fix: preserve TUN switch animations

Keep user-initiated switch animation running when the shared settings controller echoes the committed TUN state, and animate the peer surface without emitting a recursive request. Preserve snap synchronization for initialization and rollback, with real Qt coverage for both directions and rapid toggles.

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

Furious/Qt/QtWidgets.py

@@ -148,6 +148,23 @@ class AppQSwitch(Mixins.ThemeAware, QCheckBox):
 
         del blocker
 
+    def syncCheckedAnimated(self, checked: bool):
+        """Animate changed external state without emitting another request."""
+        checked = bool(checked)
+
+        if self.isChecked() == checked:
+            # A user toggle already started the canonical animation before its
+            # committed state was broadcast back through the shared authority.
+            return
+
+        blocker = QtCore.QSignalBlocker(self)
+
+        self.setChecked(checked)
+
+        del blocker
+
+        self._animateToggle(checked)
+
     def hitButton(self, position: QtCore.QPoint) -> bool:
         """Make the complete custom-painted switch track interactive."""
         return self.rect().contains(position)

Furious/Window/HomePage.py

@@ -825,7 +825,9 @@ class HomePage(Mixins.QTranslatable, QMainWindow):
         AppSettingsController().systemProxyModeChanged.connect(
             self._syncSystemProxyMode
         )
-        AppSettingsController().tunModeChanged.connect(self.tunModeSwitch.syncChecked)
+        AppSettingsController().tunModeChanged.connect(
+            self.tunModeSwitch.syncCheckedAnimated
+        )
 
         AppConnectionController().interactionEnabledChanged.connect(
             self.setConnectionControlsEnabled

Furious/Window/SettingsPage.py

@@ -661,7 +661,7 @@ class SettingsPage(Mixins.QTranslatable, QMainWindow):
         self.tunModeCard.checkBox.setEnabled(self._tunModeAvailable)
 
         AppSettingsController().tunModeChanged.connect(
-            self.tunModeCard.checkBox.syncChecked
+            self.tunModeCard.checkBox.syncCheckedAnimated
         )
 
         (

tests/test_qt_interactions.py

@@ -25,7 +25,7 @@ from Furious.Frozenlib import AppBuiltinProxyMode, AppSettings
 from Furious.Models import CoreConfiguration, ServerProfile
 from Furious.Plugins.API import RoutingOption
 from Furious.Repository import Storage, SubscriptionGroup
-from Furious.Qt import AppQDialog
+from Furious.Qt import AppQDialog, AppQSwitch
 from Furious.Widget.RoutingSelector import RoutingSelector
 from Furious.Widget.ServerTableView import ServerTableView
 from Furious.Window.HomePage import HomePage
@@ -690,7 +690,9 @@ class SharedSettingsQtWorkflowTest(unittest.TestCase):
                 )
 
                 settingsController.systemProxyModeChanged.connect(proxyCard.sync)
-                settingsController.tunModeChanged.connect(tunCard.checkBox.syncChecked)
+                settingsController.tunModeChanged.connect(
+                    tunCard.checkBox.syncCheckedAnimated
+                )
                 settingsLayout.addWidget(proxyCard)
                 settingsLayout.addWidget(tunCard)
 
@@ -740,10 +742,20 @@ class SharedSettingsQtWorkflowTest(unittest.TestCase):
                     QtCore.Qt.MouseButton.LeftButton,
                     pos=home.tunModeSwitch.rect().center(),
                 )
+
+                QTest.qWait(40)
+
+                for switch in (home.tunModeSwitch, tunCard.checkBox):
+                    self.assertGreater(switch.thumbPosition, 0.0)
+                    self.assertLess(switch.thumbPosition, 1.0)
+
+                QTest.qWait(AppQSwitch.AnimationDuration)
                 processQtEvents()
 
                 self.assertTrue(home.tunModeSwitch.isChecked())
                 self.assertTrue(tunCard.checkBox.isChecked())
+                self.assertEqual(home.tunModeSwitch.thumbPosition, 1.0)
+                self.assertEqual(tunCard.checkBox.thumbPosition, 1.0)
                 self.assertEqual(tunStates, [True])
 
                 QTest.mouseClick(
@@ -751,12 +763,42 @@ class SharedSettingsQtWorkflowTest(unittest.TestCase):
                     QtCore.Qt.MouseButton.LeftButton,
                     pos=tunCard.checkBox.rect().center(),
                 )
+
+                QTest.qWait(40)
+
+                for switch in (home.tunModeSwitch, tunCard.checkBox):
+                    self.assertGreater(switch.thumbPosition, 0.0)
+                    self.assertLess(switch.thumbPosition, 1.0)
+
+                QTest.qWait(AppQSwitch.AnimationDuration)
                 processQtEvents()
 
                 self.assertFalse(home.tunModeSwitch.isChecked())
                 self.assertFalse(tunCard.checkBox.isChecked())
+                self.assertEqual(home.tunModeSwitch.thumbPosition, 0.0)
+                self.assertEqual(tunCard.checkBox.thumbPosition, 0.0)
                 self.assertEqual(tunStates, [True, False])
 
+                QTest.mouseClick(
+                    home.tunModeSwitch,
+                    QtCore.Qt.MouseButton.LeftButton,
+                    pos=home.tunModeSwitch.rect().center(),
+                )
+                QTest.qWait(20)
+                QTest.mouseClick(
+                    home.tunModeSwitch,
+                    QtCore.Qt.MouseButton.LeftButton,
+                    pos=home.tunModeSwitch.rect().center(),
+                )
+                QTest.qWait(AppQSwitch.AnimationDuration + 40)
+                processQtEvents()
+
+                self.assertFalse(home.tunModeSwitch.isChecked())
+                self.assertFalse(tunCard.checkBox.isChecked())
+                self.assertEqual(home.tunModeSwitch.thumbPosition, 0.0)
+                self.assertEqual(tunCard.checkBox.thumbPosition, 0.0)
+                self.assertEqual(tunStates, [True, False, True, False])
+
                 connectionController.setInteractionEnabled(False)
                 processQtEvents()