import 'package:flutter/material.dart'; import 'package:photo_manager/photo_manager.dart'; abstract class LoadingDelegate { Widget buildBigImageLoading( BuildContext context, AssetEntity entity, Color themeColor); Widget buildPreviewLoading( BuildContext context, AssetEntity entity, Color themeColor); } class DefaultLoadingDelegate extends LoadingDelegate { @override Widget buildBigImageLoading( BuildContext context, AssetEntity entity, Color themeColor) { return Center( child: Container( width: 30.0, height: 30.0, child: CircularProgressIndicator( valueColor: AlwaysStoppedAnimation(themeColor), ), ), ); } @override Widget buildPreviewLoading( BuildContext context, AssetEntity entity, Color themeColor) { return Center( child: Container( width: 30.0, height: 30.0, child: CircularProgressIndicator( valueColor: AlwaysStoppedAnimation(themeColor), ), ), ); } }