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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_())

pyqt add rectangle in Qgraphicsscene

I have a scene like this
class Scene(QtWidgets.QGraphicsScene):
def __init__(self, parent=None):
super(Scene, self).__init__(parent)
def mousePressEvent(self, event):
print('scene pressed')
self.wid = MyRect(event.pos(), event.pos())
self.addItem(self.wid)
self.wid.show()
I would like class MyRect(QtWidgets.QGraphicsRectItem) with painter, mouse event and so on to be a draggable rectangle.
all stuff in MyRect
So then I could have many Rectangle to the scene and even after draw line between them and so on (kind of diagram app), but keeping objects related editable options in MyRect, MyLine , ....
I thought :
class MyRect(QtWidgets.QGraphicsRectItem):
def __init__(self, begin, end, parent=None):
super().__init__(parent)
self.begin = begin
self.end = end
def paintEvent(self, event):
print('painting')
qp = QtGui.QPainter(self)
qp.drawRect(QtCore.QRect(self.begin, self.end))
def mousePressEvent(self, event):
self.begin = event.pos()
self.end = event.pos()
self.update()
def mouseMoveEvent(self, event):
self.end = event.pos()
self.update()
def mouseReleaseEvent(self, event):
self.begin = event.pos()
self.end = event.pos()
self.update()
But I does not work (paint event not initiated whereas mousepressed event in scene is intiated)
I did not find what I wanted through the web so started totry do it by myself. I'm pretty sure it is a must known starting point but I cannot find it

First of all a QGraphicsItem is not a QWidget, so it has those events and does not handle them directly, that's what QGraphicsView and QGraphicsScene do. For example you say that you want to have a moveable rectangle because that task is simple is QGraphicsView, it is not necessary to overwrite:
from PyQt5 import QtCore, QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
view = QtWidgets.QGraphicsView(scene)
self.setCentralWidget(view)
rect_item = QtWidgets.QGraphicsRectItem(QtCore.QRectF(0, 0, 100, 100))
rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
scene.addItem(rect_item)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
If you want to change the way you paint the rectangle you must overwrite the paint() method as shown below:
from PyQt5 import QtCore, QtGui, QtWidgets
class RectItem(QtWidgets.QGraphicsRectItem):
def paint(self, painter, option, widget=None):
super(RectItem, self).paint(painter, option, widget)
painter.save()
painter.setRenderHint(QtGui.QPainter.Antialiasing)
painter.setBrush(QtCore.Qt.red)
painter.drawEllipse(option.rect)
painter.restore()
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
scene = QtWidgets.QGraphicsScene(self)
view = QtWidgets.QGraphicsView(scene)
self.setCentralWidget(view)
rect_item = RectItem(QtCore.QRectF(0, 0, 100, 100))
rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
scene.addItem(rect_item)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())
Update:
from PyQt5 import QtCore, QtGui, QtWidgets
class GraphicsScene(QtWidgets.QGraphicsScene):
def __init__(self, parent=None):
super(GraphicsScene, self).__init__(QtCore.QRectF(-500, -500, 1000, 1000), parent)
self._start = QtCore.QPointF()
self._current_rect_item = None
def mousePressEvent(self, event):
if self.itemAt(event.scenePos(), QtGui.QTransform()) is None:
self._current_rect_item = QtWidgets.QGraphicsRectItem()
self._current_rect_item.setBrush(QtCore.Qt.red)
self._current_rect_item.setFlag(QtWidgets.QGraphicsItem.ItemIsMovable, True)
self.addItem(self._current_rect_item)
self._start = event.scenePos()
r = QtCore.QRectF(self._start, self._start)
self._current_rect_item.setRect(r)
super(GraphicsScene, self).mousePressEvent(event)
def mouseMoveEvent(self, event):
if self._current_rect_item is not None:
r = QtCore.QRectF(self._start, event.scenePos()).normalized()
self._current_rect_item.setRect(r)
super(GraphicsScene, self).mouseMoveEvent(event)
def mouseReleaseEvent(self, event):
self._current_rect_item = None
super(GraphicsScene, self).mouseReleaseEvent(event)
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
scene =GraphicsScene(self)
view = QtWidgets.QGraphicsView(scene)
self.setCentralWidget(view)
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
w.resize(640, 480)
w.show()
sys.exit(app.exec_())

Make a modal QDialog minimize when QMainWindow minimized (using PyQt 5)

Example code I am using:
import sys
from PyQt5 import QtCore
from PyQt5 import QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.open_about = False
self.openAction = QtWidgets.QAction('About', self)
self.openAction.triggered.connect(self.aboutDialog)
menuBar = self.menuBar()
fileMenu = menuBar.addMenu('&File')
fileMenu.addAction(self.openAction)
self.calendar = QtWidgets.QCalendarWidget(self)
self.setCentralWidget(self.calendar)
def about_state_upd(self, value):
self.open_about = value
def aboutDialog(self):
self._about = AboutDialog(self)
self._about.exec_()
def hideEvent(self, hideEvent):
if self.open_about == True:
self._about.setVisible(False)
def showEvent(self, showEvent):
if self.open_about == True:
if self._about.isHidden() == True:
self._about.setModal(True)
self._about.setVisible(True)
class AboutDialog(QtWidgets.QDialog):
def __init__(self, parent):
super(AboutDialog, self).__init__(parent)
self.setMinimumSize(400, 350)
self.parent().about_state_upd(True)
def closeEvent(self, closeEvent):
self.parent().about_state_upd(False)
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
app_window = MainWindow()
app_window.showMaximized()
sys.exit(app.exec_())
This code basically works, but seems very complicated. Is there a simpler / cleaner way to make it so that when the modal QDialog is open, if the QMainWindow is minimized, the QDialog also gets minimized too (and reverse when QMainWindow is restored)?
Code is running on KDE Neon (Kubuntu-based distro).

