Update accessibility_controller.dart

Author: hannah-hyj

packages/devtools_app/lib/src/screens/accessibility/accessibility_controller.dart

@@ -38,7 +38,6 @@ class AccessibilityController extends DevToolsScreenController
   }
 
   void _initListeners() {
-    addAutoDisposeListener(brightness, _onBrightnessChanged);
     addAutoDisposeListener(textScale, _onTextScaleChanged);
     addAutoDisposeListener(boldText, _onBoldTextChanged);
     addAutoDisposeListener(screenReader, _onScreenReaderChanged);
@@ -49,36 +48,29 @@ class AccessibilityController extends DevToolsScreenController
     final state = serviceConnection.serviceManager.serviceExtensionManager
         .getServiceExtensionState(extensions.brightnessMode.extension);
 
-    void updateFromDeviceState(ServiceExtensionState s) {
-      final newBrightness = !s.enabled || s.value == null
+    void updateFromDevice(ServiceExtensionState s) {
+      brightness.value = !s.enabled || s.value == null
           ? BrightnessOverride.system
           : switch (s.value) {
               'Brightness.light' => BrightnessOverride.light,
               'Brightness.dark' => BrightnessOverride.dark,
               _ => BrightnessOverride.system,
             };
-      if (brightness.value != newBrightness) {
-        brightness.value = newBrightness;
-      }
     }
 
-    updateFromDeviceState(state.value);
-    addAutoDisposeListener(
-      state,
-      () => updateFromDeviceState(state.value),
-    );
+    updateFromDevice(state.value);
+    addAutoDisposeListener(state, () => updateFromDevice(state.value));
   }
 
-
-
-  void _onBrightnessChanged() {
-    final value = brightness.value;
+  /// Called when the user changes the brightness override in the UI.
+  void setBrightnessOverride(BrightnessOverride mode) {
+    brightness.value = mode;
     // Values expected by Flutter framework's 'ext.flutter.brightnessOverride':
     // - 'Brightness.light': forces light mode
     // - 'Brightness.dark': forces dark mode
     // - '': any value other than 'Brightness.light' or 'Brightness.dark' clears
     //   the override and resets to system default.
-    final paramValue = switch (value) {
+    final paramValue = switch (mode) {
       BrightnessOverride.light => 'Brightness.light',
       BrightnessOverride.dark => 'Brightness.dark',
       BrightnessOverride.system => '',
@@ -87,7 +79,7 @@ class AccessibilityController extends DevToolsScreenController
       serviceConnection.serviceManager.serviceExtensionManager
           .setServiceExtensionState(
         extensions.brightnessMode.extension,
-        enabled: value != BrightnessOverride.system,
+        enabled: mode != BrightnessOverride.system,
         value: paramValue,
       ),
     );