Use curly_braces_in_flow_control_structures for widgets (#104609)

* Use `curly_braces_in_flow_control_structures` for `widgets`

* fix comments

* fix comments

packages/flutter/lib/src/widgets/actions.dart

@@ -1503,8 +1503,9 @@ class PrioritizedAction extends Action<PrioritizedIntents> {
   @override
   bool isEnabled(PrioritizedIntents intent) {
     final FocusNode? focus = primaryFocus;
-    if  (focus == null || focus.context == null)
+    if  (focus == null || focus.context == null) {
       return false;
+    }
     for (final Intent candidateIntent in intent.orderedIntents) {
       final Action<Intent>? candidateAction = Actions.maybeFind<Intent>(
         focus.context!,

packages/flutter/lib/src/widgets/animated_cross_fade.dart

@@ -269,8 +269,9 @@ class _AnimatedCrossFadeState extends State<AnimatedCrossFade> with TickerProvid
       reverseDuration: widget.reverseDuration,
       vsync: this,
     );
-    if (widget.crossFadeState == CrossFadeState.showSecond)
+    if (widget.crossFadeState == CrossFadeState.showSecond) {
       _controller.value = 1.0;
+    }
     _firstAnimation = _initAnimation(widget.firstCurve, true);
     _secondAnimation = _initAnimation(widget.secondCurve, false);
     _controller.addStatusListener((AnimationStatus status) {
@@ -283,8 +284,9 @@ class _AnimatedCrossFadeState extends State<AnimatedCrossFade> with TickerProvid
 
   Animation<double> _initAnimation(Curve curve, bool inverted) {
     Animation<double> result = _controller.drive(CurveTween(curve: curve));
-    if (inverted)
+    if (inverted) {
       result = result.drive(Tween<double>(begin: 1.0, end: 0.0));
+    }
     return result;
   }
 
@@ -297,14 +299,18 @@ class _AnimatedCrossFadeState extends State<AnimatedCrossFade> with TickerProvid
   @override
   void didUpdateWidget(AnimatedCrossFade oldWidget) {
     super.didUpdateWidget(oldWidget);
-    if (widget.duration != oldWidget.duration)
+    if (widget.duration != oldWidget.duration) {
       _controller.duration = widget.duration;
-    if (widget.reverseDuration != oldWidget.reverseDuration)
+    }
+    if (widget.reverseDuration != oldWidget.reverseDuration) {
       _controller.reverseDuration = widget.reverseDuration;
-    if (widget.firstCurve != oldWidget.firstCurve)
+    }
+    if (widget.firstCurve != oldWidget.firstCurve) {
       _firstAnimation = _initAnimation(widget.firstCurve, true);
-    if (widget.secondCurve != oldWidget.secondCurve)
+    }
+    if (widget.secondCurve != oldWidget.secondCurve) {
       _secondAnimation = _initAnimation(widget.secondCurve, false);
+    }
     if (widget.crossFadeState != oldWidget.crossFadeState) {
       switch (widget.crossFadeState) {
         case CrossFadeState.showFirst:

packages/flutter/lib/src/widgets/animated_list.dart

@@ -488,10 +488,11 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
   int _indexToItemIndex(int index) {
     int itemIndex = index;
     for (final _ActiveItem item in _outgoingItems) {
-      if (item.itemIndex <= itemIndex)
+      if (item.itemIndex <= itemIndex) {
         itemIndex += 1;
-      else
+      } else {
         break;
+      }
     }
     return itemIndex;
   }
@@ -500,10 +501,11 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
     int index = itemIndex;
     for (final _ActiveItem item in _outgoingItems) {
       assert(item.itemIndex != itemIndex);
-      if (item.itemIndex < itemIndex)
+      if (item.itemIndex < itemIndex) {
         index -= 1;
-      else
+      } else {
         break;
+      }
     }
     return index;
   }
@@ -532,12 +534,14 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
     // Increment the incoming and outgoing item indices to account
     // for the insertion.
     for (final _ActiveItem item in _incomingItems) {
-      if (item.itemIndex >= itemIndex)
+      if (item.itemIndex >= itemIndex) {
         item.itemIndex += 1;
+      }
     }
     for (final _ActiveItem item in _outgoingItems) {
-      if (item.itemIndex >= itemIndex)
+      if (item.itemIndex >= itemIndex) {
         item.itemIndex += 1;
+      }
     }
 
