Use `curly_braces_in_flow_control_structures` for `animations`, `cupertino` (#104612)

* Use `curly_braces_in_flow_control_structures` for `animation`

* Use `curly_braces_in_flow_control_structures` for `cupertino`

* fix comments

packages/flutter/lib/src/animation/animation_controller.dart

@@ -389,8 +389,9 @@ class AnimationController extends Animation<double>
   /// If [isAnimating] is false, then [value] is not changing and the rate of
   /// change is zero.
   double get velocity {
-    if (!isAnimating)
+    if (!isAnimating) {
       return 0.0;
+    }
     return _simulation!.dx(lastElapsedDuration!.inMicroseconds.toDouble() / Duration.microsecondsPerSecond);
   }
 
@@ -456,8 +457,9 @@ class AnimationController extends Animation<double>
       'AnimationController methods should not be used after calling dispose.',
     );
     _direction = _AnimationDirection.forward;
-    if (from != null)
+    if (from != null) {
       value = from;
+    }
     return _animateToInternal(upperBound);
   }
 
@@ -489,8 +491,9 @@ class AnimationController extends Animation<double>
       'AnimationController methods should not be used after calling dispose.',
     );
     _direction = _AnimationDirection.reverse;
-    if (from != null)
+    if (from != null) {
       value = from;
+    }
     return _animateToInternal(lowerBound);
   }
 
@@ -856,13 +859,14 @@ class _InterpolationSimulation extends Simulation {
   @override
   double x(double timeInSeconds) {
     final double t = clampDouble(timeInSeconds / _durationInSeconds, 0.0, 1.0);
-    if (t == 0.0)
+    if (t == 0.0) {
       return _begin;
-    else if (t == 1.0)
+    } else if (t == 1.0) {
       return _end;
-    else
+    } else {
       return _begin + (_end - _begin) * _curve.transform(t);
     }
+  }
 
   @override
   double dx(double timeInSeconds) {

packages/flutter/lib/src/animation/animations.dart

@@ -188,22 +188,27 @@ class ProxyAnimation extends Animation<double>
   Animation<double>? get parent => _parent;
   Animation<double>? _parent;
   set parent(Animation<double>? value) {
-    if (value == _parent)
+    if (value == _parent) {
       return;
+    }
     if (_parent != null) {
       _status = _parent!.status;
       _value = _parent!.value;
-      if (isListening)
+      if (isListening) {
         didStopListening();
       }
+    }
     _parent = value;
     if (_parent != null) {
-      if (isListening)
+      if (isListening) {
         didStartListening();
-      if (_value != _parent!.value)
+      }
+      if (_value != _parent!.value) {
         notifyListeners();
-      if (_status != _parent!.status)
+      }
+      if (_status != _parent!.status) {
         notifyStatusListeners(_parent!.status);
+      }
       _status = null;
       _value = null;
     }
@@ -233,8 +238,9 @@ class ProxyAnimation extends Animation<double>
 
   @override
   String toString() {
-    if (parent == null)
+    if (parent == null) {
       return '${objectRuntimeType(this, 'ProxyAnimation')}(null; ${super.toStringDetails()} ${value.toStringAsFixed(3)})';
+    }
     return '$parent\u27A9${objectRuntimeType(this, 'ProxyAnimation')}';
   }
 }
@@ -441,8 +447,9 @@ class CurvedAnimation extends Animation<double> with AnimationWithParentMixin<do
     final Curve? activeCurve = _useForwardCurve ? curve : reverseCurve;
 
     final double t = parent.value;
-    if (activeCurve == null)
+    if (activeCurve == null) {
       return t;
+    }
     if (t == 0.0 || t == 1.0) {
       assert(() {
         final double transformedValue = activeCurve.transform(t);
@@ -464,10 +471,12 @@ class CurvedAnimation extends Animation<double> with AnimationWithParentMixin<do
 
   @override
   String toString() {
-    if (reverseCurve == null)
+    if (reverseCurve == null) {
       return '$parent\u27A9$curve';
-    if (_useForwardCurve)
+    }
+    if (_useForwardCurve) {
       return '$parent\u27A9$curve\u2092\u2099/$reverseCurve';
+    }
     return '$parent\u27A9$curve/$reverseCurve\u2092\u2099';
   }
 }
@@ -581,9 +590,10 @@ class TrainHoppingAnimation extends Animation<double>
       _lastValue = newValue;
     }
     assert(_lastValue != null);
-    if (hop && onSwitchedTrain != null)
+    if (hop && onSwitchedTrain != null) {
       onSwitchedTrain!();
     }
+  }
 
   @override
   double get value => _currentTrain!.value;
@@ -605,8 +615,9 @@ class TrainHoppingAnimation extends Animation<double>
 
   @override
   String toString() {
-    if (_nextTrain != null)
+    if (_nextTrain != null) {
       return '$currentTrain\u27A9${objectRuntimeType(this, 'TrainHoppingAnimation')}(next: $_nextTrain)';
+    }
     return '$currentTrain\u27A9${objectRuntimeType(this, 'TrainHoppingAnimation')}(no next)';
   }
 }
@@ -660,8 +671,9 @@ abstract class CompoundAnimation<T> extends Animation<T>
   /// Otherwise, default to [first].
   @override
   AnimationStatus get status {
-    if (next.status == AnimationStatus.forward || next.status == AnimationStatus.reverse)
+    if (next.status == AnimationStatus.forward || next.status == AnimationStatus.reverse) {
       return next.status;
+    }
     return first.status;
   }
 

packages/flutter/lib/src/animation/curves.dart

@@ -183,15 +183,17 @@ class Interval extends Curve {
     assert(end <= 1.0);
     assert(end >= begin);
     t = clampDouble((t - begin) / (end - begin), 0.0, 1.0);
-    if (t == 0.0 || t == 1.0)
+    if (t == 0.0 || t == 1.0) {
       return t;
+    }
     return curve.transform(t);
   }
 
