flutter/lib/src/: refactoring if-chains into switch expressions (fl…

…utter#146293) Based on issue flutter#144903, this pull request aims to bring the codebase more in line with the [Flutter repo style guide](https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#avoid-using-if-chains-or--or--with-enum-values): > ### Avoid using `if` chains or `?:` or `==` with enum values
ricardoamador · Apr 23, 2024 · a83e111 · a83e111
1 parent a91c62d
commit a83e111
Show file tree

Hide file tree

Showing 19 changed files with 111 additions and 203 deletions.
diff --git a/packages/flutter/lib/src/cupertino/dialog.dart b/packages/flutter/lib/src/cupertino/dialog.dart
@@ -639,14 +639,10 @@ class _CupertinoActionSheetState extends State<CupertinoActionSheet> {
       ),
       if (widget.cancelButton != null) _buildCancelButton(),
     ];
-
-    final Orientation orientation = MediaQuery.orientationOf(context);
-    final double actionSheetWidth;
-    if (orientation == Orientation.portrait) {
-      actionSheetWidth = MediaQuery.sizeOf(context).width - (_kActionSheetEdgeHorizontalPadding * 2);
-    } else {
-      actionSheetWidth = MediaQuery.sizeOf(context).height - (_kActionSheetEdgeHorizontalPadding * 2);
-    }
+    final double actionSheetWidth = switch (MediaQuery.orientationOf(context)) {
+      Orientation.portrait  => MediaQuery.sizeOf(context).width,
+      Orientation.landscape => MediaQuery.sizeOf(context).height,
+    };
 
     return SafeArea(
       child: ScrollConfiguration(
@@ -660,7 +656,7 @@ class _CupertinoActionSheetState extends State<CupertinoActionSheet> {
           child: CupertinoUserInterfaceLevel(
             data: CupertinoUserInterfaceLevelData.elevated,
             child: Container(
-              width: actionSheetWidth,
+              width: actionSheetWidth - _kActionSheetEdgeHorizontalPadding * 2,
               margin: const EdgeInsets.symmetric(
                 horizontal: _kActionSheetEdgeHorizontalPadding,
                 vertical: _kActionSheetEdgeVerticalPadding,

diff --git a/packages/flutter/lib/src/foundation/diagnostics.dart b/packages/flutter/lib/src/foundation/diagnostics.dart
@@ -2113,16 +2113,11 @@ class FlagProperty extends DiagnosticsProperty<bool> {
 
   @override
   String valueToString({ TextTreeConfiguration? parentConfiguration }) {
-    if (value ?? false) {
-      if (ifTrue != null) {
-        return ifTrue!;
-      }
-    } else if (value == false) {
-      if (ifFalse != null) {
-        return ifFalse!;
-      }
-    }
-    return super.valueToString(parentConfiguration: parentConfiguration);
+    return switch (value) {
+      true when ifTrue != null => ifTrue!,
+      false when ifFalse != null => ifFalse!,
+      _ => super.valueToString(parentConfiguration: parentConfiguration),
+    };
   }
 
   @override
@@ -2139,17 +2134,11 @@ class FlagProperty extends DiagnosticsProperty<bool> {
 
   @override
   DiagnosticLevel get level {
-    if (value ?? false) {
-      if (ifTrue == null) {
-        return DiagnosticLevel.hidden;
-      }
-    }
-    if (value == false) {
-      if (ifFalse == null) {
-        return DiagnosticLevel.hidden;
-      }
-    }
-    return super.level;
+    return switch (value) {
+      true  when ifTrue == null => DiagnosticLevel.hidden,
+      false when ifFalse == null => DiagnosticLevel.hidden,
+      _ => super.level,
+    };
   }
 }
 

