Arch Linux

eichan

Member

Registered: 2018-01-08

Posts: 31

GUI issues with java on several apps

Hello everyone,

I need help with two Java apps for which I'm having different, but maybe related, GUI issues. You'll find a GIF and a screenshot showing the issues here.

In AstroImageJ (the GIF), the cursor (small red cross) should be aligned with the apertures (blue circles) but it's not. There is also some weirdness in the top right corner, which should simply show you what part of the image is currently visible. So it looks like the overlay on the image is at a different scale than the image itself, and it messes things up.

In Aperture Photometry Tool (the screenshot), the smaller image is supposed to be a magnifyier, showing you a zoomed version of what's under the cursor when you hover on the main image. Well that doesn't work, it's only showing the bottom left corner and never updates. I'm supposed to click on the image to interact with it but when I click I get an error saying I didn't click on the image. So in this case, it feels like the software doesn't know where the cursor is.

I use Arch with KDE Plasma on a XPS 9360 laptop. Note that I'm HiDPI, and I suspect this to be the cause... I use java-14-openjdk, but have tried with the Oracle JRE (15), as well as java-11-openjdk, with no difference at all in the result. I even tried installing another DE (Sway) to see if the problem remains, and yes it does. No difference. I tried all the solutions suggested in the ArchWiki page, but with no success. Always same problem.

Note that when I boot on Windows, these two softwares work without a problem. I use other Java apps that work fine under Linux, but those two (and I really need them) don't. Since most of my workflow is on Linux, I really can't be bothered booting to Windows anytime I need them...

Please help!

EDIT: I've tried sevral different JRE: OpenJDK 11 & 14, JDK 15, JRE 8 LTS, without success. JRE 8 does not compensate for HiDPI so everything is very small, but the problem I have with AstroImageJ is solved, which confirms my suspicion on HiDPI being the cause of at least part of my issues. But the problem remains: if I scale up the UI, the problem would likely reappear, and the bug I get on Aperture Photometry Tool isn't fixed by any of these JREs.

Last edited by eichan (2020-12-11 06:01:30)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,351

Re: GUI issues with java on several apps

This is unlikely to be fixable, see https://openjdk.java.net/jeps/263 and the linux section for why.

You could try and give the GTK LnF a shot but as the problematic pieces aren't native widgets it's likely that whatever method they internally end up using just falls to Xlib which isn't aware of HiDPI... If it isn't explicitly set, try setting the https://wiki.archlinux.org/index.php/HiDPI#X_Resources xft.dpi x resource. If that doesn't work you're likely SOL

FWIW the "official" recommendation is to try java 6... https://www.aperturephotometry.org/faqs/#q14

Last edited by V1del (2020-12-12 10:09:24)

twelveeighty

Member

Registered: 2011-09-04

Posts: 1,456

Re: GUI issues with java on several apps

FWIW the "official" recommendation is to try java 5

It's actually Java 6, not 5, but almost equally ancient (2013).

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,351

Re: GUI issues with java on several apps

Whoops I must've fat fingered, I definitely intended to write 6