   @override
   String toString() {
-    if (curve is! _Linear)
+    if (curve is! _Linear) {
       return '${objectRuntimeType(this, 'Interval')}($begin\u22EF$end)\u27A9$curve';
+    }
     return '${objectRuntimeType(this, 'Interval')}($begin\u22EF$end)';
   }
 }
@@ -348,14 +350,16 @@ class Cubic extends Curve {
     while (true) {
       final double midpoint = (start + end) / 2;
       final double estimate = _evaluateCubic(a, c, midpoint);
-      if ((t - estimate).abs() < _cubicErrorBound)
+      if ((t - estimate).abs() < _cubicErrorBound) {
         return _evaluateCubic(b, d, midpoint);
-      if (estimate < t)
+      }
+      if (estimate < t) {
         start = midpoint;
-      else
+      } else {
         end = midpoint;
       }
     }
+  }
 
   @override
   String toString() {
@@ -1219,11 +1223,12 @@ class _BounceInOutCurve extends Curve {
 
   @override
   double transformInternal(double t) {
-    if (t < 0.5)
+    if (t < 0.5) {
       return (1.0 - _bounce(1.0 - t * 2.0)) * 0.5;
-    else
+    } else {
       return _bounce(t * 2.0 - 1.0) * 0.5 + 0.5;
     }
+  }
 }
 
 
@@ -1304,11 +1309,12 @@ class ElasticInOutCurve extends Curve {
   double transformInternal(double t) {
     final double s = period / 4.0;
     t = 2.0 * t - 1.0;
-    if (t < 0.0)
+    if (t < 0.0) {
       return -0.5 * math.pow(2.0, 10.0 * t) * math.sin((t - s) * (math.pi * 2.0) / period);
-    else
+    } else {
       return math.pow(2.0, -10.0 * t) * math.sin((t - s) * (math.pi * 2.0) / period) * 0.5 + 1.0;
     }
+  }
 
   @override
   String toString() {

packages/flutter/lib/src/animation/listener_helpers.dart

@@ -26,8 +26,9 @@ mixin AnimationLazyListenerMixin {
   @protected
   void didRegisterListener() {
     assert(_listenerCounter >= 0);
-    if (_listenerCounter == 0)
+    if (_listenerCounter == 0) {
       didStartListening();
+    }
     _listenerCounter += 1;
   }
 
@@ -41,9 +42,10 @@ mixin AnimationLazyListenerMixin {
   void didUnregisterListener() {
     assert(_listenerCounter >= 1);
     _listenerCounter -= 1;
-    if (_listenerCounter == 0)
+    if (_listenerCounter == 0) {
       didStopListening();
     }
+  }
 
   /// Called when the number of listeners changes from zero to one.
   @protected
@@ -151,8 +153,9 @@ mixin AnimationLocalListenersMixin {
         return true;
       }());
       try {
-        if (_listeners.contains(listener))
+        if (_listeners.contains(listener)) {
           listener();
+        }
       } catch (exception, stack) {
         FlutterError.reportError(FlutterErrorDetails(
           exception: exception,
@@ -229,8 +232,9 @@ mixin AnimationLocalStatusListenersMixin {
     final List<AnimationStatusListener> localListeners = _statusListeners.toList(growable: false);
     for (final AnimationStatusListener listener in localListeners) {
       try {
-        if (_statusListeners.contains(listener))
+        if (_statusListeners.contains(listener)) {
           listener(status);
+        }
       } catch (exception, stack) {
         InformationCollector? collector;
         assert(() {

packages/flutter/lib/src/animation/tween.dart

@@ -320,10 +320,12 @@ class Tween<T extends Object?> extends Animatable<T> {
   /// subclass.
   @override
   T transform(double t) {
-    if (t == 0.0)
+    if (t == 0.0) {
       return begin as T;
-    if (t == 1.0)
+    }
+    if (t == 1.0) {
       return end as T;
+    }
     return lerp(t);
   }
 

packages/flutter/lib/src/animation/tween_sequence.dart

@@ -56,8 +56,9 @@ class TweenSequence<T> extends Animatable<T> {
     _items.addAll(items);
 
     double totalWeight = 0.0;
-    for (final TweenSequenceItem<T> item in _items)
+    for (final TweenSequenceItem<T> item in _items) {
       totalWeight += item.weight;
+    }
     assert(totalWeight > 0.0);
 
     double start = 0.0;
@@ -80,12 +81,14 @@ class TweenSequence<T> extends Animatable<T> {
   @override
   T transform(double t) {
     assert(t >= 0.0 && t <= 1.0);
-    if (t == 1.0)
+    if (t == 1.0) {
       return _evaluateAt(t, _items.length - 1);
+    }
     for (int index = 0; index < _items.length; index++) {
-      if (_intervals[index].contains(t))
+      if (_intervals[index].contains(t)) {
         return _evaluateAt(t, index);
       }
+    }
     // Should be unreachable.
     throw StateError('TweenSequence.evaluate() could not find an interval for $t');
   }

packages/flutter/lib/src/cupertino/activity_indicator.dart

@@ -107,12 +107,13 @@ class _CupertinoActivityIndicatorState extends State<CupertinoActivityIndicator>
   void didUpdateWidget(CupertinoActivityIndicator oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (widget.animating != oldWidget.animating) {
-      if (widget.animating)
+      if (widget.animating) {
         _controller.repeat();
-      else
+      } else {
         _controller.stop();
       }
     }
+  }
 
   @override
   void dispose() {

packages/flutter/lib/src/cupertino/bottom_tab_bar.dart

@@ -271,8 +271,9 @@ class CupertinoTabBar extends StatelessWidget implements PreferredSizeWidget {
 
