How to show two states of a rectangle in PyQt/PySide2

[illuzioner1]

I have what I thought was a simple task. I have an alert button (QGraphicsRectItem) in a graphics scene which has 2 rectangle children, each with its own, same text. I create the alert with rect 1 with a darkGray brush, a white border and white text. Rect 2 is supposed to have a yellow fill brush and black text. When I press a button I hide one set and show the other.

The problem is that the yellow rectangle doesn't show up, but its text does! What am I doing wrong?

import sys
from PyQt5 import QtGui, QtWidgets
from PyQt5.QtCore import *
from PyQt5.QtGui import QPainter, QColor
#from PyQt5.QtCore import QCoreApplication
from pynput import keyboard
 
 
class Geo:
    def __init__(self, x, y, w, h):
        self.x = x
        self.y = y
        self.w = w
        self.h = h
 
 
class Alert(QtWidgets.QGraphicsRectItem):
    def __init__(self, key_name, key_char, geo, parent=None, highlight_color=QColor(255, 255, 0, 200)):
        super(Alert, self).__init__(parent)
        self.key_name = key_name
        self.geo = geo
 
        rect = QRectF(0, 0, geo.w, geo.h)
        normal = QtWidgets.QGraphicsRectItem(rect, self)
        normal.setBrush(Qt.darkGray)
        normal.setPen(Qt.white)
        normal_txt = QtWidgets.QGraphicsSimpleTextItem(key_char, normal)
 
        brush = QtGui.QBrush(Qt.white)
        normal.setBrush(brush)
        self.normal = normal
 
        #self.highlighted = QtWidgets.QGraphicsRectItem(normal)
        self.highlighted = QtWidgets.QGraphicsRectItem(self)
        brush2 = QtGui.QBrush(highlight_color)
        self.highlighted.setBrush(brush2)
        #self.highlighted.setBrush(highlight_color)
        #self.highlighted.setBrush(brush)
        txt = QtWidgets.QGraphicsTextItem(key_char, self.highlighted)
        txt.setX(geo.w/2)
        #self.highlighted.hide()
 
    def highlight(self, on=False):
        if on:
            self.highlighted.show()
            self.normal.hide()
        else:
            self.highlighted.hide()
            self.normal.show()
 
 
class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.scene = QtWidgets.QGraphicsScene(self)
        self.scene.setItemIndexMethod(QtWidgets.QGraphicsScene.NoIndex)
 
        geo = Geo(10, 10, 50, 50)
        self.buzz = Alert("Buzz", "Buzz", geo)
        self.scene.addItem(self.buzz)
        self.buzz.setPos(QPointF(130, 120))
 
        self.create_central_widget()
 
        self.listener = keyboard.Listener(
            on_press=self.on_press,
            on_release=self.on_release)
        self.listener.start()
 
    def create_layout(self):
        self.layout = QtWidgets.QGraphicsLinearLayout()
        self.widget = QtWidgets.QGraphicsWidget()
        self.widget.setLayout(self.layout)
        self.scene.addItem(self.widget)
 
        width = self.keyboard_width
        height = self.keyboard_height
        self.setMinimumSize(width, height)
        self.scene.setSceneRect(0, 0, width, height)
 
    def create_central_widget(self):
        self.view = QtWidgets.QGraphicsView(self.scene)
        self.view.setRenderHints(QPainter.Antialiasing | QPainter.TextAntialiasing)
        self.view.setBackgroundBrush((QColor("bisque")))
        self.setCentralWidget(self.view)
        self.view.scale(3, 3)
 
    def on_press(self, key):
        self.buzz.highlight(True)
 
    def on_release(self, key):
        self.buzz.highlight(False)
 
 
def main():
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    ret = app.exec_()
    sys.exit(ret)
 
if __name__ == "__main__":
    main()

import sys
from PyQt5 import QtGui, QtWidgets
from PyQt5.QtCore import *
from PyQt5.QtGui import QPainter, QColor
#from PyQt5.QtCore import QCoreApplication
from pynput import keyboard


