height)
button = QPushButton('PyQt5 button', self)
button.setToolTip('This is an example button')
button.move(100, 70)
button.clicked.connect(self.on_click)
self.show()
#pyqtSlot()
def on_click(self):
self.ex1 = App1()
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = App()
sys.exit(app.exec_())

PyQt is slow in handling a large number of objects

I present here a simple pyqt code, but I developed my whole design and algo upon this. The problem, is that PyQt is unable to manage a large number of objects when created. This is simple code for drawing many rectangles inside a big one. And it has Zoom and pan feature too.
import sys
from PyQt4 import QtGui, QtCore
from PyQt4.QtCore import *
from PyQt4.QtGui import *
item = None
class Rectangle(QGraphicsItem):
def __init__(self, parent, x, y, width, height, scene = None, fill=None):
self.parent = parent
super(Rectangle, self).__init__()
self.setFlags(QGraphicsItem.ItemIsFocusable | QGraphicsItem.ItemIsMovable | QGraphicsItem.ItemIsSelectable)
rect = QRectF(x,y,width,height)
self.dimen = [x,y,width,height]
self.rect = rect
scene.addItem(self)
self.show_its_ui()
#Function to get relative position
def get_relative_location(self,loc):
self.loc = QPointF(loc[0],loc[1])
global item
self.loc = self.mapFromItem(item, self.loc)
self.loc = (self.loc.x(),self.loc.y())
self.loc = list(self.loc)
self.dimen[0] = self.loc[0]
self.dimen[1] = self.loc[1]
#Showing its UI in the form of a rectangle
def show_its_ui(self):
#First gets its relative location and set it.
if(item is not None):
self.get_relative_location([self.dimen[0],self.dimen[1]])
#Make a Final rectangle
rect = QRectF(self.dimen[0],self.dimen[1],self.dimen[2],self.dimen[3])
self.rect = rect
def boundingRect(self):
return self.rect.adjusted(-2, -2, 2, 2)
def parentWidget(self):
return self.scene().views()[0]
def paint(self, painter, option, widget):
pen = QPen(Qt.SolidLine)
pen.setColor(Qt.black)
pen.setWidth(1)
painter.setBrush(QtGui.QColor(255, 50, 90, 200))
painter.drawRect(self.rect)
class GraphicsView(QGraphicsView):
def __init__(self, parent=None):
super(GraphicsView, self).__init__(parent)
self.setDragMode(QGraphicsView.RubberBandDrag)
self.setRenderHint(QPainter.Antialiasing)
self.setRenderHint(QPainter.TextAntialiasing)
def wheelEvent(self, event):
factor = 1.41 ** (event.delta() / 240.0)
self.scale(factor, factor)
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent = None):
QtGui.QMainWindow.__init__(self, parent)
self.Width = 800
self.Height = 500
self.view = GraphicsView()
self.scene = QGraphicsScene(self)
self.scene.setSceneRect(0, 0, self.Width, self.Height)
self.view.setScene(self.scene)
self.initUI()
hbox = QtGui.QHBoxLayout()
hbox.addWidget(self.view)
mainWidget = QtGui.QWidget()
mainWidget.setLayout(hbox)
self.setCentralWidget(mainWidget)
def initUI(self):
self.group = QGraphicsItemGroup()
self.group.setFlags(QGraphicsItem.ItemIsFocusable | QGraphicsItem.ItemIsMovable | QGraphicsItem.ItemIsSelectable)
global item
item = self.group
self.group.setFiltersChildEvents(True)
self.group.setHandlesChildEvents(False)
self._link1 = Rectangle(self, 10, 10, self.Width, self.Height,self.scene)
self._link1.setFiltersChildEvents(True)
self._link1.setHandlesChildEvents(False)
self.group.addToGroup(self._link1)
self.scene.addItem(self.group)
self.addObjects()
#Here I added objects in the big canvas
def addObjects(self):
xpos = 20
ypos = 20
#Change the below to 5 each
width = 50
height = 50
#Generate many rectangles
while(ypos < 450):
xpos = 20
while(xpos < 750):
t = Rectangle(self._link1,xpos,ypos,width,height,self.scene,True)
self.group.addToGroup(t)
xpos += (width+2)
ypos += (height+2)
app = QtGui.QApplication(sys.argv)
mainWindow = MainWindow()
method = mainWindow
mainWindow.show()
sys.exit(app.exec_())
Try changing, the width and height values present in addObjects function of the mainwindow class, say to 5 and 5 respectively from 50. Then the whole application run at very slow speed, when you pan/zoom. Please share your suggestions in rectifying this.