diff --git a/packages/flutter/lib/src/material/calendar_date_picker.dart b/packages/flutter/lib/src/material/calendar_date_picker.dart
@@ -211,18 +211,12 @@ class _CalendarDatePickerState extends State<CalendarDatePicker> {
     _vibrate();
     setState(() {
       _mode = mode;
-      if (_selectedDate != null) {
-        if (_mode == DatePickerMode.day) {
-          SemanticsService.announce(
-            _localizations.formatMonthYear(_selectedDate!),
-            _textDirection,
-          );
-        } else {
-          SemanticsService.announce(
-            _localizations.formatYear(_selectedDate!),
-            _textDirection,
-          );
-        }
+      if (_selectedDate case final DateTime selected) {
+        final String message = switch (mode) {
+          DatePickerMode.day  => _localizations.formatMonthYear(selected),
+          DatePickerMode.year => _localizations.formatYear(selected),
+        };
+        SemanticsService.announce(message, _textDirection);
       }
     });
   }

diff --git a/packages/flutter/lib/src/material/input_decorator.dart b/packages/flutter/lib/src/material/input_decorator.dart
@@ -562,13 +562,11 @@ class FloatingLabelAlignment {
   }
 
   static String _stringify(double x) {
-    if (x == -1.0) {
-      return 'FloatingLabelAlignment.start';
-    }
-    if (x == 0.0) {
-      return 'FloatingLabelAlignment.center';
-    }
-    return 'FloatingLabelAlignment(x: ${x.toStringAsFixed(1)})';
+    return switch (x) {
+     -1.0 => 'FloatingLabelAlignment.start',
+      0.0 => 'FloatingLabelAlignment.center',
+      _ => 'FloatingLabelAlignment(x: ${x.toStringAsFixed(1)})',
+    };
   }
 
   @override

diff --git a/packages/flutter/lib/src/material/mergeable_material.dart b/packages/flutter/lib/src/material/mergeable_material.dart
@@ -579,12 +579,10 @@ class _MergeableMaterialState extends State<MergeableMaterial> with TickerProvid
         );
         slices = <Widget>[];
 
-        widgets.add(
-          SizedBox(
-            width: widget.mainAxis == Axis.horizontal ? _getGapSize(i) : null,
-            height: widget.mainAxis == Axis.vertical ? _getGapSize(i) : null,
-          ),
-        );
+        widgets.add(switch (widget.mainAxis) {
+          Axis.horizontal => SizedBox(width: _getGapSize(i)),
+          Axis.vertical   => SizedBox(height: _getGapSize(i)),
+        });
       } else {
         final MaterialSlice slice = _children[i] as MaterialSlice;
         Widget child = slice.child;

diff --git a/packages/flutter/lib/src/material/range_slider.dart b/packages/flutter/lib/src/material/range_slider.dart
@@ -1230,11 +1230,10 @@ class _RenderRangeSlider extends RenderBox with RelayoutWhenSystemFontsChangeMix
       // a tap, it consists of a call to onChangeStart with the previous value and
       // a call to onChangeEnd with the new value.
       final RangeValues currentValues = _discretizeRangeValues(values);
-      if (_lastThumbSelection == Thumb.start) {
-        _newValues = RangeValues(tapValue, currentValues.end);
-      } else if (_lastThumbSelection == Thumb.end) {
-        _newValues = RangeValues(currentValues.start, tapValue);
-      }
+      _newValues = switch (_lastThumbSelection!) {
+        Thumb.start => RangeValues(tapValue, currentValues.end),
+        Thumb.end   => RangeValues(currentValues.start, tapValue),
+      };
       _updateLabelPainter(_lastThumbSelection!);
 
       onChangeStart?.call(currentValues);
@@ -1286,11 +1285,10 @@ class _RenderRangeSlider extends RenderBox with RelayoutWhenSystemFontsChangeMix
       }
       final double currentDragValue = _discretize(dragValue);
 
-      if (_lastThumbSelection == Thumb.start) {
-        _newValues = RangeValues(math.min(currentDragValue, currentValues.end - _minThumbSeparationValue), currentValues.end);
-      } else if (_lastThumbSelection == Thumb.end) {
-        _newValues = RangeValues(currentValues.start, math.max(currentDragValue, currentValues.start + _minThumbSeparationValue));
-      }
+      _newValues = switch (_lastThumbSelection!) {
+        Thumb.start => RangeValues(math.min(currentDragValue, currentValues.end - _minThumbSeparationValue), currentValues.end),
+        Thumb.end   => RangeValues(currentValues.start, math.max(currentDragValue, currentValues.start + _minThumbSeparationValue)),
+      };
       onChanged!(_newValues);
     }
   }

