OpenMediacenterMobileFlutter/lib/preview/preview_tile.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:sqflite/sqflite.dart';

import '../api/video_api.dart';
import '../db/database.dart';
import '../log/log.dart';
import '../types/video.dart';
import '../utils/platform.dart';
import '../video_screen/videoscreen.dart';

class PreviewTile extends StatefulWidget {
  const PreviewTile(
      {Key? key, required this.dta, this.onLongPress, this.onLongPressEnd})
      : super(key: key);
  final VideoT dta;
  final Function(Image img)? onLongPress;
  final Function? onLongPressEnd;

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

class _PreviewTileState extends State<PreviewTile> {
  late Future<Image> _preview;

  @override
  void initState() {
    super.initState();

    _preview = loadData();
  }

  @override
  void didUpdateWidget(PreviewTile oldWidget) {
    super.didUpdateWidget(oldWidget);

    if (oldWidget.dta != widget.dta) {
      setState(() {
        _preview = loadData();
      });
    }
  }

  Future<void> insert(int id, Uint8List pic) async {
    await Db().db().insert(
          'previews',
          {'id': id, 'thumbnail': pic},
          conflictAlgorithm: ConflictAlgorithm.replace,
        );
  }

  Future<Image> loadData() async {
    Uint8List data;
    final id = widget.dta.id;
    if (kIsWeb) {
      data = await fetchThumbnail(id);
    } else {
      final List<Map<String, dynamic>> prev =
          await Db().db().query('previews', where: "id=$id");

      if (prev.isEmpty) {
        data = await fetchThumbnail(id);
        insert(id, data);
        Log.d("Adding $id to db");
      } else {
        data = prev.first["thumbnail"] as Uint8List;
        Log.d("using cached preview for $id");
      }
    }

    final img = Image.memory(
      data,
      width: double.infinity,
      fit: BoxFit.fitWidth,
    );

    // precache image to avoid loading time to render image
    if(context.mounted)
      await precacheImage(img.image, context);

    return img;
  }

  Widget _buildLoader() {
    return Column(children: const <Widget>[
      SizedBox(height: 50),
      SizedBox(
        width: 60,
        height: 60,
        child: CircularProgressIndicator(),
      ),
      Padding(
        padding: EdgeInsets.only(top: 16),
        child: Text('Awaiting result...'),
      ),
      SizedBox(height: 50),
    ]);
  }

  Widget _buildTile(Image image) {
    return ClipRRect(
      borderRadius: BorderRadius.circular(20.0),
      child: Stack(
        children: [
          Container(
            color: const Color(0xff3f3f3f),
            child: Column(
              children: [
                ClipRRect(
                  borderRadius: BorderRadius.circular(20.0),
                  child: image,
                ),
                const SizedBox(
                  height: 3,
                ),
                Text(
                  widget.dta.title,
                  style: TextStyle(
                      fontSize: isTV() ? 8 : 10.5, color: const Color(0xffe9e9e9)),
                  overflow: TextOverflow.clip,
                  maxLines: 1,
                ),
                const SizedBox(
                  height: 3,
                ),
              ],
            ),
          ),
          Positioned.fill(
            child: Material(
              color: Colors.transparent,
              child: GestureDetector(
                behavior: HitTestBehavior.translucent,
                onLongPress: () {
                  if (widget.onLongPress != null) widget.onLongPress!(image);
                },
                onLongPressEnd: (details) {
                  if (widget.onLongPressEnd != null) widget.onLongPressEnd!();
                },
                child: InkWell(
                  onTap: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => VideoScreen(metaData: widget.dta),
                      ),
                    );
                  },
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return ConstrainedBox(
      constraints: const BoxConstraints(minHeight: 200, minWidth: 200),
      child: FutureBuilder<Image>(
        future: _preview, // a previously-obtained Future<String> or null
        builder: (BuildContext context, AsyncSnapshot<Image> snapshot) {
          if (snapshot.connectionState != ConnectionState.done) {
            return _buildLoader();
          }

          if (snapshot.hasError) {
            return Text("Error");
          } else if (snapshot.hasData) {
            return _buildTile(snapshot.data!);
          } else {
            return _buildLoader();
          }
        },
      ),
    );
  }
}