Gtk3 on a HTML5 backend

http://blogs.gnome.org/alexl/2010/11/23/gtk3-vs-html5/

by biehl • 16 years ago

255 36 16 years ago

blogs.gnome.org

Now this is getting serious. I was considering porting xul for web apps (with the default and obvious coffeescript dsl, so that no xml verbosity would be needed), but gtk3 is even more outstanding. Any idea when it will be out?

krakensden• 16 years ago

It's not a product, it's a demo he hacked up to see if it was worth pursuing.

emehrkay• 16 years ago

Didn't some people do this with VNC a few months back? Either way, this is damn cool.

pixelbath• 16 years ago

It looks cool, but (and please forgive my ignorance in this subject)...

Isn't this the sort of thing X was built for? Client rendering, but the underlying app in a remote server? How is rendering this in the browser more useful/cool?

(edit: typo)

postfuturist• 16 years ago

Browsers exist in more places than X clients.

sedachv2• 16 years ago

Getting X tunneled over HTTP is actually pretty complicated:

* The client/server thing is reversed * X expects everything to be fully asynchronous (WebSockets get a lot of hype but they're pretty useless at this stage IMO) * XRender is a big mismatch to canvas drawing API (the old X drawing protocol is in some ways better, in many ways (esp. color) much worse)

fab13n• 16 years ago

If this turns into a complete and mature implementation, I won't miss anything when Ubuntu drops X11 next year, quite the opposite!

mwg66• 16 years ago

I can think of potential use cases similar to what 280 North are doing with Atlas and Cappuccino.

Check out http://280atlas.com/

nailer• 16 years ago

Yep, in the sense of cocoa vs gtk. But rather than a port to js, it's a port to canvas.

travisglines• 16 years ago

Thats awesome, I'm more than a little jealous I didn't think of that.

cpr• 16 years ago

This actually makes some sense (if I understand it correctly), vs. a VNC client solution in a browser.

You can, in theory, use the higher-level hints given at the toolkit level to optimize the bits sent for each toolkit API invocation.

sedachv2• 16 years ago

(re-posting my comment from the blog because I want to hear people's opinion)

This is extremely useful for getting apps written for the desktop to run on the browser for remote access and virtualization.

I don’t know if there are any companies with GTK3 desktop apps that need this right now, but for the past six months I’ve been working on doing exactly the same thing for JazzScheme (http://jazzscheme.org/). JazzScheme has its own widget set and UI library that runs on top of Cairo. Instead of sending bitmap data across I’m providing a thin indirection layer on top of Cairo surface and HTML 5 canvas (they’re almost identical in terms of drawing commands).

We’re using it for a pretty involved business app that needs a desktop version. Doing a web version any other way would have been a complete nightmare.

xtacy• 16 years ago

The GTK ports on Mac are pretty bad looking. This would make them awesomer again!

tvon• 16 years ago

Does it just use the default GTK+ theme, or are there rendering issues?

kragen3• 16 years ago

Does anyone else remember the X11 browser plugin? It was an X server that ran as a plugin in Netscape and IE, with a little bit of magic ("xrx") to handle authentication to the web server. So you could visit a web page and start running, say, FrameMaker in your browser.

There's a guide to getting it set up still alive at http://www.csn.ul.ie/~caolan/TechTexts/Broadway.html

This was in 1996, in the X11R6.3 release ("Broadway"), the same release they came out with LBX, the low-bandwidth extension to X, so that you could run your X11 apps over a modem with reasonable throughput.

It never got much adoption. I don't really know why. My guess, though, is that it didn't address the real reasons people were moving from X11 to browser apps: server load, security, ease of administration, latency-tolerance, and ease of development.

Today, server load and latency tolerance are a lot less important than they were in 1996, because computers are a hundred times faster and hundreds of millions of people have ping times under 20 milliseconds, ten times faster than you'd get on a modem.

But security, ease of administration, and ease of development are a lot more important now than they were in 1996.

