MaterialStateColor class abstract

Defines a Color that is also a MaterialStateProperty.

This class exists to enable widgets with Color valued properties to also accept MaterialStateProperty<Color> values. A material state color property represents a color which depends on a widget's "interactive state". This state is represented as a Set of MaterialStates, like MaterialState.pressed, MaterialState.focused and MaterialState.hovered.

MaterialStateColor should only be used with widgets that document their support, like TimePickerThemeData.dayPeriodColor.

To use a MaterialStateColor, you can either:

1. Create a subclass of MaterialStateColor and implement the abstract resolve method.
2. Use MaterialStateColor.resolveWith and pass in a callback that will be used to resolve the color in the given states.

If a MaterialStateColor is used for a property or a parameter that doesn't support resolving MaterialStateProperty<Color>s, then its default color value will be used for all states.

To define a const MaterialStateColor, you'll need to extend MaterialStateColor and override its resolve method. You'll also need to provide a defaultValue to the super constructor, so that we can know at compile-time what its default color is.

class MyColor extends MaterialStateColor {
  const MyColor() : super(_defaultColor);

  static const int _defaultColor = 0xcafefeed;
  static const int _pressedColor = 0xdeadbeef;

  @override
  Color resolve(Set<MaterialState> states) {
    if (states.contains(MaterialState.pressed)) {
      return const Color(_pressedColor);
    }
    return const Color(_defaultColor);
  }
}