Add theme change support for AssetViewer

Signed-off-by: Loren Eteval <loren.eteval@proton.me>

Furious/Utility/Utility.py

@@ -206,26 +206,6 @@ def getAbsolutePath(path):
     return path if os.path.isabs(path) else str(ROOT_DIR / path)
 
 
-def swapListItem(listOrTuple, index0, index1):
-    swap = listOrTuple[index0]
-
-    listOrTuple[index0] = listOrTuple[index1]
-    listOrTuple[index1] = swap
-
-
-def moveToCenter(widget, parent=None):
-    geometry = widget.geometry()
-
-    if parent is None:
-        center = QApplication.primaryScreen().availableGeometry().center()
-    else:
-        center = parent.geometry().center()
-
-    geometry.moveCenter(center)
-
-    widget.move(geometry.topLeft())
-
-
 def getUbuntuRelease():
     try:
         result = subprocess.run(
@@ -248,3 +228,23 @@ def getUbuntuRelease():
         # Any non-exit exceptions
 
         return ''
+
+
+def swapListItem(listOrTuple, index0, index1):
+    swap = listOrTuple[index0]
+
+    listOrTuple[index0] = listOrTuple[index1]
+    listOrTuple[index1] = swap
+
+
+def moveToCenter(widget, parent=None):
+    geometry = widget.geometry()
+
+    if parent is None:
+        center = QApplication.primaryScreen().availableGeometry().center()
+    else:
+        center = parent.geometry().center()
+
+    geometry.moveCenter(center)
+
+    widget.move(geometry.topLeft())

Furious/Widget/AssetViewer.py

@@ -7,6 +7,7 @@ from Furious.Utility.Utility import (
     SupportThemeChangedCallback,
     bootstrapIcon,
     bootstrapIconWhite,
+    getUbuntuRelease,
     moveToCenter,
 )
 from Furious.Utility.Translator import Translatable, gettext as _
@@ -168,6 +169,11 @@ class AssetViewerWidget(
         self.listWidget.setSelectionMode(QListWidget.SelectionMode.ExtendedSelection)
         self.listWidget.setIconSize(QtCore.QSize(64, 64))
 
+        if PLATFORM == 'Linux' and getUbuntuRelease() == '20.04':
+            self.initialTheme = darkdetect.theme()
+        else:
+            self.initialTheme = None
+
         self.flushItem()
         self.setCentralWidget(self.listWidget)
 
@@ -238,14 +244,14 @@ class AssetViewerWidget(
         for index in indexes:
             os.remove(AssetViewerWidget.AssetDir / self.listWidget.item(index).text())
 
-    def flushItem(self):
+    def flushItemByTheme(self, theme):
         self.listWidget.clear()
 
         for filename in os.listdir(AssetViewerWidget.AssetDir):
             if os.path.isfile(AssetViewerWidget.AssetDir / filename):
                 item = QListWidgetItem(filename)
 
-                if darkdetect.theme() == 'Dark':
+                if theme == 'Dark':
                     if PLATFORM == 'Windows':
                         # Windows. Always use black icon
                         item.setIcon(bootstrapIcon('file-earmark.svg'))
@@ -256,6 +262,15 @@ class AssetViewerWidget(
 
                 self.listWidget.addItem(item)
 
+    def flushItem(self):
+        if PLATFORM == 'Linux' and getUbuntuRelease() == '20.04':
+            assert self.initialTheme is not None
+
+            # Ubuntu 20.04. Flush by initial theme
+            self.flushItemByTheme(self.initialTheme)
+        else:
+            self.flushItemByTheme(darkdetect.theme())
+
     def closeEvent(self, event):
         event.ignore()
 
@@ -268,8 +283,12 @@ class AssetViewerWidget(
         self.setWindowIcon(bootstrapIcon('rocket-takeoff-window.svg'))
 
     def themeChangedCallback(self, theme):
-        # TODO
-        pass
+        if PLATFORM == 'Linux' and getUbuntuRelease() == '20.04':
+            # Ubuntu 20.04 system dark theme does not
+            # change menu color. Do nothing
+            pass
+        else:
+            self.flushItemByTheme(theme)
 
     def retranslate(self):
         with StateContext(self):