Dart for Android apps with 120fps

https://github.com/domokit/sky_sdk

by xbmcuser • 11 years ago

115 61 11 years ago

github.com

Osiris• 11 years ago

Whose sponsoring the development of such a large project? It looks like the lead is a Google employee?

tosh9• 11 years ago

Eric Seidel is working on this, previously he worked on Chrome (WebKit, Blink, …).

guelo• 11 years ago

I've been half expecting that Google would announce something like this at IO as a counter to Swift. But this makes it look like an unofficial side project.

afsina• 11 years ago

AFAIK Eric Siedel and Adam Barth were two lead developers from Chrome team. Probably they have a good core team working on this.

tosh9• 11 years ago

TL;DR framework to build native Android applications using Dart that have highly performant native UI (think React-Native retained mode, functional style).

Related talk & demo: https://www.youtube.com/watch?v=PnIWl33YMwA

The exciting thing here is that from a developer's point of view sky is just a Dart package and you can immediately start to write an Android application but still keep a fast feedback loop similar to web development (like you've seen in React-Native demos).

tosh9• 11 years ago

It is still a bit early but the Q&A in the end hints that eventually you might be able to have a Dart code base that drives native apps on Android, iOS and basically any platform you want to support with a development cycle that feels like web development (tooling, feedback cycle, debugging power) and yet gives you highly performant native apps (120fps, very responsive to touch interactions).

sosuke2• 11 years ago

Is this not possible in Java on Android?

tosh9• 11 years ago

There are people who don't enjoy building stuff in Java and want an alternative (like Dart). There are also people who don't want to learn (or like) the existing Android APIs.

Sky opens the door to use Dart on the server side, on the web as well as for highly performant native apps for Android (and eventually for other platforms like iOS).

sosuke2• 11 years ago

That makes more sense to me, Sky looks pretty cool.

esteer• 11 years ago

Sky opens the door to use Dart on the server side, on the web as well as for highly performant native apps for Android (and eventually for other platforms like iOS).

What's wrong with using GWT and J2ObjC other than the fact that there are people who don't enjoy building stuff in Java?

the8472• 11 years ago

If they just don't like the language, why not just run a different language on the JVM?

comex2• 11 years ago

I guess 120Hz mobile screens are in the "soon" category now?

http://www.blurbusters.com/mobile-120hz-ips-displays-for-sma...

I'd be quite interested to see one for myself and get an idea whether it makes for a noticeably smoother experience. I expect there will be a lot of trouble getting software to reliably hit that number, though, especially Android...

tosh9• 11 years ago

Somewhat related: VR apps will likely require more than 60fps, definitely more than 30fps, diminishing returns beyond 120fps (see 3min interview w/ Palmer Luckey, Oculus VR founder: https://youtu.be/BQoPvZGjYvQ).

Zr40• 11 years ago

Even with a 60 Hz screen this will be advantageous. If the application is fast enough to render at 120 fps, rendering at 60 fps means that the UI thread will be idle at least half of the time, so the processor will draw less battery power.

runeks• 11 years ago

I don't get it. How will you achieve enabling your application to render at 120 fps, instead of 60 fps, without leveraging a twice as powerful CPU/GPU, which will use roughly twice as much power?

I would think the added power draw from rendering at 120 Hz would come from all the applications needing double the number of graphics-calculations they need at 60 fps.

Jyaif• 11 years ago

Also, rendering at 120Hz allows you to motion blur the UI on 60Hz screens very simply.

higherpurpose2• 11 years ago

I hope so, 120Hz screens would be nice for VR. I think Samsung's latest Super AMOLEDs already have 90Hz or so.

rasz_pl• 11 years ago

whats the point of 120Hz screen when you have 100ms touch input lag?

comex2• 11 years ago

At least scrolling and zooming animations can be smoother even if they aren't quite caught up with the finger. shrug

tdkl2• 11 years ago

At least it makes more sense then 4K in 5" size factor.

joosters5• 11 years ago

The Ars Technica article on this - http://arstechnica.com/gadgets/2015/05/01/googles-dart-langu... - has a worrying comment:

...the majority of the app is served over HTTP, allowing for continuous deployment where everyone always runs the newest version. URLs are a base layer of DART, so everything is internet aware. The downside to this is that the demo app doesn't work when you're offline, and starting the app takes a second or two because it needs to download data.

So this is effectively a permanent 'wget |sh' kind of system? Sign me up!

russell_h• 11 years ago

Like a web browser?

joosters5• 11 years ago

My web browser doesn't have many permissions to access my data (texts, contacts, location etc) - apps, on the other hand, may have a wide range of permissions and so are open to abuse.

tosh9• 11 years ago

You forgot to quote the next sentence:

"Both of these could be solved with caching, though."

