cached_network_image 3.2.0

Flutter library to load and cache network images. Can also be used with placeholder and error widgets.

example/lib/main.dart

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';
import 'package:baseflow_plugin_template/baseflow_plugin_template.dart';
import 'package:flutter_blurhash/flutter_blurhash.dart';

void main() {
  CachedNetworkImage.logLevel = CacheManagerLogLevel.debug;

  runApp(BaseflowPluginExample(
    pluginName: 'CachedNetworkImage',
    githubURL: 'https://github.com/Baseflow/flutter_cache_manager',
    pubDevURL: 'https://pub.dev/packages/flutter_cache_manager',
    pages: [
      BasicContent.createPage(),
      ListContent.createPage(),
      GridContent.createPage(),
    ],
  ));
}

/// Demonstrates a [StatelessWidget] containing [CachedNetworkImage]
class BasicContent extends StatelessWidget {
  const BasicContent({Key? key}) : super(key: key);

  static ExamplePage createPage() {
    return ExamplePage(Icons.image, (context) => const BasicContent());
  }

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            _blurHashImage(),
            _sizedContainer(
              const Image(
                image: CachedNetworkImageProvider(
                  'https://via.placeholder.com/350x150',
                ),
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                progressIndicatorBuilder: (context, url, progress) => Center(
                  child: CircularProgressIndicator(
                    value: progress.progress,
                  ),
                ),
                imageUrl:
                    'https://images.unsplash.com/photo-1532264523420-881a47db012d?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9',
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                placeholder: (context, url) =>
                    const CircularProgressIndicator(),
                imageUrl: 'https://via.placeholder.com/200x150',
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                imageUrl: 'https://via.placeholder.com/300x150',
                imageBuilder: (context, imageProvider) => Container(
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: imageProvider,
                      fit: BoxFit.cover,
                      colorFilter: const ColorFilter.mode(
                        Colors.red,
                        BlendMode.colorBurn,
                      ),
                    ),
                  ),
                ),
                placeholder: (context, url) =>
                    const CircularProgressIndicator(),
                errorWidget: (context, url, error) => const Icon(Icons.error),
              ),
            ),
            CachedNetworkImage(
              imageUrl: 'https://via.placeholder.com/300x300',
              placeholder: (context, url) => const CircleAvatar(
                backgroundColor: Colors.amber,
                radius: 150,
              ),
              imageBuilder: (context, image) => CircleAvatar(
                backgroundImage: image,
                radius: 150,
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                imageUrl: 'https://notAvalid.uri',
                placeholder: (context, url) =>
                    const CircularProgressIndicator(),
                errorWidget: (context, url, error) => const Icon(Icons.error),
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                imageUrl: 'not a uri at all',
                placeholder: (context, url) =>
                    const CircularProgressIndicator(),
                errorWidget: (context, url, error) => const Icon(Icons.error),
              ),
            ),
            _sizedContainer(
              CachedNetworkImage(
                maxHeightDiskCache: 10,
                imageUrl: 'https://via.placeholder.com/350x200',
                placeholder: (context, url) =>
                    const CircularProgressIndicator(),
                errorWidget: (context, url, error) => const Icon(Icons.error),
                fadeOutDuration: const Duration(seconds: 1),
                fadeInDuration: const Duration(seconds: 3),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _blurHashImage() {
    return SizedBox(
      width: double.infinity,
      child: CachedNetworkImage(
        placeholder: (context, url) => const AspectRatio(
          aspectRatio: 1.6,
          child: BlurHash(hash: 'LEHV6nWB2yk8pyo0adR*.7kCMdnj'),
        ),
        imageUrl: 'https://blurha.sh/assets/images/img1.jpg',
        fit: BoxFit.cover,
      ),
    );
  }

  Widget _sizedContainer(Widget child) {
    return SizedBox(
      width: 300.0,
      height: 150.0,
      child: Center(child: child),
    );
  }
}

/// Demonstrates a [ListView] containing [CachedNetworkImage]
class ListContent extends StatelessWidget {
  const ListContent({Key? key}) : super(key: key);

  static ExamplePage createPage() {
    return ExamplePage(Icons.list, (context) => const ListContent());
  }

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemBuilder: (BuildContext context, int index) => Card(
        child: Column(
          children: <Widget>[
            CachedNetworkImage(
              imageUrl: 'https://loremflickr.com/320/240/music?lock=$index',
              placeholder: (BuildContext context, String url) => Container(
                width: 320,
                height: 240,
                color: Colors.purple,
              ),
            ),
          ],
        ),
      ),
      itemCount: 250,
    );
  }
}

/// Demonstrates a [GridView] containing [CachedNetworkImage]
class GridContent extends StatelessWidget {
  const GridContent({Key? key}) : super(key: key);

  static ExamplePage createPage() {
    return ExamplePage(Icons.grid_on, (context) => const GridContent());
  }

  @override
  Widget build(BuildContext context) {
    return GridView.builder(
      itemCount: 250,
      gridDelegate:
          const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
      itemBuilder: (BuildContext context, int index) => CachedNetworkImage(
        imageUrl: 'https://loremflickr.com/100/100/music?lock=$index',
        placeholder: _loader,
        errorWidget: _error,
      ),
    );
  }

  Widget _loader(BuildContext context, String url) {
    return const Center(
      child: CircularProgressIndicator(),
    );
  }

  Widget _error(BuildContext context, String url, dynamic error) {
    return const Center(child: Icon(Icons.error));
  }
}