defaultStyleOf method

@override ButtonStyle defaultStyleOf(BuildContext context)

Returns a ButtonStyle that's based primarily on the Theme's ThemeData.textTheme and ThemeData.colorScheme, but has most values filled out (non-null).

The returned style can be overridden by the style parameter and by the style returned by themeStyleOf that some button-specific themes like TextButtonTheme or ElevatedButtonTheme override. For example the default style of the TextButton subclass can be overridden with its TextButton.style constructor parameter, or with a TextButtonTheme.

Concrete button subclasses should return a ButtonStyle with as many non-null properties as possible, where all of the non-null WidgetStateProperty properties resolve to non-null values.

Properties that can be null

Some properties, like ButtonStyle.fixedSize would override other values in the same ButtonStyle if set, so they are allowed to be null. Here is a summary of properties that are allowed to be null when returned in the ButtonStyle returned by this function, an why:

• ButtonStyle.fixedSize because it would override other values in the same ButtonStyle, like ButtonStyle.maximumSize.
• ButtonStyle.side because null is a valid value for a button that has no side. OutlinedButton returns a non-null default for this, however.
• ButtonStyle.backgroundBuilder and ButtonStyle.foregroundBuilder because they would override the ButtonStyle.foregroundColor and ButtonStyle.backgroundColor of the same ButtonStyle.

See also:

• themeStyleOf, returns the ButtonStyle of this button's component theme.

Implementation

@override
material.ButtonStyle defaultStyleOf(widgets.BuildContext context) {
  final face = context.face;

  final metrics = _ButtonMetrics.fromSize(size, compact: compact);

  final foreground = widgets.WidgetStateProperty.resolveWith<widgets.Color?>(
    (states) => _resolveColors(context, states).foreground,
  );

  return material.ButtonStyle(
    textStyle: widgets.WidgetStatePropertyAll(face.type(metrics.typeToken)),

    backgroundColor: widgets.WidgetStateProperty.resolveWith<widgets.Color?>(
      (states) => _resolveColors(context, states).background,
    ),

    foregroundColor: foreground,

    iconColor: foreground,

    overlayColor: const widgets.WidgetStatePropertyAll(
      widgets.Color(0x00000000),
    ),

    shadowColor: const widgets.WidgetStatePropertyAll(
      widgets.Color(0x00000000),
    ),

    surfaceTintColor: const widgets.WidgetStatePropertyAll(
      widgets.Color(0x00000000),
    ),

    elevation: const widgets.WidgetStatePropertyAll(0),

    padding: widgets.WidgetStatePropertyAll(
      widgets.EdgeInsets.symmetric(
        horizontal: face.space(metrics.horizontalSpace),
        vertical: face.space(metrics.verticalSpace),
      ),
    ),

    minimumSize: widgets.WidgetStatePropertyAll(
      widgets.Size(0, face.rem(metrics.minHeight)),
    ),

    maximumSize: const widgets.WidgetStatePropertyAll(widgets.Size.infinite),

    iconSize: widgets.WidgetStatePropertyAll(face.rem(metrics.iconSize)),

    // Актуальное место для настройки icon alignment.
    //
    // ButtonStyleButton.iconAlignment уже deprecated.
    iconAlignment: iconPosition,

    side: widgets.WidgetStateProperty.resolveWith<widgets.BorderSide?>((
      states,
    ) {
      final border = _resolveColors(context, states).border;

      if (border == null) {
        return widgets.BorderSide.none;
      }

      return widgets.BorderSide(color: border);
    }),

    shape: widgets.WidgetStatePropertyAll(
      material.RoundedRectangleBorder(
        borderRadius: widgets.BorderRadius.circular(face.radius('lg')),
      ),
    ),

    mouseCursor: widgets.WidgetStateMouseCursor.adaptiveClickable,

    // Carpenter сам управляет metrics.
    visualDensity: material.VisualDensity.standard,

    // Не добавляем Material minimum tap target поверх
    // Carpenter размеров.
    tapTargetSize: material.MaterialTapTargetSize.shrinkWrap,

    animationDuration: face.motion.fast,

    enableFeedback: true,

    alignment: widgets.Alignment.center,

    // Hover / focus / pressed уже выражаются Carpenter-цветами.
    splashFactory: material.NoSplash.splashFactory,
  );
}