diff --git a/packages/flutter/lib/src/material/selectable_text.dart b/packages/flutter/lib/src/material/selectable_text.dart
@@ -117,12 +117,10 @@ class _SelectableTextSelectionGestureDetectorBuilder extends TextSelectionGestur
     final Offset editableOffset = renderEditable.maxLines == 1
         ? Offset(renderEditable.offset.pixels - _dragStartViewportOffset, 0.0)
         : Offset(0.0, renderEditable.offset.pixels - _dragStartViewportOffset);
-    final double effectiveScrollPosition = _scrollPosition - _dragStartScrollOffset;
-    final bool scrollingOnVerticalAxis = _scrollDirection == AxisDirection.up || _scrollDirection == AxisDirection.down;
-    final Offset scrollableOffset = Offset(
-      !scrollingOnVerticalAxis ? effectiveScrollPosition : 0.0,
-      scrollingOnVerticalAxis ? effectiveScrollPosition : 0.0,
-    );
+    final Offset scrollableOffset = switch (axisDirectionToAxis(_scrollDirection ?? AxisDirection.left)) {
+      Axis.horizontal => Offset(_scrollPosition - _dragStartScrollOffset, 0),
+      Axis.vertical   => Offset(0, _scrollPosition - _dragStartScrollOffset),
+    };
     renderEditable.selectWordsInRange(
       from: details.globalPosition - details.offsetFromOrigin - editableOffset - scrollableOffset,
       to: details.globalPosition,

diff --git a/packages/flutter/lib/src/material/slider_theme.dart b/packages/flutter/lib/src/material/slider_theme.dart
@@ -1619,20 +1619,18 @@ class RectangularSliderTrackShape extends SliderTrackShape with BaseSliderTrackS
       context.canvas.drawRect(rightTrackSegment, rightTrackPaint);
     }
 
-    final bool showSecondaryTrack = (secondaryOffset != null) &&
-        ((textDirection == TextDirection.ltr)
-            ? (secondaryOffset.dx > thumbCenter.dx)
-            : (secondaryOffset.dx < thumbCenter.dx));
+    final bool showSecondaryTrack = secondaryOffset != null && switch (textDirection) {
+      TextDirection.rtl => secondaryOffset.dx < thumbCenter.dx,
+      TextDirection.ltr => secondaryOffset.dx > thumbCenter.dx,
+    };
 
     if (showSecondaryTrack) {
       final ColorTween secondaryTrackColorTween = ColorTween(begin: sliderTheme.disabledSecondaryActiveTrackColor, end: sliderTheme.secondaryActiveTrackColor);
       final Paint secondaryTrackPaint = Paint()..color = secondaryTrackColorTween.evaluate(enableAnimation)!;
-      final Rect secondaryTrackSegment = Rect.fromLTRB(
-        (textDirection == TextDirection.ltr) ? thumbCenter.dx : secondaryOffset.dx,
-        trackRect.top,
-        (textDirection == TextDirection.ltr) ? secondaryOffset.dx : thumbCenter.dx,
-        trackRect.bottom,
-      );
+      final Rect secondaryTrackSegment = switch (textDirection) {
+        TextDirection.rtl => Rect.fromLTRB(secondaryOffset.dx, trackRect.top, thumbCenter.dx, trackRect.bottom),
+        TextDirection.ltr => Rect.fromLTRB(thumbCenter.dx, trackRect.top, secondaryOffset.dx, trackRect.bottom),
+      };
       if (!secondaryTrackSegment.isEmpty) {
         context.canvas.drawRect(secondaryTrackSegment, secondaryTrackPaint);
       }

diff --git a/packages/flutter/lib/src/material/tabs.dart b/packages/flutter/lib/src/material/tabs.dart
@@ -1536,18 +1536,14 @@ class _TabBarState extends State<TabBar> {
 
