MaterialStateColor class Null safety

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.

link
This example defines a MaterialStateColor with a const constructor. 
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);
  }
}

Inheritance
Implemented types

Constructors

MaterialStateColor(int defaultValue)
Abstract const constructor. This constructor enables subclasses to provide const constructors so that they can be used in const expressions.
const

Properties

alpha → int
The alpha channel of this color in an 8 bit value.
read-onlyinherited
blue → int
The blue channel of this color in an 8 bit value.
read-onlyinherited
green → int
The green channel of this color in an 8 bit value.
read-onlyinherited
hashCode → int
The hash code for this object.
read-onlyinherited
opacity → double
The alpha channel of this color as a double.
read-onlyinherited
red → int
The red channel of this color in an 8 bit value.
read-onlyinherited
runtimeType → Type
A representation of the runtime type of the object.
read-onlyinherited
value → int
A 32 bit value representing this color.
finalinherited

Methods

computeLuminance() → double
Returns a brightness value between 0 for darkest and 1 for lightest.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
inherited
resolve(Set<MaterialState> states) → Color
Returns a Color that's to be used when a Material component is in the specified state.
override
toString() → String
A string representation of this object.
inherited
withAlpha(int a) → Color
Returns a new color that matches this color with the alpha channel replaced with a (which ranges from 0 to 255).
inherited
withBlue(int b) → Color
Returns a new color that matches this color with the blue channel replaced with b (which ranges from 0 to 255).
inherited
withGreen(int g) → Color
Returns a new color that matches this color with the green channel replaced with g (which ranges from 0 to 255).
inherited
withOpacity(double opacity) → Color
Returns a new color that matches this color with the alpha channel replaced with the given opacity (which ranges from 0.0 to 1.0).
inherited
withRed(int r) → Color
Returns a new color that matches this color with the red channel replaced with r (which ranges from 0 to 255).
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

resolveWith(MaterialPropertyResolver<Color> callback) → MaterialStateColor
Creates a MaterialStateColor from a MaterialPropertyResolver<Color> callback function.
override