Remove direct dependency on dart:io (#90)

CHANGELOG.md

@@ -1,3 +1,6 @@
+## [0.5.1]
+- Remove direct dependencies on dart:io to support Flutter Web
+
 ## [0.5.0]
 - Support loading animation from network in a web app
 - Fix a couple of bugs with the web dev compiler

lib/src/lottie.dart

@@ -1,4 +1,3 @@
-import 'dart:io';
 import 'dart:typed_data';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
@@ -72,7 +71,7 @@ class Lottie extends StatefulWidget {
 
   /// Creates a widget that displays an [LottieComposition] obtained from a [File].
   static LottieBuilder file(
-    File file, {
+    Object /*io.File|html.File*/ file, {
     Animation<double> controller,
     bool animate,
     bool repeat,

lib/src/lottie_builder.dart

@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:io';
 import 'dart:typed_data';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';
@@ -83,7 +82,7 @@ class LottieBuilder extends StatefulWidget {
   /// `android.permission.READ_EXTERNAL_STORAGE` permission.
   ///
   LottieBuilder.file(
-    File file, {
+    Object /*io.File|html.File*/ file, {
     this.controller,
     this.animate,
     this.reverse,

lib/src/providers/file_provider.dart

@@ -1,25 +1,24 @@
-import 'dart:io';
 import 'dart:ui' as ui;
-import 'package:flutter/rendering.dart';
 import 'package:path/path.dart' as p;
 import '../composition.dart';
 import '../lottie_image_asset.dart';
 import 'load_image.dart';
 import 'lottie_provider.dart';
+import 'provider_io.dart' if (dart.library.html) 'provider_web.dart' as io;
 
 class FileLottie extends LottieProvider {
   FileLottie(this.file, {LottieImageProviderFactory imageProviderFactory})
       : super(imageProviderFactory: imageProviderFactory);
 
-  final File file;
+  final Object /*io.File|html.File*/ file;
 
   @override
   Future<LottieComposition> load() async {
-    var cacheKey = 'file-${file.path}';
+    var cacheKey = 'file-${io.filePath(file)}';
     return sharedLottieCache.putIfAbsent(cacheKey, () async {
-      var bytes = await file.readAsBytes();
+      var bytes = await io.loadFile(file);
       var composition = await LottieComposition.fromBytes(bytes,
-          name: p.basenameWithoutExtension(file.path));
+          name: p.basenameWithoutExtension(io.filePath(file)));
 
       for (var image in composition.images.values) {
         image.loadedImage ??= await _loadImage(composition, image);
@@ -33,11 +32,7 @@ class FileLottie extends LottieProvider {
       LottieComposition composition, LottieImageAsset lottieImage) {
     var imageProvider = getImageProvider(lottieImage);
 
-    if (imageProvider == null) {
+    imageProvider ??= io.loadImageForFile(file, lottieImage);
-      var imagePath = p.url.join(
-          p.dirname(file.path), lottieImage.dirName, lottieImage.fileName);
-      imageProvider = FileImage(File(imagePath));
-    }
 
     return loadImage(composition, lottieImage, imageProvider);
   }
@@ -52,5 +47,5 @@ class FileLottie extends LottieProvider {
   int get hashCode => file.hashCode;
 
   @override
-  String toString() => '$runtimeType(file: ${file.path})';
+  String toString() => '$runtimeType(file: ${io.filePath(file)})';
 }

lib/src/providers/network_provider.dart

@@ -6,8 +6,7 @@ import '../composition.dart';
 import '../lottie_image_asset.dart';
 import 'load_image.dart';
 import 'lottie_provider.dart';
-import 'network_provider_io.dart'
+import 'provider_io.dart' if (dart.library.html) 'provider_web.dart' as network;
-    if (dart.library.html) 'network_provider_web.dart' as network;
 
