aves/lib/widgets/fullscreen/info/info_page.dart

import 'package:aves/model/collection_lens.dart';
import 'package:aves/model/image_entry.dart';
import 'package:aves/widgets/common/coma_divider.dart';
import 'package:aves/widgets/common/providers/media_query_data_provider.dart';
import 'package:aves/widgets/fullscreen/info/basic_section.dart';
import 'package:aves/widgets/fullscreen/info/location_section.dart';
import 'package:aves/widgets/fullscreen/info/metadata_section.dart';
import 'package:aves/widgets/fullscreen/info/xmp_section.dart';
import 'package:flutter/material.dart';
import 'package:flutter/scheduler.dart';
import 'package:outline_material_icons/outline_material_icons.dart';
import 'package:provider/provider.dart';
import 'package:tuple/tuple.dart';

class InfoPage extends StatefulWidget {
  final CollectionLens collection;
  final ImageEntry entry;
  final ValueNotifier<bool> visibleNotifier;

  const InfoPage({
    Key key,
    @required this.collection,
    @required this.entry,
    this.visibleNotifier,
  }) : super(key: key);

  @override
  State<StatefulWidget> createState() => InfoPageState();
}

class InfoPageState extends State<InfoPage> {
  ScrollController _scrollController = ScrollController();
  bool _scrollStartFromTop = false;

  CollectionLens get collection => widget.collection;

  ImageEntry get entry => widget.entry;

  @override
  void initState() {
    super.initState();
    entry.locate();
  }

  @override
  Widget build(BuildContext context) {
    const horizontalPadding = EdgeInsets.symmetric(horizontal: 8);

    final appBar = SliverAppBar(
      leading: IconButton(
        icon: const Icon(OMIcons.arrowUpward),
        onPressed: _goToImage,
        tooltip: 'Back to image',
      ),
      title: const Text('Info'),
      floating: true,
    );

    return MediaQueryDataProvider(
      child: Scaffold(
        body: SafeArea(
          child: NotificationListener(
            onNotification: _handleTopScroll,
            child: Selector<MediaQueryData, Tuple2<double, double>>(
              selector: (c, mq) => Tuple2(mq.size.width, mq.viewInsets.bottom),
              builder: (c, mq, child) {
                final mqWidth = mq.item1;
                final mqViewInsetsBottom = mq.item2;
                final split = mqWidth > 400;
                final locationAtTop = split && entry.hasGps;

                final locationSection = LocationSection(
                  collection: collection,
                  entry: entry,
                  showTitle: !locationAtTop,
                  visibleNotifier: widget.visibleNotifier,
                );
                final basicAndLocationSliver = locationAtTop
                    ? SliverToBoxAdapter(
                        child: Row(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Expanded(child: BasicSection(entry: entry)),
                            const SizedBox(width: 8),
                            Expanded(child: locationSection),
                          ],
                        ),
                      )
                    : SliverList(
                        delegate: SliverChildListDelegate.fixed(
                          [
                            BasicSection(entry: entry),
                            locationSection,
                          ],
                        ),
                      );
                final tagSliver = XmpTagSectionSliver(
                  collection: collection,
                  entry: entry,
                );
                final metadataSliver = MetadataSectionSliver(
                  entry: entry,
                  visibleNotifier: widget.visibleNotifier,
                );

                return CustomScrollView(
                  controller: _scrollController,
                  slivers: [
                    appBar,
                    SliverPadding(
                      padding: horizontalPadding + const EdgeInsets.only(top: 8),
                      sliver: basicAndLocationSliver,
                    ),
                    SliverPadding(
                      padding: horizontalPadding,
                      sliver: tagSliver,
                    ),
                    SliverPadding(
                      padding: horizontalPadding + EdgeInsets.only(bottom: 8 + mqViewInsetsBottom),
                      sliver: metadataSliver,
                    ),
                  ],
                );
              },
            ),
          ),
        ),
        resizeToAvoidBottomInset: false,
      ),
    );
  }

  bool _handleTopScroll(Notification notification) {
    if (notification is ScrollNotification) {
      if (notification is ScrollStartNotification) {
        final metrics = notification.metrics;
        _scrollStartFromTop = metrics.pixels == metrics.minScrollExtent;
      }
      if (_scrollStartFromTop) {
        if (notification is ScrollEndNotification) {
          _scrollStartFromTop = false;
        } else if (notification is OverscrollNotification) {
          if (notification.overscroll < 0) {
            _goToImage();
            _scrollStartFromTop = false;
          }
        }
      }
    }
    return false;
  }

  void _goToImage() {
    BackUpNotification().dispatch(context);
    _scrollController.animateTo(
      0,
      duration: Duration(milliseconds: (300 * timeDilation).toInt()),
      curve: Curves.easeInOut,
    );
  }
}

class SectionRow extends StatelessWidget {
  final String title;

  const SectionRow(this.title);

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        const Expanded(child: ComaDivider(alignment: Alignment.centerRight)),
        Padding(
          padding: const EdgeInsets.all(16.0),
          child: Text(
            title,
            style: const TextStyle(
              fontSize: 20,
              fontFamily: 'Concourse Caps',
            ),
          ),
        ),
        const Expanded(child: ComaDivider(alignment: Alignment.centerLeft)),
      ],
    );
  }
}

class InfoRowGroup extends StatelessWidget {
  final Map<String, String> keyValues;

  const InfoRowGroup(this.keyValues);

  @override
  Widget build(BuildContext context) {
    if (keyValues.isEmpty) return const SizedBox.shrink();
    final lastKey = keyValues.keys.last;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SelectableText.rich(
          TextSpan(
            children: keyValues.entries
                .expand(
                  (kv) => [
                    TextSpan(text: '${kv.key}     ', style: const TextStyle(color: Colors.white70, height: 1.7)),
                    TextSpan(text: '${kv.value}${kv.key == lastKey ? '' : '\n'}'),
                  ],
                )
                .toList(),
          ),
          style: const TextStyle(fontFamily: 'Concourse'),
        ),
      ],
    );
  }
}

class BackUpNotification extends Notification {}