So, I suspect this won't get widely adopted, but it could go either way. I hope it does!

ssp• 16 years ago

Notice the dropdown menu when he types in the address: it says "Broadway 2.0".

kragen3• 16 years ago

I just read the post; I didn't watch the video.

crizCraig• 16 years ago

Minimizing latency is still very important in mobile, times of network congestion, and the many places around the world that still have slow connections. HTML also has the benefits that it's indexable and semi-open-source. So I hope this is not widely adopted, but it would be awesome for porting existing apps and maybe replacing Flash in some instances.

gromy• 16 years ago

I think this raises the question: how much longer will the web still be indexable in the classical HTML sense?

loewenskind3• 16 years ago

Why would someone implement such an awful protocol as X11 when they could just directly render. They could make application-level X11 clients for legacy X apps running on some server somewhere if they wish, there's no reason to cripple the whole experience with X11.

kragen3• 16 years ago

It's hard to understand your question because the quality of its writing is as poor as its punctuation. Can you clarify? What do you mean by "directly render", "application-level X11 clients", "they", and "server"?

Perhaps you were suggesting that remotely displaying a window of, say, FrameMaker in your browser would be better done by rasterizing the application window on the same machine where FrameMaker was running, as with Xvnc, only as a browser plugin.

That is indeed a workable and fairly simple solution, but it usually uses a lot more bandwidth on the network and memory on the machine running FrameMaker than just running X11, particularly with LBX or ssh compressing the X11 protocol.

vib• 16 years ago

"Each toplevel window is mapped to a canvas element" Does this means it's not crawl-able, or is it?

tjarratt• 16 years ago

I'm not an expert, but I believe this to be correct - the contents of the canvas elements are created/managed by javascript, so they would likely appear empty to most spiders.

Additionally, I don't believe there is any good way to crawl the contents of a canvas element - the best you can get from it is an image representation as a data uri, so no text or html elements with semantic meaning.

drivebyacct2• 16 years ago

I was just lying on the couch thinking about this idea. Well, I have much larger, grander idea that is a mix of Palm/HP's new Mocha platform and some play at ubiquitous interfaces and data powering apps on many devices simultaneously. I was thinking though, that some of the frontends for rtorrent look neat, but still fail to look native.

What if the browser exposed the GTK resources and allowed web applications to render using the same visual components as native applications on the platform. That'd be sweeet.

olalonde• 16 years ago

How come is the UI so responsive (much more than what I'm used to with remote X sessions)? Is it because both the app and the HTTP server run on the same machine?

albertzeyer• 16 years ago

The technical description:

Each toplevel window is mapped to a canvas element, and the content in the windows is updated by streaming commands over a multipart/x-mixed-replace XMLHttpRequest that uses gzip Content-Encoding to compress the data. Window data is pushed as region copies (for scrolling) and image diffs. Images are sent as data: uris of uncompressed png data.

Input is gathered via dom events and sent to the server using websockets.

This doesn't really sound that impressive. It's kind of cool and you could also do the same and port some RDP or VNC client over which would be even cooler. But I don't really feel that this is the way to go. It would be much nicer if the native HTML widgets would be used.

tjpick• 16 years ago

I personally don't give much of a crap about native HTML. That's just a transport, and let's face it, for doing apps it's shit. What I would want it to have is deep linking, back button behaviour and the other nice bits of HTTP.

pyre• 16 years ago

There is not a 1-to-1 mapping between all Gtk+ widgets and all HTML widgets.

aberkowitz• 16 years ago

There doesn't have to be an exact one-to-one mapping. I doubt there are many Gtk+ widgets that cannot be reasonably emulated in the latest browsers.

pornel• 16 years ago

HTML5 allows making any element focusable and supports ARIA that exposes custom elements to accessibility API, so you can make pretty good custom widgets using DHTML.

limmeau• 16 years ago

Related work: the Rich Ajax Platform, an implementation of Eclipse's SWT using the Qooxdoo Javascript framework.

seanalltogether• 16 years ago

The biggest gotcha with these kinds of demos is, and always will be, keyboard input. Unless browser vendors are willing to relinquish all keyboard controls for a special kind of popup window, HTML5 VNC type solutions are dead in the water.

guruz• 16 years ago

The Qt guys have a similar thing. It however needs the Google native client plugin.

http://labs.qt.nokia.com/2010/06/25/qt-for-google-native-cli...

There's also the QWebClient which does not need a plugin, but also does not look very beautiful or native.

http://labs.qt.nokia.com/2009/09/18/qt-in-the-cloud-with-qwe...

Gtk3 on a HTML5 backend

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