[Web] [CanvasKit] WebGL context is not cleaned up / lost #50721
Description
When swiping through the pages in the example you see that they are disposed but the context is not lost / cleaned up. This leads to the following error:
Too many active WebGL contexts. Oldest context will be lost.
Notice how in this example the flutter logo disappears after the error occurred.
Related to #50719.
/cc @hterkelsen
import 'dart:html';
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
@override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
PageController pageController;
@override
void initState() {
super.initState();
pageController = PageController(initialPage: 1);
ui.platformViewRegistry
.registerViewFactory('xyz', (int viewId) => SpanElement());
}
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(),
body: Column(
children: [
FlutterLogo(size: 48),
Flexible(
child: PageView.builder(
controller: pageController,
itemCount: 20,
itemBuilder: (context, index) => Page(index: index,),
),
),
],
),
),
);
}
}
class Page extends StatefulWidget {
const Page({
Key key,
this.index,
}) : super(key: key);
final int index;
@override
_PageState createState() => _PageState();
}
class _PageState extends State<Page> {
@override
void dispose() {
super.dispose();
print('Page ${widget.index} disposed');
}
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[
Text('Page ${widget.index}'),
Expanded(child: HtmlElementView(viewType: 'xyz')),
],
);
}
}[✓] Flutter (Channel master, v1.15.4-pre.51, on Mac OS X 10.15.3 19D76, locale en-CH)
• Flutter version 1.15.4-pre.51 at /Users/ben/flutter
• Framework revision dc636069fc (6 hours ago), 2020-02-12 22:22:49 -0800
• Engine revision e0ebaea590
• Dart version 2.8.0 (build 2.8.0-dev.9.0 e4c39721c4)
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
• Android SDK at /Users/ben/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-29, build-tools 28.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 11.3.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 11.3.1, Build version 11C504
• CocoaPods version 1.8.3
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 3.5)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 43.0.1
• Dart plugin version 191.8593
• Java version OpenJDK Runtime Environment (build 1.8.0_202-release-1483-b49-5587405)
[✓] VS Code (version 1.41.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.7.1
[✓] Connected device (3 available)
• macOS • macOS • darwin-x64 • Mac OS X 10.15.3 19D76
• Chrome • chrome • web-javascript • Google Chrome 80.0.3987.100
• Web Server • web-server • web-javascript • Flutter Tools
• No issues found!