     final double index = _controller!.index.toDouble();
     final double value = _controller!.animation!.value;
-    final double offset;
-    if (value == index - 1.0) {
-      offset = leadingPosition ?? middlePosition;
-    } else if (value == index + 1.0) {
-      offset = trailingPosition ?? middlePosition;
-    } else if (value == index) {
-      offset = middlePosition;
-    } else if (value < index) {
-      offset = leadingPosition == null ? middlePosition : lerpDouble(middlePosition, leadingPosition, index - value)!;
-    } else {
-      offset = trailingPosition == null ? middlePosition : lerpDouble(middlePosition, trailingPosition, value - index)!;
-    }
+    final double offset = switch (value - index) {
+      -1.0 || 1.0 => leadingPosition ?? middlePosition,
+      0 => middlePosition,
+      < 0 when leadingPosition == null => middlePosition,
+      > 0 when trailingPosition == null => middlePosition,
+      < 0 => lerpDouble(middlePosition, leadingPosition, index - value)!,
+      _   => lerpDouble(middlePosition, trailingPosition, value - index)!,
+    };
 
     _scrollController!.jumpTo(offset);
   }

diff --git a/packages/flutter/lib/src/material/toggle_buttons.dart b/packages/flutter/lib/src/material/toggle_buttons.dart
@@ -738,26 +738,16 @@ class ToggleButtons extends StatelessWidget {
         ?? theme.textTheme.bodyMedium!;
       final BoxConstraints? currentConstraints = constraints
         ?? toggleButtonsTheme.constraints;
-      final Size minimumSize = currentConstraints == null
-        ? const Size.square(kMinInteractiveDimension)
-        : Size(currentConstraints.minWidth, currentConstraints.minHeight);
-      final Size? maximumSize = currentConstraints == null
-        ? null
-        : Size(currentConstraints.maxWidth, currentConstraints.maxHeight);
+      final Size minimumSize = currentConstraints?.smallest
+        ?? const Size.square(kMinInteractiveDimension);
+      final Size? maximumSize = currentConstraints?.biggest;
       final Size minPaddingSize;
       switch (tapTargetSize ?? theme.materialTapTargetSize) {
         case MaterialTapTargetSize.padded:
-          if (direction == Axis.horizontal) {
-            minPaddingSize = const Size(
-              0.0,
-              kMinInteractiveDimension,
-            );
-          } else {
-            minPaddingSize = const Size(
-              kMinInteractiveDimension,
-              0.0,
-            );
-          }
+          minPaddingSize = switch (direction) {
+            Axis.horizontal => const Size(0.0, kMinInteractiveDimension),
+            Axis.vertical   => const Size(kMinInteractiveDimension, 0.0),
+          };
           assert(minPaddingSize.width >= 0.0);
           assert(minPaddingSize.height >= 0.0);
         case MaterialTapTargetSize.shrinkWrap:
@@ -1658,12 +1648,10 @@ class _RenderInputPadding extends RenderShiftedBox {
     }
 
     // Only adjust one axis to ensure the correct button is tapped.
-    Offset center;
-    if (direction == Axis.horizontal) {
-      center = Offset(position.dx, child!.size.height / 2);
-    } else {
-      center = Offset(child!.size.width / 2, position.dy);
-    }
+    final Offset center = switch (direction) {
+      Axis.horizontal => Offset(position.dx, child!.size.height / 2),
+      Axis.vertical   => Offset(child!.size.width / 2, position.dy),
+    };
     return result.addWithRawTransform(
       transform: MatrixUtils.forceToPoint(center),
       position: center,

diff --git a/packages/flutter/lib/src/painting/colors.dart b/packages/flutter/lib/src/painting/colors.dart
@@ -31,34 +31,14 @@ Color _colorFromHue(
   double secondary,
   double match,
 ) {
-  double red;
-  double green;
-  double blue;
-  if (hue < 60.0) {
-    red = chroma;
-    green = secondary;
-    blue = 0.0;
-  } else if (hue < 120.0) {
-    red = secondary;
-    green = chroma;
-    blue = 0.0;
-  } else if (hue < 180.0) {
-    red = 0.0;
-    green = chroma;
-    blue = secondary;
-  } else if (hue < 240.0) {
-    red = 0.0;
-    green = secondary;
-    blue = chroma;
-  } else if (hue < 300.0) {
-    red = secondary;
-    green = 0.0;
-    blue = chroma;
-  } else {
-    red = chroma;
-    green = 0.0;
-    blue = secondary;
-  }
+  final (double red, double green, double blue) = switch (hue) {
+    <  60.0 => (chroma, secondary, 0.0),
+    < 120.0 => (secondary, chroma, 0.0),
+    < 180.0 => (0.0, chroma, secondary),
+    < 240.0 => (0.0, secondary, chroma),
+    < 300.0 => (secondary, 0.0, chroma),
+    _       => (chroma, 0.0, secondary),
+  };
   return Color.fromARGB((alpha * 0xFF).round(), ((red + match) * 0xFF).round(), ((green + match) * 0xFF).round(), ((blue + match) * 0xFF).round());
 }
 

