[flutter_svg] feat: Expose the colorMapper property in SvgPicture

[ricardodalarme]

Description

This pull request exposes the existing colorMapper functionality in the flutter_svg package, allowing developers to customize SVG colors during parsing.

Related Issue

• [flutter_svg] Change colors for multi color svg flutter#158634

Motivation

The colorMapper functionality was already present within the flutter_svg package but was not directly accessible through the SvgPicture constructors. By exposing this property, developers gain a powerful and flexible way to dynamically modify the colors of SVG assets based on custom logic. This can be useful for various scenarios, such as theming or branding.

Example Usage

import 'package:flutter/material.dart';
import 'package:flutter_svg/flutter_svg.dart';

const String svgString = '''
<svg viewBox="0 0 100 100">
  <rect width="50" height="50" fill="#FF0000" />
  <circle cx="75" cy="75" r="25" fill="#00FF00" />
</svg>
''';

class MyColorMapper extends ColorMapper {
  const MyColorMapper();

  @override
  Color substitute(
      String? id, String elementName, String attributeName, Color color) {
    if (color == const Color(0xFFFF0000)) {
      return Colors.blue;
    }
    if (color == const Color(0xFF00FF00)) {
      return Colors.yellow;
    }
    return color;
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      body: Center(
        child: SvgPicture.string(
          svgString,
          width: 200,
          height: 200,
          colorMapper: const MyColorMapper(),
        ),
      ),
    ),
  ));
}

[flutter-dashboard]

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[domesticmouse]

Please add tests and bump version in pubspec.yaml

[ricardodalarme]

@domesticmouse done!

[ricardodalarme]

Hey @domesticmouse, I just updated the PR by formatting the code and updating the README to include a code excerpt in the code example. Could you please take another look?

[domesticmouse]

PTAL @stuartmorgan-g

[jonahwilliams]

LGTM

this is going to collide with #8986

[ricardodalarme]

hey @jonahwilliams @domesticmouse I’ve reviewed #8986 and I believe it’s safe to merge this PR. Although flutter_svg depends on vector_graphics_compiler, I didn’t find any direct or indirect references to parseWithoutOptimizers (the function modified in the other PR) that could impact those changes.

[stuartmorgan-g]

@jonahwilliams This has two approvals; was it waiting for anything else to be autosubmited?

[jonahwilliams]

Nope, this one is good.