application: Reconfigure stylesheet on application palette changes

Author: ales-erjavec

orangecanvas/application/application.py

@@ -110,6 +110,7 @@ def maybe_match_prefix(prefix: str, path: str) -> Optional[str]:
 
 class CanvasApplication(QApplication):
     fileOpenRequest = Signal(QUrl)
+    applicationPaletteChanged = Signal()
 
     __args = None
 
@@ -160,6 +161,8 @@ def event(self, event):
                 self.fileOpenRequest.emit(event.url())
         elif event.type() == QEvent.PolishRequest:
             self.configureStyle()
+        elif event.type() == QEvent.Type.ApplicationPaletteChange:
+            self.applicationPaletteChanged.emit()
         return super().event(event)
 
     def exec(self) -> int:

orangecanvas/application/tests/test_application.py

@@ -3,13 +3,21 @@
 import time
 import unittest
 
+from AnyQt.QtGui import QPalette
+from AnyQt.QtTest import QSignalSpy
+
 from orangecanvas.utils import shtools as sh
 from orangecanvas.application import application as appmod
 from orangecanvas.utils.shtools import temp_named_file
 
 
 def application_test_helper():
     app = appmod.CanvasApplication([])
+    p = app.palette()
+    spy = QSignalSpy(app.applicationPaletteChanged)
+    p.setColor(QPalette.Base, p.color(QPalette.Text))
+    app.setPalette(p)
+    assert list(spy) == [[]]
     app.quit()
     return
 

orangecanvas/application/tests/test_main.py

@@ -5,6 +5,9 @@
 from typing import Iterable
 from unittest.mock import patch, Mock
 
+from AnyQt.QtCore import Qt
+from AnyQt.QtGui import QPalette
+
 from orangecanvas import config
 from orangecanvas.application.canvasmain import CanvasMainWindow
 from orangecanvas.config import Config, EntryPoint
@@ -131,3 +134,19 @@ def test_run_with_file(self):
             res = m.run(["-", "--no-welcome", "--no-splash", fname])
             CanvasMainWindow.open_scheme_file.assert_called_with(fname)
         self.assertEqual(res, 42)
+
+    @with_patched_main_application
+    def test_run_stylesheet_reconfigure(self):
+        m = Main()
+        m.parse_arguments(["-", "--config", f"{__name__}.TestConfig"])
+        m.window = m.create_main_window()
+        m.application = self.app
+
+        def setpalette(color):
+            self.app.setPalette(QPalette(color))
+            m._Main__reconfigure_stylesheet()
+
+        setpalette(Qt.white)
+        sheet = m.window.styleSheet()
+        setpalette(Qt.black)
+        self.assertNotEqual(sheet, m.window.styleSheet())

orangecanvas/main.py

@@ -1,15 +1,14 @@
 """
 """
 import argparse
-
 import os
 import sys
 import gc
 import logging
 import pickle
 import shlex
 import warnings
-from typing import List, Optional, IO, Any
+from typing import List, Optional, IO, Any, Iterable
 
 from urllib.request import getproxies
 from contextlib import ExitStack, closing
@@ -176,6 +175,7 @@ def setup_application(self):
         # sys.argv[0] must be in QApplication's argv list.
         self.application = CanvasApplication(sys.argv[:1] + self.arguments)
         self.application.setWindowIcon(self.config.application_icon())
+        self.application.applicationPaletteChanged.connect(self.__reconfigure_stylesheet)
         # Update the arguments
         self.arguments = self.application.arguments()[1:]
         fix_set_proxy_env()
@@ -289,7 +289,7 @@ def create_main_window(self) -> CanvasMainWindow:
         """Create the (initial) main window."""
         return CanvasMainWindow()
 
-    window: CanvasMainWindow
+    window: Optional[CanvasMainWindow] = None
 
     def setup_main_window(self):
         stylesheet = self.main_window_stylesheet()
@@ -377,6 +377,16 @@ def tear_down_sys_redirections(self):
         if self.__stdout__ is not None:
             sys.stdout = self.__stdout__
 
+    def _main_windows(self) -> Iterable[CanvasMainWindow]:
+        first = self.window
+        return (*((first,) if first else ()), *CanvasMainWindow._instances)
+
+    def __reconfigure_stylesheet(self) -> None:
+        ssheet = self.main_window_stylesheet()
+        for inst in self._main_windows():
+            if inst.styleSheet() != ssheet:
+                inst.setStyleSheet(ssheet)
+
 
 def fix_win_pythonw_std_stream():
     """