getGridImage function
Implementation
Future<ui.Image> getGridImage() {
if (_gridImage != null) return Future.value(_gridImage!);
final completer = Completer<ui.Image>();
AssetImage('packages/blossom_color_picker/assets/grid.png')
.resolve(ImageConfiguration())
.addListener(ImageStreamListener((ImageInfo info, bool _) {
_gridImage = info.image;
completer.complete(_gridImage);
}));
return completer.future;
}