Mouse size is 2x smaller than it should be on x11 w/ 2x scaling enabled (for HiDPI)

[rbreaves]

Description

The mouse cursor is 2x smaller than it should be and am unable to scale it up as a flatpak using env variables or overrides for xcursor scaling.

Things I tried were this..

sudo flatpak override --env=XCURSOR_THEME=Adwaita com.github.maoschanz.drawing
sudo flatpak override --env=XCURSOR_SIZE=72 com.github.maoschanz.drawing
flatpak run com.github.maoschanz.drawing

# attempt 2
env GDK_BACKEND="x11" GDK_SCALE=2 CLUTTER_SCALE=2 GDK_DPI_SCALE=2 flatpak run com.github.maoschanz.drawing

# a lot of things scaled up but not the mouse cursor, stayed the same size.

Steps to reproduce the bug

1. Install Ubuntu 20.04 or newer (or Ubuntu Budgie) - login to x11 desktop
2. Runs these commands, logoff and back on. (best if you have a 4k laptop)

gsettings set org.gnome.settings-daemon.plugins.xsettings overrides "[{'Gdk/WindowScalingFactor', <2>}]"
gsettings set org.gnome.desktop.interface scaling-factor 2

3. Install drawing from a flatpak and observe small cursor.

System

• Device (desktop computer/tablet/phone/...): MacBookPro11,4 1.0
• OS: Ubuntu 20.04.3 LTS x86_64
• Desktop environment: Budgie
• Package format: flatpak
• App version: 0.8.5

[maoschanz]

only when hovering the canvas, or does it happen with the UI elements (buttons, menus, etc.) too?

[rbreaves]

@maoschanz All parts of the application, so yea canvas & the UI elements.

Normally I'd have set this

env GDK_BACKEND="x11" GDK_SCALE=2 CLUTTER_SCALE=2 GDK_DPI_SCALE=2

like this

env GDK_BACKEND="x11" GDK_SCALE=2 CLUTTER_SCALE=1 GDK_DPI_SCALE=1

But I wanted to see if the cursor would scale at all with those variables all set & yea that didn't work, but yea the UI became massive when setting those like that lol. You probably only need to check for GDK_SCALE but you could check other parameters individually too I guess. People seem to set things in so many different ways..

I am working on a script to help people scale their Gnome and Budgie DEs and trying to make as few individual edits as possible. This is the first app of its kind that I have seen that didn't just work with my scaling method or using the GDK Window Scaling feature combined with xrandr scaling.

https://github.com/rbreaves/betterScale

[maoschanz]

it could be a side-effect of my attempt to hardcode the scaling of the image on the canvas as 100%, as a temporary fix to #207 until proper HiDPI support is implemented (#243)

https://github.com/maoschanz/drawing/blob/bdc46f1631a8bbf2b9af4aad61dd34e2551055e0/src/image.py#L52

but it's very weird, it shouldn't do that, the only downside should be a very tiny image with poor CPU performance

sadly the SDK version "41" doesn't work correctly regarding env variables, so nowadays i can't even get the absurdly big UI at all to test it

[rbreaves]

Well funnily enough literally everything about your app scales perfectly under x11 and HiDPI when using my specific scaling method except for that mouse cursor lol.

I think everyone pretty well knows the horrible state Linux is in in terms of HiDPI support. I hear things are better under wayland but atm I prefer some features that only x11 can give me. I would like to flesh out betterScale more and start to get linux users and distros to either adopt it or re-implement their current scaling methods and UI to essentially follow the same type of implementation.

From what I have seen under most distros is simply a very broken x11 fractional scaling option if there is one at all. If it is not broken then a sliding scale of like 4 levels which is hardly enough.. or early on insane CPU usage. Seems the CPU usage has come way down or I wouldn't be using it right now.

[rbreaves]

Really great app by the way, I am very impressed with its tight UI and focus. You could definitely grow this into something much larger imo. I also love that you kept the menu structure working with Global Menus like the vala-appmenu or Unity. Many devs don't implement that as much these days or flatpak packaging will sometimes prevent it from working (of course not in this case - it's working great!).

[maoschanz]

for some reason, on my office's desktop computer it works fine (flatpak, 20.04, X11, 200%) the only difference is that it's GNOME Shell

maybe there is also something with the mouse cursor theme(s) installed on the system, versus those in the flatpak sandbox?

[rbreaves]

Huh.. that is odd. I’m running Ubuntu Budgie 20.04 but I’d figured the cursor issue would have shown up for gnome or Budgie. :/

I am actually scaling up my resolution slightly via xrandr virtual frame buffer & then back down but that should be virtually undetected by any app.