   /// Change the active tab item's icon and title colors to active.
   Widget _wrapActiveItem(BuildContext context, Widget item, { required bool active }) {
-    if (!active)
+    if (!active) {
       return item;
+    }
 
     final Color activeColor = CupertinoDynamicColor.resolve(
       this.activeColor ?? CupertinoTheme.of(context).primaryColor,

packages/flutter/lib/src/cupertino/button.dart

@@ -214,15 +214,17 @@ class _CupertinoButtonState extends State<CupertinoButton> with SingleTickerProv
   }
 
   void _animate() {
-    if (_animationController.isAnimating)
+    if (_animationController.isAnimating) {
       return;
+    }
     final bool wasHeldDown = _buttonHeldDown;
     final TickerFuture ticker = _buttonHeldDown
         ? _animationController.animateTo(1.0, duration: kFadeOutDuration, curve: Curves.easeInOutCubicEmphasized)
         : _animationController.animateTo(0.0, duration: kFadeInDuration, curve: Curves.easeOutCubic);
     ticker.then<void>((void value) {
-      if (mounted && wasHeldDown != _buttonHeldDown)
+      if (mounted && wasHeldDown != _buttonHeldDown) {
         _animate();
+      }
     });
   }
 

packages/flutter/lib/src/cupertino/colors.dart

@@ -928,8 +928,9 @@ class CupertinoDynamicColor extends Color with Diagnosticable {
   ///  * [resolve], which is similar to this function, but returns a
   ///    non-nullable value, and does not allow a null `resolvable` color.
   static Color? maybeResolve(Color? resolvable, BuildContext context) {
-    if (resolvable == null)
+    if (resolvable == null) {
       return null;
+    }
     assert(context != null);
     return (resolvable is CupertinoDynamicColor)
       ? resolvable.resolveFrom(context)
@@ -1045,10 +1046,12 @@ class CupertinoDynamicColor extends Color with Diagnosticable {
 
   @override
   bool operator ==(Object other) {
-    if (identical(this, other))
+    if (identical(this, other)) {
       return true;
-    if (other.runtimeType != runtimeType)
+    }
+    if (other.runtimeType != runtimeType) {
       return false;
+    }
     return other is CupertinoDynamicColor
         && other.value == value
         && other.color == color
@@ -1097,27 +1100,36 @@ class CupertinoDynamicColor extends Color with Diagnosticable {
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);
-    if (_debugLabel != null)
+    if (_debugLabel != null) {
       properties.add(MessageProperty('debugLabel', _debugLabel!));
+    }
     properties.add(createCupertinoColorProperty('color', color));
-    if (_isPlatformBrightnessDependent)
+    if (_isPlatformBrightnessDependent) {
       properties.add(createCupertinoColorProperty('darkColor', darkColor));
-    if (_isHighContrastDependent)
+    }
+    if (_isHighContrastDependent) {
       properties.add(createCupertinoColorProperty('highContrastColor', highContrastColor));
-    if (_isPlatformBrightnessDependent && _isHighContrastDependent)
+    }
+    if (_isPlatformBrightnessDependent && _isHighContrastDependent) {
       properties.add(createCupertinoColorProperty('darkHighContrastColor', darkHighContrastColor));
-    if (_isInterfaceElevationDependent)
+    }
+    if (_isInterfaceElevationDependent) {
       properties.add(createCupertinoColorProperty('elevatedColor', elevatedColor));
-    if (_isPlatformBrightnessDependent && _isInterfaceElevationDependent)
+    }
+    if (_isPlatformBrightnessDependent && _isInterfaceElevationDependent) {
       properties.add(createCupertinoColorProperty('darkElevatedColor', darkElevatedColor));
-    if (_isHighContrastDependent && _isInterfaceElevationDependent)
+    }
+    if (_isHighContrastDependent && _isInterfaceElevationDependent) {
       properties.add(createCupertinoColorProperty('highContrastElevatedColor', highContrastElevatedColor));
-    if (_isPlatformBrightnessDependent && _isHighContrastDependent && _isInterfaceElevationDependent)
+    }
+    if (_isPlatformBrightnessDependent && _isHighContrastDependent && _isInterfaceElevationDependent) {
       properties.add(createCupertinoColorProperty('darkHighContrastElevatedColor', darkHighContrastElevatedColor));
+    }
 
-    if (_debugResolveContext != null)
+    if (_debugResolveContext != null) {
       properties.add(DiagnosticsProperty<Element>('last resolved', _debugResolveContext));
     }
+  }
 }
 
 /// Creates a diagnostics property for [CupertinoDynamicColor].

packages/flutter/lib/src/cupertino/dialog.dart

@@ -1567,10 +1567,11 @@ class _ActionButtonParentDataWidget
 
       // Force a repaint.
       final AbstractNode? targetParent = renderObject.parent;
-      if (targetParent is RenderObject)
+      if (targetParent is RenderObject) {
         targetParent.markNeedsPaint();
       }
     }
+  }
 
   @override
   Type get debugTypicalAncestorWidgetClass =>
@@ -1905,8 +1906,9 @@ class _RenderCupertinoDialogActions extends RenderBox
   bool _hasCancelButton;
   bool get hasCancelButton => _hasCancelButton;
   set hasCancelButton(bool newValue) {
-    if (newValue == _hasCancelButton)
+    if (newValue == _hasCancelButton) {
       return;
+    }
 
     _hasCancelButton = newValue;
     markNeedsLayout();
@@ -1915,8 +1917,9 @@ class _RenderCupertinoDialogActions extends RenderBox
   Color get dialogColor => _buttonBackgroundPaint.color;
   final Paint _buttonBackgroundPaint;
   set dialogColor(Color value) {
-    if (value == _buttonBackgroundPaint.color)
+    if (value == _buttonBackgroundPaint.color) {
       return;
+    }
 
     _buttonBackgroundPaint.color = value;
     markNeedsPaint();
@@ -1925,8 +1928,9 @@ class _RenderCupertinoDialogActions extends RenderBox
   Color get dialogPressedColor => _pressedButtonBackgroundPaint.color;
   final Paint _pressedButtonBackgroundPaint;
   set dialogPressedColor(Color value) {
-    if (value == _pressedButtonBackgroundPaint.color)
+    if (value == _pressedButtonBackgroundPaint.color) {
       return;
+    }
 
     _pressedButtonBackgroundPaint.color = value;
     markNeedsPaint();
@@ -1935,8 +1939,9 @@ class _RenderCupertinoDialogActions extends RenderBox
   Color get dividerColor => _dividerPaint.color;
   final Paint _dividerPaint;
   set dividerColor(Color value) {
-    if (value == _dividerPaint.color)
+    if (value == _dividerPaint.color) {
       return;
+    }
 
