Added workaround for QLCDNumber.

Added example workaround for QLCDNumber, along with an explanation of
the issues styling the LCD number by default with stylesheets.

ISSUES.md

@@ -7,6 +7,8 @@ There are limitations to what can be styled with stylesheets, as well as rare bu
   - [Menu Hover Background Color](#menu-hover-background-color)
 - [QDial](#qdial)
   - [Custom Style](#custom-style)
+- [QLCDNumber](#qlcdnumber)
+  - [LCD Color](#lcd-color)
 - [QMdiSubwindow](#qmdisubwindow)
   - [Title Bar Icons](#title-bar-icons)
 - [QSlider](#qslider)
@@ -43,6 +45,14 @@ There are limitations to what can be styled with stylesheets, as well as rare bu
 
 <img src="/assets/custom_dial.png" alt="Custom Dial" width="500" height="192"/>
 
+# QLCDNumber
+
+### LCD Color
+
+The LCD display of a `QLCDNumber` cannot be customized via a stylesheet. An example of how to style a `QLCDNumber` is available in [lcd.py](/example/lcd.py). This works out-of-the-box, and can be a drop-in replacement for `QLCDNumber`.
+
+<img src="/assets/custom_lcd.png" alt="Custom Dial" width="500" height="132"/>
+
 # QMdiSubwindow
 
 ### Title Bar Icons

example/lcd.py

@@ -0,0 +1,123 @@
+#!/usr/bin/env python
+#
+# The MIT License (MIT)
+#
+# Copyright (c) <2022-Present> <Alex Huszagh>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the 'Software'), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+
+'''
+    dial
+    ====
+
+    Example showing how to override the `paintEvent` and `eventFilter`
+    for a `QDial`, creating a visually consistent, stylish `QDial` that
+    supports highlighting the handle on the active or hovered dial.
+'''
+
+import math
+import shared
+import sys
+
+parser = shared.create_parser()
+parser.add_argument(
+    '--no-align',
+    help='''allow larger widgets without forcing alignment.''',
+    action='store_true'
+)
+args, unknown = shared.parse_args(parser)
+QtCore, QtGui, QtWidgets = shared.import_qt(args)
+compat = shared.get_compat_definitions(args)
+colors = shared.get_colors(args, compat)
+
+class LCD(QtWidgets.QLCDNumber):
+    '''QLCDNumber with a custom palette.'''
+
+    def __init__(self, widget=None):
+        super().__init__(widget)
+        self.setContentsMargins(1, 1, 1, 1)
+        if args.stylesheet == 'native':
+            return
+
+        # The color of the non-flat LCD numbers is still controlled
+        # via the `color` stylesheet attribute.
+        r, g, b, a = colors.HighLightDark.getRgb()
+        color = (r, g, b, a / 255)
+        self.setStyleSheet(f'QLCDNumber {{ color: rgba{color}; }}')
+
+        palette = self.palette()
+        palette.setColor(compat.BackgroundPalette, colors.Background)
+        palette.setColor(compat.LightPalette, colors.Selected)
+        palette.setColor(compat.DarkPalette, colors.Notch)
+        self.setPalette(palette)
+
+class Ui:
+    '''Main class for the user interface.'''
+
+    def setup(self, MainWindow):
+        MainWindow.setObjectName('MainWindow')
+        MainWindow.resize(1068, 824)
+        self.centralwidget = QtWidgets.QWidget(MainWindow)
+        self.layout = QtWidgets.QHBoxLayout(self.centralwidget)
+        self.layout.setSpacing(0)
+        if not args.no_align:
+            self.layout.setAlignment(compat.AlignVCenter)
+        MainWindow.setCentralWidget(self.centralwidget)
+
+        self.lcd1 = LCD(self.centralwidget)
+        self.lcd1.display(15)
+        self.lcd1.setDigitCount(2)
+        self.layout.addWidget(self.lcd1)
+
+        self.lcd2 = LCD(self.centralwidget)
+        self.lcd2.display(31)
+        self.lcd2.setHexMode()
+        self.lcd2.setDigitCount(2)
+        self.layout.addWidget(self.lcd2)
+
+        self.lcd3 = LCD(self.centralwidget)
+        self.lcd3.display(15)
+        self.lcd3.setSegmentStyle(compat.LCDOutline)
+        self.lcd3.setFrameShape(compat.NoFrame)
+        self.lcd3.setDigitCount(2)
+        self.layout.addWidget(self.lcd3)
+
+        self.lcd4 = LCD(self.centralwidget)
+        self.lcd4.display(15)
+        self.lcd4.setSegmentStyle(compat.LCDFlat)
+        self.lcd4.setFrameShape(compat.NoFrame)
+        self.lcd4.setDigitCount(2)
+        self.layout.addWidget(self.lcd4)
+
+
+def main():
+    'Application entry point'
+
+    app, window = shared.setup_app(args, unknown, compat)
+
+    # setup ui
+    ui = Ui()
+    ui.setup(window)
+    window.setWindowTitle('QLCDNumber')
+
+    shared.set_stylesheet(args, app, compat)
+    return shared.exec_app(args, app, window, compat)
+
+if __name__ == '__main__':
+    sys.exit(main())

