virtualbox.org

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ModEdit; related ticket: #19082: VirtualBox Manager scaled *down*, when a mix of HiDPI and non-HiDPI screens are attached

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I recently updated VirtualBox on a development machine running Debian to version 6.0.14. Since the update, the ui of VirtualBox is so small, it is basically unusable. All elements of the ui are scaled consistently, however the windows themselves are not smaller than usual. For instance the text and image in the about-box are now tiny, but the box is still the same size as before, it is now just mostly empty.

I have looked around and it seems like this is similar to viewtopic.php?f=7&t=92965 (sorry, not allowed to do urls yet), however I am using VirtualBox from the official repositories.

Jean-Pierre Höhmann wrote:however I am using VirtualBox from the official repositories.

And I assume that you're using the Debian-specific package. BTW, you didn't mention which Debian version you have installed, please be specific...

Can you uninstall what you have and try the "All Distributions" one? That would be the last package in the VirtualBox for Linux Hosts page.

Thanks for you quick reply. I am on Debian 10 Buster. Sorry i forgot to specify that. It seems this will only happen when plugged into an external screen, so i have no way to test right now whether switching to the generic version fixes it. I will try next week.

Jean-Pierre Höhmann wrote:It seems this will only happen when plugged into an external screen

That's another detail that you didn't mention in the first post.

And let me take a leap of faith here and say that it's a HiDPI one, or the laptop is HiDPI and the ext. display is not?

I'm having a similar issue. Ubuntu 18.04, with the VirtualBox 6.0.14 deb for Ubuntu 18.04 downloaded from the downloads page linked to in this thread.

I'm running a Lenovo X1C laptop (HiDPi displa) with a standard 1080px external monitor attached. The fonts are pretty small (see attached screenshot), and I also have to resize any dialog box that the manager pops up.

Is there anything I can do increase the size of the fonts to make them closer to the fonts used by the rest of the system?

Ross

See viewtopic.php?f=7&t=88116 and specifically how to set your QT_AUTO_SCREEN_SCALE_FACTOR, QT_SCREEN_SCALE_FACTORS, and QT_SCALE_FACTOR.

That's another detail that you didn't mention in the first post.

Yup, my bad, sorry. This device runs plugged in almost all of the time and it didn't occur to me to unplug the external screens.

The issue occurs with the following setup:
Lenovo T490 internal Monitor, 1920*1080, 14", plugged into external HP displays, 1920*1200, 24"-ish

The issue does not occur:
(2) If the device is not plugged into an external screen at all, and (2) if it is plugged into a 4k screen.

So this seems to indeed be related to mixing HiDPI-screens with non-HiDPI screens.

Oddly, however, the font gets smaller when a non-HiDPI screen is plugged in, while it is fine, when the device is on its own, which is the exact inverse of what you would expect.

I have installed the generic build of VirtualBox, however this exhibits the same issue.

This is a fresh system, so I think it is unlikely, that a misconfiguration would be at play. My configuration is Debian-default, with minimal adjustments (none of which are related to gui-toolkits). No other apps that rely on qt are installed, so there is nothing on here that wasn't brought in either by Debian, or by VirtualBox itself. I have however checked for the environment variables you mentioned and can confirm, that none of them are set. As far as I can tell, all relevant settings are default.

I have read through the thread you mentioned and the description seems to match this issue, however VirtualBox does not seem to output any errors for me. Is there anything else I should do to debug this?

Jean-Pierre Höhmann wrote:however VirtualBox does not seem to output any errors for me

I don't see any reason that it would...

Jean-Pierre Höhmann wrote:Is there anything else I should do to debug this?

Try to find out more about those three QT-related settings:

• QT_AUTO_SCREEN_SCALE_FACTOR
• QT_SCREEN_SCALE_FACTORS
• QT_SCALE_FACTOR

Unfortunately I can't replicate your setup, and by extension your mishap, so I can't help you with that any more...

But please post the solution if you find it, it would be really appreciated.

Hm… the more I look at this, the more more it seems to me like this is a bug, not a misconfiguration. Do you think it would make sense to file this as a bug with Oracle?

For anyone else stumbling onto this thread:
These environment variables are unrelated to the issue. They are originally a clutch to scale up applications that are not meant to run on HiDPI screens. Since this issue is caused by screens that are not HiDPI, setting QT_AUTO_SCREEN_SCALE_FACTOR will have no result whatsoever. QT_SCREEN_SCALE_FACTORS can be used to force scaling all applications even on low-res screens as a workaround. This will – however – break all well-behaved QT-applications.

I have submitted a ticket here: https://www.virtualbox.org/ticket/19082