     final AnimationController controller = AnimationController(
@@ -596,12 +600,14 @@ class SliverAnimatedListState extends State<SliverAnimatedList> with TickerProvi
       // Decrement the incoming and outgoing item indices to account
       // for the removal.
       for (final _ActiveItem item in _incomingItems) {
-        if (item.itemIndex > outgoingItem.itemIndex)
+        if (item.itemIndex > outgoingItem.itemIndex) {
           item.itemIndex -= 1;
+        }
       }
       for (final _ActiveItem item in _outgoingItems) {
-        if (item.itemIndex > outgoingItem.itemIndex)
+        if (item.itemIndex > outgoingItem.itemIndex) {
           item.itemIndex -= 1;
+        }
       }
 
       setState(() => _itemsCount -= 1);

packages/flutter/lib/src/widgets/animated_switcher.dart

@@ -272,8 +272,9 @@ class _AnimatedSwitcherState extends State<AnimatedSwitcher> with TickerProvider
     // transitions.
     if (widget.transitionBuilder != oldWidget.transitionBuilder) {
       _outgoingEntries.forEach(_updateTransitionForEntry);
-      if (_currentEntry != null)
+      if (_currentEntry != null) {
         _updateTransitionForEntry(_currentEntry!);
+      }
       _markChildWidgetCacheAsDirty();
     }
 
@@ -307,8 +308,9 @@ class _AnimatedSwitcherState extends State<AnimatedSwitcher> with TickerProvider
       _markChildWidgetCacheAsDirty();
       _currentEntry = null;
     }
-    if (widget.child == null)
+    if (widget.child == null) {
       return;
+    }
     final AnimationController controller = AnimationController(
       duration: widget.duration,
       reverseDuration: widget.reverseDuration,
@@ -380,10 +382,12 @@ class _AnimatedSwitcherState extends State<AnimatedSwitcher> with TickerProvider
 
   @override
   void dispose() {
-    if (_currentEntry != null)
+    if (_currentEntry != null) {
       _currentEntry!.controller.dispose();
-    for (final _ChildEntry entry in _outgoingEntries)
+    }
+    for (final _ChildEntry entry in _outgoingEntries) {
       entry.controller.dispose();
+    }
     super.dispose();
   }
 

packages/flutter/lib/src/widgets/app.dart

@@ -1409,8 +1409,9 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
       assert(route != null, 'The pageRouteBuilder for WidgetsApp must return a valid non-null Route.');
       return route;
     }
-    if (widget.onGenerateRoute != null)
+    if (widget.onGenerateRoute != null) {
       return widget.onGenerateRoute!(settings);
+    }
     return null;
   }
 
@@ -1454,12 +1455,14 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
     assert(mounted);
     // The back button dispatcher should handle the pop route if we use a
     // router.
-    if (_usesRouterWithDelegates)
+    if (_usesRouterWithDelegates) {
       return false;
+    }
 
     final NavigatorState? navigator = _navigator?.currentState;
-    if (navigator == null)
+    if (navigator == null) {
       return false;
+    }
     return navigator.maybePop();
   }
 
@@ -1468,12 +1471,14 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
     assert(mounted);
     // The route name provider should handle the push route if we uses a
     // router.
-    if (_usesRouterWithDelegates)
+    if (_usesRouterWithDelegates) {
       return false;
+    }
 
     final NavigatorState? navigator = _navigator?.currentState;
-    if (navigator == null)
+    if (navigator == null) {
       return false;
+    }
     navigator.pushNamed(route);
     return true;
   }
@@ -1487,17 +1492,19 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
     // Attempt to use localeListResolutionCallback.
     if (widget.localeListResolutionCallback != null) {
       final Locale? locale = widget.localeListResolutionCallback!(preferredLocales, widget.supportedLocales);
-      if (locale != null)
+      if (locale != null) {
         return locale;
+      }
     }
     // localeListResolutionCallback failed, falling back to localeResolutionCallback.
     if (widget.localeResolutionCallback != null) {
       final Locale? locale = widget.localeResolutionCallback!(
         preferredLocales != null && preferredLocales.isNotEmpty ? preferredLocales.first : null,
         widget.supportedLocales,
       );
-      if (locale != null)
+      if (locale != null) {
         return locale;
+      }
     }
     // Both callbacks failed, falling back to default algorithm.
     return basicLocaleListResolution(preferredLocales, supportedLocales);
@@ -1533,13 +1540,16 @@ class _WidgetsAppState extends State<WidgetsApp> with WidgetsBindingObserver {
       final Set<Type> unsupportedTypes =
         _localizationsDelegates.map<Type>((LocalizationsDelegate<dynamic> delegate) => delegate.type).toSet();
       for (final LocalizationsDelegate<dynamic> delegate in _localizationsDelegates) {
-        if (!unsupportedTypes.contains(delegate.type))
+        if (!unsupportedTypes.contains(delegate.type)) {
           continue;
-        if (delegate.isSupported(appLocale))
+        }
+        if (delegate.isSupported(appLocale)) {
           unsupportedTypes.remove(delegate.type);
+        }
       }
-      if (unsupportedTypes.isEmpty)
+      if (unsupportedTypes.isEmpty) {
         return true;
+      }
 
