rnd package #

Makes working with random values in Dart / Flutter easier:

1. It provides an easy to access, global instance of Random.
2. It adds helpful extension methods to Random.

Global instance #

To make it easy to set up and propagate a Random instance throughout your app, the rnd package exposes a global instance via the rnd property. This makes generating a random value as simple as:

import 'package:rnd/rnd.dart';
rnd(10); // random double between 0-10
rnd.getBool(0.8); // 80% chance to get true

You can also get and set the seed for the global instance via rndSeed.

Extension methods on Random #

Adds the following methods to all instances of Random. Read the docs for more info.

• getInt(min, max, {curve}) // see "Curves" below
• getDouble(min, max, {curve})
• getBool(chance)
• getBit(chance) // 0 or 1
• getSign(chance) // -1 or 1
• getDeg() // 0-360
• getRad() // 0-2pi
• getColor({...}) // see docs for params
• getItem(list, {remove, curve})
• shuffle(list, {copy}) // randomize list

It also defines a call method, which lets you get a random double value by calling a Random instance directly:

Random myRandom = new Random();
print(myRandom()); // double between 0-1
print(myRandom(10)); // 0-10
print(myRandom(5,10)); // 5-10

This pairs well with the global instance for quickly getting random values:

new Point(rnd(maxX), rnd(maxY))

Curves #

The getDouble, getInt, and getItem methods support a curve param which transforms the value distribution. For example:

rnd.getInt(0, 100, curve: Curves.easeIn)

This would favor values nearer to 0, whereas easeOut would favor values nearer to 100. The included example app visualizes the effect of different curves.

Hue #

The included Hue class provides named hue values for use with getColor. For example, Hue.green == 120.

rnd.getColor(hue: Hue.red); // red, green, blue, yellow, cyan, magenta