• BrowserViewportService

It does under MudHidden component:
https://github.com/MudBlazor/MudBlazor/blob/47e4ff38716aa367de9bfc9833a87d4066b39487/src/MudBlazor.Docs/Pages/Components/Hidden/Examples/BrowserResizeEventExample.razor

If we want to have a dedicated page for this, probably should show two ways of using the service, with implementing IBrowserViewportObserver like example above and with using lambda like your example.

Another issue is that we don't actually recommend using:

IResizeObserver
IScrollListener

Instead, we recommend using:

IResizeObserverFactory
IScrollListenerFactory

Due to this problem #4631
In short IResizeObserver, IScrollListener implement IDisposable and when you register such services as transient (which they are), the MS DI container captures these services and never actually releases them, leading to a memory leak: https://learn.microsoft.com/en-us/answers/questions/2336787/why-does-di-container-retain-references-to-transie
MS relevant code:
https://github.com/dotnet/runtime/blob/f0db8f9d9668ba03897739152d02623acbd04466/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/ServiceProviderEngineScope.cs#L78
https://github.com/dotnet/runtime/blob/f0db8f9d9668ba03897739152d02623acbd04466/src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceLookup/ServiceCallSite.cs#L26

The IScrollManager does not implement IDisposable, and the services IBrowserViewportService, IKeyInterceptorService, and IPopoverService are newly implemented with this issue in mind. They are not registered as transient services.

@ScarletKuro Thank you, didn't know that, thought the framework would handle the disposing of all disposable services => updated the examples to use the factories.

I know I'm late to the party, and this is fantastic and sorely needed to be added to the main documentation. However, I would like to see ScrollManager fixed to not allow "Lock Scroll" to happen more than once. Currently ScrollManager can "Lock Scroll" an unlimited number of times and you will need to "unlock" scroll that many times to unlock it. It should track it's locked and ignore additional lock requests in my opinion. Similar to MudOverlay's lockscroll feature.

Also the ScrollListener example is a bit wonky, can't scroll the test div there's no scrollbar:

Additionally it would be nice to show scroll listener for "page" or body scroll? (passing null to selector sets this to "document", passing a selector instead of null would replace the .Selector line. Basic usage is still good enough but we are leaving a bit of meat on the bone by not expanding it.

@versile2 I'm not quite sure why this doesn't display a scrollbar for you (Server, Chromium):

I just answered it myself by typing "Chromium"...
No idea why this doesn't work in Firefox => will look into it
Ah it does work, the background-choice just wasn't the best for light mode in Firefox:

• ScrollManager: Do you mean I should track this within the example and adapt the example ui or do you refer to updating the service itself?
• ScrollListener: Ah, you are right, sry, oversight by me

=> As the current one is closed: Should I just create a new small branch "Service page additions"?

@versile2 / @91378246 feel free to add adjustments PR.

Yes new PR for adjustments.
I'm testing on Chrome but yes I think the background is the issue. Also Would be "prettier" if the text didn't shift when it adds a decimal place. But not required.
The ScrollManager is fine for this PR and probably out of scope for your change. When time permits if you have time it would be a nice fix. Not required for what you've done.

@versile2 Added a PR: #11977. Please tell me if I understood you correctly. Regarding the scroll position of the body: I couldn't get it work (attaching to html/body/mud-layout etc. does nothing and if I try document it throws).