     _dividerPaint.color = value;
     markNeedsPaint();
@@ -1945,8 +1950,9 @@ class _RenderCupertinoDialogActions extends RenderBox
   bool get isActionSheet => _isActionSheet;
   bool _isActionSheet;
   set isActionSheet(bool value) {
-    if (value == _isActionSheet)
+    if (value == _isActionSheet) {
       return;
+    }
 
     _isActionSheet = value;
     markNeedsPaint();
@@ -1981,9 +1987,10 @@ class _RenderCupertinoDialogActions extends RenderBox
 
   @override
   void setupParentData(RenderBox child) {
-    if (child.parentData is! _ActionButtonParentData)
+    if (child.parentData is! _ActionButtonParentData) {
       child.parentData = _ActionButtonParentData();
     }
+  }
 
   @override
   double computeMinIntrinsicWidth(double height) {
@@ -2000,10 +2007,12 @@ class _RenderCupertinoDialogActions extends RenderBox
     if (childCount == 0) {
       return 0.0;
     } else if (isActionSheet) {
-      if (childCount == 1)
+      if (childCount == 1) {
         return firstChild!.computeMaxIntrinsicHeight(width) + dividerThickness;
-      if (hasCancelButton && childCount < 4)
+      }
+      if (hasCancelButton && childCount < 4) {
         return _computeMinIntrinsicHeightWithCancel(width);
+      }
       return _computeMinIntrinsicHeightStacked(width);
     } else if (childCount == 1) {
       // If only 1 button, display the button across the entire dialog.
@@ -2070,8 +2079,9 @@ class _RenderCupertinoDialogActions extends RenderBox
       // No buttons. Zero height.
       return 0.0;
     } else if (isActionSheet) {
-      if (childCount == 1)
+      if (childCount == 1) {
         return firstChild!.computeMaxIntrinsicHeight(width) + dividerThickness;
+      }
       return _computeMaxIntrinsicHeightStacked(width);
     } else if (childCount == 1) {
       // One button. Our max intrinsic height is equal to the button's.

packages/flutter/lib/src/cupertino/interface_level.dart

@@ -66,8 +66,9 @@ class CupertinoUserInterfaceLevel extends InheritedWidget {
   static CupertinoUserInterfaceLevelData of(BuildContext context) {
     assert(context != null);
     final CupertinoUserInterfaceLevel? query = context.dependOnInheritedWidgetOfExactType<CupertinoUserInterfaceLevel>();
-    if (query != null)
+    if (query != null) {
       return query._data;
+    }
     throw FlutterError(
       'CupertinoUserInterfaceLevel.of() called with a context that does not contain a CupertinoUserInterfaceLevel.\n'
       'No CupertinoUserInterfaceLevel ancestor could be found starting from the context that was passed '
@@ -95,8 +96,9 @@ class CupertinoUserInterfaceLevel extends InheritedWidget {
   static CupertinoUserInterfaceLevelData? maybeOf(BuildContext context) {
     assert(context != null);
     final CupertinoUserInterfaceLevel? query = context.dependOnInheritedWidgetOfExactType<CupertinoUserInterfaceLevel>();
-    if (query != null)
+    if (query != null) {
       return query._data;
+    }
     return null;
   }
 

packages/flutter/lib/src/cupertino/localizations.dart

@@ -351,8 +351,9 @@ class DefaultCupertinoLocalizations implements CupertinoLocalizations {
 
   @override
   String datePickerMinuteSemanticsLabel(int minute) {
-    if (minute == 1)
+    if (minute == 1) {
       return '1 minute';
+    }
     return '$minute minutes';
   }
 

packages/flutter/lib/src/cupertino/nav_bar.dart

@@ -160,8 +160,9 @@ Widget _wrapWithBackground({
     child: result,
   );
 
-  if (backgroundColor.alpha == 0xFF)
+  if (backgroundColor.alpha == 0xFF) {
     return childWithBackground;
+  }
 
   return ClipRect(
     child: BackdropFilter(

packages/flutter/lib/src/cupertino/picker.dart

@@ -439,12 +439,14 @@ class _RenderCupertinoPickerSemantics extends RenderProxyBox {
 
   // This method exists to allow controller to be non-null. It is only called with a null oldValue from constructor.
   void _updateController(FixedExtentScrollController? oldValue, FixedExtentScrollController value) {
-    if (value == oldValue)
+    if (value == oldValue) {
       return;
-    if (oldValue != null)
+    }
+    if (oldValue != null) {
       oldValue.removeListener(_handleScrollUpdate);
-    else
+    } else {
       _currentIndex = value.initialItem;
+    }
     value.addListener(_handleScrollUpdate);
     _controller = value;
   }
@@ -452,8 +454,9 @@ class _RenderCupertinoPickerSemantics extends RenderProxyBox {
   TextDirection get textDirection => _textDirection;
   TextDirection _textDirection;
   set textDirection(TextDirection value) {
-    if (textDirection == value)
+    if (textDirection == value) {
       return;
+    }
     _textDirection = value;
     markNeedsSemanticsUpdate();
   }
@@ -469,8 +472,9 @@ class _RenderCupertinoPickerSemantics extends RenderProxyBox {
   }
 
   void _handleScrollUpdate() {
-    if (controller.selectedItem == _currentIndex)
+    if (controller.selectedItem == _currentIndex) {
       return;
+    }
     _currentIndex = controller.selectedItem;
     markNeedsSemanticsUpdate();
   }
@@ -483,8 +487,9 @@ class _RenderCupertinoPickerSemantics extends RenderProxyBox {
 
