Discussion: WinUI should be cross-platform

[SuperJMN]

Hello everyone.

For those that don't know me, I've been a veteran, die hard XAML developer since 2008. I've been involved in almost everything that was minimally related XAML (including WPF, Xamarin Forms and UWP, among others) and the only reason I'm writing this is to help and to be the voice a huge number of Forgotten Developers that are out of the loop already and jumped ship because they lost their hopes in Microsoft doing the right thing when it comes to application models, especially GUI related like the topic in discussion.

After long talks with the community, and being myself involved in projects like Uno Platform and AvaloniaUI this is that I've got.

Here, I'm trying to condense all the opinions and points of views that are that I've collected during these conversations. As you will see, they are very critic with the path that WinUI is seemingly taking.

The Forgotten Developers are silent or just ignored

As I said before, they are already out of the loop or simply exhausted. Some of them have tried to call your attention for years and were ignored or silenced.

As a summary, the Forgotten Developers:

• Usually reject anything that runs on a browser or is based on HTML+JS
• Switched to other platforms/frameworks with resignation because they had no better option for web/mobile.
• They are tired of seeing how Microsoft keeps failing to deliver a GUI framework that allows the so called "write once, run everywhere".
• They don't want a slight evolutionary upgrade over WPF/UWP

Key points to consider

• Recognize the importance of WPF. 14 years ago, it changed the way we designed GUIs with a completely new approach. Its power was unprecedented. Many, many developers still compare other XAML-based presentation techs to WPF. The level of freedom it provides (you can potentially do anything with WPF), has made developers reluctant to use other XAML frameworks, especially those who don't develop mobile/web applications.
• The Universal Windows Platform (UWP) wanted to get the best of WPF, but it was too late. It took years for it to offer a similar functionality. In some aspects, it's better than WPF, but still has some major drawbacks:
  • It's not universal. The death of Windows 10 Mobile, that is another interesting subject to analyze, truncated the One Windows vision to the minimum expression.
  • Sandbox restrictions make UWP a no go for advanced applications.
  • The channel of distribution is the Microsoft Store, something that has been proven inadecuate for a wide variety of applications. The certification process itself is painful and slow. Add that compiling applications for .NET Native is troublesome to say the least.
  • A notable lack of third party controls. Notable examples: DataGrid and Charts, among others
• Frameworks like Xamarin Forms have diverged too much in the wrong direction. Concretely, Xamarin Forms has turned into an endogamous ecosystem that offers nothing but immediate short-term satisfaction of a cross-platform need. It's become into a big bunch of patches to overcome the inherent restrictions of its "highest common denominator" approach. Moreover, Xamarin Forms is synonym of iOS and Android only.

This isn't a rant, but the sad reality.

So, what's my proposal?

Take the best out of WPF and UWP:

• A fully-fledged set of standard controls, rich enough to cover almost every need devs have, including DataGrids and Charts.
• Markup Extensions
• Adaptive triggers
• Data Templates
• Bindings
• Dependency Properties with value coercion
• Styles
• Control support for validation
• MVVM-ready

And make it CROSS-PLATFORM!

• Support Windows, Linux, Mac, iOS, Android and WebAssembly

WinUI SHOULD NOT repeat the errors of WPF and UWP

What actions should be taken?

• Don't couple WinUI to DirectX
• Think cross-platform: there are graphic engines that are capable of drawing accelerated graphics in each platform. Windows could be the reference platform, but other OSes should see WinUI the best way to create GUIs.
• AvaloniaUI already IS already cross-platform. Why don't ask people in the project for help and feedback to improve WinUI?

[binsys]

Most of WinUI's technology comes from Sliverlight, and Sliverlight has actually achieved cross-platform. So WinUI cross-platform depends on strategy, not technology.

[Qws]

Honestly... it's actually so pathetic Microsoft is now trying to play catch up... they only care about "big" marketshare, they are not looking what their customers/product fans want.

Microsoft is the reason why DESKTOP APP development has shifted to the outdated WEB development, even when web is so horrible.

I'm sure every XAML dev agree that HTML/CSS is so garbage.

But still... HTML, CSS, DOM... with frameworks like React, Angular, Vue who are trying to make it something little bit more pleasant. People still focused on this outdated web, not on Microsoft's new closed-source Windows-only platform that dies every 2-4 year for a new one.

XAML based Win-app platform should have open-sourced YEARS ago. It should have write once deploy on WEBSITE, Windows, Mac, Linux, Android (any platform customer wants). Windows Store should have been crossplatform with an XAML/UWP app renderer. (similar how Google Chrome is crossplatform with HTML/CSS renderer).

During Microsoft's golden age, a XAML based crossplatform app could have destroyed the web, then we wouldn't had to deal with this CSS, HTML, DOM and countless frameworks.

But no, Microsoft obsession with proprietary software made them lose to the web.

Meanwhile Google's Flutter is becoming what I always wanted for XAML.

