How draw Polygon from MouseEvents on top of Image in Qlabel - python

Using Python , PYQT5 I want to draw a Polygon on top a Image, which is in a Qlabel widget. I used a simple Qmainwindow with a label widget generated in QT designer (code is below).
I am aware that there are several informations out abaut drawing in a Qmainwindow like here:
PyQT5: How to interactively paint on image within QLabel Widget? - which has no solution within a Qlabel widget.
Draw over image in a QLabel with PyQt5 - marked solution is unclear because also painting on top of Qlabel is not solved
PYQT5 drawing line - paintevent on Qlabel is working, but not on top of the image
Painting in a QLabel with paintEvent - but also not solved to draw on top of an image.
Let me know, if you have a solution for this problem.
import sys
from PyQt5.QtCore import Qt
from PyQt5 import QtWidgets, uic, QtCore, QtGui
from PyQt5.QtGui import QPixmap, QPainter, QPolygon, QPen, QBrush
from PyQt5.QtCore import QPoint
from polygon_ui import Ui_MainWindow
class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, *args, obj=None, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
self.setupUi(self)
pixmap = QPixmap("img.png")
self.label.setPixmap(pixmap)
self.label.mousePressEvent = self.getPixel
self.pol = []
def getPixel(self, event):
x = event.pos().x()
y = event.pos().y()
self.pol.append(QPoint(int(x),int(y)))
print(x,y, self.pol)
def paintEvent(self, event):
painter = QPainter(self)
#painter.drawPixmap(self.rect(), self.image)
painter.setPen(QPen(Qt.black, 5, Qt.SolidLine))
painter.setBrush(QBrush(Qt.red, Qt.VerPattern))
#points = QPolygon([ QPoint(10,10), QPoint(10,100),
# QPoint(100,10), QPoint(100,100)])
points = QPolygon(self.pol)
painter.drawPolygon(points)
def mouseMoveEvent(self, event):
pass
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())
the code for polygon_ui is here - was simply generated by QT-Designer using Mainwindow + Qlabel:
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(621, 641)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.label = QtWidgets.QLabel(self.centralwidget)
self.label.setGeometry(QtCore.QRect(10, 10, 600, 600))
self.label.setObjectName("label")
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 621, 21))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.label.setText(_translate("MainWindow", "TextLabel"))

