[Enhancement] Implement an effect that manage the full screen mode

[Cfun1]

Summary

Provide an option to hide/unhide the status bar on some pages only, at Xamarin.Forms level, currently one needs to use a DependencyService to achieve this.

API

FullScreenEffect

Properties

API	Description
Mode	Full screen mode platform dependent, may affect StatusBar, navigation visibility
IsPersistent	True: Keep Full Screen mode set even after navigating away from page that enabled it. False: Restore the initial Full screen state/mode (what if changed meanwhile?) once navigating away from the page.

xPlat Mode	Android	iOS	UWP
?	Enabled	Enabled	FullScreen
?	Disabled	Disabled	CompactOverlay
?	Immersive		Auto
?	LeanBack		Maximized
?	StickyImmersive		PreferredLaunchViewSize

Intended Use Case

My initial goal is to set a page in full screen with an attached effect to it.
Used besides (or even without) Shell.NavBarIsVisible="False" it will enable full screen mode.
xct:FullScreenEffect.Mode="Enabled"
What do you guys think?

Scenarios

• This can be used on pages that dev want it to be in full screen, like a Login page.

<ContentPage  xct:FullScreenEffect.Mode="Enabled"...

• If a dev want to keep the app in full screen even after navigating away from that page

<ContentPage xct:FullScreenEffect.Mode="Enabled" xct:FullScreenEffect.IsPersistent="True"

References

Android: https://developer.android.com/training/system-ui/immersive
UWP: https://docs.microsoft.com/en-us/uwp/api/windows.ui.viewmanagement.applicationviewwindowingmode?view=winrt-19041
iOS: https://developer.apple.com/documentation/uikit/uiviewcontroller/1621453-modalpresentationcapturesstatusb
https://developer.apple.com/documentation/uikit/uiviewcontroller/1621440-prefersstatusbarhidden

Who Will Do The Work?

• I am willing to take this on myself
• Just putting this out there for someone to pick up

[pictos]

@Cfun1 on Android we have different ways to hide the statusbar as you can see here, do you plan to manage that on android? Do you have any implementation spec?

[Cfun1]

@pictos I was thinking about the SYSTEM_UI_FLAG_FULLSCREEN only but if you think it better with all so yea.
The only spec I have so far is the one described in the issue, still some questions pending. Also still not clear if such feature suggestion will be approved from the usage case point of view.

[pictos]

@Cfun1 I'm ok with this feature, I think that will be a great addition to the lib. Let me see your questions and try to answer them in next hour

[Cfun1]

1- Should we trigger Shell.NavBarIsVisible="False"/ NavigationPage.HasNavigationBar="False" along when is applied ?
2- Should I follow the same shared effect design in xct, or using platform specific API (will have to take a look on how it works)?

[pictos]

1. TBH makes sense to hide the navigationBar when the user enters this full-screen mode. We can do for both Shell and NavigationPage, I believe that will be very straight forward to implement;
2. In this case we can implement this on all platforms (Android, iOS, and UWP)? If yes we can move with the normal effect, if not we need to discuss a little bit more if makes senses to use it as Platform Specific APIs

[pictos]

@Cfun1 since you want to work on this, I already added in-progress label. Please let me know if you can work on this