example/shared.py

@@ -245,6 +245,10 @@ def get_compat_definitions(args):
         ns.MouseButtonRelease = ns.EventType.MouseButtonRelease
         ns.MouseMove = ns.EventType.MouseMove
         ns.WindowPalette = ns.ColorRole.Window
+        ns.WindowTextPalette = ns.ColorRole.WindowText
+        ns.BackgroundPalette = ns.ColorRole.Background
+        ns.LightPalette = ns.ColorRole.LightPalette
+        ns.DarkPalette = ns.ColorRole.DarkPalette
         ns.PlaceholderText = ns.ColorRole.PlaceholderText
         ns.ToolTipBase = ns.ColorRole.ToolTipBase
         ns.ToolTipText = ns.ColorRole.ToolTipText
@@ -526,6 +530,10 @@ def get_compat_definitions(args):
         ns.MouseButtonRelease = QtCore.QEvent.MouseButtonRelease
         ns.MouseMove = QtCore.QEvent.MouseMove
         ns.WindowPalette = QtGui.QPalette.Window
+        ns.WindowTextPalette = QtGui.QPalette.WindowText
+        ns.BackgroundPalette = QtGui.QPalette.Background
+        ns.LightPalette = QtGui.QPalette.Light
+        ns.DarkPalette = QtGui.QPalette.Dark
         ns.PlaceholderText = QtGui.QPalette.PlaceholderText
         ns.ToolTipBase = QtGui.QPalette.ToolTipBase
         ns.ToolTipText = QtGui.QPalette.ToolTipText
@@ -739,6 +747,7 @@ def get_colors(args, compat):
     ns.MidTone = compat.QtGui.QColor(127, 127, 127)
     ns.ViewBackground = compat.QtGui.QColor(0, 0, 0)
     ns.TabBackground = compat.QtGui.QColor(0, 0, 0)
+    ns.HighLightDark = compat.QtGui.QColor(255, 0, 0)
     if 'dark' in args.stylesheet:
         ns.Background = compat.QtGui.QColor(49, 54, 59)
         ns.Foreground = compat.QtGui.QColor(239, 240, 241)
@@ -754,6 +763,7 @@ def get_colors(args, compat):
         ns.MidTone = compat.QtGui.QColor(118, 121, 124)
         ns.ViewBackground = compat.QtGui.QColor(29, 32, 35)
         ns.TabBackground = compat.QtGui.QColor(44, 48, 52)
+        ns.HighLightDark = compat.QtGui.QColor(42, 121, 163)
     elif 'light' in args.stylesheet:
         ns.Background = compat.QtGui.QColor(239, 240, 241)
         ns.Foreground = compat.QtGui.QColor(49, 54, 59)
@@ -769,6 +779,7 @@ def get_colors(args, compat):
         ns.MidTone = compat.QtGui.QColor(186, 185, 184)
         ns.ViewBackground = compat.QtGui.QColor(239, 240, 241)
         ns.TabBackground = compat.QtGui.QColor(217, 216, 215)
+        ns.HighLightDark = compat.QtGui.QColor(45, 147, 200, 127)
 
     return ns