OpenMediacenterMobileFlutter/lib/preview/preview_tile.dart

import 'dart:convert';
import 'dart:typed_data';

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

import '../api/api.dart';
import '../db/database.dart';
import '../log/log.dart';
import '../platform.dart';
import '../types/video.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();
    Log.d("initial load of tile");
  }

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

    if (oldWidget.dta != widget.dta) {
      setState(() {
        _preview = loadData();
      });
      Log.i("load of tile due to change");
    }
  }

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

  Future<Uint8List> _fetchThumbnail(int id) async {
    final base64str =
        await API.query("video", "readThumbnail", {'Movieid': id});
    return base64Decode(base64str.substring(23));
  }

  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
    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(
            child: Column(
              children: [
                Text(
                  widget.dta.title,
                  style: TextStyle(fontSize: isTV() ? 8 : 10.5),
                  overflow: TextOverflow.clip,
                  maxLines: 1,
                ),
                image
              ],
            ),
            color: Color(0x6a94a6ff),
          ),
          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 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();
        }
      },
    );
  }
}