 class NetworkLottie extends LottieProvider {
   NetworkLottie(this.url,
@@ -22,7 +21,7 @@ class NetworkLottie extends LottieProvider {
     var cacheKey = 'network-$url';
     return sharedLottieCache.putIfAbsent(cacheKey, () async {
       var resolved = Uri.base.resolve(url);
-      var bytes = await network.load(resolved, headers: headers);
+      var bytes = await network.loadHttp(resolved, headers: headers);
 
       var composition = await LottieComposition.fromBytes(bytes,
           name: p.url.basenameWithoutExtension(url));

lib/src/providers/network_provider_web.dart

@@ -1,16 +0,0 @@
-import 'dart:html';
-import 'dart:typed_data';
-
-Future<Uint8List> load(Uri uri, {Map<String, String> headers}) async {
-  var request = await HttpRequest.request(uri.toString(),
-      requestHeaders: headers, responseType: 'blob');
-
-  var reader = FileReader();
-  reader.readAsArrayBuffer(request.response as Blob);
-  await reader.onLoadEnd.first;
-  if (reader.readyState != FileReader.DONE) {
-    throw Exception('Error while reading $uri');
-  }
-
-  return reader.result as Uint8List;
-}

lib/src/providers/provider_io.dart

@@ -1,10 +1,13 @@
 import 'dart:io';
 import 'dart:typed_data';
 import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+import 'package:path/path.dart' as p;
+import '../lottie_image_asset.dart';
 
 final HttpClient _sharedHttpClient = HttpClient()..autoUncompress = false;
 
-Future<Uint8List> load(Uri uri, {Map<String, String> headers}) async {
+Future<Uint8List> loadHttp(Uri uri, {Map<String, String> headers}) async {
   var request = await _sharedHttpClient.getUrl(uri);
   headers?.forEach((String name, String value) {
     request.headers.add(name, value);
@@ -21,3 +24,19 @@ Future<Uint8List> load(Uri uri, {Map<String, String> headers}) async {
 
   return bytes;
 }
+
+Future<Uint8List> loadFile(Object file) {
+  return (file as File).readAsBytes();
+}
+
+String filePath(Object file) {
+  return (file as File).path;
+}
+
+ImageProvider loadImageForFile(Object file, LottieImageAsset lottieImage) {
+  var fileIo = file as File;
+
+  var imagePath = p.url
+      .join(p.dirname(fileIo.path), lottieImage.dirName, lottieImage.fileName);
+  return FileImage(File(imagePath));
+}

lib/src/providers/provider_web.dart

@@ -0,0 +1,35 @@
+import 'dart:html';
+import 'dart:typed_data';
+import 'package:flutter/rendering.dart';
+import '../lottie_image_asset.dart';
+
+Future<Uint8List> loadHttp(Uri uri, {Map<String, String> headers}) async {
+  var request = await HttpRequest.request(uri.toString(),
+      requestHeaders: headers, responseType: 'blob');
+
+  return _loadBlob(request.response as Blob);
+}
+
+Future<Uint8List> loadFile(Object file) {
+  return _loadBlob(file as File);
+}
+
+Future<Uint8List> _loadBlob(Blob file) async {
+  var reader = FileReader();
+  reader.readAsArrayBuffer(file);
+
+  await reader.onLoadEnd.first;
+  if (reader.readyState != FileReader.DONE) {
+    throw Exception('Error while reading blob');
+  }
+
+  return reader.result as Uint8List;
+}
+
+String filePath(Object file) {
+  return (file as File).relativePath;
+}
+
+ImageProvider loadImageForFile(Object file, LottieImageAsset lottieImage) {
+  return null;
+}

pubspec.yaml

@@ -1,6 +1,6 @@
 name: lottie
 description: Render After Effects animations natively on Flutter. This package is a pure Dart implementation of a Lottie player.
-version: 0.5.0
+version: 0.5.1
 homepage: https://github.com/xvrh/lottie-flutter
 
 environment: