Implement switch expressions in lib/src/material/ (#142634)

nate-thegrate · web-flow · commit 5b947c889b27 · 2024-02-01T22:31:10.000Z
This PR is step 5 in the journey to solve issue #136139 and make the entire Flutter repo more readable.

(previous pull requests: #139048, #139882, #141591, #142279)

The current focus is on `packages/flutter/lib/src/material/`.  
The previous PR covered files in this directory starting with `a`, `b`, and `c`; this pull request is for `d` through `m`.
diff --git a/packages/flutter/lib/src/material/dropdown.dart b/packages/flutter/lib/src/material/dropdown.dart
@@ -119,13 +119,10 @@ class _DropdownMenuItemButton<T> extends StatefulWidget {
 
 class _DropdownMenuItemButtonState<T> extends State<_DropdownMenuItemButton<T>> {
   void _handleFocusChange(bool focused) {
-    final bool inTraditionalMode;
-    switch (FocusManager.instance.highlightMode) {
-      case FocusHighlightMode.touch:
-        inTraditionalMode = false;
-      case FocusHighlightMode.traditional:
-        inTraditionalMode = true;
-    }
+    final bool inTraditionalMode = switch (FocusManager.instance.highlightMode) {
+      FocusHighlightMode.touch       => false,
+      FocusHighlightMode.traditional => true,
+    };
 
     if (focused && inTraditionalMode) {
       final _MenuLimits menuLimits = widget.route.getMenuLimits(
@@ -377,13 +374,10 @@ class _DropdownMenuRouteLayout<T> extends SingleChildLayoutDelegate {
       return true;
     }());
     assert(textDirection != null);
-    final double left;
-    switch (textDirection!) {
-      case TextDirection.rtl:
-        left = clampDouble(buttonRect.right, 0.0, size.width) - childSize.width;
-      case TextDirection.ltr:
-        left = clampDouble(buttonRect.left, 0.0, size.width - childSize.width);
-    }
+    final double left = switch (textDirection!) {
+      TextDirection.rtl => clampDouble(buttonRect.right, 0.0, size.width) - childSize.width,
+      TextDirection.ltr => clampDouble(buttonRect.left, 0.0, size.width - childSize.width),
+    };
 
     return Offset(left, menuLimits.top);
   }
@@ -1379,28 +1373,17 @@ class _DropdownButtonState<T> extends State<DropdownButton<T>> with WidgetsBindi
 
   Color get _iconColor {
     // These colors are not defined in the Material Design spec.
+    final Brightness brightness = Theme.of(context).brightness;
     if (_enabled) {
-      if (widget.iconEnabledColor != null) {
-        return widget.iconEnabledColor!;
-      }
-
-      switch (Theme.of(context).brightness) {
-        case Brightness.light:
-          return Colors.grey.shade700;
-        case Brightness.dark:
-          return Colors.white70;
-      }
+      return widget.iconEnabledColor ?? switch (brightness) {
+        Brightness.light => Colors.grey.shade700,
+        Brightness.dark  => Colors.white70,
+      };
     } else {
-      if (widget.iconDisabledColor != null) {
-        return widget.iconDisabledColor!;
-      }
-
-      switch (Theme.of(context).brightness) {
-        case Brightness.light:
-          return Colors.grey.shade400;
-        case Brightness.dark:
-          return Colors.white10;
-      }
+      return widget.iconDisabledColor ?? switch (brightness) {
+        Brightness.light => Colors.grey.shade400,
+        Brightness.dark  => Colors.white10,
+      };
     }
   }
 
diff --git a/packages/flutter/lib/src/material/dropdown_menu.dart b/packages/flutter/lib/src/material/dropdown_menu.dart
@@ -546,17 +546,10 @@ class _DropdownMenuState<T> extends State<DropdownMenu<T>> {
       // paddings so its leading icon will be aligned with the leading icon of
       // the text field.
       final double padding = entry.leadingIcon == null ? (leadingPadding ?? _kDefaultHorizontalPadding) : _kDefaultHorizontalPadding;
-      final ButtonStyle defaultStyle;
-      switch (textDirection) {
-        case TextDirection.rtl:
-          defaultStyle = MenuItemButton.styleFrom(
-            padding: EdgeInsets.only(left: _kDefaultHorizontalPadding, right: padding),
-          );
-        case TextDirection.ltr:
-          defaultStyle = MenuItemButton.styleFrom(
-            padding: EdgeInsets.only(left: padding, right: _kDefaultHorizontalPadding),
-          );
-      }
+      final ButtonStyle defaultStyle = switch (textDirection) {
+        TextDirection.rtl => MenuItemButton.styleFrom(padding: EdgeInsets.only(left: _kDefaultHorizontalPadding, right: padding)),
+        TextDirection.ltr => MenuItemButton.styleFrom(padding: EdgeInsets.only(left: padding, right: _kDefaultHorizontalPadding)),
+      };
 
