freezer/lib/ui/cached_image.dart

import 'package:flutter/material.dart';
import 'package:palette_generator/palette_generator.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:photo_view/photo_view.dart';
import 'package:freezer/translations.i18n.dart';

ImagesDatabase imagesDatabase = ImagesDatabase();

class ImagesDatabase {
  /*
  !!! Using the wrappers so i don't have to rewrite most of the code, because of migration to cached network image
  */

  void saveImage(String url) {
    CachedNetworkImageProvider(url);
  }

  Future<PaletteGenerator> getPaletteGenerator(String url) {
    return PaletteGenerator.fromImageProvider(CachedNetworkImageProvider(url));
  }

  Future<Color> getPrimaryColor(String url) async {
    PaletteGenerator paletteGenerator = await getPaletteGenerator(url);
    return paletteGenerator.dominantColor!.color;
  }

  Future<bool> isDark(String url) async {
    PaletteGenerator paletteGenerator = await getPaletteGenerator(url);
    return paletteGenerator.colors.first.computeLuminance() > 0.5
        ? false
        : true;
  }
}

class CachedImage extends StatefulWidget {
  final String url;
  final double? width;
  final double? height;
  final bool circular;
  final bool fullThumb;
  final bool rounded;

  const CachedImage(
      {Key? key,
      required this.url,
      this.height,
      this.width,
      this.circular = false,
      this.fullThumb = false,
      this.rounded = false})
      : super(key: key);

  @override
  _CachedImageState createState() => _CachedImageState();
}

class _CachedImageState extends State<CachedImage> {
  @override
  Widget build(BuildContext context) {
    if (widget.rounded)
      return ClipRRect(
        borderRadius: BorderRadius.circular(4.0),
        child: CachedImage(
            url: widget.url,
            height: widget.height,
            width: widget.width,
            circular: false,
            rounded: false,
            fullThumb: widget.fullThumb),
      );

    if (widget.circular)
      return ClipOval(
          child: CachedImage(
        url: widget.url,
        height: widget.height,
        width: widget.width,
        circular: false,
        rounded: false,
        fullThumb: widget.fullThumb,
      ));

    if (!widget.url.startsWith('http'))
      return Image.asset(
        widget.url,
        width: widget.width,
        height: widget.height,
      );

    return CachedNetworkImage(
      imageUrl: widget.url,
      width: widget.width,
      height: widget.height,
      placeholder: (context, url) {
        if (widget.fullThumb)
          return Image.asset(
            'assets/cover.jpg',
            width: widget.width,
            height: widget.height,
          );
        return Image.asset('assets/cover_thumb.jpg',
            width: widget.width, height: widget.height);
      },
      errorWidget: (context, url, error) => Image.asset('assets/cover.jpg',
          width: widget.width, height: widget.height),
    );
  }
}

class ZoomableImage extends StatefulWidget {
  final String url;
  final bool rounded;
  final double? width;
  final bool enableHero;
  final Object? heroTag;

  ZoomableImage({
    required this.url,
    this.rounded = false,
    this.width,
    this.enableHero = true,
    this.heroTag,
  });

  @override
  _ZoomableImageState createState() => _ZoomableImageState();
}

class _ZoomableImageState extends State<ZoomableImage> {
  PhotoViewController? controller;
  bool photoViewOpened = false;
  late final Object? _key =
      widget.enableHero ? (widget.heroTag ?? UniqueKey()) : null;

  @override
  void initState() {
    super.initState();
    controller = PhotoViewController()..outputStateStream.listen(listener);
  }

  // Listener of PhotoView scale changes. Used for closing PhotoView by pinch-in
  void listener(PhotoViewControllerValue value) {
    if (value.scale! < 0.16 && photoViewOpened) {
      Navigator.pop(context);
      photoViewOpened =
          false; // to avoid multiple pop() when picture are being scaled out too slowly
    }
  }

  @override
  Widget build(BuildContext context) {
    print('key: ' + _key.toString());
    final image = CachedImage(
      url: widget.url,
      rounded: widget.rounded,
      width: widget.width,
      fullThumb: true,
    );
    final child = _key != null
        ? Hero(
            tag: _key!,
            child: image,
          )
        : image;
    return GestureDetector(
      child: Semantics(
        child: child,
        label: "Album art".i18n,
      ),
      onTap: () {
        Navigator.of(context).push(PageRouteBuilder(
            opaque: false, // transparent background
            pageBuilder: (context, animation, __) {
              print('key: ' + _key.toString());
              photoViewOpened = true;
              return FadeTransition(
                opacity: animation,
                child: PhotoView(
                    imageProvider: CachedNetworkImageProvider(widget.url),
                    maxScale: 8.0,
                    minScale: 0.2,
                    controller: controller,
                    heroAttributes: _key == null
                        ? null
                        : PhotoViewHeroAttributes(tag: _key!),
                    backgroundDecoration: const BoxDecoration(
                        color: Color.fromARGB(0x90, 0, 0, 0))),
              );
            }));
      },
    );
  }
}