Implementing `switch` expressions in the `cupertino/` directory (#141591)

Refactors code to use the new `switch` expressions.

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

@@ -904,14 +904,11 @@ class _ContextMenuRoute<T> extends PopupRoute<T> {
   // Get the alignment for the _ContextMenuSheet's Transform.scale based on the
   // contextMenuLocation.
   static AlignmentDirectional getSheetAlignment(_ContextMenuLocation contextMenuLocation) {
-    switch (contextMenuLocation) {
-      case _ContextMenuLocation.center:
-        return AlignmentDirectional.topCenter;
-      case _ContextMenuLocation.right:
-        return AlignmentDirectional.topEnd;
-      case _ContextMenuLocation.left:
-        return AlignmentDirectional.topStart;
-    }
+    return switch (contextMenuLocation) {
+      _ContextMenuLocation.center => AlignmentDirectional.topCenter,
+      _ContextMenuLocation.right  => AlignmentDirectional.topEnd,
+      _ContextMenuLocation.left   => AlignmentDirectional.topStart,
+    };
   }
 
   // The place to start the sheetRect animation from.
@@ -1223,20 +1220,14 @@ class _ContextMenuRouteStaticState extends State<_ContextMenuRouteStatic> with T
   }
 
   Alignment _getChildAlignment(Orientation orientation, _ContextMenuLocation contextMenuLocation) {
-    switch (contextMenuLocation) {
-      case _ContextMenuLocation.center:
-        return orientation == Orientation.portrait
-          ? Alignment.bottomCenter
-          : Alignment.topRight;
-      case _ContextMenuLocation.right:
-        return orientation == Orientation.portrait
-          ? Alignment.bottomCenter
-          : Alignment.topLeft;
-      case _ContextMenuLocation.left:
-        return orientation == Orientation.portrait
-          ? Alignment.bottomCenter
-          : Alignment.topRight;
+    if (orientation == Orientation.portrait) {
+      return Alignment.bottomCenter;
     }
+    return switch (contextMenuLocation) {
+      _ContextMenuLocation.left   => Alignment.topRight,
+      _ContextMenuLocation.center => Alignment.topRight,
+      _ContextMenuLocation.right  => Alignment.topLeft,
+    };
   }
 
   void _setDragOffset(Offset dragOffset) {
@@ -1307,16 +1298,12 @@ class _ContextMenuRouteStaticState extends State<_ContextMenuRouteStatic> with T
       ),
     );
 
-    switch (contextMenuLocation) {
-      case _ContextMenuLocation.center:
-        return <Widget>[child, spacer, sheet];
-      case _ContextMenuLocation.right:
-        return orientation == Orientation.portrait
-          ? <Widget>[child, spacer, sheet]
-          : <Widget>[sheet, spacer, child];
-      case _ContextMenuLocation.left:
-        return <Widget>[child, spacer, sheet];
-    }
+    return switch (contextMenuLocation) {
+      _ContextMenuLocation.right when orientation == Orientation.portrait => <Widget>[child, spacer, sheet],
+      _ContextMenuLocation.right  => <Widget>[sheet, spacer, child],
+      _ContextMenuLocation.center => <Widget>[child, spacer, sheet],
+      _ContextMenuLocation.left   => <Widget>[child, spacer, sheet],
+    };
   }
 
   // Build the animation for the _ContextMenuSheet.
@@ -1475,29 +1462,12 @@ class _ContextMenuSheet extends StatelessWidget {
       ),
     );
 
-    switch (_contextMenuLocation) {
-      case _ContextMenuLocation.center:
-        return _orientation == Orientation.portrait
-          ? <Widget>[
-            const Spacer(),
-            menu,
-            const Spacer(),
-          ]
-        : <Widget>[
-            menu,
-            const Spacer(),
-          ];
-      case _ContextMenuLocation.right:
-        return <Widget>[
-          const Spacer(),
-          menu,
-        ];
-      case _ContextMenuLocation.left:
-        return <Widget>[
-          menu,
-          const Spacer(),
-        ];
-    }
+    return switch (_contextMenuLocation) {
+      _ContextMenuLocation.center when _orientation == Orientation.portrait => <Widget>[const Spacer(), menu, const Spacer()],
+      _ContextMenuLocation.center => <Widget>[menu, const Spacer()],
+      _ContextMenuLocation.right  => <Widget>[const Spacer(), menu],
+      _ContextMenuLocation.left   => <Widget>[menu, const Spacer()],
+    };
   }
 
   @override

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

@@ -1757,25 +1757,8 @@ class _CupertinoDatePickerMonthYearState extends State<CupertinoDatePicker> {
     double totalColumnWidths = 3 * _kDatePickerPadSize;
 
     for (int i = 0; i < columnWidths.length; i++) {
-      late final double offAxisFraction;
-      switch (i) {
-        case 0:
-          offAxisFraction = -0.3 * textDirectionFactor;
-        default:
-          offAxisFraction = 0.5 * textDirectionFactor;
-      }
-
-      EdgeInsets padding = const EdgeInsets.only(right: _kDatePickerPadSize);
-      if (textDirectionFactor == -1) {
-        padding = const EdgeInsets.only(left: _kDatePickerPadSize);
-      }
-
-      Widget selectionOverlay = _centerSelectionOverlay;
-      if (i == 0) {
-        selectionOverlay = _startSelectionOverlay;
-      } else if (i == columnWidths.length - 1) {
-        selectionOverlay = _endSelectionOverlay;
-      }
+      final (bool first, bool last) = (i == 0, i == columnWidths.length - 1);
+      final double offAxisFraction = textDirectionFactor * (first ? -0.3 : 0.5);
 
       totalColumnWidths += columnWidths[i] + (2 * _kDatePickerPadSize);
 
@@ -1785,18 +1768,24 @@ class _CupertinoDatePickerMonthYearState extends State<CupertinoDatePicker> {
           offAxisFraction,
           (BuildContext context, Widget? child) {
             return Container(
-              alignment: i == columnWidths.length - 1
-                  ? alignCenterLeft
-                  : alignCenterRight,
-              padding: i == 0 ? null : padding,
+              alignment: last ? alignCenterLeft : alignCenterRight,
+              padding: switch (textDirectionFactor) {
+                _ when first => null,
+                -1 => const EdgeInsets.only(left: _kDatePickerPadSize),
+                _  => const EdgeInsets.only(right: _kDatePickerPadSize),
+              },
               child: Container(
-                alignment: i == 0 ? alignCenterLeft : alignCenterRight,
+                alignment: first ? alignCenterLeft : alignCenterRight,
                 width: columnWidths[i] + _kDatePickerPadSize,
                 child: child,
               ),
             );
           },
-          selectionOverlay,
+          switch (last) {
+            _ when first => _startSelectionOverlay,
+            false => _centerSelectionOverlay,
+            true  => _endSelectionOverlay,
+          },
         ),
       ));
     }
@@ -1958,12 +1947,10 @@ class _CupertinoTimerPickerState extends State<CupertinoTimerPicker> {
   late TextDirection textDirection;
   late CupertinoLocalizations localizations;
   int get textDirectionFactor {
-    switch (textDirection) {
-      case TextDirection.ltr:
-        return 1;
-      case TextDirection.rtl:
-        return -1;
-    }
+    return switch (textDirection) {
+      TextDirection.ltr =>  1,
+      TextDirection.rtl => -1,
+    };
   }
 
   // The currently selected values of the picker.

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

@@ -140,13 +140,10 @@ Widget _wrapWithBackground({
   if (updateSystemUiOverlay) {
     final bool isDark = backgroundColor.computeLuminance() < 0.179;
     final Brightness newBrightness = brightness ?? (isDark ? Brightness.dark : Brightness.light);
-    final SystemUiOverlayStyle overlayStyle;
-    switch (newBrightness) {
-      case Brightness.dark:
-        overlayStyle = SystemUiOverlayStyle.light;
-      case Brightness.light:
-        overlayStyle = SystemUiOverlayStyle.dark;
-    }
+    final SystemUiOverlayStyle overlayStyle = switch (newBrightness) {
+      Brightness.dark  => SystemUiOverlayStyle.light,
+      Brightness.light => SystemUiOverlayStyle.dark,
+    };
     // [SystemUiOverlayStyle.light] and [SystemUiOverlayStyle.dark] set some system
     // navigation bar properties,
     // Before https://github.com/flutter/flutter/pull/104827 those properties

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

@@ -673,12 +673,10 @@ class _CupertinoBackGestureDetectorState<T> extends State<_CupertinoBackGestureD
   }
 
   double _convertToLogical(double value) {
-    switch (Directionality.of(context)) {
-      case TextDirection.rtl:
-        return -value;
-      case TextDirection.ltr:
-        return value;
-    }
+    return switch (Directionality.of(context)) {
+      TextDirection.rtl => -value,
+      TextDirection.ltr =>  value,
+    };
   }
 
   @override

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

@@ -450,13 +450,10 @@ class _RenderCupertinoSlider extends RenderConstrainedBox implements MouseTracke
   double get _trackLeft => _kPadding;
   double get _trackRight => size.width - _kPadding;
   double get _thumbCenter {
-    final double visualPosition;
-    switch (textDirection) {
-      case TextDirection.rtl:
-        visualPosition = 1.0 - _value;
-      case TextDirection.ltr:
-        visualPosition = _value;
-    }
+    final double visualPosition = switch (textDirection) {
+      TextDirection.rtl => 1.0 - _value,
+      TextDirection.ltr => _value,
+    };
     return lerpDouble(_trackLeft + CupertinoThumbPainter.radius, _trackRight - CupertinoThumbPainter.radius, visualPosition)!;
   }
 
@@ -468,12 +465,10 @@ class _RenderCupertinoSlider extends RenderConstrainedBox implements MouseTracke
     if (isInteractive) {
       final double extent = math.max(_kPadding, size.width - 2.0 * (_kPadding + CupertinoThumbPainter.radius));
       final double valueDelta = details.primaryDelta! / extent;
-      switch (textDirection) {
-        case TextDirection.rtl:
-          _currentDragValue -= valueDelta;
-        case TextDirection.ltr:
-          _currentDragValue += valueDelta;
-      }
+      _currentDragValue += switch (textDirection) {
+        TextDirection.rtl => -valueDelta,
+        TextDirection.ltr =>  valueDelta,
+      };
       onChanged!(_discretizedCurrentDragValue);
     }
   }

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

@@ -322,12 +322,10 @@ class _CupertinoSwitchState extends State<CupertinoSwitch> with TickerProviderSt
         ..curve = Curves.linear
         ..reverseCurve = Curves.linear;
       final double delta = details.primaryDelta! / _kTrackInnerLength;
-      switch (Directionality.of(context)) {
-        case TextDirection.rtl:
-          _positionController.value -= delta;
-        case TextDirection.ltr:
-          _positionController.value += delta;
-      }
+      _positionController.value += switch (Directionality.of(context)) {
+        TextDirection.rtl => -delta,
+        TextDirection.ltr =>  delta,
+      };
     }
   }
 
@@ -674,13 +672,10 @@ class _RenderCupertinoSwitch extends RenderConstrainedBox {
     final double currentValue = _state.position.value;
     final double currentReactionValue = _state._reaction.value;
 
-    final double visualPosition;
-    switch (textDirection) {
-      case TextDirection.rtl:
-        visualPosition = 1.0 - currentValue;
-      case TextDirection.ltr:
-        visualPosition = currentValue;
-    }
+    final double visualPosition = switch (textDirection) {
+      TextDirection.rtl => 1.0 - currentValue,
+      TextDirection.ltr => currentValue,
+    };
 
     final Paint paint = Paint()
       ..color = Color.lerp(trackColor, activeColor, currentValue)!;

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

@@ -92,26 +92,18 @@ class CupertinoTextSelectionToolbarButton extends StatefulWidget {
 
     assert(debugCheckHasCupertinoLocalizations(context));
     final CupertinoLocalizations localizations = CupertinoLocalizations.of(context);
-    switch (buttonItem.type) {
-      case ContextMenuButtonType.cut:
-        return localizations.cutButtonLabel;
-      case ContextMenuButtonType.copy:
-        return localizations.copyButtonLabel;
-      case ContextMenuButtonType.paste:
-        return localizations.pasteButtonLabel;
-      case ContextMenuButtonType.selectAll:
-        return localizations.selectAllButtonLabel;
-      case ContextMenuButtonType.lookUp:
-        return localizations.lookUpButtonLabel;
-      case ContextMenuButtonType.searchWeb:
-        return localizations.searchWebButtonLabel;
-      case ContextMenuButtonType.share:
-        return localizations.shareButtonLabel;
-      case ContextMenuButtonType.liveTextInput:
-      case ContextMenuButtonType.delete:
-      case ContextMenuButtonType.custom:
-        return '';
-    }
+    return switch (buttonItem.type) {
+      ContextMenuButtonType.cut       => localizations.cutButtonLabel,
+      ContextMenuButtonType.copy      => localizations.copyButtonLabel,
+      ContextMenuButtonType.paste     => localizations.pasteButtonLabel,
+      ContextMenuButtonType.selectAll => localizations.selectAllButtonLabel,
+      ContextMenuButtonType.lookUp    => localizations.lookUpButtonLabel,
+      ContextMenuButtonType.searchWeb => localizations.searchWebButtonLabel,
+      ContextMenuButtonType.share     => localizations.shareButtonLabel,
+      ContextMenuButtonType.liveTextInput
+        || ContextMenuButtonType.delete
+        || ContextMenuButtonType.custom => '',
+    };
   }
 
   @override