geopattern's Introduction

geopattern_flutter

Flutter Port of jasonlong/geo_pattern

Geometric Patterns for Flutter using CustomPainters.

Simple Example

import 'dart:convert';

import 'package:crypto/crypto.dart';
import 'package:flutter/material.dart';
import 'package:geopattern_flutter/geopattern_flutter.dart';
import 'package:geopattern_flutter/patterns/mosaic_squares.dart';

void main() => runApp(App());

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final hash = sha1.convert(utf8.encode("flutter")).toString();
    return LayoutBuilder(builder: (context, constraints) {
      final pattern = MosaicSquares.fromHash(hash);
      return CustomPaint(
          size: Size(constraints.maxWidth, constraints.maxHeight),
          painter: FullPainter(pattern: pattern, background: Colors.blueGrey));
    });
  }
}

creates

Patterns are fully customizable, for example a pattern created as

final pattern = ConcentricCircles(
  radius: 40,
  strokeWidth: 8,
  nx: 6,
  ny: 6,
  strokeColors: List.generate(
      36,
      (int i) => Color.fromARGB(
          10 + (gen.nextDouble() * 100).round(),
          50 + gen.nextInt(2) * 150,
          50 + gen.nextInt(2) * 150,
          50 + gen.nextInt(2) * 150)),
  fillColors: List.generate(
      36,
      (int i) => Color.fromARGB(
          10 + (gen.nextDouble() * 100).round(),
          50 + gen.nextInt(2) * 150,
          50 + gen.nextInt(2) * 150,
          50 + gen.nextInt(2) * 150)));

renders

Each pattern has an associated size. The FillPainter class implements CustomPainter such that the pattern is repetitively painted across the entire width and height of the canvas. However, each Pattern has a paint(Canvas, Offset) method that can be used to paint on its own.

There is an example for using a pattern as a background for SliverAppBar in example/appbar.dart

Demo