Qt for WebAssembly

Emscripten does not run on native arm on any OS. On Mac M1, it requires the Rosetta 2 emulation to work. "emsdk only officially supports x86_64 today." https://github.com/emscripten-core/emsdk/issues/671

Because the change that adds multipart support for wasm, 6b171dc6c0c0f0a822b212df77b58b28bd92716c, is not in 5.15.x, but will be part of Qt 6 webassembly. That said, that patch would probably apply fairly cleanly to 5.15 if you want to to recompile Qt.

I am not sure Qt signals would work. You should certainly be able to so callbacks though.

Thanks, HTTPS interfaces can be used without any problems. Unfortunately, I had a thinking mistake here. Thanks Lorn

@linoleo Hey, sorry for replying lately. The problem should be a bug in Firefox like @haiku said. You should use opencv.js instead, it is not solved actually.

This is on my list of things to do, but probably won't get done. You can use javascript WebRTC API to implement this and use Emscripten's built-in ways to access the javascript API from c++ https://emscripten.org/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.html

It is possible to call c/c++ functions from javascript as well as call javascript from c/c++. Look at https://emscripten.org/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.html

Threads are still considered experimental in webassembly, in the browsers as well as Qt WebAssembly. Which is why we do not enable them by default. They require the user to tweak the browsers config settings. They also need to be served from https due to the shared memory. AND they are not real threads, and so work a bit different than unix threads, so it can be a bit tricky.

@Anton1978 I wonder if your question actually: 'how to set up WASM compiler in Qt Creator' ? I simply couldn't get this to work (5.15.2). A co-worker had the same trouble independently, so I don't think it was just me. I gave up and worked with only qmake, make. This worked.

Can you try 5.15.1 or 5.15.2, as there was a bug on windows that stopped those files from being copied.

@YongQ wow u r so damn good

Just to be sure I understand the issue: you may have multiple documents to save and each asks to save separately ?

I just saw that a QNetworkReply::TimeoutError code exists. Shouldn't this code be set when a timeout occurred ? Is this a bug or did I misunderstand something ?

@lorn-potter Thanks for getting back to me! I'm trying to build this project: https://github.com/herewegoblueno/cs1230-final Just to provide context, this works well when built for Mac. And yes I am importing GL/glew.h myself. Also by the way I've also noticed that the compilers don't recognize the standard libraries like <vector>, <map>, etc (or maybe that's just the static checker? not sure if those will result in compile time errors since I can't build due to glew anyways)

Hi, What I'm doing on Android is the following: I build a qml ui and some corresponding c++ and inline js code that make sure that the qml ui can communicate with the android java layer through the android webview utilizing webchannel messageing. See: https://github.com/r0ller/qwa/tree/main/qmlwasm1 Files: main.qml (just the ui logic) main.cpp (opening webchannel port) messageboard.cpp (sending/receiving messages through webchannel port) The java layer passes the call to a c/c++ backend lib via JNI and the returned response is sent back to qml via webmessage channel. The corresponding code: https://github.com/r0ller/qwa/blob/main/Android/qmlwasm1/app/src/main/java/com/bitroller/qmlwasm1/MainActivity.java All that works fine, the error does not appear in the Android but only in the nodejs use case when reloading the client from the nodejs server. However, the ui part what gets loaded from the server is the same what I load in the webview on Android. I also don't get any errors when the project is built with the same qml ui as native. By the way, you can find both the apk and the nodejs code in the repo so running the nodejs variant is just issuing "node index.js" in the qwa_node directory after cloning ;) Installing the apk of course is a few clicks and taps more. (Yesterday I added a springanimated rect to the qml ui which I did not copy over to the android project so there's a difference but that's not the point here.) BR, r0ller

I noticed, that although I am not able to "write" Text in the input field, I can paste text from elsewhere?