       ButtonStyle effectiveStyle = entry.style ?? defaultStyle;
       final Color focusedBackgroundColor = effectiveStyle.foregroundColor?.resolve(<MaterialState>{MaterialState.focused})
diff --git a/packages/flutter/lib/src/material/expand_icon.dart b/packages/flutter/lib/src/material/expand_icon.dart
@@ -152,12 +152,10 @@ class _ExpandIconState extends State<ExpandIcon> with SingleTickerProviderStateM
       return widget.color!;
     }
 
-    switch (Theme.of(context).brightness) {
-      case Brightness.light:
-        return Colors.black54;
-      case Brightness.dark:
-        return Colors.white60;
-    }
+    return switch (Theme.of(context).brightness) {
+      Brightness.light => Colors.black54,
+      Brightness.dark  => Colors.white60,
+    };
   }
 
   @override
diff --git a/packages/flutter/lib/src/material/filled_button.dart b/packages/flutter/lib/src/material/filled_button.dart
@@ -425,12 +425,10 @@ class FilledButton extends ButtonStyleButton {
   /// [padding] is reduced from 24 to 16.
   @override
   ButtonStyle defaultStyleOf(BuildContext context) {
-    switch (_variant) {
-      case _FilledButtonVariant.filled:
-        return _FilledButtonDefaultsM3(context);
-      case _FilledButtonVariant.tonal:
-        return _FilledTonalButtonDefaultsM3(context);
-    }
+    return switch (_variant) {
+      _FilledButtonVariant.filled => _FilledButtonDefaultsM3(context),
+      _FilledButtonVariant.tonal  => _FilledTonalButtonDefaultsM3(context),
+    };
   }
 
   /// Returns the [FilledButtonThemeData.style] of the closest
diff --git a/packages/flutter/lib/src/material/flexible_space_bar.dart b/packages/flutter/lib/src/material/flexible_space_bar.dart
@@ -185,32 +185,20 @@ class FlexibleSpaceBar extends StatefulWidget {
 
 class _FlexibleSpaceBarState extends State<FlexibleSpaceBar> {
   bool _getEffectiveCenterTitle(ThemeData theme) {
-    if (widget.centerTitle != null) {
-      return widget.centerTitle!;
-    }
-    switch (theme.platform) {
-      case TargetPlatform.android:
-      case TargetPlatform.fuchsia:
-      case TargetPlatform.linux:
-      case TargetPlatform.windows:
-        return false;
-      case TargetPlatform.iOS:
-      case TargetPlatform.macOS:
-        return true;
-    }
+    return widget.centerTitle ?? switch (theme.platform) {
+      TargetPlatform.android || TargetPlatform.fuchsia || TargetPlatform.linux || TargetPlatform.windows => false,
+      TargetPlatform.iOS || TargetPlatform.macOS => true,
+    };
   }
 
   Alignment _getTitleAlignment(bool effectiveCenterTitle) {
     if (effectiveCenterTitle) {
       return Alignment.bottomCenter;
     }
-    final TextDirection textDirection = Directionality.of(context);
-    switch (textDirection) {
-      case TextDirection.rtl:
-        return Alignment.bottomRight;
-      case TextDirection.ltr:
-        return Alignment.bottomLeft;
-    }
+    return switch (Directionality.of(context)) {
+      TextDirection.rtl => Alignment.bottomRight,
+      TextDirection.ltr => Alignment.bottomLeft,
+    };
   }
 
   double _getCollapsePadding(double t, FlexibleSpaceBarSettings settings) {
diff --git a/packages/flutter/lib/src/material/floating_action_button.dart b/packages/flutter/lib/src/material/floating_action_button.dart
@@ -814,26 +814,22 @@ class _FABDefaultsM3 extends FloatingActionButtonThemeData {
 
   @override
   ShapeBorder? get shape {
-    switch (type) {
-      case _FloatingActionButtonType.regular:
-       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0)));
-      case _FloatingActionButtonType.small:
-       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(12.0)));
-      case _FloatingActionButtonType.large:
-       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(28.0)));
-      case _FloatingActionButtonType.extended:
-       return const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0)));
-     }
+    return switch (type) {
+      _FloatingActionButtonType.regular  => const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0))),
+      _FloatingActionButtonType.small    => const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(12.0))),
+      _FloatingActionButtonType.large    => const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(28.0))),
+      _FloatingActionButtonType.extended => const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(16.0))),
+    };
   }
 