If you want to add elements such as polygons, lines, circles, etc. on an image then do not complicate yourself with a QLabel since for example with your current code you are painting in the window that is below the QLabel so it will not be seen , a possible solution using with QLabel is to get the QPixmap and paint it on top.
A better alternative is to use the Qt Graphics Framework, where the image is set to a QGraphicsPixmapItem, and a polygon as a child of the QGraphicsPixmapItem as I show below:
from PyQt5 import QtCore, QtGui, QtWidgets
class GraphicsView(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
self.setScene(scene)
self._pixmap_item = QtWidgets.QGraphicsPixmapItem()
scene.addItem(self.pixmap_item)
self._polygon_item = QtWidgets.QGraphicsPolygonItem(self.pixmap_item)
self.polygon_item.setPen(QtGui.QPen(QtCore.Qt.black, 5, QtCore.Qt.SolidLine))
self.polygon_item.setBrush(QtGui.QBrush(QtCore.Qt.red, QtCore.Qt.VerPattern))
#property
def pixmap_item(self):
return self._pixmap_item
#property
def polygon_item(self):
return self._polygon_item
def setPixmap(self, pixmap):
self.pixmap_item.setPixmap(pixmap)
def resizeEvent(self, event):
self.fitInView(self.pixmap_item, QtCore.Qt.KeepAspectRatio)
super().resizeEvent(event)
def mousePressEvent(self, event):
sp = self.mapToScene(event.pos())
lp = self.pixmap_item.mapFromScene(sp)
poly = self.polygon_item.polygon()
poly.append(lp)
self.polygon_item.setPolygon(poly)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
view = GraphicsView()
self.setCentralWidget(view)
view.setPixmap(QtGui.QPixmap("img.png"))
self.resize(640, 480)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
Update:
If you want to use the OP design, the implementation is trivial.
Option1:
Create a file called graphicsview.py where the GraphicsView logic is implemented:
graphicsview.py
from PyQt5 import QtCore, QtGui, QtWidgets
class GraphicsView(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
self.setScene(scene)
self._pixmap_item = QtWidgets.QGraphicsPixmapItem()
scene.addItem(self.pixmap_item)
self._polygon_item = QtWidgets.QGraphicsPolygonItem(self.pixmap_item)
self.polygon_item.setPen(QtGui.QPen(QtCore.Qt.black, 5, QtCore.Qt.SolidLine))
self.polygon_item.setBrush(QtGui.QBrush(QtCore.Qt.red, QtCore.Qt.VerPattern))
#property
def pixmap_item(self):
return self._pixmap_item
#property
def polygon_item(self):
return self._polygon_item
def setPixmap(self, pixmap):
self.pixmap_item.setPixmap(pixmap)
def resizeEvent(self, event):
self.fitInView(self.pixmap_item, QtCore.Qt.KeepAspectRatio)
super().resizeEvent(event)
def mousePressEvent(self, event):
sp = self.mapToScene(event.pos())
lp = self.pixmap_item.mapFromScene(sp)
poly = self.polygon_item.polygon()
poly.append(lp)
self.polygon_item.setPolygon(poly)
Replace QLabel with QGraphicsView in polygon_ui:
polygon_ui.py
from PyQt5 import QtCore, QtGui, QtWidgets
from graphicsview import GraphicsView
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(621, 641)
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.label = GraphicsView(self.centralwidget)
self.label.setGeometry(QtCore.QRect(10, 10, 600, 600))
self.label.setObjectName("label")
# ...
Restore the main.py
main.py
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from polygon_ui import Ui_MainWindow
class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, *args, obj=None, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
self.setupUi(self)
pixmap = QtGui.QPixmap("img.png")
self.label.setPixmap(pixmap)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())
Option2:
Another approach is to promote the widget, and in SO there are many examples of that type so I will obviate showing the procedure:
How to insert video in ui file which made at qt designer?
Clear QLineEdit on click event
Create a widget to embed into QMainWindow
where do I write the class for a single promoted QWidget from Qt designer
Option3:
Another simpler alternative is to use QLabel as a container and set the GraphicsView with a layout:
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from polygon_ui import Ui_MainWindow
class GraphicsView(QtWidgets.QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
self.setScene(scene)
self._pixmap_item = QtWidgets.QGraphicsPixmapItem()
scene.addItem(self.pixmap_item)
self._polygon_item = QtWidgets.QGraphicsPolygonItem(self.pixmap_item)
self.polygon_item.setPen(QtGui.QPen(QtCore.Qt.black, 5, QtCore.Qt.SolidLine))
self.polygon_item.setBrush(QtGui.QBrush(QtCore.Qt.red, QtCore.Qt.VerPattern))
#property
def pixmap_item(self):
return self._pixmap_item
#property
def polygon_item(self):
return self._polygon_item
def setPixmap(self, pixmap):
self.pixmap_item.setPixmap(pixmap)
def resizeEvent(self, event):
self.fitInView(self.pixmap_item, QtCore.Qt.KeepAspectRatio)
super().resizeEvent(event)
def mousePressEvent(self, event):
sp = self.mapToScene(event.pos())
lp = self.pixmap_item.mapFromScene(sp)
poly = self.polygon_item.polygon()
poly.append(lp)
self.polygon_item.setPolygon(poly)
class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self, *args, obj=None, **kwargs):
super(MainWindow, self).__init__(*args, **kwargs)
self.setupUi(self)
self.graphicsview = GraphicsView()
lay = QtWidgets.QVBoxLayout(self.label)
lay.addWidget(self.graphicsview)
pixmap = QtGui.QPixmap("img.png")
self.graphicsview.setPixmap(pixmap)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())