[tomasfabian]

I expect that WinUI 3 will be a target platform in MAUI. Uno platform has already announced that WinUI 3 Preview got support. So, @jeromelaban / Microsoft what we probably really need is Uno/MAUI unification? MAUI is less useful IMO than Flutter or Uno without a web (browser) target.

Please leave your comments in the MAUI repository, too.

WPF(Silverlight) everywhere!

[handicraftsman]

Porting DirectX to other platforms seems a vaste work, maybe the solution is to use OpenGL or Vulkan instead of DirectX

Google has ANGLE which allows running OpenGL ES natively on any platform by translating calls and shaders into native API (desktop gl [possibly provided by swiftshader software renderer], vulkan, directx, metal). It is also a core part of Chrome and Flutter, running alongside with Skia.

Microsoft could do a small (maybe just as a starting point) subset of DirectX for GUI apps and make it translate into native APIs just like ANGLE does.

[handicraftsman]

What comes to the "different linux distro support" problem, linux users are often skilled enough to fix incompatibility themselves, and even then there is Flatpak which unifies packaging for desktops just like Docker does that for servers.

[theromis]

Mentioned in Lonje chat https://www.lonje.com/message/1968439855/

[Shadowblitz16]

I really think WinUI should also support native theming on Mac and Linux while still supporting custom theming. I'm not sure about Mac users but the Linux community likes to control how their desktop looks. They already have Gtk which I think would be a good thing to wrap into the WinUi framework

[handicraftsman]

I really think WinUI should also support native theming on Mac and Linux while still supporting custom theming. I'm not sure about Mac users but the Linux community likes to control how their desktop looks. They already have Gtk which I think would be a good thing to wrap into the WinUi framework

It is most definitely hard to do as WinUI is a style language, and underlying XAML frameworks require you to do theming yourself, while default themings are provided too.

[mdtauk]

I have suggested in the past, that the project should be structured in a way that enables the community to develop a Metal Renderer for macOS and iOS - and possibly a Skia renderer for Android.

The same default Styles and Templates could be used on all platforms, or Android and macOS styled default templates and resources could be created.

[VBAndCs]

Love the phrase "The Forgotten Developers". I know lots of them who are talented, experienced, passionate about technologies. They are veteran .Net developers. I have no doubt they, generally speaking, can make better apps than many kids who thrive on app development for iOS and Android. If WinUI can provide a pleasant and robust path for them to utilize their extensive experience in C# + .Net + Xaml to make apps for Windows, Android, iOS and Web, many will jump on the wagon and the world will benefit from their high-quality apps. WinUI + Uno Platform could be the ultimate call.

Microsoft flushed us out of the market, by it's unwise windows-protective strategy. This can end up flushing windows itself out of life!

[plantoscloud]

No it shouldn't be cross-platform. It's called Windows UI for a reason. Let's just get a UI system that works across all of Windows (platforms and languages) to start with hey? That hasn't even been achieved yet. We are still split between .net framework, .net core, uwp, and then the C++ story, which at least has uwp, but no game dev's use it, because UWP/WinRT still has some issues - distribution, forced taskbar & titlebar popups when in fullscreen (yikes).

Thinking about cross-platform would be a colossal waste of resources. Get it right on Windows first please. And get .net 5 out the door, and fix UWP and the windowing story, and put DirectX onto C#. And fix the GC. There is still so much to do in the narrow scenario, just on Windows.

And to the OP.

• UWP is universal. To say it's not universal is a false claim (they never meant to target Android, thank god). The original promise has been delivered. All Windows devices run UWP. Windows Mobile was a separate OS, they had to get rid of it. All new Windows platforms will be Windows (10 or 10X). Eventually based on CoreOS I suppose. And they will all run Windows applications. Just because we don't have a Windows phone at the moment is incidental. We have all the other device types. And we'll have Neo and Duo soon.
• Sandbox restrictions - These are good things. Win32 style system-wide access should be stamped out in general. If you have a specific requirement, you should put forward your requirement so that we can discuss how it could/should be done inside a UWP container and if you should be allowed to do it the way you are suggesting. And work out if UWP needs that feature. Because I can think of some advanced applications that could be written in UWP no problem. I can has program! You need to discuss specifics.
• .net native is being replaced and the distribution story will change with .net 5. I think it's fair to say that Microsoft are working on this. Surely they know of the issues. But you should file specific issues to target the real underlying problems here.
• "Don't couple WinUI to DirectX" - WTF? It absolutely should be coupled with DirectX, that is the native Windows graphics stack. Please don't even consider anything else. I absolutely do not want to come across OpenGL rendering surfaces under the hood. That would break compatibility and cause all sorts of mayhem.

what do you think about OpenXR?

[SavoySchuler]

Thank you all for your feedback and passionate discussion on this. There are a few a cross-platform technologies that now exist and have matured since this conversation started such as MAUI, React Native for Windows, and Uno Platform. We know this will not be the direction of WinUI in the foreseeable future and will be closing this issue.

Thank you again for supporting the team with your contributions to this discussion and throughout the rest of the repo. You are sincerely appreciated!