105 lines
2.4 KiB
Dart
105 lines
2.4 KiB
Dart
import 'package:flutter/foundation.dart';
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import 'package:flutter/material.dart';
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import 'package:blurhash_dart/blurhash_dart.dart' as b;
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import 'package:image/image.dart' as image;
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class BlurHash extends StatefulWidget {
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final double width;
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final double height;
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final String blurhash;
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final BoxFit fit;
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const BlurHash({
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super.key,
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String? blurhash,
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required this.width,
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required this.height,
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this.fit = BoxFit.cover,
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}) : blurhash = blurhash ?? 'LEHV6nWB2yk8pyo0adR*.7kCMdnj';
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@override
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State<BlurHash> createState() => _BlurHashState();
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}
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class _BlurHashState extends State<BlurHash> {
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Uint8List? _data;
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static Future<Uint8List> getBlurhashData(
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BlurhashData blurhashData,
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) async {
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final blurhash = b.BlurHash.decode(blurhashData.hsh);
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final img = blurhash.toImage(blurhashData.w, blurhashData.h);
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return Uint8List.fromList(image.encodePng(img));
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}
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Future<Uint8List?> _computeBlurhashData() async {
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if (_data != null) return _data!;
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final ratio = widget.width / widget.height;
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var width = 32;
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var height = 32;
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if (ratio > 1.0) {
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height = (width / ratio).round();
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} else {
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width = (height * ratio).round();
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}
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return _data ??= await compute(
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getBlurhashData,
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BlurhashData(
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hsh: widget.blurhash,
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w: width,
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h: height,
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),
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);
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}
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@override
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Widget build(BuildContext context) {
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return FutureBuilder<Uint8List?>(
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future: _computeBlurhashData(),
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initialData: _data,
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builder: (context, snapshot) {
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final data = snapshot.data;
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if (data == null) {
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return Container(
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width: widget.width,
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height: widget.height,
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color: Theme.of(context).colorScheme.onInverseSurface,
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);
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}
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return Image.memory(
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data,
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fit: widget.fit,
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width: widget.width,
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height: widget.height,
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);
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},
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);
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}
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}
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class BlurhashData {
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final String hsh;
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final int w;
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final int h;
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const BlurhashData({
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required this.hsh,
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required this.w,
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required this.h,
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});
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factory BlurhashData.fromJson(Map<String, dynamic> json) => BlurhashData(
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hsh: json['hsh'],
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w: json['w'],
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h: json['h'],
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);
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Map<String, dynamic> toJson() => {
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'hsh': hsh,
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'w': w,
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'h': h,
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};
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}
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