diff --git a/packages/flutter/lib/src/painting/flutter_logo.dart b/packages/flutter/lib/src/painting/flutter_logo.dart
@@ -330,17 +330,11 @@ class _FlutterLogoPainter extends BoxPainter {
     if (canvasSize.isEmpty) {
       return;
     }
-    final Size logoSize;
-    if (_config._position > 0.0) {
-      // horizontal style
-      logoSize = const Size(820.0, 232.0);
-    } else if (_config._position < 0.0) {
-      // stacked style
-      logoSize = const Size(252.0, 306.0);
-    } else {
-      // only the mark
-      logoSize = const Size(202.0, 202.0);
-    }
+    final Size logoSize = switch (_config._position) {
+      > 0.0 => const Size(820.0, 232.0), // horizontal style
+      < 0.0 => const Size(252.0, 306.0), // stacked style
+      _     => const Size(202.0, 202.0), // only the mark
+    };
     final FittedSizes fittedSize = applyBoxFit(BoxFit.contain, logoSize, canvasSize);
     assert(fittedSize.source == logoSize);
     final Rect rect = Alignment.center.inscribe(fittedSize.destination, offset & canvasSize);

diff --git a/packages/flutter/lib/src/physics/spring_simulation.dart b/packages/flutter/lib/src/physics/spring_simulation.dart
@@ -153,14 +153,11 @@ abstract class _SpringSolution {
     double initialPosition,
     double initialVelocity,
   ) {
-    final double cmk = spring.damping * spring.damping - 4 * spring.mass * spring.stiffness;
-    if (cmk == 0.0) {
-      return _CriticalSolution(spring, initialPosition, initialVelocity);
-    }
-    if (cmk > 0.0) {
-      return _OverdampedSolution(spring, initialPosition, initialVelocity);
-    }
-    return _UnderdampedSolution(spring, initialPosition, initialVelocity);
+    return switch (spring.damping * spring.damping - 4 * spring.mass * spring.stiffness) {
+      > 0.0 => _OverdampedSolution(spring, initialPosition, initialVelocity),
+      < 0.0 => _UnderdampedSolution(spring, initialPosition, initialVelocity),
+      _     => _CriticalSolution(spring, initialPosition, initialVelocity),
+    };
   }
 
   double x(double time);

diff --git a/packages/flutter/lib/src/rendering/box.dart b/packages/flutter/lib/src/rendering/box.dart
@@ -540,14 +540,11 @@ class BoxConstraints extends Constraints {
         if (affectedFieldsList.length > 1) {
           affectedFieldsList.add('and ${affectedFieldsList.removeLast()}');
         }
-        String whichFields = '';
-        if (affectedFieldsList.length > 2) {
-          whichFields = affectedFieldsList.join(', ');
-        } else if (affectedFieldsList.length == 2) {
-          whichFields = affectedFieldsList.join(' ');
-        } else {
-          whichFields = affectedFieldsList.single;
-        }
+        final String whichFields = switch (affectedFieldsList.length) {
+          1 => affectedFieldsList.single,
+          2 => affectedFieldsList.join(' '),
+          _ => affectedFieldsList.join(', '),
+        };
         throwError(ErrorSummary('BoxConstraints has ${affectedFieldsList.length == 1 ? 'a NaN value' : 'NaN values' } in $whichFields.'));
       }
       if (minWidth < 0.0 && minHeight < 0.0) {