Related

QGraphicsView wrong size at start

I have a problem, i have made a QGraphicsView with 2 rectangles inside. I wanted them to resize when i resize the Dialog so i rewrite a dialog class. It works but at start i have the wrong sized rectangle
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtWidgets import QGraphicsScene, QGraphicsEllipseItem
import sys
# Redéfinition de dialog pour utiliser resize event
class MyDialog (QtWidgets.QDialog) :
def resizeEvent(self, event):
print("resize")
#print(view.sceneRect())
view.fitInView(scene.sceneRect(), QtCore.Qt.KeepAspectRatio) ######## I DONT KNOW WHY THIS LINE MAKE THE VIEW TOO SMALL AT START
QtWidgets.QDialog.resizeEvent(self, event)
#view.fitInView(rectangle)
class Ui_Dialog(object):
def setupUi(self, Dialog):
Dialog.setObjectName("Dialog")
Dialog.resize(556, 580)
self.verticalLayout = QtWidgets.QVBoxLayout(Dialog)
self.verticalLayout.setObjectName("verticalLayout")
self.graphicsView = QtWidgets.QGraphicsView(Dialog)
self.graphicsView.setObjectName("graphicsView")
self.verticalLayout.addWidget(self.graphicsView)
global view
view = self.graphicsView
triangle = QtWidgets.QGraphicsRectItem(10,10,200,200)
rectangle = QtWidgets.QGraphicsRectItem(100,100,200,200)
global scene
scene = QtWidgets.QGraphicsScene()
scene.addItem(rectangle)
scene.addItem(triangle)
self.graphicsView.setScene(scene)
#self.graphicsView.fitInView(scene.sceneRect(), QtCore.Qt.KeepAspectRatio)
#view.fitInView(scene.sceneRect(), QtCore.Qt.KeepAspectRatio)
self.graphicsView_2 = QtWidgets.QGraphicsView(Dialog)
self.graphicsView_2.setObjectName("graphicsView_2")
self.verticalLayout.addWidget(self.graphicsView_2)
self.buttonBox = QtWidgets.QDialogButtonBox(Dialog)
self.buttonBox.setOrientation(QtCore.Qt.Horizontal)
self.buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
self.buttonBox.setObjectName("buttonBox")
self.verticalLayout.addWidget(self.buttonBox)
self.retranslateUi(Dialog)
self.buttonBox.accepted.connect(Dialog.accept)
self.buttonBox.rejected.connect(Dialog.reject)
QtCore.QMetaObject.connectSlotsByName(Dialog)
def retranslateUi(self, Dialog):
_translate = QtCore.QCoreApplication.translate
Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
Dialog = MyDialog()
ui = Ui_Dialog()
ui.setupUi(Dialog)
Dialog.show()
sys.exit(app.exec_())
When i start the QDialog it looks like this
And when i resize the window it looks like i wanted it to look like
Note: It is recommended not to modify the code generated by Qt Designer, so for my answer to work you must regenerate the file using pyuic5: pyuic5 your_file.ui -o gui.py -x.
So that the fitInView method uses some property that is not updated until it makes the QGraphicsView visible, so the solution is to verify that it is visible:
main.py
from PyQt5 import QtCore, QtGui, QtWidgets
from gui import Ui_Dialog
class MyDialog(QtWidgets.QDialog, Ui_Dialog):
def __init__(self, parent=None):
super().__init__(parent)
self.setupUi(self)
triangle = QtWidgets.QGraphicsRectItem(10, 10, 200, 200)
rectangle = QtWidgets.QGraphicsRectItem(100, 100, 200, 200)
scene = QtWidgets.QGraphicsScene()
scene.addItem(rectangle)
scene.addItem(triangle)
self.graphicsView.setScene(scene)
def resizeEvent(self, event):
if self.isVisible():
self.graphicsView.fitInView(
self.graphicsView.scene().sceneRect(), QtCore.Qt.KeepAspectRatio
)
super().resizeEvent(event)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
w = MyDialog()
w.show()
sys.exit(app.exec_())

