[Flutter Web] FontLoader doesn't work on web.

[johnsonmh]

Steps to Reproduce

Run the following app on Web:

import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:http/http.dart' as http;

Future<ByteData> fetchFont() async {
  final response = await http.get(
      'https://raw.githubusercontent.com/google/fonts/master/ofl/montserrat/Montserrat-Light.ttf');

  if (response.statusCode == 200) {
    return ByteData.view(response.bodyBytes.buffer);
  } else {
    // If that call was not successful, throw an error.
    throw Exception('Failed to load font');
  }
}

void main() async {
  var fontLoader = FontLoader('Montserrat');
  fontLoader.addFont(fetchFont());
  await fontLoader.load();

  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Custom Fonts',
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Custom Fonts')),
      body: Center(
        child: Text(
          'Montserrat is displayed here',
          style: TextStyle(fontFamily: 'Montserrat'),
        ),
      ),
    );
  }
}

Target Platform:: Web
Target OS version/browser:: MacOS/chrome

Logs

The following error is produced in the chrome console:

:57711/favicon.ico:1 Failed to load resource: the server responded with a status of 404 (Not Found)
errors.dart:145 Uncaught (in promise) Error: Unsupported operation: loadFontFromList is not supported.
    at Object.throw_ [as throw] (errors.dart:194)
    at Object.loadFontFromList (text.dart:1384)
    at font_loader.FontLoader.new.loadFont (font_loader.dart:75)
    at font_loader.dart:62
    at _RootZone.runUnary (zone.dart:1379)
    at _FutureListener.then.handleValue (future_impl.dart:137)
    at handleValueCallback (future_impl.dart:678)
    at Function._propagateToListeners (future_impl.dart:707)
    at _Future.new.[_completeWithValue] (future_impl.dart:522)
    at async._AsyncCallbackEntry.new.callback (future_impl.dart:552)
    at Object._microtaskLoop (schedule_microtask.dart:41)
    at _startMicrotaskLoop (schedule_microtask.dart:50)
    at async_patch.dart:166

Flutter doctor output:

[✓] Flutter (Channel master, v1.10.2-pre.950, on Mac OS X 10.14.6 18G87, locale en-US)
    • Flutter version 1.10.2-pre.950 at /Users/johnsonmh/mdc/flutter
    • Framework revision 6cb6857f92 (13 days ago), 2019-11-14 16:50:17 -0500
    • Engine revision 77c3512ec8
    • Dart version 2.7.0


[!] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /Users/johnsonmh/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-stable, build-tools 29.0.2
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
    ! Some Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses

[✓] Xcode - develop for iOS and macOS (Xcode 11.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 11.0, Build version 11A420a
    • CocoaPods version 1.7.5

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio
    • Android Studio at /Applications/Android Studio with Blaze.app/Contents
    • Flutter plugin version 41.2.3
    • Dart plugin version 192.7761
    • Java version OpenJDK Runtime Environment (build 1.8.0_212-release-1586-b4-5784211)

[✓] Android Studio (version 3.5)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 39.0.3
    • Dart plugin version 191.8423
    • Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)

[✓] Connected device (4 available)
    • iPhone 11 Pro Max • 51ED21D6-0095-4C79-8B9B-A556005909CF • ios            • com.apple.CoreSimulator.SimRuntime.iOS-13-0 (simulator)
    • macOS             • macOS                                • darwin-x64     • Mac OS X 10.14.6 18G87
    • Chrome            • chrome                               • web-javascript • Google Chrome 78.0.3904.108
    • Web Server        • web-server                           • web-javascript • Flutter Tools

! Doctor found issues in 1 category.

[johnsonmh]

The above demo does not compile on MacOS Desktop either.

[jonahwilliams]

Duplicate of #45459

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.