Top-Left quarter portion of the guest's desktop becomes unresponsive to left mouse button clicks

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Nexus2112
Posts: 2
Joined: 30. Nov 2022, 21:16

Top-Left quarter portion of the guest's desktop becomes unresponsive to left mouse button clicks

Post by Nexus2112 »

Hi,

I have been having a problem for a while now where the top-left quarter portion of the guest's desktop becomes unresponsive to left mouse button clicks. I have done a lot of research on this issue to find a solution or a way to explain/reproduce it. I have found a few topics on this which gave me a lot of good information but none of these topics ever lead to a permanent fix by virtualbox developpers. Also, these unclosed topics could be pretty old (up to 7 years). So I am trying to write here to maybe get someone to fix this. First, let me link to similar topics which helped me a lot to reproduce it then I will explain.

(I cant paste links as a new user but until I can, here's information to find the tickets and topics open that are related to my problem)

ticket: 16296 (This topic actually have in the comments the information to reproduce it and isolate the problem)
ticket: 14743
ticket: 14903

Also, on this very forum,
topic: 79034

Again, sorry for repeating those topics/tickets but they seems to be forgotten... yet the problems still exists years after the issue was noticed.

Setup
- Dual Widescreen + laptop screen (I believe only dual widescreen is enough according to all the comments in the topics above)
- Windows Host
- Ubuntu 22.04 Guest with Guest Addition (The bug is so old that according to comments in the topics above, I believe that any Ubuntu with Guest Addition works. Guest Addition is where the problem actually happens)

How To Reproduce
- Launch the VM on a single screen, windowed mode (right screen for me)
- In the VM, open any text editor (I use QT Creator but I reproduced it in other editors too)
- In the VM, highlight a section of text by clicking, holding and dragging.
- In the VM, drag and drop this text outside the VM (i.e. on the Windows Desktop). Make sure the end of the click is outside the VM on the host (on left screen for me)

Done. After those steps, the text editor that is open is now unresponsive in the top-left corner.

Comments
I found that the click Press/Release state seems to be broken when the bug happens. Almost like if the state is reversed (when I don't Press the left mouse button, it is registered as pressed and when I press, it is registered as released). It is so annoying that in the past, I found myself in a situtation where I kept clicking everywhere fast with both left and right clicks until the state is restore by chance. But even if the state of the click is back to normal, the dragAndDrop part of Guest Addition remains in a confused state where it feels like it waits for a release of the mouse when it can never happens (thus the VM is unresponsive on the top-left part like it is blocked by an invisible screen waiting for the dragAndDrop to end).

To reproduce this bug, I drag and drop somewhere it doesn't make sense (like the desktop itself) but even by drag and dropping into another text editor outside the VM, the drag and drop doesn't work and it triggers the bug.

You might believe this is a weird use case. But this happens to me frequently while programming apparently. I think it does happen to me often because when I am programming - hightlighting, copying and pasting stuff around - sometimes the VM is slowed because of the quick stuff happening (maybe also a process like Intellisense taking too much CPU) and while it is slowed I do something outside the VM but probably that the VM being slowed has not registered that I stopped drag and dropping something and ... there you go. It registers a drag and drop of text outside the VM and trigger the bug. I used to kill the VM and restart it to solve the issue until I found an annoying work-around online:

How to solve
The problem comes from the drag and drop feature in Guest Addition. So to make the screen responsive again, execute:

Code: Select all

kill -15 $(ps aux | grep "VBoxClient --draganddrop" | grep "Sl" | awk '{print $2;}')
This solution ALWAYS works for me when the problem happens.

Don't restore the killed process

Code: Select all

/usr/bin/VBoxClient --draganddrop
When I restart "VBoxClient --draganddrop" the bug becomes worse and the whole VM becomes unresponsive... forcing me to kill "VBoxClient --draganddrop" and not restore it.

Please solve this issue. It is old. It is very annoying. And it is now reproducible.
fth0
Volunteer
Posts: 5668
Joined: 14. Feb 2019, 03:06
Primary OS: Mac OS X other
VBox Version: PUEL
Guest OSses: Linux, Windows 10, ...
Location: Germany

Re: Top-Left quarter portion of the guest's desktop becomes unresponsive to left mouse button clicks

Post by fth0 »

Kudos for the investigation and the summary. A few months ago, I did a similar investigation of this problem, and I also found the tickets in the Bugtracker. AFAIK, the personnel situation described in 14743#comment:18 hasn't changed to the better, so you'd still would have to find someone else to do the hard work. In the meantime, I can give you a few additional details I discovered:
Nexus2112 wrote:Dual Widescreen + laptop screen (I believe only dual widescreen is enough according to all the comments in the topics above)
A single laptop screen was enough to reproduce the issue for me. I used a 1600x900 VM window on a 1920x1080 screen.
Nexus2112 wrote:the VM is unresponsive on the top-left part like it is blocked by an invisible screen waiting for the dragAndDrop to end
There is an invisible overlay DnD window. You can use xwininfo -tree to find it.
Nexus2112 wrote:I used to kill the VM and restart it to solve the issue until I found an annoying work-around online
I found a better workaround, that may be of use to you: Mark a text from outside the invisible DnD window (in the guest or on the host) and drag and drop it into the invisible DnD window.
Nexus2112
Posts: 2
Joined: 30. Nov 2022, 21:16

Re: Top-Left quarter portion of the guest's desktop becomes unresponsive to left mouse button clicks

Post by Nexus2112 »

Thanks for the quick reply.

It is sad that a simple bug like this cannot be solved because of a personnel issue. It doesn't feel like a hard bug to solve (depending on the quality of the code).
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