How can I get widget size which inside layout

I have a QLabel in QWidget's layout ,
I try to use sizeHint or geometry but it doesn't work.
how can I get QLabel actural width and height ?
from PySide2 import QtCore, QtGui, QtWidgets
class Ui_Form(object):
def setupUi(self, Form):
Form.setObjectName("Form")
Form.resize(689, 439)
self.horizontalLayout = QtWidgets.QHBoxLayout(Form)
self.horizontalLayout.setObjectName("horizontalLayout")
self.label = QtWidgets.QLabel(Form)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.label.sizePolicy().hasHeightForWidth())
self.label.setSizePolicy(sizePolicy)
self.label.setObjectName("label")
self.horizontalLayout.addWidget(self.label)
self.retranslateUi(Form)
QtCore.QMetaObject.connectSlotsByName(Form)
def retranslateUi(self, Form):
Form.setWindowTitle(QtWidgets.QApplication.translate("Form", "Form", None, -1))
self.label.setText(QtWidgets.QApplication.translate("Form", "TextLabel", None, -1))
import sys,os,asyncio
from PySide2 import QtWidgets
from PySide2.QtWidgets import (QApplication, QMainWindow, QMessageBox)
from qasync import QEventLoop, asyncSlot, asyncClose
from TestLB2 import Ui_Form
class LB(QtWidgets.QWidget, Ui_Form):
def __init__(self, *args, **kwargs):
super(LB, self).__init__(*args, **kwargs)
self.setupUi(self)
print(self.frameGeometry().width())
print(self.label.geometry().width())
print(self.label.sizeHint().width())
if __name__ == '__main__':
# mp.freeze_support()
app = QApplication(sys.argv)
loop = QEventLoop(app)
asyncio.set_event_loop(loop)
w = LB()
w.show()
sys.exit(app.exec_())
with loop:
loop.run_forever()
For efficiency reasons, only the geometric properties are updated when necessary, in the case of layouts and widgets they are only updated when they are displayed, therefore you do not get the desired values. The solution is to obtain that information an instant after displaying it using a QTimer.
import asyncio
import os
import sys
from PySide2 import QtCore, QtWidgets
from qasync import QEventLoop, asyncSlot, asyncClose
from TestLB2 import Ui_Form
class LB(QtWidgets.QWidget, Ui_Form):
def __init__(self, *args, **kwargs):
super(LB, self).__init__(*args, **kwargs)
self.setupUi(self)
#
self.label.setStyleSheet("QLabel{background-color: red}")
QtCore.QTimer.singleShot(0, lambda: print(self.label.width()))
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
loop = QEventLoop(app)
asyncio.set_event_loop(loop)
w = LB()
w.show()
with loop:
loop.run_forever()