   @override
   void assembleSemanticsNode(SemanticsNode node, SemanticsConfiguration config, Iterable<SemanticsNode> children) {
-    if (children.isEmpty)
+    if (children.isEmpty) {
       return super.assembleSemanticsNode(node, config, children);
+    }
     final SemanticsNode scrollable = children.first;
     final Map<int, SemanticsNode> indexedChildren = <int, SemanticsNode>{};
     scrollable.visitChildren((SemanticsNode child) {

packages/flutter/lib/src/cupertino/refresh.dart

@@ -76,8 +76,9 @@ class _RenderCupertinoSliverRefresh extends RenderSliver
   set refreshIndicatorLayoutExtent(double value) {
     assert(value != null);
     assert(value >= 0.0);
-    if (value == _refreshIndicatorExtent)
+    if (value == _refreshIndicatorExtent) {
       return;
+    }
     _refreshIndicatorExtent = value;
     markNeedsLayout();
   }
@@ -89,8 +90,9 @@ class _RenderCupertinoSliverRefresh extends RenderSliver
   bool _hasLayoutExtent;
   set hasLayoutExtent(bool value) {
     assert(value != null);
-    if (value == _hasLayoutExtent)
+    if (value == _hasLayoutExtent) {
       return;
+    }
     _hasLayoutExtent = value;
     markNeedsLayout();
   }

packages/flutter/lib/src/cupertino/route.dart

@@ -186,30 +186,37 @@ mixin CupertinoRouteTransitionMixin<T> on PageRoute<T> {
   static bool _isPopGestureEnabled<T>(PageRoute<T> route) {
     // If there's nothing to go back to, then obviously we don't support
     // the back gesture.
-    if (route.isFirst)
+    if (route.isFirst) {
       return false;
+    }
     // If the route wouldn't actually pop if we popped it, then the gesture
     // would be really confusing (or would skip internal routes), so disallow it.
-    if (route.willHandlePopInternally)
+    if (route.willHandlePopInternally) {
       return false;
+    }
     // If attempts to dismiss this route might be vetoed such as in a page
     // with forms, then do not allow the user to dismiss the route with a swipe.
-    if (route.hasScopedWillPopCallback)
+    if (route.hasScopedWillPopCallback) {
       return false;
+    }
     // Fullscreen dialogs aren't dismissible by back swipe.
-    if (route.fullscreenDialog)
+    if (route.fullscreenDialog) {
       return false;
+    }
     // If we're in an animation already, we cannot be manually swiped.
-    if (route.animation!.status != AnimationStatus.completed)
+    if (route.animation!.status != AnimationStatus.completed) {
       return false;
+    }
     // If we're being popped into, we also cannot be swiped until the pop above
     // it completes. This translates to our secondary animation being
     // dismissed.
-    if (route.secondaryAnimation!.status != AnimationStatus.dismissed)
+    if (route.secondaryAnimation!.status != AnimationStatus.dismissed) {
       return false;
+    }
     // If we're in a gesture already, we cannot start another.
-    if (isPopGestureInProgress(route))
+    if (isPopGestureInProgress(route)) {
       return false;
+    }
 
     // Looks like a back gesture would be welcome!
     return true;
@@ -657,9 +664,10 @@ class _CupertinoBackGestureDetectorState<T> extends State<_CupertinoBackGestureD
   }
 
   void _handlePointerDown(PointerDownEvent event) {
-    if (widget.enabledCallback())
+    if (widget.enabledCallback()) {
       _recognizer.addPointer(event);
     }
+  }
 
   double _convertToLogical(double value) {
     switch (Directionality.of(context)) {
@@ -746,10 +754,11 @@ class _CupertinoBackGestureController<T> {
     // If the user releases the page before mid screen with sufficient velocity,
     // or after mid screen, we should animate the page out. Otherwise, the page
     // should be animated back in.
-    if (velocity.abs() >= _kMinFlingVelocity)
+    if (velocity.abs() >= _kMinFlingVelocity) {
       animateForward = velocity <= 0;
-    else
+    } else {
       animateForward = controller.value > 0.5;
+    }
 
     if (animateForward) {
       // The closer the panel is to dismissing, the shorter the animation is.
@@ -840,12 +849,15 @@ class _CupertinoEdgeShadowDecoration extends Decoration {
     double t,
   ) {
     assert(t != null);
-    if (a == null && b == null)
+    if (a == null && b == null) {
       return null;
-    if (a == null)
+    }
+    if (a == null) {
       return b!._colors == null ? b : _CupertinoEdgeShadowDecoration._(b._colors!.map<Color>((Color color) => Color.lerp(null, color, t)!).toList());
-    if (b == null)
+    }
+    if (b == null) {
       return a._colors == null ? a : _CupertinoEdgeShadowDecoration._(a._colors!.map<Color>((Color color) => Color.lerp(null, color, 1.0 - t)!).toList());
+    }
     assert(b._colors != null || a._colors != null);
     // If it ever becomes necessary, we could allow decorations with different
     // length' here, similarly to how it is handled in [LinearGradient.lerp].
@@ -860,15 +872,17 @@ class _CupertinoEdgeShadowDecoration extends Decoration {
 
   @override
   _CupertinoEdgeShadowDecoration lerpFrom(Decoration? a, double t) {
-    if (a is _CupertinoEdgeShadowDecoration)
+    if (a is _CupertinoEdgeShadowDecoration) {
       return _CupertinoEdgeShadowDecoration.lerp(a, this, t)!;
+    }
     return _CupertinoEdgeShadowDecoration.lerp(null, this, t)!;
   }
 
   @override
   _CupertinoEdgeShadowDecoration lerpTo(Decoration? b, double t) {
-    if (b is _CupertinoEdgeShadowDecoration)
+    if (b is _CupertinoEdgeShadowDecoration) {
       return _CupertinoEdgeShadowDecoration.lerp(this, b, t)!;
+    }
     return _CupertinoEdgeShadowDecoration.lerp(this, null, t)!;
   }
 
@@ -879,8 +893,9 @@ class _CupertinoEdgeShadowDecoration extends Decoration {
 
   @override
   bool operator ==(Object other) {
-    if (other.runtimeType != runtimeType)
+    if (other.runtimeType != runtimeType) {
       return false;
+    }
     return other is _CupertinoEdgeShadowDecoration
         && other._colors == _colors;
   }

packages/flutter/lib/src/cupertino/search_field.dart

@@ -331,9 +331,10 @@ class _CupertinoSearchTextFieldState extends State<CupertinoSearchTextField>
   void _defaultOnSuffixTap() {
     final bool textChanged = _effectiveController.text.isNotEmpty;
     _effectiveController.clear();
-    if (widget.onChanged != null && textChanged)
+    if (widget.onChanged != null && textChanged) {
       widget.onChanged!(_effectiveController.text);
     }
+  }
 
