lemmur-app-android/lib/pages/instance.dart

import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:lemmy_api_client/lemmy_api_client.dart';

import '../util/text_color.dart';
import '../widgets/badge.dart';
import '../widgets/markdown_text.dart';

class InstancePage extends HookWidget {
  final String instanceUrl;
  final Future<FullSiteView> siteFuture;
  final Future<List<CommunityView>> communitiesFuture;

  void _share() {
    print('SHARE');
  }

  void _openMoreMenu() {
    print('OPEN MORE MENU');
  }

  InstancePage({@required this.instanceUrl})
      : assert(instanceUrl != null),
        siteFuture = LemmyApi(instanceUrl).v1.getSite(),
        communitiesFuture =
            LemmyApi(instanceUrl).v1.listCommunities(sort: SortType.hot);

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final siteSnap = useFuture(siteFuture);
    final commsSnap = useFuture(communitiesFuture);
    final colorOnCard = textColorBasedOnBackground(theme.cardColor);

    if (!siteSnap.hasData) {
      return Scaffold(
        appBar: AppBar(
          iconTheme: theme.iconTheme,
          backgroundColor: theme.cardColor,
          elevation: 0,
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              if (siteSnap.hasError) ...[
                Icon(Icons.error),
                Padding(
                  padding: const EdgeInsets.all(8),
                  child: Text('ERROR: ${siteSnap.error}'),
                )
              ] else
                CircularProgressIndicator(semanticsLabel: 'loading')
            ],
          ),
        ),
      );
    }

    final site = siteSnap.data;

    return Scaffold(
      body: DefaultTabController(
        length: 3,
        child: NestedScrollView(
          headerSliverBuilder: (context, innerBoxIsScrolled) {
            return <Widget>[
              SliverAppBar(
                expandedHeight: 200,
                floating: false,
                pinned: true,
                elevation: 0,
                backgroundColor: theme.cardColor,
                iconTheme: theme.iconTheme,
                title: Text(
                  '${site.site.name}',
                  style: TextStyle(color: colorOnCard),
                ),
                actions: [
                  IconButton(icon: Icon(Icons.share), onPressed: _share),
                  IconButton(
                      icon: Icon(Icons.more_vert), onPressed: _openMoreMenu),
                ],
                flexibleSpace: FlexibleSpaceBar(
                  background: Stack(children: [
                    if (site.site.banner != null)
                      CachedNetworkImage(imageUrl: site.site.banner),
                    SafeArea(
                      child: Center(
                        child: Column(
                          children: [
                            Padding(
                              padding: const EdgeInsets.only(top: 40),
                              child: CachedNetworkImage(
                                  width: 100,
                                  height: 100,
                                  imageUrl: site.site.icon),
                            ),
                            Text(site.site.name,
                                style: theme.textTheme.headline6),
                            Text(instanceUrl, style: theme.textTheme.caption)
                          ],
                        ),
                      ),
                    ),
                  ]),
                ),
              ),
              SliverPersistentHeader(
                delegate: _SliverAppBarDelegate(
                  TabBar(
                    labelColor: theme.textTheme.bodyText1.color,
                    unselectedLabelColor: Colors.grey,
                    tabs: [
                      Tab(text: 'Posts'),
                      Tab(text: 'Comments'),
                      Tab(text: 'About'),
                    ],
                  ),
                ),
                pinned: true,
              ),
            ];
          },
          body: TabBarView(
            children: [
              ListView(
                children: [
                  Center(child: Text('posts go here')),
                ],
              ),
              ListView(
                children: [
                  Center(child: Text('comments go here')),
                ],
              ),
              _AboutTab(site, communitiesFuture: communitiesFuture),
            ],
          ),
        ),
      ),
    );
  }
}

class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
  _SliverAppBarDelegate(this._tabBar);

  final TabBar _tabBar;

  @override
  double get minExtent => _tabBar.preferredSize.height;
  @override
  double get maxExtent => _tabBar.preferredSize.height;

  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    final theme = Theme.of(context);
    return Container(child: _tabBar, color: theme.cardColor);
  }

  @override
  bool shouldRebuild(_SliverAppBarDelegate oldDelegate) {
    return false;
  }
}

class _AboutTab extends HookWidget {
  final FullSiteView site;
  final Future<List<CommunityView>> communitiesFuture;

  const _AboutTab(this.site, {@required this.communitiesFuture})
      : assert(communitiesFuture != null);

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final commSnap = useFuture(communitiesFuture);

    return SingleChildScrollView(
      child: SafeArea(
        top: false,
        child: Column(
          // padding: EdgeInsets.only(top: 0),
          children: [
            Padding(
              padding: const EdgeInsets.symmetric(horizontal: 15, vertical: 15),
              child: MarkdownText(site.site.description),
            ),
            _Divider(),
            SizedBox(
              height: 25,
              child: ListView(
                scrollDirection: Axis.horizontal,
                children: [
                  SizedBox(width: 7),
                  _Badge('X users online'),
                  _Badge('${site.site.numberOfUsers} users'),
                  _Badge('${site.site.numberOfCommunities} communities'),
                  _Badge('${site.site.numberOfPosts} posts'),
                  _Badge('${site.site.numberOfComments} comments'),
                  SizedBox(width: 15),
                ],
              ),
            ),
            _Divider(),
            Text(
              'Trending communities:',
              style: theme.textTheme.headline6.copyWith(fontSize: 18),
            ),
            if (commSnap.hasData)
              ...commSnap.data.getRange(0, 6).map((e) => ListTile(
                    onTap: () => print('GO TO COMMUNITY ${e.name}'),
                    title: Text(e.name),
                    leading: e.icon != null
                        ? CachedNetworkImage(
                            height: 50,
                            width: 50,
                            imageUrl: e.icon,
                            imageBuilder: (context, imageProvider) => Container(
                                  decoration: BoxDecoration(
                                    shape: BoxShape.circle,
                                    image: DecorationImage(
                                      fit: BoxFit.cover,
                                      image: imageProvider,
                                    ),
                                  ),
                                ))
                        : SizedBox(width: 50),
                  ))
            else if (commSnap.hasError)
              Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text("Can't load communities, ${commSnap.error}"),
              )
            else
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 10),
                child: CircularProgressIndicator(),
              ),
            ListTile(
              title: Center(child: Text('See all')),
              onTap: () => print('GO TO COMMUNITIES'),
            ),
            SizedBox(height: 20),
          ],
        ),
      ),
    );
  }
}

class _Badge extends StatelessWidget {
  final String text;

  _Badge(this.text);

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return Padding(
      padding: const EdgeInsets.only(left: 8),
      child: Badge(
        child: Text(
          text,
          style:
              TextStyle(color: textColorBasedOnBackground(theme.accentColor)),
        ),
        // TODO: change border radius
      ),
    );
  }
}

class _Divider extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 15, vertical: 10),
      child: Divider(),
    );
  }
}