Embed QGraphics in widget

I have a main widget inside a window who contains a lot of widgets. How can I insert a QGraphics view and a QGraphicsScene in that widget? I have not found a direct insertion method, so I am trying using a wrapper, in this case a box layout but it is not a good solution. The QGraphicsScene stands out from the layout limits.
Code:
class UiVentana(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super().__init__(parent)
self.setFixedSize(1500, 1015)
widget_central = QtWidgets.QWidget(self)
wrapper = QtWidgets.QHBoxLayout(widget_central)
scene = QtWidgets.QGraphicsScene(wrapper)
vista = QtWidgets.QGraphicsView(scene)
wrapper.addWidget(vista)
self.diedrico = Diedrico() # This is a class who draw things, not relevant
self.diedrico.setFixedSize(2000, 2000)
scene.addWidget(self.diedrico)
self.setCentralWidget(widget_central)
I would like to get this result:
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QWidget
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QPen, QColor
import sys
class Diedrico(QWidget):
def __init__(self, parent):
super().__init__(parent)
def paintEvent(self, event):
qp = QPainter(self)
qp.setPen(QPen(QColor(Qt.black), 5))
qp.drawRect(500, 500, 1000, 1000)
class UiVentana(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(UiVentana, self).__init__(parent)
self.resize(520, 520)
self.widget_central = QtWidgets.QWidget(self)
scrol = QtWidgets.QScrollArea(self.widget_central)
scrol.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
scrol.setGeometry(QtCore.QRect(30, 30, 500, 500))
scrol.setWidgetResizable(False)
contenido = QtWidgets.QWidget()
contenido.setGeometry(QtCore.QRect(0, 0, 2000, 2000))
scrol.setWidget(contenido)
self.Diedrico = Diedrico(contenido)
self.Diedrico.setGeometry(QtCore.QRect(0, 0, 2000, 2000))
self.setCentralWidget(self.widget_central)
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
ui = UiVentana()
ui.show()
sys.exit(app.exec_())
But using QGraphics instead of a scroll area
The QGraphicsProxyWidget that is created using the widget takes into account the minimum size of the widget to set the boundingRect, and the QGraphicsScene uses the boundingRect to set the initial scene rect.
from PyQt5 import QtCore, QtGui, QtWidgets
class Diedrico(QtWidgets.QWidget):
def paintEvent(self, event):
qp = QtGui.QPainter(self)
pen = QtGui.QPen(QtGui.QColor(QtCore.Qt.black), 5)
qp.setPen(pen)
qp.drawRect(500, 500, 1000, 1000)
def minimumSizeHint(self):
return QtCore.QSize(2000, 2000)
class UiVentana(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(UiVentana, self).__init__(parent)
self.resize(520, 520)
widget_central = QtWidgets.QWidget()
self.setCentralWidget(widget_central)
lay = QtWidgets.QVBoxLayout(widget_central)
scene = QtWidgets.QGraphicsScene(self)
view = QtWidgets.QGraphicsView(scene)
diedrico = Diedrico()
scene.addWidget(diedrico)
lay.addWidget(view)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
ui = UiVentana()
ui.show()
sys.exit(app.exec_())