   @override
   Widget build(BuildContext context) {

packages/flutter/lib/src/cupertino/segmented_control.dart

@@ -303,8 +303,9 @@ class _SegmentedControlState<T extends Object> extends State<CupertinoSegmentedC
   }
 
   void _onTap(T currentKey) {
-    if (currentKey != _pressedKey)
+    if (currentKey != _pressedKey) {
       return;
+    }
     if (currentKey != widget.groupValue) {
       widget.onValueChanged(currentKey);
     }
@@ -312,20 +313,25 @@ class _SegmentedControlState<T extends Object> extends State<CupertinoSegmentedC
   }
 
   Color? getTextColor(int index, T currentKey) {
-    if (_selectionControllers[index].isAnimating)
+    if (_selectionControllers[index].isAnimating) {
       return _textColorTween.evaluate(_selectionControllers[index]);
-    if (widget.groupValue == currentKey)
+    }
+    if (widget.groupValue == currentKey) {
       return _unselectedColor;
+    }
     return _selectedColor;
   }
 
   Color? getBackgroundColor(int index, T currentKey) {
-    if (_selectionControllers[index].isAnimating)
+    if (_selectionControllers[index].isAnimating) {
       return _childTweens[index].evaluate(_selectionControllers[index]);
-    if (widget.groupValue == currentKey)
+    }
+    if (widget.groupValue == currentKey) {
       return _selectedColor;
-    if (_pressedKey == currentKey)
+    }
+    if (_pressedKey == currentKey) {
       return _pressedColor;
+    }
     return _unselectedColor;
   }
 

packages/flutter/lib/src/cupertino/slider.dart

@@ -359,21 +359,24 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   double _value;
   set value(double newValue) {
     assert(newValue != null && newValue >= 0.0 && newValue <= 1.0);
-    if (newValue == _value)
+    if (newValue == _value) {
       return;
+    }
     _value = newValue;
-    if (divisions != null)
+    if (divisions != null) {
       _position.animateTo(newValue, curve: Curves.fastOutSlowIn);
-    else
+    } else {
       _position.value = newValue;
+    }
     markNeedsSemanticsUpdate();
   }
 
   int? get divisions => _divisions;
   int? _divisions;
   set divisions(int? value) {
-    if (value == _divisions)
+    if (value == _divisions) {
       return;
+    }
     _divisions = value;
     markNeedsPaint();
   }
@@ -381,8 +384,9 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   Color get activeColor => _activeColor;
   Color _activeColor;
   set activeColor(Color value) {
-    if (value == _activeColor)
+    if (value == _activeColor) {
       return;
+    }
     _activeColor = value;
     markNeedsPaint();
   }
@@ -390,8 +394,9 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   Color get thumbColor => _thumbColor;
   Color _thumbColor;
   set thumbColor(Color value) {
-    if (value == _thumbColor)
+    if (value == _thumbColor) {
       return;
+    }
     _thumbColor = value;
     markNeedsPaint();
   }
@@ -399,8 +404,9 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   Color get trackColor => _trackColor;
   Color _trackColor;
   set trackColor(Color value) {
-    if (value == _trackColor)
+    if (value == _trackColor) {
       return;
+    }
     _trackColor = value;
     markNeedsPaint();
   }
@@ -408,13 +414,15 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   ValueChanged<double>? get onChanged => _onChanged;
   ValueChanged<double>? _onChanged;
   set onChanged(ValueChanged<double>? value) {
-    if (value == _onChanged)
+    if (value == _onChanged) {
       return;
+    }
     final bool wasInteractive = isInteractive;
     _onChanged = value;
-    if (wasInteractive != isInteractive)
+    if (wasInteractive != isInteractive) {
       markNeedsSemanticsUpdate();
     }
+  }
 
   ValueChanged<double>? onChangeStart;
   ValueChanged<double>? onChangeEnd;
@@ -423,8 +431,9 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   TextDirection _textDirection;
   set textDirection(TextDirection value) {
     assert(value != null);
-    if (_textDirection == value)
+    if (_textDirection == value) {
       return;
+    }
     _textDirection = value;
     markNeedsPaint();
   }
@@ -436,8 +445,9 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
 
   double get _discretizedCurrentDragValue {
     double dragValue = clampDouble(_currentDragValue, 0.0, 1.0);
-    if (divisions != null)
+    if (divisions != null) {
       dragValue = (dragValue * divisions!).round() / divisions!;
+    }
     return dragValue;
   }
 
@@ -499,9 +509,10 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   @override
   void handleEvent(PointerEvent event, BoxHitTestEntry entry) {
     assert(debugHandleEvent(event, entry));
-    if (event is PointerDownEvent && isInteractive)
+    if (event is PointerDownEvent && isInteractive) {
       _drag.addPointer(event);
     }
+  }
 
   @override
   void paint(PaintingContext context, Offset offset) {
@@ -563,12 +574,14 @@ class _RenderCupertinoSlider extends RenderConstrainedBox {
   double get _semanticActionUnit => divisions != null ? 1.0 / divisions! : _kAdjustmentUnit;
 
   void _increaseAction() {
-    if (isInteractive)
+    if (isInteractive) {
       onChanged!(clampDouble(value + _semanticActionUnit, 0.0, 1.0));
     }
+  }
 
   void _decreaseAction() {
-    if (isInteractive)
+    if (isInteractive) {
       onChanged!(clampDouble(value - _semanticActionUnit, 0.0, 1.0));
     }
+  }
 }

packages/flutter/lib/src/cupertino/sliding_segmented_control.dart

@@ -534,8 +534,9 @@ class _SegmentedControlState<T> extends State<CupertinoSlidingSegmentedControl<T
   }
 
   void onHighlightChangedByGesture(T newValue) {
-    if (highlighted == newValue)
+    if (highlighted == newValue) {
       return;
+    }
     setState(() { highlighted = newValue; });
     // Additionally, start the thumb animation if the highlighted segment
     // changes. If the thumbController is already running, the render object's
@@ -548,14 +549,16 @@ class _SegmentedControlState<T> extends State<CupertinoSlidingSegmentedControl<T
   }
 
   void onPressedChangedByGesture(T? newValue) {
-    if (pressed != newValue)
+    if (pressed != newValue) {
       setState(() { pressed = newValue; });
     }
+  }
 
   void onTapUp(TapUpDetails details) {
     // No gesture should interfere with an ongoing thumb drag.
-    if (isThumbDragging)
+    if (isThumbDragging) {
       return;
+    }
     final T segment = segmentForXPosition(details.localPosition.dx);
     onPressedChangedByGesture(null);
     if (segment != widget.groupValue) {
@@ -818,9 +821,10 @@ class _RenderSegmentedControl<T> extends RenderBox
     }
 
     _thumbScale = value;
-    if (state.highlighted != null)
+    if (state.highlighted != null) {
       markNeedsPaint();
     }
+  }
 
   int? get highlightedIndex => _highlightedIndex;
   int? _highlightedIndex;
@@ -995,8 +999,9 @@ class _RenderSegmentedControl<T> extends RenderBox
   Rect? moveThumbRectInBound(Rect? thumbRect, List<RenderBox> children) {
     assert(hasSize);
     assert(children.length >= 2);
-    if (thumbRect == null)
+    if (thumbRect == null) {
       return null;
+    }
 
     final Offset firstChildOffset = (children.first.parentData! as _SegmentedControlContainerBoxParentData).offset;
     final double leftMost = firstChildOffset.dx;

packages/flutter/lib/src/cupertino/switch.dart

@@ -206,9 +206,10 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
     super.didUpdateWidget(oldWidget);
     _drag.dragStartBehavior = widget.dragStartBehavior;
 
-    if (needsPositionAnimation || oldWidget.value != widget.value)
+    if (needsPositionAnimation || oldWidget.value != widget.value) {
       _resumePositionAnimation(isLinear: needsPositionAnimation);
     }
+  }
 
   // `isLinear` must be true if the position animation is trying to move the
   // thumb to the closest end after the most recent drag animation, so the curve
@@ -221,15 +222,17 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
     position
       ..curve = isLinear ? Curves.linear : Curves.ease
       ..reverseCurve = isLinear ? Curves.linear : Curves.ease.flipped;
-    if (widget.value)
+    if (widget.value) {
       _positionController.forward();
-    else
+    } else {
       _positionController.reverse();
     }
+  }
 
   void _handleTapDown(TapDownDetails details) {
-    if (isInteractive)
+    if (isInteractive) {
       needsPositionAnimation = false;
+    }
       _reactionController.forward();
   }
 
@@ -248,9 +251,10 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
   }
 
   void _handleTapCancel() {
-    if (isInteractive)
+    if (isInteractive) {
       _reactionController.reverse();
     }
+  }
 
   void _handleDragStart(DragStartDetails details) {
     if (isInteractive) {
@@ -281,8 +285,9 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
     // Deferring the animation to the next build phase.
     setState(() { needsPositionAnimation = true; });
     // Call onChanged when the user's intent to change value is clear.
-    if (position.value >= 0.5 != widget.value)
+    if (position.value >= 0.5 != widget.value) {
       widget.onChanged!(!widget.value);
+    }
     _reactionController.reverse();
   }
 
@@ -302,8 +307,9 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
 
   @override
   Widget build(BuildContext context) {
-    if (needsPositionAnimation)
+    if (needsPositionAnimation) {
       _resumePositionAnimation();
+    }
     return MouseRegion(
       cursor: isInteractive && kIsWeb ? SystemMouseCursors.click : MouseCursor.defer,
       child: Opacity(
@@ -423,8 +429,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   bool _value;
   set value(bool value) {
     assert(value != null);
-    if (value == _value)
+    if (value == _value) {
       return;
+    }
     _value = value;
     markNeedsSemanticsUpdate();
   }
@@ -433,8 +440,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   Color _activeColor;
   set activeColor(Color value) {
     assert(value != null);
-    if (value == _activeColor)
+    if (value == _activeColor) {
       return;
+    }
     _activeColor = value;
     markNeedsPaint();
   }
@@ -443,8 +451,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   Color _trackColor;
   set trackColor(Color value) {
     assert(value != null);
-    if (value == _trackColor)
+    if (value == _trackColor) {
       return;
+    }
     _trackColor = value;
     markNeedsPaint();
   }
@@ -453,8 +462,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   CupertinoThumbPainter _thumbPainter;
   set thumbColor(Color value) {
     assert(value != null);
-    if (value == thumbColor)
+    if (value == thumbColor) {
       return;
+    }
     _thumbPainter = CupertinoThumbPainter.switchThumb(color: value);
     markNeedsPaint();
   }
@@ -462,8 +472,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   ValueChanged<bool>? get onChanged => _onChanged;
   ValueChanged<bool>? _onChanged;
   set onChanged(ValueChanged<bool>? value) {
-    if (value == _onChanged)
+    if (value == _onChanged) {
       return;
+    }
     final bool wasInteractive = isInteractive;
     _onChanged = value;
     if (wasInteractive != isInteractive) {
@@ -476,8 +487,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   TextDirection _textDirection;
   set textDirection(TextDirection value) {
     assert(value != null);
-    if (_textDirection == value)
+    if (_textDirection == value) {
       return;
+    }
     _textDirection = value;
     markNeedsPaint();
   }
@@ -500,8 +512,9 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
   void describeSemanticsConfiguration(SemanticsConfiguration config) {
     super.describeSemanticsConfiguration(config);
 
-    if (isInteractive)
+    if (isInteractive) {
       config.onTap = _state._handleTap;
+    }
 
     config.isEnabled = isInteractive;
     config.isToggled = _value;

packages/flutter/lib/src/cupertino/tab_view.dart

@@ -190,8 +190,9 @@ class _CupertinoTabViewState extends State<CupertinoTabView> {
         settings: settings,
       );
     }
-    if (widget.onGenerateRoute != null)
+    if (widget.onGenerateRoute != null) {
       return widget.onGenerateRoute!(settings);
+    }
     return null;
   }
 

packages/flutter/lib/src/cupertino/text_field.dart

@@ -930,21 +930,26 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with Restoratio
   bool _shouldShowSelectionHandles(SelectionChangedCause? cause) {
     // When the text field is activated by something that doesn't trigger the
     // selection overlay, we shouldn't show the handles either.
-    if (!_selectionGestureDetectorBuilder.shouldShowSelectionToolbar)
+    if (!_selectionGestureDetectorBuilder.shouldShowSelectionToolbar) {
       return false;
+    }
 
     // On iOS, we don't show handles when the selection is collapsed.
-    if (_effectiveController.selection.isCollapsed)
+    if (_effectiveController.selection.isCollapsed) {
       return false;
+    }
 
-    if (cause == SelectionChangedCause.keyboard)
+    if (cause == SelectionChangedCause.keyboard) {
       return false;
+    }
 
-    if (cause == SelectionChangedCause.scribble)
+    if (cause == SelectionChangedCause.scribble) {
       return true;
+    }
 
-    if (_effectiveController.text.isNotEmpty)
+    if (_effectiveController.text.isNotEmpty) {
       return true;
+    }
 
     return false;
   }
@@ -1088,8 +1093,9 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with Restoratio
                 // Also call onChanged when the clear button is tapped.
                 final bool textChanged = _effectiveController.text.isNotEmpty;
                 _effectiveController.clear();
-                if (widget.onChanged != null && textChanged)
+                if (widget.onChanged != null && textChanged) {
                   widget.onChanged!(_effectiveController.text);
+                }
               } : null,
               child: Padding(
                 padding: const EdgeInsets.symmetric(horizontal: 6.0),

packages/flutter/lib/src/cupertino/text_selection_toolbar.dart

@@ -580,10 +580,11 @@ class _CupertinoTextSelectionToolbarItemsElement extends RenderObjectElement {
   void visitChildren(ElementVisitor visitor) {
     slotToChild.values.forEach(visitor);
     for (final Element child in _children) {
-      if (!_forgottenChildren.contains(child))
+      if (!_forgottenChildren.contains(child)) {
         visitor(child);
       }
     }
+  }
 
   @override
   void forgetChild(Element child) {

packages/flutter/lib/src/cupertino/thumb_painter.dart

@@ -79,8 +79,9 @@ class CupertinoThumbPainter {
       Radius.circular(rect.shortestSide / 2.0),
     );
 
-    for (final BoxShadow shadow in shadows)
+    for (final BoxShadow shadow in shadows) {
       canvas.drawRRect(rrect.shift(shadow.offset), shadow.toPaint());
+    }
 
     canvas.drawRRect(
       rrect.inflate(0.5),

packages/flutter/test/cupertino/nav_bar_transition_test.dart

@@ -1016,8 +1016,9 @@ void main() {
       await tester.pump(const Duration(milliseconds: 1));
       expect(flying(tester, find.text('Page 2')), findsOneWidget);
       final Size size = tester.getSize(flying(tester, find.text('Page 2')));
-      if (previousSize != null)
+      if (previousSize != null) {
         expect(size, previousSize);
+      }
       previousSize = size;
     }
   });

packages/flutter/test/cupertino/route_test.dart

@@ -981,20 +981,24 @@ void main() {
     testWidgets('when route is not fullscreenDialog, it has a _CupertinoEdgeShadowDecoration', (WidgetTester tester) async {
       PaintPattern paintsShadowRect({required double dx, required Color color}) {
         return paints..everything((Symbol methodName, List<dynamic> arguments) {
-          if (methodName != #drawRect)
+          if (methodName != #drawRect) {
             return true;
+          }
           final Rect rect = arguments[0] as Rect;
           final Color paintColor = (arguments[1] as Paint).color;
-          if (rect.top != 0 || rect.width != 1.0 || rect.height != 600)
           // _CupertinoEdgeShadowDecoration draws the shadows with a series of
           // differently colored 1px-wide rects. Skip rects that aren't being
           // drawn by the _CupertinoEdgeShadowDecoration.
+          if (rect.top != 0 || rect.width != 1.0 || rect.height != 600) {
             return true;
-          if ((rect.left - dx).abs() >= 1)
+          }
           // Skip calls for rects until the one with the given position offset
+          if ((rect.left - dx).abs() >= 1) {
             return true;
-          if (paintColor.value == color.value)
+          }
+          if (paintColor.value == color.value) {
             return true;
+          }
           throw '''
   For a rect with an expected left-side position: $dx (drawn at ${rect.left}):
               Expected a rect with color: $color,
@@ -1067,14 +1071,16 @@ void main() {
     testWidgets('when route is fullscreenDialog, it has no visible _CupertinoEdgeShadowDecoration', (WidgetTester tester) async {
       PaintPattern paintsNoShadows() {
         return paints..everything((Symbol methodName, List<dynamic> arguments) {
-          if (methodName != #drawRect)
+          if (methodName != #drawRect) {
             return true;
+          }
           final Rect rect = arguments[0] as Rect;
           // _CupertinoEdgeShadowDecoration draws the shadows with a series of
           // differently colored 1px rects. Skip all rects not drawn by a
           // _CupertinoEdgeShadowDecoration.
-          if (rect.width != 1.0)
+          if (rect.width != 1.0) {
             return true;
+          }
           throw '''
     Expected: no rects with a width of 1px.
           Found: $rect.

packages/flutter/test/cupertino/sliding_segmented_control_test.dart

@@ -25,8 +25,9 @@ Rect currentUnscaledThumbRect(WidgetTester tester, { bool useGlobalCoordinate =
   // Using dynamic to access private class in test.
   // ignore: avoid_dynamic_calls
   final Rect local = renderSegmentedControl.currentThumbRect as Rect;
-  if (!useGlobalCoordinate)
+  if (!useGlobalCoordinate) {
     return local;
+  }
 
   final RenderBox segmentedControl = renderSegmentedControl as RenderBox;
   return local.shift(segmentedControl.localToGlobal(Offset.zero));