Guest not booting in full-screen

[Winxp-on-Macos]

Oracle VB 5.2.12 with VB additions of same version
Host: OS X 10.12.latest

Problem is reproducible on Windows XP and Ubuntu 16.04 LTS 64Bits.

When a guest runs it runs and is used always in full-screen. Also booting and shutting down in full-screen <<< that's the configuration the network here users desire .
However it boots in standalone window (or stand-alone window maximized) instead of full-screen if immediately after push on Guest Start button (Oracle VM VirtualBox Manager) user switches on host to another workspace (Desktop) - which is the problem me likes to ask if a common one?

[socratis]

A guest that starts full screen on OSX gets its own desktop. That's the way full-screen applications work on OSX. Try it with a video on YouTube...

[Winxp-on-Macos]

I see this too.
However in the case here if on host user switches to other Desktop (to an arbitrary one, nothing in common with Desktop the VB runs on) immediately after had pushed guest's start button in VB Manager the guest starts in standalone window. If user refrains from that immediate switch to other Desktop guest starts as expected in own Desktop and full-size.

[ChipMcK]

here is a list of macOS tutorials that are dealing with multiple monitors.
You should notice that macOS controls the screens, not the applications.

• Essential Tools & Tips for Working With Multiple Mac Monitors
• Mission Control 101: How to Use Multiple Desktops on a Mac
• How to avoid a blank second display when using full-screen mode in an OS X app | Macworld
• How to Keep the Mac Dock on One Screen in a Dual Monitor Setup
• Windows apps steal focus after choosing app fro...
• Window focus issues in Unity mode

[Winxp-on-Macos]

Does the term "Desktop" used in my elaborations really mean the same as term "monitor" or "screen" which ChipMcK is using in her/his answer?
"Desktop" addressed on this side is virtual network provided by host OS. The setup here is one display + multiple virtual desktops. Will articles provided kindly apply in same way?
Is it really the way the OS but not app controls also the mode of running app's window?
Please note the choice if guest in full-screen or standalone is made on VirtualBox side not on that of host.

[socratis]

Does the term "Desktop" used in my elaborations really mean the same as term "monitor" or "screen" which ChipMcK is using in her/his answer?

It depends. And especially if you're from a non-English speaking country/OS setup, the meaning may be lost in translation...

"Desktop" addressed on this side is virtual network provided by host OS.

Network? I think you mean "virtual screen".

Will articles provided kindly apply in same way?

Read them. Then you can answer your own question.

Is it really the way the OS but not app controls also the mode of running app's window?

If an application is requesting FullScreen mode, then the OS gives that "screen" a new desktop (that's the term used in OSX). So, yes.

Please note the choice if guest in full-screen or standalone is made on VirtualBox side not on that of host.

That's on every application. The application decides if it wants to go full screen. Then OSX obliges and takes it full screen. Is this your first time using OSX?

[ChipMcK]

MacOS: Full-Screen request results in a Desktop. You may assign an app to a certain DeskTop. System Preferences --->> Mission Control plus Cntrl+Right Click Options on the Dock's Badge/Icon.

This discussion should be in an Apple forum, as it is "How do I control my Host?", not "How to use VBox?'.

[Winxp-on-Macos]

Thank you for all the information from you. Well I will track on OSX side too.
In the beginning this effect was not occurring. It started to be reproducible at certain time of point, possibly it was upgrade from OS X 10.9 to Mac OS 10.12 (but I am not sure if me is right now regarding the point of time).
However I like to point out one question more:
> The application decides if it wants to go full screen, then .....
So theoretically the root cause can still be on app's side.

[socratis]

So theoretically the root cause can still be on app's side.

No. It's YOU. YOU decide that you want to go full screen. VirtualBox listens, passes the info to OSX and OSX creates a new desktop. This is how things are. Do not go on a witch hunt when there are no witches!

[ChipMcK]

Check this out Independent screens?

[Winxp-on-Macos]

Investigation in OS X has been started. Thank you for your hints.

No. It's YOU. YOU decide that you want to go full screen.

When it comes to me - the user - all i did was to enable full-screen for guest in VB Manager several years ago. Since then guest is started, rebooted and shutted down several times a day. It starts in fullscreen. Nowadays but occasionally user switches on host side to other Desktop/Workspace immediately after had invoked guest start (Start button in VB Manager). No explicit nor intentional switch to stand-alone mode.

[socratis]

Please search the Mac forums, not on the VirtualBox forums.

This discussion should be in an Apple forum, as it is "How do I control my Host?", not "How to use VBox?'.

I agree with ChipMcK 100% and this discussion is going nowhere, but in circles.

possibly it was upgrade from OS X 10.9 to Mac OS 10.12

There's nothing more to discuss here, VirtualBox is following OSX standard practices. Locking this.