Master PyQt5 GUI with pushbuttons that open additional GUI

Using Python3 and PyQt5, I want to have a GUI that has a button on it that, when pressed, opens another widget which also has buttons and other controls. In the future, the master GUI will have many buttons that will open many additional widgets. I'm looking at having one widget with an embedded matplotlib.pyplot. At the moment, I am struggling to open a second widget.
Main Program
import sys
from PyQt5 import QtWidgets
from gui import Ui_MainWindow as Ui_MainWindow1
from gui2 import Ui_MainWindow as Ui_MainWindow2
class Window(QtWidgets.QMainWindow, Ui_MainWindow1):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.ui_gui = Ui_MainWindow1()
self.ui_gui.setupUi(self)
self.pb.clicked.connect(self.on_pb_clicked)
self.graph = Graph(self)
def on_pb_clicked(self):
print('pb clicked')
self.graph.show()
class Graph(QtWidgets.QMainWindow, Ui_MainWindow2):
def __init__(self, parent=None):
super(Graph, self).__init__(parent)
self.ui_graph = Ui_MainWindow2()
self.ui_graph.setupUi(self)
if __name__ == "__main__":
#import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow1()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
gui = gui2. Both look like the below.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(282, 219)
self.centralWidget = QtWidgets.QWidget(MainWindow)
self.centralWidget.setObjectName("centralWidget")
self.pb = QtWidgets.QPushButton(self.centralWidget)
self.pb.setGeometry(QtCore.QRect(100, 60, 75, 23))
self.pb.setObjectName("pb")
MainWindow.setCentralWidget(self.centralWidget)
self.menuBar = QtWidgets.QMenuBar(MainWindow)
self.menuBar.setGeometry(QtCore.QRect(0, 0, 282, 21))
self.menuBar.setObjectName("menuBar")
MainWindow.setMenuBar(self.menuBar)
self.mainToolBar = QtWidgets.QToolBar(MainWindow)
self.mainToolBar.setObjectName("mainToolBar")
MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.mainToolBar)
self.statusBar = QtWidgets.QStatusBar(MainWindow)
self.statusBar.setObjectName("statusBar")
MainWindow.setStatusBar(self.statusBar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
self.pb.setText(_translate("MainWindow", "pb"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
I want to click the button on gui and have the gui2 appear. NB gui will not equal gui2 in the future.
Since Window and Graph inherit from Ui_Window1 and Ui_Window2, respectively, you should call self.setupUi(self) in Window.__init__ and Graph.__init__ instead of creating separate instances of Ui_Window1 and Ui_Window2, i.e.
class Window(QtWidgets.QMainWindow, Ui_MainWindow1):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.setupUi(self)
self.pb.clicked.connect(self.on_pb_clicked)
self.graph = Graph(self)
# just to see the two windows side-by-side
self.move(500, 400)
self.graph.move(self.x()+self.width()+20, self.y())
def on_pb_clicked(self):
print('pb clicked')
self.graph.show()
class Graph(QtWidgets.QMainWindow, Ui_MainWindow2):
def __init__(self, parent=None):
super(Graph, self).__init__(parent)
self.setupUi(self)
The main part of the program should then be something like
if __name__ == "__main__":
#import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = Window()
MainWindow.show()
app.exec()
You use QMetaObject::connectSlotsByName() to enable the automatic calling of the on_pb_clicked() slot.
You do not need to use self.pb.clicked.connect(self.on_pb_clicked)
You need #QtCore.pyqtSlot()
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from gui_1 import Ui_MainWindow as Ui_MainWindow1
from gui_2 import Ui_MainWindow as Ui_MainWindow2
class Graph(QtWidgets.QMainWindow, Ui_MainWindow2):
def __init__(self, parent=None):
super(Graph, self).__init__(parent)
self.setupUi(self)
self.setWindowTitle("window Graph")
self.setGeometry(QtCore.QRect(850, 260, 282, 219))
# self.pb.clicked.connect(self.on_pb_clicked) # ---
#QtCore.pyqtSlot() # +++
def on_pb_clicked(self):
print('pb clicked -> Graph')
class Window(QtWidgets.QMainWindow, Ui_MainWindow1):
def __init__(self):
super().__init__()
self.setupUi(self)
self.setWindowTitle("main Window")
# self.pb.clicked.connect(self.on_pb_clicked) # ---
self.graph = Graph(self)
#QtCore.pyqtSlot() # +++
def on_pb_clicked(self):
print('pb clicked -> "main Window')
self.graph.show()
if __name__ == "__main__":
app = QtWidgets.QApplication(sys.argv)
w = Window()
w.show()
sys.exit(app.exec_())

