[bug] Another talk about the canvas not respond to zoom/pan

[yikscloud]

Actually this problems frustrated me for years since I start to use krita, it just not respond to mouse scroll/middle click to zoom/pan canvas, but it works on other parts(UI…).

This happens sometimes when I jump off the app then switch back, but it not always appeared, sometimes bugs come when I just save image. And I cannot fix it unless I restart the program(sometimes even this wont fix it, I must relogin). I found other reports this issues either(seems it exists for years), but non of these simple fix works for me( reinstall drivers/krita, click sidebar, click window bar etc…).

And today I decide to research it seriously.

I enabled the tablet logging and the log viewer, I see these things below

As you can see, seems the canvas is focused and it reads the mouse middle button(button 4) and the scroll event, but just not pan and zoom(zoom works on ctrl+/- and the zoom scrollbar on bottom). That’s really weird

[yikscloud]

Then I found this ,

These log lines seems very suspicious
1.I use mouse to zoom/pan, nothing happens, but it prints the mouse event
2.Switch to use tablet pen, the pen stucks a while, then drawing something, but still refuse to zoom
3.Use mouse again, now the zoom works
I will record this as a video later, so it will be clear

[AhabGreybeard]

I’ve changed the category of this topic to be more specific.

[Grum999]

Hi

@yikscloud

it just not respond to mouse scroll/middle click to zoom/pan canvas

It’s not clear to me.

On my side, mouse scroll/middle click works properly to zoom/pan canvas.

So I may do it wrong or do not understand exactly what happen (or does not happen) on your side.

@yikscloud

I enabled the tablet logging and the log viewer

how did you activated it?

Some additional information can help to understand:

• version of Krita
• operating system
• are we talking about mouse or tablet? I’m not sure
• how to activate these log event
• how to reproduce the problem
• …

Grum999

[yikscloud]

To active the logger:

1. dockers -
   
   2.ctrl+P open the commander, type tablet
   
   

[yikscloud]

The zoom/pan issue is, I cannot zoom/pan canvas with my mouse wheel/middle mouse button. But the mouse wheel works on other part like scroll the brush list. And the tablet pen(has a button register as middle mouse button) still not work. Ctrl + drag to zoom mode not works too. These hotkey is set correctly, and in most contition it works again when I restart Krita.
About the reproduce: most time is I minimize the krita or just focus on other app window, then switch back to krita, then it has some chance to trigger the bug.
Some other post related to this:

Suddenly unable to scroll to zoom in/out with mousewheel

Type of device* : PC Brand and version of the device: Home-built PC System** : Windows 10 * graphics tablet/display tablet/2-in-1 laptop/Android tablet: Huion H1060P I have been using Krita on my PC for several months with no such issues, but today I suddenly lost the ability to zoom in and out using my mouse wheel. I have tried the following solutions: Checking the mouse wheel in other programs Checking the zoom in/out settings Closing and opening the program Restarting my PC Uninstallin…

[Grum999]

@yikscloud

I cannot zoom/pan canvas with my mouse wheel/middle mouse button.

What are your settings?

On my side:

And I have no problem.

If your settings are the same and it doesn’t work, there’s probably a problem somewhere else or a bug; if your settings doesn’t define pan&zoom canvas with mouse, it may be the source of the problem

Grum999

[yikscloud]

Here is my settings, it works when the bug not comming

I try this settings below either, but wont fix the issue

[Grum999]

Yes it seems normal
Except I’m not sure why, the “Pan mode” is greyed

Not easy to help more on my side I think
I can’t reproduce the problem and looking on forum there’s some other similar topics but seems nobody find a solution.

Grum999

[yikscloud]

Thanks Grum for the effort in trying to help! Really appreciate it! I will keep to find some other way to find the problem
The shortcut grey cause krita not allow to delete them

[yikscloud]

Thanks for your testing! I can replicate the issue on your step.
1.Open krita, open any drawing or create a new file
2.Scroll mouse on canvas
3.window-new window, create a file or open something, scroll on the canvas, freeze.

Sometimes issue not happen, just click some other place(like desktop) between step2 and step3.

I submit a issue on KDE on this replicate step 489587 – Scroll on canvas freeze when switch between Krita windows

[YRH]

Hi @yikscloud , I tried this on my Windows 11 system, and it does not happen for me. There must be some additional factor at play. I tried without a tablet, just with my mouse. I tried windows, views, tabs, and sub-windows, all of it seems to work fine. I can still pan, zoom, rotate with my mouse.

Could you or @oscar maybe record a video of demonstrating this problem (full desktop with all Krita windows, if there are multiple)?

[yikscloud]

Sorry for reply late, I will upload a video later

[yikscloud]

I made a video to show how I reproduce the bug, it’s a bit long, hopes it can help something

Krita Canvas Scroll Bug

[YRH]

Hi, thanks for the video!

It seems this is cropped a bit. I understand that you have a normal toolbar, it’s just off-screen, yes?

Am I right that to trigger the bug you simply need to open a new window and already the mouse wheel doesn’t work? Nothing like that happens for me, even with 5.2.2 version it works normally in this situation.

I noticed some differences with your Krita:

• When you open the new window, it does not automatically get focus and get maximized, you needed to click on the task bar to bring it up.
  For me, it automatically opens in front of me.
• Your Krita UI seems to have some modifications, like an additional menu item.

Can you install Krita on another PC/laptop and try to reproduce the bug there? Another option would be to wipe all your custom settings on your current system, but I don’t recommend that and I’m not certain how to safely backup all customizations/resources.

You could also try upgrading to the latest Krita 5.2.3, but it probably won’t help.

My expectation is that this is somehow limited to your particular system. Maybe due to the modifications you did, or due to the combination of software you run.

[yikscloud]

Thanks for your detailed reply!

Yes, the taskbar is cropped by obs, sorry for that. I trim the videos a bit so it can be a bit shorter(Krita new window open needs fifteen seconds ), but seems I trim one step that I click on my desktop by accident.

After I click new window and before the new window appears, I just click nothing on desktop to simulate I switch to other programs. For me, if I do this, new krita window will not popup automatically, I must click the krita icon on desktop and select the new one.

The most abnormal thing is krita catch the mouse event but no reaction to this, I doubt there is some code to let krita think this event is a exception situation so just ignore it. I see something like this in the code like below one, But still find where the problems at.

   void debugEvent(QEvent *event)
    {
      if (!KisTabletDebugger::instance()->debugEnabled()) return;

      QString msg1 = useBlocking && ignoringQtCursorEvents() ? "[BLOCKED] " : "[       ]";
      Event *specificEvent = static_cast<Event*>(event);
      dbgTablet << KisTabletDebugger::instance()->eventToString(*specificEvent, msg1);
    }

Very appreciate for your advice, I will check it and see what I can do to fix that issue.

[YRH]

Oh, I see, so it takes a long time before that window opens. I’ll see if I can manage to do the same (click somewhere before it opens).

[yikscloud]

I found if you press ctrl+alt+del call the task processer and then click to focus krita again can fix this, hope it can help someone with same issue!
By the way, this fixing is same way as when you play dark souls 1 remasterd, and then controller no response( ex you click other program while playing)