       FlutterError.reportError(FlutterErrorDetails(
         exception: "Warning: This application's locale, $appLocale, is not supported by all of its localization delegates.",

packages/flutter/lib/src/widgets/async.dart

@@ -246,10 +246,12 @@ class AsyncSnapshot<T> {
   /// Throws [error], if [hasError]. Throws [StateError], if neither [hasData]
   /// nor [hasError].
   T get requireData {
-    if (hasData)
+    if (hasData) {
       return data!;
-    if (hasError)
+    }
+    if (hasError) {
       Error.throwWithStackTrace(error!, stackTrace!);
+    }
     throw StateError('Snapshot has neither data nor error');
   }
 
@@ -294,8 +296,9 @@ class AsyncSnapshot<T> {
 
   @override
   bool operator ==(Object other) {
-    if (identical(this, other))
+    if (identical(this, other)) {
       return true;
+    }
     return other is AsyncSnapshot<T>
         && other.connectionState == connectionState
         && other.data == data

packages/flutter/lib/src/widgets/autofill.dart

@@ -186,8 +186,9 @@ class AutofillGroupState extends State<AutofillGroup> with AutofillScopeMixin {
   void dispose() {
     super.dispose();
 
-    if (!_isTopmostAutofillGroup || widget.onDisposeAction == null)
+    if (!_isTopmostAutofillGroup || widget.onDisposeAction == null) {
       return;
+    }
     switch (widget.onDisposeAction) {
       case AutofillContextAction.cancel:
         TextInput.finishAutofillContext(shouldSave: false);

packages/flutter/lib/src/widgets/automatic_keep_alive.dart

@@ -69,8 +69,9 @@ class _AutomaticKeepAliveState extends State<AutomaticKeepAlive> {
   @override
   void dispose() {
     if (_handles != null) {
-      for (final Listenable handle in _handles!.keys)
+      for (final Listenable handle in _handles!.keys) {
         handle.removeListener(_handles![handle]!);
+      }
     }
     super.dispose();
   }
@@ -368,33 +369,38 @@ mixin AutomaticKeepAliveClientMixin<T extends StatefulWidget> on State<T> {
   @protected
   void updateKeepAlive() {
     if (wantKeepAlive) {
-      if (_keepAliveHandle == null)
+      if (_keepAliveHandle == null) {
         _ensureKeepAlive();
+      }
     } else {
-      if (_keepAliveHandle != null)
+      if (_keepAliveHandle != null) {
         _releaseKeepAlive();
+      }
     }
   }
 
   @override
   void initState() {
     super.initState();
-    if (wantKeepAlive)
+    if (wantKeepAlive) {
       _ensureKeepAlive();
+    }
   }
 
   @override
   void deactivate() {
-    if (_keepAliveHandle != null)
+    if (_keepAliveHandle != null) {
       _releaseKeepAlive();
+    }
     super.deactivate();
   }
 
   @mustCallSuper
   @override
   Widget build(BuildContext context) {
-    if (wantKeepAlive && _keepAliveHandle == null)
+    if (wantKeepAlive && _keepAliveHandle == null) {
       _ensureKeepAlive();
+    }
     return const _NullWidget();
   }
 }

packages/flutter/lib/src/widgets/banner.dart

@@ -135,8 +135,9 @@ class BannerPainter extends CustomPainter {
 
   @override
   void paint(Canvas canvas, Size size) {
-    if (!_prepared)
+    if (!_prepared) {
       _prepare();
+    }
     canvas
       ..translate(_translationX(size.width), _translationY(size.height))
       ..rotate(_rotation)