Changing the color of a QGraphicsItem

I am working on a simple software, which has a GUI. (I'm using PyQt)
I have 2 radiobuttons. If the first is selected, then by clicking on the Graphicsscene a GraphicsItem will be added to the scene.
I would like to have a button, which would change the color of these points by pressing it. The color doesn't matter. It could be red for example. How could I do that? Thank you!
For placing the widgets I used the Qt Designer, and then created a subclass called SimpleWindow.
Here is the code:
The points class:
from PyQt5.QtCore import QRectF, Qt
from PyQt5.QtWidgets import QGraphicsItem
class Point(QGraphicsItem):
def __init__(self, x, y):
super(Point, self).__init__()
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.rectF = QRectF(0, 0, 4, 4)
self.x=x
self.y=y
def boundingRect(self):
return self.rectF
def paint(self, painter=None, style=None, widget=None):
painter.fillRect(self.rectF, Qt.black)
import sys
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtGui import QPen, QBrush
from PyQt5.QtWidgets import QGraphicsScene
The scene:
class PointsGraphicsScene(QGraphicsScene):
def __init__(self, parent=None):
QGraphicsScene.__init__(self, parent)
self.setSceneRect(0, 0, 200, 200)
self.opt = ""
def setOption(self, opt):
self.opt = opt
def mousePressEvent(self, event):
pen = QPen(QtCore.Qt.black)
brush = QBrush(QtCore.Qt.black)
x = event.scenePos().x()
y = event.scenePos().y()
if self.opt == "Generate":
p = point.Point(x, y)
p.setPos(x, y)
self.addItem(p)
elif self.opt == "Select":
print(x, y)
The dialog window:
import sys
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QButtonGroup
import window
from scene import PointsGraphicsScene
class SimpleWindow(QtWidgets.QMainWindow, window.Ui_Dialog):
def __init__(self, parent=None):
super(SimpleWindow, self).__init__(parent)
self.setupUi(self)
self.scene = PointsGraphicsScene(self)
self.graphicsView.setScene(self.scene)
self.graphicsView.setAlignment(QtCore.Qt.AlignLeft |
QtCore.Qt.AlignTop)
group = QButtonGroup(self)
group.addButton(self.radioButton)
group.addButton(self.radioButton_2)
group.buttonClicked.connect(lambda btn:
self.scene.setOption(btn.text()))
self.radioButton.setChecked(True)
self.scene.setOption(self.radioButton.text())
app = QtWidgets.QApplication(sys.argv)
form = SimpleWindow()
form.show()
app.exec_()
This is the the class generated by the Designer.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_Dialog(object):
def setupUi(self, Dialog):
Dialog.setObjectName("Dialog")
Dialog.resize(538, 269)
self.graphicsView = QtWidgets.QGraphicsView(Dialog)
self.graphicsView.setGeometry(QtCore.QRect(130, 10, 371, 221))
self.graphicsView.setObjectName("graphicsView")
self.radioButton = QtWidgets.QRadioButton(Dialog)
self.radioButton.setGeometry(QtCore.QRect(20, 30, 82, 31))
self.radioButton.setObjectName("radioButton")
self.radioButton_2 = QtWidgets.QRadioButton(Dialog)
self.radioButton_2.setGeometry(QtCore.QRect(20, 80, 82, 17))
self.radioButton_2.setObjectName("radioButton_2")
self.retranslateUi(Dialog)
QtCore.QMetaObject.connectSlotsByName(Dialog)
def retranslateUi(self, Dialog):
_translate = QtCore.QCoreApplication.translate
Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
self.radioButton.setText(_translate("Dialog", "Generate"))
self.radioButton_2.setText(_translate("Dialog", "Select"))
The first thing is to create a method that changes the color, in this case we will call it setBrush():
class Point(QGraphicsItem):
def __init__(self, x, y):
super(Point, self).__init__()
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.rectF = QRectF(0, 0, 4, 4)
self.x=x
self.y=y
self._brush = QBrush(Qt.black)
def setBrush(self, brush):
self._brush = brush
self.update()
def boundingRect(self):
return self.rectF
def paint(self, painter=None, style=None, widget=None):
painter.fillRect(self.rectF, self._brush)
The second thing to do is create the button and locate it in some position. then the QPushButton clicked signal is connected to some slot. Then we get the items of the scene through the items() method and change the color with setBrush():
class SimpleWindow(QtWidgets.QMainWindow, window.Ui_Dialog):
def __init__(self, parent=None):
super(SimpleWindow, self).__init__(parent)
self.setupUi(self)
self.scene = PointsGraphicsScene(self)
self.graphicsView.setScene(self.scene)
self.graphicsView.setAlignment(QtCore.Qt.AlignLeft |
QtCore.Qt.AlignTop)
group = QButtonGroup(self)
group.addButton(self.radioButton)
group.addButton(self.radioButton_2)
group.buttonClicked.connect(lambda btn:
self.scene.setOption(btn.text()))
self.radioButton.setChecked(True)
self.scene.setOption(self.radioButton.text())
button = QPushButton("change color", self)
button.move(20, 140)
button.clicked.connect(self.onClicked)
def onClicked(self):
for item in self.scene.items():
item.setBrush(QColor("red"))
app = QtWidgets.QApplication(sys.argv)
form = SimpleWindow()
form.show()
app.exec_()

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