class Geo:
    def __init__(self, x, y, w, h):
        self.x = x
        self.y = y
        self.w = w
        self.h = h


class Alert(QtWidgets.QGraphicsRectItem):
    def __init__(self, key_name, key_char, geo, parent=None, highlight_color=QColor(255, 255, 0, 200)):
        super(Alert, self).__init__(parent)
        self.key_name = key_name
        self.geo = geo

        rect = QRectF(0, 0, geo.w, geo.h)
        normal = QtWidgets.QGraphicsRectItem(rect, self)
        normal.setBrush(Qt.darkGray)
        normal.setPen(Qt.white)
        normal_txt = QtWidgets.QGraphicsSimpleTextItem(key_char, normal)

        brush = QtGui.QBrush(Qt.white)
        normal.setBrush(brush)
        self.normal = normal

        #self.highlighted = QtWidgets.QGraphicsRectItem(normal)
        self.highlighted = QtWidgets.QGraphicsRectItem(self)
        brush2 = QtGui.QBrush(highlight_color)
        self.highlighted.setBrush(brush2)
        #self.highlighted.setBrush(highlight_color)
        #self.highlighted.setBrush(brush)
        txt = QtWidgets.QGraphicsTextItem(key_char, self.highlighted)
        txt.setX(geo.w/2)
        #self.highlighted.hide()

    def highlight(self, on=False):
        if on:
            self.highlighted.show()
            self.normal.hide()
        else:
            self.highlighted.hide()
            self.normal.show()


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)
        self.scene = QtWidgets.QGraphicsScene(self)
        self.scene.setItemIndexMethod(QtWidgets.QGraphicsScene.NoIndex)

        geo = Geo(10, 10, 50, 50)
        self.buzz = Alert("Buzz", "Buzz", geo)
        self.scene.addItem(self.buzz)
        self.buzz.setPos(QPointF(130, 120))

        self.create_central_widget()

        self.listener = keyboard.Listener(
            on_press=self.on_press,
            on_release=self.on_release)
        self.listener.start()

    def create_layout(self):
        self.layout = QtWidgets.QGraphicsLinearLayout()
        self.widget = QtWidgets.QGraphicsWidget()
        self.widget.setLayout(self.layout)
        self.scene.addItem(self.widget)

        width = self.keyboard_width
        height = self.keyboard_height
        self.setMinimumSize(width, height)
        self.scene.setSceneRect(0, 0, width, height)

    def create_central_widget(self):
        self.view = QtWidgets.QGraphicsView(self.scene)
        self.view.setRenderHints(QPainter.Antialiasing | QPainter.TextAntialiasing)
        self.view.setBackgroundBrush((QColor("bisque")))
        self.setCentralWidget(self.view)
        self.view.scale(3, 3)

    def on_press(self, key):
        self.buzz.highlight(True)

    def on_release(self, key):
        self.buzz.highlight(False)


def main():
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    ret = app.exec_()
    sys.exit(ret)

if __name__ == "__main__":
    main()

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[d_stranz]

I don't see where you are setting the rect for self.highlighted (which you do set for normal / self.normal). So self.highlighted has zero size.

But this hide / show mechanism seems pretty complicated when all you want to do in actuality is to change the color of a rectangle. Why not simply set a new brush on a -single- QGraphicsRectItem instead of flip / flopping two of them?

[illuzioner1]

You're right, that was the problem. In my shifting things around I lost the 'rect' in the second rectangle. Good idea on the brush. This is a simplified version of what I'm doing so I'll have to see if that works (as pixmaps are a possibility).

Thank you for the help!

[d_stranz]

(as pixmaps are a possibility)

Same principle as a brush. In Qt, QPixmap instances are reference-counted, so there is no overhead associated with changing the pixmap for a QGraphicsPixmapItem. QGraphicsPixmapItem::setPixmap() takes a const reference to a QPixmap, which implies that the graphics item stores a local copy, but that's not necessarily the case. Even when setting a pixmap is pass-by-value, the reference counting means that no actual copy is made unless the target of the copy modifies the original pixmap (ie. copy-on-write semantics apply).