   @override
   double? get iconSize {
-    switch (type) {
-      case _FloatingActionButtonType.regular: return 24.0;
-      case _FloatingActionButtonType.small: return  24.0;
-      case _FloatingActionButtonType.large: return 36.0;
-      case _FloatingActionButtonType.extended: return 24.0;
-    }
+    return switch (type) {
+      _FloatingActionButtonType.regular  => 24.0,
+      _FloatingActionButtonType.small    => 24.0,
+      _FloatingActionButtonType.large    => 36.0,
+      _FloatingActionButtonType.extended => 24.0,
+    };
   }
 
   @override EdgeInsetsGeometry? get extendedPadding => EdgeInsetsDirectional.only(start: hasChild && _isExtended ? 16.0 : 20.0, end: 20.0);
diff --git a/packages/flutter/lib/src/material/floating_action_button_location.dart b/packages/flutter/lib/src/material/floating_action_button_location.dart
@@ -656,12 +656,10 @@ mixin FabStartOffsetX on StandardFabLocation {
   /// Calculates x-offset for start-aligned [FloatingActionButtonLocation]s.
   @override
   double getOffsetX(ScaffoldPrelayoutGeometry scaffoldGeometry, double adjustment) {
-    switch (scaffoldGeometry.textDirection) {
-      case TextDirection.rtl:
-        return StandardFabLocation._rightOffsetX(scaffoldGeometry, adjustment);
-      case TextDirection.ltr:
-        return StandardFabLocation._leftOffsetX(scaffoldGeometry, adjustment);
-    }
+    return switch (scaffoldGeometry.textDirection) {
+      TextDirection.rtl => StandardFabLocation._rightOffsetX(scaffoldGeometry, adjustment),
+      TextDirection.ltr => StandardFabLocation._leftOffsetX(scaffoldGeometry, adjustment),
+    };
   }
 }
 
@@ -679,12 +677,10 @@ mixin FabEndOffsetX on StandardFabLocation {
   /// Calculates x-offset for end-aligned [FloatingActionButtonLocation]s.
   @override
   double getOffsetX(ScaffoldPrelayoutGeometry scaffoldGeometry, double adjustment) {
-    switch (scaffoldGeometry.textDirection) {
-      case TextDirection.rtl:
-        return StandardFabLocation._leftOffsetX(scaffoldGeometry, adjustment);
-      case TextDirection.ltr:
-        return StandardFabLocation._rightOffsetX(scaffoldGeometry, adjustment);
-    }
+    return switch (scaffoldGeometry.textDirection) {
+      TextDirection.rtl => StandardFabLocation._leftOffsetX(scaffoldGeometry, adjustment),
+      TextDirection.ltr => StandardFabLocation._rightOffsetX(scaffoldGeometry, adjustment),
+    };
   }
 }
 
diff --git a/packages/flutter/lib/src/material/icon_button.dart b/packages/flutter/lib/src/material/icon_button.dart
@@ -944,16 +944,12 @@ class _IconButtonM3 extends ButtonStyleButton {
   /// * `splashFactory` - Theme.splashFactory
   @override
   ButtonStyle defaultStyleOf(BuildContext context) {
-    switch (variant) {
-      case _IconButtonVariant.filled:
-        return _FilledIconButtonDefaultsM3(context, toggleable);
-      case _IconButtonVariant.filledTonal:
-        return _FilledTonalIconButtonDefaultsM3(context, toggleable);
-      case _IconButtonVariant.outlined:
-        return _OutlinedIconButtonDefaultsM3(context, toggleable);
-      case _IconButtonVariant.standard:
-        return _IconButtonDefaultsM3(context, toggleable);
-    }
+    return switch (variant) {
+      _IconButtonVariant.filled      => _FilledIconButtonDefaultsM3(context, toggleable),
+      _IconButtonVariant.filledTonal => _FilledTonalIconButtonDefaultsM3(context, toggleable),
+      _IconButtonVariant.outlined    => _OutlinedIconButtonDefaultsM3(context, toggleable),
+      _IconButtonVariant.standard    => _IconButtonDefaultsM3(context, toggleable),
+    };
   }
 
   /// Returns the [IconButtonThemeData.style] of the closest [IconButtonTheme] ancestor.
diff --git a/packages/flutter/lib/src/material/input_decorator.dart b/packages/flutter/lib/src/material/input_decorator.dart
diff --git a/packages/flutter/lib/src/material/list_tile.dart b/packages/flutter/lib/src/material/list_tile.dart
diff --git a/packages/flutter/lib/src/material/material_localizations.dart b/packages/flutter/lib/src/material/material_localizations.dart
diff --git a/packages/flutter/lib/src/material/menu_anchor.dart b/packages/flutter/lib/src/material/menu_anchor.dart
