eo_color

EO-Color logo

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EO-Color is an Elegant and Object-oriented implementation of the Material Design color palettes. It is intended to be used as:

  • an alternative to the Flutter's built-in colors
  • a base framework for more specific color packages

A key benefit of EO-Color is to improve the source code readability and maintainability by providing a declarative interface.

The use of obscure numeric indexes such as 100, 200 ... 800, 900 to select the shade of a color has been deliberately dropped in favour of a more friendly approach: the use of adverbs (ultra, very, bit, etc) and adjectives (light, dark, etc). For example, to get a light shade of grey, simply declare Grey.light().

Getting Started

Like any object-oriented package, this one utilizes interfaces to define concepts such as color palettes and swatches. Therefore, it is no surprise that the two core interfaces are Palette and Swatch.

Palette interface

It represents color palettes from which a color can be picked. Tipically, classes that implement Palette provide named constructors in which the desired color is selected to be retrieved afterwards - via color property.

Material Design palette classes

These are classes whose name is the color they represent, such as "Grey". For example: Grey() represents the primary grey color, equivalent to the Flutter's cryptic Colors.grey.shade500; Grey.light()Colors.grey.shade200; Grey.veryDark()Colors.grey.shade900; and so on.

Palettes in action

import 'package:eo_color/palettes.dart';
import 'package:flutter/material.dart';

class Greyish extends StatelessWidget {

  static const _light = Grey.light();

  @override
  Widget build(BuildContext context) {
    return Container(
      color: _light.color,
    );
  }
}

Equivalence between the Material Design indexes and constructors

  • Note:
    • The "Normal" column refers to classes that represent non-accented colors: Amber, Green, Red, etc.
    • The "Accent" column refers to classes that represent accented colors: AmberAccent, GreenAccent, RedAccent, etc.
IndexNormalAccent
50ultraLight
100veryLightlight
200light()
300lighter
400bitLighterdarker
500()
600bitDarker
700darkerdark
800dark
900veryDark

Supported palette colors

Swatch interface

A color swatch is a collection of related colors, such as the colors of the rainbow, shades of grey, etc. Its single property colors retrieves several colors at once as an Iterable<Color>. For instance, Greys().colors retrieves ten shades of grey - as defined by the Material Design standard.

Color Swatch Classes

These are classes whose name is the plural of a color, such as "Greys". For example: Greys().colors retrieves an Iterable<Color> containing ten shades of grey; the higher the index, the darker the color.

Swatch in action

import 'package:eo_color/swatches.dart';
import 'package:flutter/material.dart';

/// Rectangle filled with a gradient of ten shades of a Material Design color.
class RectGradient extends StatelessWidget {
  /// Rectangle filled with the given color swatch.
  const RectGradient(Swatch swatch, {Key? key})
      : _swatch = swatch,
        super(key: key);

  /// Rectangle filled with ten shades of grey.
  const RectGradient.grey({Key? key}) : this(const Greys(), key: key);

  // Material Design color swatch.
  final Swatch _swatch;

  @override
  Widget build(BuildContext context) {
    return Container(
      height: kToolbarHeight / 2,
      decoration: BoxDecoration(
        gradient: LinearGradient(
          end: Alignment.bottomLeft,
          begin: Alignment.topRight,
          colors: _swatch.colors.toList(growable: false),
        ),
      ),
    );
  }
}

Supported color swatches

Showcase application

The showcase application provides a fully working example, focused on demonstrating exactly three color palettes in action - BlueGrey, Grey, and Brown. You can take the code in this showcase and experiment with it.

To run the showcase application:

git clone https://github.com/dartoos-dev/eo_color.git
cd eo_color/example/
flutter run -d chrome

This should launch the showcase application on Chrome in debug mode.

EO-Color-Showcase

References

Libraries

eo_color
palettes
The color palettes.
swatches
The color swatches.