dartterm/lib/assets.dart

import 'dart:ui' as ui;

import 'package:flutter/services.dart';

class Assets {
  final Map<String, ui.Image> _loaded = {};
  final Set<String> _waiting = {};

  Future<ui.Image> _getImageAsync(String name) async {
    final assetImageByteData = await rootBundle.load(name);
    final codec =
        await ui.instantiateImageCodec(assetImageByteData.buffer.asUint8List());
    final image = (await codec.getNextFrame()).image;

    _loaded[name] = image;
    return image;
  }

  ui.Image? getImageIfAvailable(String name) {
    if (!_waiting.contains(name)) {
      _waiting.add(name);
      _getImageAsync(name);
    }
    return _loaded[name];
  }
}

final assets = Assets();

ui.Image? getImageIfAvailable(String name) {
  return assets.getImageIfAvailable(name);
}