May be you can use this: http://korbinin.blogspot.fr/search/label/minimize%20button
from PyQt4.QtCore import *
from PyQt4.QtGui import *
class MainForm(QDialog):
def __init__(self, fn=None,parent=None):
super(MainForm, self).__init__(parent,\
flags=Qt.WindowMinimizeButtonHint|Qt.WindowMaximizeButtonHint)

Thanks to the people on the PyQt Mailing list, I managed to get a workaround for KDE. Instead of using exec_(), I am just using show() - then I use setDisabled() on QMainWindow to make dialog act in a modal fashion. Here is a (very quick and basic) example for anyone interested:
import sys
from PyQt5 import QtCore
from PyQt5 import QtWidgets
class MainWindow(QtWidgets.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.openAction = QtWidgets.QAction('About', self)
self.openAction.triggered.connect(self.aboutDialog)
menuBar = self.menuBar()
fileMenu = menuBar.addMenu('&File')
fileMenu.addAction(self.openAction)
self.calendar = QtWidgets.QCalendarWidget(self)
self.setCentralWidget(self.calendar)
def aboutDialog(self):
self._about = AboutDialog(self)
self.setDisabled (True)
self._about.show()
def enableWidgets(self):
self.setDisabled(False)
class AboutDialog(QtWidgets.QDialog):
def __init__(self, parent):
super(AboutDialog, self).__init__(parent)
self.setMinimumSize(400, 350)
def closeEvent(self, parent):
self.parent().enableWidgets()
def changeEvent(self, event):
if event.type() == QtCore.QEvent.WindowStateChange:
if self.windowState() & QtCore.Qt.WindowMinimized:
self.parent().showMinimized()
else:
self.parent().showMaximized()
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
app_window = MainWindow()
app_window.showMaximized()
sys.exit(app.exec_())
Link to PyQt Mailing List posts.

How to contol KeyEvent in Qt

With the window declared with CustomWidget as super class: class App(CustomWidget) hitting Alt+A properly prints 'keyPressEvent: Alt + a' message.
But the KeyEvent functionality is broken when the CustomWidget is assigned to window with setCentralWidget() or is set with layer.addWidget(widget). What is missing in a code?
from PyQt4 import QtCore, QtGui
class CustomWidget(QtGui.QWidget):
def __init__(self, parent):
QtGui.QWidget.__init__(self, parent=parent)
def keyPressEvent(self, event):
if event.modifiers() == QtCore.Qt.AltModifier:
if event.key() == QtCore.Qt.Key_A:
print 'keyPressEvent: Alt + a'
# super(CustomWidget, self).keyPressEvent(event)
class App(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QMainWindow.__init__(self, parent=parent)
centralWidget = CustomWidget(self)
self.setCentralWidget(centralWidget)
mainLayout=QtGui.QVBoxLayout()
centralWidget.setLayout(mainLayout)
widget = CustomWidget(self)
mainLayout.addWidget(widget)
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
w = App()
w.show()
sys.exit(app.exec_())

The widget must have focus to receive the event. Make sure you call setFocusPolicy() to have the CustomWidget accept and maintain focus after creating the window.
QWidget, keyPressEvent
QWidget, setFocusPolicy

Working Solution:
Important: At the end of GroupBox' keyPressEvent() method we have to pass the Event up to the super. Or the Event will not get propagated to the parent widget: super(QtGui.QGroupBox, self).keyPressEvent(event)
import sys
from PyQt4 import QtCore, QtGui
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent):
QtGui.QMainWindow.__init__(self, parent=parent)
self.setFocusPolicy(QtCore.Qt.StrongFocus)
def keyPressEvent(self, event):
if event.modifiers() == QtCore.Qt.ControlModifier:
if event.key() == QtCore.Qt.Key_T:
print 'MainWindow: Control + t'
if event.key() == QtCore.Qt.Key_M:
print 'MainWindow: Control + m'
class GroupBox(QtGui.QGroupBox):
def __init__(self, parent=None):
QtGui.QGroupBox.__init__(self, parent=parent)
self.setFocusPolicy(QtCore.Qt.StrongFocus)
def keyPressEvent(self, event):
if event.modifiers() == QtCore.Qt.ControlModifier:
if event.key() == QtCore.Qt.Key_T:
print 'GroupBox: Control + t'
if event.key() == QtCore.Qt.Key_S:
print 'GroupBox: Control + s'
super(QtGui.QGroupBox, self).keyPressEvent(event)
class App(MainWindow):
def __init__(self, parent=None):
MainWindow.__init__(self, parent=parent)
centralWidget = QtGui.QWidget(self)
self.setCentralWidget(centralWidget)
mainLayout=QtGui.QVBoxLayout()
centralWidget.setLayout(mainLayout)
groupBox = GroupBox(self)
mainLayout.addWidget(groupBox)
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
w = App()
w.show()
sys.exit(app.exec_())

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)
...