Sounds like it is up to you if the app you deploy to the app store will have this ability or not or on which side of the spectrum you want to be.

When you look at the Facebook app (or other popular apps) they've found ways to 'update' parts of the application (or behave differently eg for a/b testing of new functionality) without the user having to download a new version.

joosters5• 11 years ago

Yup. It's up to 'you' - you being the app writer. The poor shmuck who downloads the app has no choice or control over it.

myko2• 11 years ago

I assume the final apk to be released would actually package the Dart code/server within itself? Kind of like React Native.

shadowmint• 11 years ago

This is a significantly more compelling use for Dart than anything else I've seen.

Dart team; stop screwing around and pay attention to this! Dart has failed as a browser script language, but its a good language in itself.

A cross platform language for building high performance apps, with a good package management solution and tooling... Thats a compelling use case. Something like a cross platform Swift...

Add some compiles to native binaries (or some kind of runtime bundling like xamarin do) and you'd have a pretty interesting piece of tech there.

('lets focus on our to javascript compiler for the dart compiled from typescript because the dart runtime is never going into Chrome or any other browser' is not. Stop running down that ridiculous road already)

higherpurpose2• 11 years ago

I'd rather see the apps written in Go.

yoklov• 11 years ago

And I'd rather see them written in native code, using a native API that doesn't require awkwardly traveling through Java.

Such is life.

akhilcacharya• 11 years ago

How would that..work? Pretty much the entirety of Android apps function based on subclassing Activities, Fragments, etc - how would this work in a language without java-like inheritance?

cel1ne• 11 years ago

The problem with Android isn't Java, but that it has one of most terrible, buggy, undocumented and confusing SDKs I have ever seen. It tries hard to touch every anti-pattern on the planet.

Android could be much more performant, but one would have to replace almost everything regarding UI and layout. Apps built with Dart cannot be much faster unless they do that.

I thought about rewriting/extending the base-class "View.java" to get more performance and less bugs (the default layouting algorithm seems to have exponential runtime! [0]), but the problem is

a) it would break compatibility with many other UI-components and

b) the behaviour and structure of the code is almost impossible to understand and imitate.

Just look at this beast: 8866 LOC without comments in one class [1].

[0] https://stackoverflow.com/questions/17493819/is-android-layo...

[1] http://grepcode.com/file/repository.grepcode.com/java/ext/co...

bicx• 11 years ago

What do you mean? There are tons of comments in that class.

jsnell• 11 years ago

8866 LOC after lines containing comments have been excluded from the count, I'd assume.

bane• 11 years ago

That's kind of scary that it passed internal code reviews and made it into production without comments. It speaks to Google's internal processes quite a bit.

myko2• 11 years ago

Android is a different beast within Google.

I'm hoping with Rubin out this changes and Android is held to similar standards as the rest of the company.

duaneb• 11 years ago

It has comments. They do not contribute to the line count.

gagege• 11 years ago

The obtuse answers on that thread are also the typical types of answers I see from the Android community as well. It's like the people heavily involved in Android are unaware that there is a whole other world of nicer and more efficient SDKs out there.

aboodman• 11 years ago

Did you watch the video? This project replaces everything about ui and layout within your app.

TazeTSchnitzel• 11 years ago

Trying to open [1] in Firefox froze the browser for several seconds. Wow, Google.

eklavya• 11 years ago

Qt is also one one of the options. With it you get apps for all the platforms.

dheera• 11 years ago

What are the hardware display refresh rates of these devices? If it can do 120fps I'm more interested in putting my phone on a spinning motor and turning it into a volumetric projector.

xxgreg• 11 years ago

Building an Android app with Sky is basically similar to using phonegap. i.e. You use HTML/CSS and web components, but it promises better performance and a more modern api.

The codebase is a forked version of chromium, but with a lot of legacy web cruft removed. The DOM api is replaced with a new more modern api. CSS has some important performance bottlenecks removed.

It also allows linking to off main thread code written in C++, Java, Go, JS, Python and Dart. Main thread code must be written in Dart.

They are aiming for the performance of native, but with a development toolset similar to the web.

IMHO a very worthwhile experiment.

Edit: The specs here give an idea of what the system is/does.

https://github.com/domokit/mojo/tree/master/sky/specs

on_and_off2• 11 years ago

That's an interesting experiment. The demo is extremely underwhelming though. I have to wait ~5 seconds for each screen to load, while on a wifi network. I don't know if it is dues to Dart framework or the http code loading, but it is way too high to be acceptable. The stocks app demo is a trivial exemple. A simple list with nothing else except for a nav drawer. It is very fluid but also extremely barebone.

Same thing for the square spinning at 60 fps. Call me back when there are 1000 of these.

Don't get me wrong, it is a very interesting experiment but it is hard to get excited for something so limited.

Dart for Android apps with 120fps

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