LineNumberRuler does not always properly refresh when changing Monitors

[akoch-yatta]

Description
When moving between Monitors when a Java Editor is opened the LineNumberRulerColumn does not seems to properly redraw everything

Reproduction

1. Open a Java File
2. Scroll down a bit
3. Move the IDE to another monitor, see

Bildschirmaufnahme.2025-05-13.151746.mp4

Expected Behavior
The line number should always be correct

Necessary configuration:
Left monitor was 175%, right monitor was 150%. Could be important that I moved from the bigger to the smaller monitor.

Additional knowledge
Perhaps just some additional buffer image must be reset.
In LineNumberRulerColumn there is already a listener reacting on the ZoomChanged event. There seems to be something missing

[ShahzaibIbrahim]

While doing git bisect, I tried finding the last good commit (Where was this last broken) and I checked all the commits from last two years for the class LineNumberRulerColumn (a441f984fb25d26386fbe032e0c6b0a8c6d606f4 -> the last commit I checked). Hence, it is not a regression.

[HeikoKlare]

The issue is probably related to changes in SWT, not in LineNumberRuler. Did you check for changes in SWT as well?

[HeikoKlare]

A bunch of tests is failing the PR: eclipse-platform/eclipse.platform.swt#2157
So this is probably not ready for review? I also don't think that we should notify listeners asynchronously in general. I would just do the processing of the notification in StyledText/TextLayout in a deferred way.

[akoch-yatta]

... I also don't think that we should notify listeners asynchronously in general. I would just do the processing of the notification in StyledText/TextLayout in a deferred way.

Hmm, why? I mean that synchronous notification led to this issue and it could lead to issues in other places as well. As far as I understand, the problem arises, because we react on the event and the state change then leads to issues/inconsistencies, because e.g. redraws were triggered after that. Should we make sure by design, that all custom widgets are triggered after the refresh is done?

[ShahzaibIbrahim]

@HeikoKlare tests are passing now.