flutter/dev/tools/gen_defaults/lib/tabs_template.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'template.dart';

class TabsTemplate extends TokenTemplate {
  const TabsTemplate(
    super.blockName,
    super.fileName,
    super.tokens, {
    super.colorSchemePrefix = '_colors.',
    super.textThemePrefix = '_textTheme.',
  });

  @override
  String generate() => '''
class _${blockName}PrimaryDefaultsM3 extends TabBarThemeData {
  _${blockName}PrimaryDefaultsM3(this.context, this.isScrollable)
    : super(indicatorSize: TabBarIndicatorSize.label);

  final BuildContext context;
  late final ColorScheme _colors = Theme.of(context).colorScheme;
  late final TextTheme _textTheme = Theme.of(context).textTheme;
  final bool isScrollable;

  // This value comes from Divider widget defaults. Token db deprecated 'primary-navigation-tab.divider.color' token.
  @override
  Color? get dividerColor => ${componentColor("md.comp.divider")};

  // This value comes from Divider widget defaults. Token db deprecated 'primary-navigation-tab.divider.height' token.
  @override
  double? get dividerHeight => ${getToken("md.comp.divider.thickness")};

  @override
  Color? get indicatorColor => ${componentColor("md.comp.primary-navigation-tab.active-indicator")};

  @override
  Color? get labelColor => ${componentColor("md.comp.primary-navigation-tab.with-label-text.active.label-text")};

  @override
  TextStyle? get labelStyle => ${textStyle("md.comp.primary-navigation-tab.with-label-text.label-text")};

  @override
  Color? get unselectedLabelColor => ${componentColor("md.comp.primary-navigation-tab.with-label-text.inactive.label-text")};

  @override
  TextStyle? get unselectedLabelStyle => ${textStyle("md.comp.primary-navigation-tab.with-label-text.label-text")};

  @override
  MaterialStateProperty<Color?> get overlayColor {
    return MaterialStateProperty.resolveWith((Set<MaterialState> states) {
      if (states.contains(MaterialState.selected)) {
        if (states.contains(MaterialState.pressed)) {
          return ${componentColor('md.comp.primary-navigation-tab.active.pressed.state-layer')};
        }
        if (states.contains(MaterialState.hovered)) {
          return ${componentColor('md.comp.primary-navigation-tab.active.hover.state-layer')};
        }
        if (states.contains(MaterialState.focused)) {
          return ${componentColor('md.comp.primary-navigation-tab.active.focus.state-layer')};
        }
        return null;
      }
      if (states.contains(MaterialState.pressed)) {
        return ${componentColor('md.comp.primary-navigation-tab.inactive.pressed.state-layer')};
      }
      if (states.contains(MaterialState.hovered)) {
        return ${componentColor('md.comp.primary-navigation-tab.inactive.hover.state-layer')};
      }
      if (states.contains(MaterialState.focused)) {
        return ${componentColor('md.comp.primary-navigation-tab.inactive.focus.state-layer')};
      }
      return null;
    });
  }

  @override
  InteractiveInkFeatureFactory? get splashFactory => Theme.of(context).splashFactory;

  @override
  TabAlignment? get tabAlignment => isScrollable ? TabAlignment.startOffset : TabAlignment.fill;

  static double indicatorWeight(TabBarIndicatorSize indicatorSize) {
    return switch (indicatorSize) {
      TabBarIndicatorSize.label => ${getToken('md.comp.primary-navigation-tab.active-indicator.height')},
      TabBarIndicatorSize.tab   => ${getToken('md.comp.secondary-navigation-tab.active-indicator.height')},
    };
  }

  // TODO(davidmartos96): This value doesn't currently exist in
  // https://m3.material.io/components/tabs/specs
  // Update this when the token is available.
  static const EdgeInsetsGeometry iconMargin = EdgeInsets.only(bottom: 2);
}

class _${blockName}SecondaryDefaultsM3 extends TabBarThemeData {
  _${blockName}SecondaryDefaultsM3(this.context, this.isScrollable)
    : super(indicatorSize: TabBarIndicatorSize.tab);

  final BuildContext context;
  late final ColorScheme _colors = Theme.of(context).colorScheme;
  late final TextTheme _textTheme = Theme.of(context).textTheme;
  final bool isScrollable;

  // This value comes from Divider widget defaults. Token db deprecated 'secondary-navigation-tab.divider.color' token.
  @override
  Color? get dividerColor => ${componentColor("md.comp.divider")};

  // This value comes from Divider widget defaults. Token db deprecated 'secondary-navigation-tab.divider.height' token.
  @override
  double? get dividerHeight => ${getToken("md.comp.divider.thickness")};

  @override
  Color? get indicatorColor => ${componentColor("md.comp.secondary-navigation-tab.active-indicator")};

  @override
  Color? get labelColor => ${componentColor("md.comp.secondary-navigation-tab.active.label-text")};

  @override
  TextStyle? get labelStyle => ${textStyle("md.comp.secondary-navigation-tab.label-text")};

  @override
  Color? get unselectedLabelColor => ${componentColor("md.comp.secondary-navigation-tab.inactive.label-text")};

  @override
  TextStyle? get unselectedLabelStyle => ${textStyle("md.comp.secondary-navigation-tab.label-text")};

  @override
  MaterialStateProperty<Color?> get overlayColor {
    return MaterialStateProperty.resolveWith((Set<MaterialState> states) {
      if (states.contains(MaterialState.selected)) {
        if (states.contains(MaterialState.pressed)) {
          return ${componentColor('md.comp.secondary-navigation-tab.pressed.state-layer')};
        }
        if (states.contains(MaterialState.hovered)) {
          return ${componentColor('md.comp.secondary-navigation-tab.hover.state-layer')};
        }
        if (states.contains(MaterialState.focused)) {
          return ${componentColor('md.comp.secondary-navigation-tab.focus.state-layer')};
        }
        return null;
      }
      if (states.contains(MaterialState.pressed)) {
        return ${componentColor('md.comp.secondary-navigation-tab.pressed.state-layer')};
      }
      if (states.contains(MaterialState.hovered)) {
        return ${componentColor('md.comp.secondary-navigation-tab.hover.state-layer')};
      }
      if (states.contains(MaterialState.focused)) {
        return ${componentColor('md.comp.secondary-navigation-tab.focus.state-layer')};
      }
      return null;
    });
  }

  @override
  InteractiveInkFeatureFactory? get splashFactory => Theme.of(context).splashFactory;

  @override
  TabAlignment? get tabAlignment => isScrollable ? TabAlignment.startOffset : TabAlignment.fill;

  static double indicatorWeight = ${getToken('md.comp.secondary-navigation-tab.active-indicator.height')};
}
''';
}