Initial commit

lib/flutter_gifimage.dart

@@ -0,0 +1,245 @@
+/*
+  author: Jpeng
+  email: peng8350@gmail.com
+  time:2019-7-26 3:30
+*/
+
+library flutter_gifimage;
+
+import 'dart:io';
+import 'dart:ui' as ui show Codec;
+import 'dart:ui';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+
+/// cache gif fetched image
+class GifCache {
+  final Map<String, List<ImageInfo>?> caches = Map();
+
+  void clear() {
+    caches.clear();
+  }
+
+  bool evict(Object key) {
+    final List<ImageInfo>? pendingImage = caches.remove(key);
+    if (pendingImage != null) {
+      return true;
+    }
+    return false;
+  }
+}
+
+/// controll gif
+class GifController extends AnimationController {
+  GifController(
+      {required TickerProvider vsync,
+      double value = 0.0,
+      Duration? reverseDuration,
+      Duration? duration,
+      AnimationBehavior? animationBehavior})
+      : super.unbounded(
+            value: value,
+            reverseDuration: reverseDuration,
+            duration: duration,
+            animationBehavior: animationBehavior ?? AnimationBehavior.normal,
+            vsync: vsync);
+
+  @override
+  void reset() {
+    value = 0.0;
+  }
+}
+
+class GifImage extends StatefulWidget {
+  GifImage({
+    required this.image,
+    required this.controller,
+    this.semanticLabel,
+    this.excludeFromSemantics = false,
+    this.width,
+    this.height,
+    this.onFetchCompleted,
+    this.color,
+    this.colorBlendMode,
+    this.fit,
+    this.alignment = Alignment.center,
+    this.repeat = ImageRepeat.noRepeat,
+    this.centerSlice,
+    this.matchTextDirection = false,
+    this.gaplessPlayback = false,
+  });
+  final VoidCallback? onFetchCompleted;
+  final GifController controller;
+  final ImageProvider image;
+  final double? width;
+  final double? height;
+  final Color? color;
+  final BlendMode? colorBlendMode;
+  final BoxFit? fit;
+  final AlignmentGeometry alignment;
+  final ImageRepeat repeat;
+  final Rect? centerSlice;
+  final bool matchTextDirection;
+  final bool gaplessPlayback;
+  final String? semanticLabel;
+  final bool excludeFromSemantics;
+
+  @override
+  State<StatefulWidget> createState() {
+    return new GifImageState();
+  }
+
+  static GifCache cache = GifCache();
+}
+
+class GifImageState extends State<GifImage> {
+  List<ImageInfo>? _infos;
+  int _curIndex = 0;
+  bool _fetchComplete = false;
+  ImageInfo? get _imageInfo {
+    if (!_fetchComplete) return null;
+    return _infos == null ? null : _infos![_curIndex];
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    widget.controller.addListener(_listener);
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+    widget.controller.removeListener(_listener);
+  }
+
+  @override
+  void didUpdateWidget(GifImage oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.image != oldWidget.image) {
+      fetchGif(widget.image).then((imageInfors) {
+        if (mounted)
+          setState(() {
+            _infos = imageInfors;
+            _fetchComplete = true;
+            _curIndex = widget.controller.value.toInt();
+            if (widget.onFetchCompleted != null) {
+              widget.onFetchCompleted!();
+            }
+          });
+      });
+    }
+    if (widget.controller != oldWidget.controller) {
+      oldWidget.controller.removeListener(_listener);
+      widget.controller.addListener(_listener);
+    }
+  }
+
+  void _listener() {
+    if (_curIndex != widget.controller.value && _fetchComplete) {
+      if (mounted)
+        setState(() {
+          _curIndex = widget.controller.value.toInt();
+        });
+    }
+  }
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+    if (_infos == null) {
+      fetchGif(widget.image).then((imageInfors) {
+        if (mounted)
+          setState(() {
+            _infos = imageInfors;
+            _fetchComplete = true;
+            _curIndex = widget.controller.value.toInt();
+            if (widget.onFetchCompleted != null) {
+              widget.onFetchCompleted!();
+            }
+          });
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final RawImage image = new RawImage(
+      image: _imageInfo?.image,
+      width: widget.width,
+      height: widget.height,
+      scale: _imageInfo?.scale ?? 1.0,
+      color: widget.color,
+      colorBlendMode: widget.colorBlendMode,
+      fit: widget.fit,
+      alignment: widget.alignment,
+      repeat: widget.repeat,
+      centerSlice: widget.centerSlice,
+      matchTextDirection: widget.matchTextDirection,
+    );
+    if (widget.excludeFromSemantics) return image;
+    return new Semantics(
+      container: widget.semanticLabel != null,
+      image: true,
+      label: widget.semanticLabel == null ? '' : widget.semanticLabel,
+      child: image,
+    );
+  }
+}
+
+final HttpClient _sharedHttpClient = HttpClient()..autoUncompress = false;
+
+HttpClient get _httpClient {
+  HttpClient client = _sharedHttpClient;
+  assert(() {
+    if (debugNetworkImageHttpClientProvider != null)
+      client = debugNetworkImageHttpClientProvider!();
+    return true;
+  }());
+  return client;
+}
+
+Future<List<ImageInfo>?> fetchGif(ImageProvider provider) async {
+  List<ImageInfo>? infos = [];
+  late dynamic data;
+  String key = provider is NetworkImage
+      ? provider.url
+      : provider is AssetImage
+          ? provider.assetName
+          : provider is MemoryImage
+              ? provider.bytes.toString()
+              : "";
+  if (GifImage.cache.caches.containsKey(key)) {
+    infos = GifImage.cache.caches[key];
+    return infos;
+  }
+  if (provider is NetworkImage) {
+    final Uri resolved = Uri.base.resolve(provider.url);
+    final HttpClientRequest request = await _httpClient.getUrl(resolved);
+    provider.headers?.forEach((String name, String value) {
+      request.headers.add(name, value);
+    });
+    final HttpClientResponse response = await request.close();
+    data = await consolidateHttpClientResponseBytes(
+      response,
+    );
+  } else if (provider is AssetImage) {
+    AssetBundleImageKey key = await provider.obtainKey(ImageConfiguration());
+    data = await key.bundle.load(key.name);
+  } else if (provider is FileImage) {
+    data = await provider.file.readAsBytes();
+  } else if (provider is MemoryImage) {
+    data = provider.bytes;
+  }
+
+  ui.Codec codec = await PaintingBinding.instance
+      .instantiateImageCodec(data.buffer.asUint8List());
+  infos = [];
+  for (int i = 0; i < codec.frameCount; i++) {
+    FrameInfo frameInfo = await codec.getNextFrame();
+    //scale ??
+    infos.add(ImageInfo(image: frameInfo.image));
+  }
+  GifImage.cache.caches.putIfAbsent(key, () => infos);
+  return infos;
+}