rainbow_color 2.0.1

Simplified multi-color interpolation. Map a numerical domain to a smooth-transitioning color range.

rainbow_color

RainbowColor simplifies interpolation a numerical domain onto a multi-color range. RainbowColor accepts a numerical domain (i.e. a start and end number) and a spectrum of two or more colors, and offers the list access operator ([]) for interpolation.

This package also provides RainbowColorTween, a multi-color variant of the standard ColorTween, eliminating the need to build more complex TweenSequence for equal-weight transitions.

Usage

To interpolate a color among the spectrum, use the list access operator, e.g.

import 'package:rainbow_color/rainbow_color.dart';

var rb = Rainbow(spectrum: [Color(0xFFFF0000), Color(0xFFFFFFFF), Color(0xff00ff00)],
                 rangeStart: -10,
                 rangeEnd: 10);
Color warmColor = rb[-9.32];
Color coldColor = rb[8.44];

Or use RainbowColorTween in place of ColorTween to interpolate among multiple colors instead of two.

@override
  void initState() {
    super.initState();
    _controller = AnimationController(duration: widget.duration, vsync: this);
    _clAnim = RainbowColorTween([Color(0x33FFAAAA),
                                 Color(0x33000000),
                                 Color(0x00000000)]).animate(_controller)
                                                    ..addListener(() { 
                                                         setState(() {}); 
                                                    });
}

See Also

This is a Flutter-oriented version of the vanilla Dart package rainbow_vis.