chatapp3-flutter/lib/ui_kit/widgets/svga/sc_svga_asset_widget.dart

import 'package:flutter/material.dart';
import 'package:flutter_svga/flutter_svga.dart';

class SCSvgaAssetWidget extends StatefulWidget {
  const SCSvgaAssetWidget({
    super.key,
    required this.assetPath,
    this.width,
    this.height,
    this.active = true,
    this.loop = false,
    this.fit = BoxFit.contain,
    this.filterQuality = FilterQuality.low,
    this.allowDrawingOverflow = false,
    this.fallback,
  });

  final String assetPath;
  final double? width;
  final double? height;
  final bool active;
  final bool loop;
  final BoxFit fit;
  final FilterQuality filterQuality;
  final bool allowDrawingOverflow;
  final Widget? fallback;

  @override
  State<SCSvgaAssetWidget> createState() => _SCSvgaAssetWidgetState();
}

class _SCSvgaAssetWidgetState extends State<SCSvgaAssetWidget>
    with SingleTickerProviderStateMixin {
  static final Map<String, MovieEntity> _cache = <String, MovieEntity>{};
  static final Map<String, Future<MovieEntity>> _loadingTasks =
      <String, Future<MovieEntity>>{};

  late final SVGAAnimationController _controller;
  String? _loadedAssetPath;
  bool _hasError = false;

  @override
  void initState() {
    super.initState();
    _controller = SVGAAnimationController(vsync: this);
    _loadAsset();
  }

  @override
  void didUpdateWidget(covariant SCSvgaAssetWidget oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.assetPath != widget.assetPath) {
      _loadAsset();
      return;
    }
    if (oldWidget.active != widget.active || oldWidget.loop != widget.loop) {
      _syncPlayback(
        restartIfActive: widget.active && oldWidget.active != widget.active,
      );
    }
  }

  Future<void> _loadAsset() async {
    final assetPath = widget.assetPath;
    setState(() {
      _hasError = false;
    });
    try {
      final movieEntity = await _obtainMovieEntity(assetPath);
      if (!mounted || widget.assetPath != assetPath) {
        return;
      }
      setState(() {
        _loadedAssetPath = assetPath;
        _controller.videoItem = movieEntity;
      });
      _syncPlayback(restartIfActive: true);
    } catch (error) {
      debugPrint('[SCSVGA] load failed asset=$assetPath error=$error');
      if (!mounted || widget.assetPath != assetPath) {
        return;
      }
      setState(() {
        _hasError = true;
      });
    }
  }

  Future<MovieEntity> _obtainMovieEntity(String assetPath) async {
    final cached = _cache[assetPath];
    if (cached != null) {
      return cached;
    }

    final loadingTask = _loadingTasks[assetPath];
    if (loadingTask != null) {
      return loadingTask;
    }

    final future = () async {
      final entity = await SVGAParser.shared.decodeFromAssets(assetPath);
      entity.autorelease = false;
      _cache[assetPath] = entity;
      return entity;
    }();

    _loadingTasks[assetPath] = future;
    try {
      return await future;
    } finally {
      _loadingTasks.remove(assetPath);
    }
  }

  void _syncPlayback({bool restartIfActive = false}) {
    if (_controller.videoItem == null) {
      return;
    }

    if (!widget.active) {
      _controller.stop();
      _controller.reset();
      return;
    }

    if (widget.loop) {
      if (restartIfActive || !_controller.isAnimating) {
        _controller.reset();
        _controller.repeat();
      }
      return;
    }

    if (restartIfActive || !_controller.isAnimating) {
      _controller.reset();
      _controller.repeat(count: 1);
    }
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (_hasError) {
      return _buildFallback();
    }

    final videoItem = _controller.videoItem;
    if (videoItem == null || _loadedAssetPath != widget.assetPath) {
      return _buildFallback();
    }

    return SizedBox(
      width: widget.width,
      height: widget.height,
      child: IgnorePointer(
        child: SVGAImage(
          _controller,
          fit: widget.fit,
          clearsAfterStop: false,
          filterQuality: widget.filterQuality,
          allowDrawingOverflow: widget.allowDrawingOverflow,
        ),
      ),
    );
  }

  Widget _buildFallback() {
    return SizedBox(
      width: widget.width,
      height: widget.height,
      child: widget.fallback ?? const SizedBox.shrink(),
    );
  }
}