checkboxTheme static method

Implementation

static CheckboxThemeData checkboxTheme({
  /// Typically the same `ColorScheme` that is also used for your `ThemeData`.
  required final ColorScheme colorScheme,

  /// Selects which color from the passed in colorScheme to use as the main
  /// color for the checkbox.
  ///
  /// All colors in the color scheme are not good choices, but some work well.
  ///
  /// If not defined, [colorScheme.primary] will be used. This is more in-line
  /// with M3 design, but applied to M2 switch. The M3 color design
  /// specification for the secondary color, is a poor choice for toggles and
  /// switches, primary color works better.
  final SchemeColor? baseSchemeColor,

  /// The splash radius of the circular Material ink response.
  ///
  /// Defaults to kRadialReactionRadius = 20.
  final double? splashRadius,

  /// Defines if unselected [Checkbox] is also themed to be [baseSchemeColor].
  ///
  /// If false, it is grey like in Flutter SDK.
  ///
  /// If undefined, defaults to false.
  final bool? unselectedIsColored,

  /// Defines if the theme uses tinted interaction effects.
  ///
  /// If undefined, defaults to false.
  final bool? useTintedInteraction,

  /// Defines if the theme uses tinted disabled color.
  ///
  /// If undefined, defaults to false.
  final bool? useTintedDisable,

  /// A temporary flag used to opt-in to Material 3 features.
  ///
  /// If set to true, the theme will use Material3 default styles when
  /// properties are undefined, if false defaults will use FlexColorScheme's
  /// own opinionated default values.
  ///
  /// The M2/M3 defaults will only be used for properties that are not
  /// defined, if defined they keep their defined values.
  ///
  /// If undefined, defaults to false.
  final bool? useMaterial3,
}) {
  final bool useM3 = useMaterial3 ?? false;
  final bool isBaseColor = unselectedIsColored ?? false;
  final bool tintInteract = useTintedInteraction ?? false;
  final bool tintDisable = useTintedDisable ?? false;
  // Get selected color, defaults to primary.
  final SchemeColor baseScheme = baseSchemeColor ?? SchemeColor.primary;
  final Color baseColor = schemeColor(baseScheme, colorScheme);
  final Color onBaseColor = schemeColorPair(baseScheme, colorScheme);
  final bool isLight = colorScheme.brightness == Brightness.light;

  // Using these tinted overlay variable in all themes for ease of
  // reasoning and duplication.
  final Color overlay = colorScheme.surface;
  final Color tint = baseColor;
  final double factor = _tintAlphaFactor(tint, colorScheme.brightness, true);

  return CheckboxThemeData(
    splashRadius: splashRadius,
    side: MaterialStateBorderSide.resolveWith((Set<MaterialState> states) {
      if (useM3) {
        if (states.contains(MaterialState.disabled)) {
          if (states.contains(MaterialState.selected)) {
            return const BorderSide(width: 2.0, color: Colors.transparent);
          }
          if (tintDisable) {
            return BorderSide(
                width: 2.0,
                color: tintedDisable(colorScheme.onSurface, baseColor));
          }
          return BorderSide(
              width: 2.0,
              color: colorScheme.onSurface.withAlpha(kAlphaDisabled));
        }

        if (states.contains(MaterialState.selected)) {
          return const BorderSide(width: 0.0, color: Colors.transparent);
        }
        if (states.contains(MaterialState.error)) {
          return BorderSide(width: 2.0, color: colorScheme.error);
        }
        if (states.contains(MaterialState.pressed)) {
          if (isBaseColor) return BorderSide(width: 2.0, color: baseColor);
          return BorderSide(width: 2.0, color: colorScheme.onSurface);
        }
        if (states.contains(MaterialState.hovered)) {
          if (isBaseColor) return BorderSide(width: 2.0, color: baseColor);
          return BorderSide(width: 2.0, color: colorScheme.onSurface);
        }
        if (states.contains(MaterialState.focused)) {
          if (isBaseColor) return BorderSide(width: 2.0, color: baseColor);
          return BorderSide(width: 2.0, color: colorScheme.onSurface);
        }
        if (isBaseColor) return BorderSide(width: 2.0, color: baseColor);
        return BorderSide(width: 2.0, color: colorScheme.onSurfaceVariant);
      }
      // M2 version
      else {
        if (states.contains(MaterialState.disabled)) {
          if (states.contains(MaterialState.selected)) {
            return const BorderSide(width: 2.0, color: Colors.transparent);
          }
          if (tintDisable) {
            return BorderSide(
              width: 2.0,
              color: tintedDisable(colorScheme.onSurface, baseColor),
            );
          }
          return BorderSide(
            width: 2.0,
            color: colorScheme.onSurface.withAlpha(kAlphaDisabled),
          );
        }
        if (states.contains(MaterialState.selected)) {
          return const BorderSide(width: 2.0, color: Colors.transparent);
        }
        if (isBaseColor) return BorderSide(width: 2.0, color: baseColor);
        // This is M2 SDK default.
        return BorderSide(
            width: 2.0, color: isLight ? Colors.black54 : Colors.white70);
      }
    }),
    fillColor: MaterialStateProperty.resolveWith<Color>(
      (Set<MaterialState> states) {
        if (useM3) {
          if (states.contains(MaterialState.disabled)) {
            if (states.contains(MaterialState.selected)) {
              if (tintDisable) {
                return tintedDisable(colorScheme.onSurface, baseColor);
              }
              return colorScheme.onSurface.withAlpha(kAlphaDisabled);
            }
            return Colors.transparent;
          }
          if (states.contains(MaterialState.selected)) {
            if (states.contains(MaterialState.error)) {
              return colorScheme.error;
            }
            return baseColor;
          }
          return Colors.transparent;
        }
        // M2 version
        else {
          if (states.contains(MaterialState.disabled)) {
            if (states.contains(MaterialState.selected)) {
              if (tintDisable) {
                return tintedDisable(colorScheme.onSurface, baseColor);
              }
              return isLight ? Colors.grey.shade400 : Colors.grey.shade800;
            }
            return Colors.transparent;
          }
          if (states.contains(MaterialState.selected)) {
            return baseColor;
          }
          return Colors.transparent;
        }
      },
    ),
    checkColor: MaterialStateProperty.resolveWith<Color>(
      (Set<MaterialState> states) {
        if (useM3) {
          if (states.contains(MaterialState.disabled)) {
            if (states.contains(MaterialState.selected)) {
              return colorScheme.surface;
            }
            return Colors.transparent;
          }
          if (states.contains(MaterialState.selected)) {
            if (states.contains(MaterialState.error)) {
              return colorScheme.onError;
            }
            return onBaseColor;
          }
          return Colors.transparent;
        }
        // M2 version
        else {
          if (states.contains(MaterialState.disabled)) {
            return isLight ? Colors.grey.shade200 : Colors.grey.shade900;
          }
          if (states.contains(MaterialState.selected)) {
            return onBaseColor;
          }
          return isLight ? Colors.grey.shade50 : Colors.grey.shade400;
        }
      },
    ),
    overlayColor: MaterialStateProperty.resolveWith<Color>(
      (Set<MaterialState> states) {
        // Error state only exists in M3 mode.
        if (states.contains(MaterialState.error) && useM3) {
          if (states.contains(MaterialState.pressed)) {
            return colorScheme.error.withAlpha(kAlphaPressed);
          }
          if (states.contains(MaterialState.hovered)) {
            return colorScheme.error.withAlpha(kAlphaHovered);
          }
          if (states.contains(MaterialState.focused)) {
            return colorScheme.error.withAlpha(kAlphaFocused);
          }
        }
        if (states.contains(MaterialState.selected)) {
          if (states.contains(MaterialState.pressed)) {
            if (tintInteract) return tintedPressed(overlay, tint, factor);
            return colorScheme.onSurface.withAlpha(kAlphaPressed);
          }
          if (states.contains(MaterialState.hovered)) {
            if (tintInteract) return tintedHovered(overlay, tint, factor);
            return baseColor.withAlpha(kAlphaHovered);
          }
          if (states.contains(MaterialState.focused)) {
            if (tintInteract) return tintedFocused(overlay, tint, factor);
            return baseColor.withAlpha(kAlphaFocused);
          }
          return Colors.transparent;
        }
        if (states.contains(MaterialState.pressed)) {
          if (tintInteract) return tintedPressed(overlay, tint, factor);
          return baseColor.withAlpha(kAlphaPressed);
        }
        if (states.contains(MaterialState.hovered)) {
          if (tintInteract) return tintedHovered(overlay, tint, factor);
          return colorScheme.onSurface.withAlpha(kAlphaHovered);
        }
        if (states.contains(MaterialState.focused)) {
          if (tintInteract) return tintedFocused(overlay, tint, factor);
          return colorScheme.onSurface.withAlpha(kAlphaFocused);
        }
        return Colors.transparent;
      },
    ),
  );
}