Scaling dependent display bugs when upgrading to Eclipse 2025-09

[Greglar4]

Hello,

We are in the process of upgrading our RCP application from Eclipse 2024-09 to 2025-09. We noticed some scaling dependent display bugs after upgrading. I've uploaded photos of three examples.

Here, the lines and breaks in the diagram nodes should not be there, and go away when at 100% scaling, but are present at 125% scaling.

This one might be hard to notice, but the Arguments and Issues section rectangles are cut off at the bottom by the Metrics and Status headers. The rectangles should have a bottom border, but it isn't visible. This again goes away at 100% scaling, but is present at 125% scaling.

This is just a displayed PNG, and it has several dark horizontal lines which shouldn't be there. They also disappear at 100% scaling, but are present at 125% scaling.

I saw this umbrella issue, #1961, and was wondering if these issues could be related to that. We have only tested on Windows, but can report back when we're able to test on a Mac.

Thanks!

Greg

[HeikoKlare]

Which framework do you use for those diagrams? Is it GEF Classic? In that case you should probably disable monitor-specific scaling for the application when using a release prior to 2025-12.

With the 2025-12 release, GEF Classic will have an enhanced HiDPI support that supports monitor-specific scaling. Some information can be found here: https://github.com/eclipse-gef/gef-classic/blob/master/org.eclipse.gef.doc.isv/guide-src/guide.adoc#highdpi-support
It will be enabled by default. So you might think about moving to Eclipse 2025-12 to be released next week if you want to have the monitor-specific scaling on Windows.

Note that this functionality (and thus also those issues) are specific to Windows, so you will probably not notice any comparable issues on MacOS (or Linux).

The missing borders (for example in Forms UIs) at specific zooms are something that is still being worked on, as there is no really good solution for the issue based on how Eclipse SWT handles scaling. A current proposal that should fix the exact issue you show in your screenshot is: #2849

[Greglar4]

Yes, we do use GEF classic for the diagrams, so I think we will just wait until next week and upgrade straight to 2025-12.

Thanks for the information!