Migrate dart:html to package:web to support WASM.

Author: timbotimbo

example/pubspec.yaml

@@ -6,15 +6,17 @@ description: Demonstrates how to use the flutter_unity_widget plugin.
 publish_to: "none"# Remove this line if you wish to publish to pub.dev
 
 environment:
-sdk: ">=2.12.0 <4.0.0"
+sdk: ">=2.17.0 <4.0.0"
+# >=2.17 or higher is needed for pointer_interceptor to work on web with WASM.
+
 
 dependencies:
 cupertino_icons: ^1.0.0
 flutter:
 sdk: flutter
 flutter_unity_widget:
 path: ../
-pointer_interceptor: ^0.9.3+2
+pointer_interceptor: ^0.10.0
 
 dev_dependencies:
 flutter_test:

lib/flutter_unity_widget.dart

@@ -3,7 +3,7 @@ library flutter_unity_widget;
 export'src/facade_controller.dart';
 export'src/facade_widget.dart'
 if (dart.library.io) 'src/io/unity_widget.dart'
-if (dart.library.html) 'src/web/unity_widget.dart';
+if (dart.library.js_interop) 'src/web/unity_widget.dart';
 export'src/helpers/events.dart';
 export'src/helpers/misc.dart';
 export'src/helpers/types.dart';

lib/src/web/web_unity_widget_controller.dart

@@ -1,8 +1,9 @@
 import'dart:developer';
 import'dart:async';
 import'dart:convert';
-import'dart:html'as html;
+import'dart:js_interop';
 
+import'package:web/web.dart'as web;
 import'package:flutter/foundation.dart';
 import'package:flutter/services.dart';
 import'package:flutter_web_plugins/flutter_web_plugins.dart';
@@ -23,13 +24,16 @@ class UnityWebEvent{
 finaldynamic data;
 }
 
+// use JSON.stringify to turn JS objects into strings which we can json decode.
+@JS('JSON.stringify')
+externalJSStringjsonStringify(JSAny value);
+
 classWebUnityWidgetControllerextendsUnityWidgetController{
 finalWebUnityWidgetState _unityWidgetState;
 
 staticRegistrar? webRegistrar;
 
-late html.MessageEvent _unityFlutterBiding;
-late html.MessageEvent _unityFlutterBidingFn;
+lateJSFunction _messageListener;
 
 bool unityReady =false;
 bool unityPause =true;
@@ -99,27 +103,52 @@ class WebUnityWidgetController extends UnityWidgetController{
 
 _registerEvents(){
 if (kIsWeb){
- html.window.addEventListener('message', (event){
-final raw = (event as html.MessageEvent).data.toString();
-// ignore: unnecessary_null_comparison
-if (raw ==''|| raw ==null) return;
-if (raw =='unityReady'){
- unityReady =true;
- unityPause =false;
-
- _unityStreamController.add(UnityCreatedEvent(0,{}));
-return;
- }
-
-try{
-_processEvents(UnityWebEvent(
- name: event.data['name'],
- data: event.data['data'],
- ));
- } catch (e){
-log('Unexpected format', error: e);
+ _messageListener = ((web.Event event){
+if (event is web.MessageEvent){
+final jsData = event.data;
+String data ="";
+
+// Handle a raw JS Object [Object object] instead of a json string.
+if (jsData isJSObject){
+try{
+ data =jsonStringify(jsData).toDart;
+ } catch (e){
+log('Failed to stringify JS object', error: e);
+return;
+ }
+ }
+// this can be either a raw string like "unityReady" or a json string "{\"name\":\"\", ..}"
+elseif (jsData isJSString){
+ data = jsData.toDart;
+ }
+
+if (data.isNotEmpty){
+if (data =='unityReady'){
+ unityReady =true;
+ unityPause =false;
+ _unityStreamController.add(UnityCreatedEvent(0,{}));
+return;
+ } else{
+try{
+final decoded = json.decode(data);
+if (decoded isMap<String, dynamic> &&
+ decoded.containsKey("name") &&
+ decoded.containsKey("data")){
+_processEvents(UnityWebEvent(
+ name: decoded['name'],
+ data: decoded['data'],
+ ));
+ } else{
+log('Unexpected json object', error: data);
+ }
+ } catch (e){
+log('Unexpected json object', error: e);
+ }
+ }
+ }
  }
- });
+ }).toJS;
+ web.window.addEventListener('message', _messageListener);
  }
  }
 
@@ -189,11 +218,13 @@ class WebUnityWidgetController extends UnityWidgetController{
 
 voidcallUnityFn({requiredString fnName}){
 if (kIsWeb){
- _unityFlutterBidingFn =html.MessageEvent(
+final web.MessageEvent_unityFlutterBidingFn =web.MessageEvent(
 'unityFlutterBidingFnCal',
- data: fnName,
+ web.MessageEventInit(
+ data: fnName.toJS,
+ ),
  );
-html.window.dispatchEvent(_unityFlutterBidingFn);
+web.window.dispatchEvent(_unityFlutterBidingFn);
  }
  }
 
@@ -203,27 +234,29 @@ class WebUnityWidgetController extends UnityWidgetController{
 requiredString message,
  }){
 if (kIsWeb){
- _unityFlutterBiding =html.MessageEvent(
+final web.MessageEvent_unityFlutterBiding =web.MessageEvent(
 'unityFlutterBiding',
- data: json.encode({
-"gameObject": gameObject,
-"methodName": methodName,
-"message": message,
- }),
+ web.MessageEventInit(
+ data: json.encode({
+"gameObject": gameObject,
+"methodName": methodName,
+"message": message,
+ }).toJS,
+ ),
  );
-html.window.dispatchEvent(_unityFlutterBiding);
+web.window.dispatchEvent(_unityFlutterBiding);
 postProcess();
  }
  }
 
 /// This method makes sure Unity has been refreshed and is ready to receive further messages.
 voidpostProcess(){
-html.Element? frame =html.document
+web.Element? frame =web.window.document
  .querySelector('flt-platform-view')
 ?.querySelector('iframe');
 
-if (frame !=null){
-(frameas html.IFrameElement).focus();
+if (frame !=null&& frame is web.HTMLIFrameElement){
+ frame.focus();
  }
  }
 
@@ -292,9 +325,7 @@ class WebUnityWidgetController extends UnityWidgetController{
 voiddispose(){
 _cancelSubscriptions();
 if (kIsWeb){
- html.window.removeEventListener('message', (_){});
- html.window.removeEventListener('unityFlutterBiding', (event){});
- html.window.removeEventListener('unityFlutterBidingFnCal', (event){});
+ web.window.removeEventListener('message', _messageListener);
  }
  }
 }

pubspec.yaml

@@ -8,8 +8,8 @@ version: 2022.2.2
 homepage: https://github.com/juicycleff/flutter-unity-view-widget/tree/master
 
 environment:
-sdk: ">=2.16.0 <4.0.0"
-flutter: ">=3.3.0"
+sdk: ">=3.2.0 <4.0.0"
+flutter: ">=3.16.0"
 
 dependencies:
 flutter:
@@ -21,6 +21,7 @@ dependencies:
 plugin_platform_interface: ^2.1.2
 webview_flutter: ^4.0.0
 webview_flutter_web: ^0.2.2
+web: '>=0.3.0 <2.0.0'# Needs to resolve to >=0.5.0 to use WebAssembly (WASM).
 # ffi: ^1.2.1 // required for windows support
 
 dev_dependencies: