defaultStyleOf method

  1. @override
ButtonStyle defaultStyleOf(
  1. BuildContext context
)
override

Defines the button's default appearance.

The button child's Text and Icon widgets are rendered with the ButtonStyle's foreground color. The button's InkWell adds the style's overlay color when the button is focused, hovered or pressed. The button's background color becomes its Material color.

All of the ButtonStyle's defaults appear below. In this list "Theme.foo" is shorthand for Theme.of(context).foo. Color scheme values like "onSurface(0.38)" are shorthand for onSurface.withOpacity(0.38). WidgetStateProperty valued properties that are not followed by a sublist have the same value for all states, otherwise the values are as specified for each state, and "others" means all other states.

The "default font size" below refers to the font size specified in the defaultStyleOf method (or 14.0 if unspecified), scaled by the MediaQuery.textScalerOf(context).scale method. The names of the EdgeInsets constructors and EdgeInsetsGeometry.lerp have been abbreviated for readability.

The color of the ButtonStyle.textStyle is not used, the ButtonStyle.foregroundColor color is used instead.

Material 2 defaults

  • textStyle - Theme.textTheme.button
  • backgroundColor
    • disabled - Theme.colorScheme.onSurface(0.12)
    • others - Theme.colorScheme.primary
  • foregroundColor
    • disabled - Theme.colorScheme.onSurface(0.38)
    • others - Theme.colorScheme.onPrimary
  • overlayColor
    • hovered - Theme.colorScheme.onPrimary(0.08)
    • focused or pressed - Theme.colorScheme.onPrimary(0.12)
  • shadowColor - Theme.shadowColor
  • elevation
    • disabled - 0
    • default - 2
    • hovered or focused - 4
    • pressed - 8
  • padding
    • default font size <= 14 - horizontal(16)
    • 14 < default font size <= 28 - lerp(horizontal(16), horizontal(8))
    • 28 < default font size <= 36 - lerp(horizontal(8), horizontal(4))
    • 36 < default font size - horizontal(4)
  • minimumSize - Size(64, 36)
  • fixedSize - null
  • maximumSize - Size.infinite
  • side - null
  • shape - RoundedRectangleBorder(borderRadius: BorderRadius.circular(4))
  • mouseCursor
    • disabled - SystemMouseCursors.basic
    • others - SystemMouseCursors.click
  • visualDensity - theme.visualDensity
  • tapTargetSize - theme.materialTapTargetSize
  • animationDuration - kThemeChangeDuration
  • enableFeedback - true
  • alignment - Alignment.center
  • splashFactory - InkRipple.splashFactory

The default padding values for the ElevatedButton.icon factory are slightly different:

  • padding
    • default font size <= 14 - start(12) end(16)
    • 14 < default font size <= 28 - lerp(start(12) end(16), horizontal(8))
    • 28 < default font size <= 36 - lerp(horizontal(8), horizontal(4))
    • 36 < default font size - horizontal(4)

The default value for side, which defines the appearance of the button's outline, is null. That means that the outline is defined by the button shape's OutlinedBorder.side. Typically the default value of an OutlinedBorder's side is BorderSide.none, so an outline is not drawn.

Material 3 defaults

If ThemeData.useMaterial3 is set to true the following defaults will be used:

  • textStyle - Theme.textTheme.labelLarge
  • backgroundColor
    • disabled - Theme.colorScheme.onSurface(0.12)
    • others - Theme.colorScheme.surfaceContainerLow
  • foregroundColor
    • disabled - Theme.colorScheme.onSurface(0.38)
    • others - Theme.colorScheme.primary
  • overlayColor
    • hovered - Theme.colorScheme.primary(0.08)
    • focused or pressed - Theme.colorScheme.primary(0.1)
  • shadowColor - Theme.colorScheme.shadow
  • surfaceTintColor - Colors.transparent
  • elevation
    • disabled - 0
    • default - 1
    • hovered - 3
    • focused or pressed - 1
  • padding
    • default font size <= 14 - horizontal(24)
    • 14 < default font size <= 28 - lerp(horizontal(24), horizontal(12))
    • 28 < default font size <= 36 - lerp(horizontal(12), horizontal(6))
    • 36 < default font size - horizontal(6)
  • minimumSize - Size(64, 40)
  • fixedSize - null
  • maximumSize - Size.infinite
  • side - null
  • shape - StadiumBorder()
  • mouseCursor
    • disabled - SystemMouseCursors.basic
    • others - SystemMouseCursors.click
  • visualDensity - Theme.visualDensity
  • tapTargetSize - Theme.materialTapTargetSize
  • animationDuration - kThemeChangeDuration
  • enableFeedback - true
  • alignment - Alignment.center
  • splashFactory - Theme.splashFactory

For the ElevatedButton.icon factory, the start (generally the left) value of ButtonStyle.padding is reduced from 24 to 16.

Implementation

@override
ButtonStyle defaultStyleOf(BuildContext context) {
  final ThemeData theme = Theme.of(context);
  final ColorScheme colorScheme = theme.colorScheme;

  return Theme.of(context).useMaterial3
    ? _ElevatedButtonDefaultsM3(context)
    : styleFrom(
        backgroundColor: colorScheme.primary,
        foregroundColor: colorScheme.onPrimary,
        disabledBackgroundColor: colorScheme.onSurface.withOpacity(0.12),
        disabledForegroundColor: colorScheme.onSurface.withOpacity(0.38),
        shadowColor: theme.shadowColor,
        elevation: 2,
        textStyle: theme.textTheme.labelLarge,
        padding: _scaledPadding(context),
        minimumSize: const Size(64, 36),
        maximumSize: Size.infinite,
        shape: const RoundedRectangleBorder(borderRadius: BorderRadius.all(Radius.circular(4))),
        enabledMouseCursor: SystemMouseCursors.click,
        disabledMouseCursor: SystemMouseCursors.basic,
        visualDensity: theme.visualDensity,
        tapTargetSize: theme.materialTapTargetSize,
        animationDuration: kThemeChangeDuration,
        enableFeedback: true,
        alignment: Alignment.center,
        splashFactory: InkRipple.splashFactory,
      );
}