Fix automatic HiDPI scaling on Linux

[cristatus]

Apache NetBeans version

Apache NetBeans 23 release candidate

What happened

Netbeans 23 launcher auto-detects HiDPI and set's GDK_SCALE=2. However, some jdk especially 21 and JBR distributions handle scaling naively. Setting GDK_SCALE=2 in launch script results in 4x scaling.

Language / Project Type / NetBeans Component

No response

How to reproduce

Use temurin jdk 21 or Jetbrain JDK 21 and luanch netbeans 23. The netbeans UI on HiDPI screen with 2x scale looks like 4x scaled.

Did this work correctly in an earlier version?

Apache NetBeans 22

Operating System

Arch Linux

JDK

21

Apache NetBeans packaging

Apache NetBeans binary zip

Anything else

No response

Are you willing to submit a pull request?

Yes

[mbien]

GDK_SCALE might be a workaround from JDK 8 times, before JEP 263. Although the JDK does check the value too:
https://github.com/openjdk/jdk/blob/ab06a878f888827026424530781f0af414a8a611/src/java.desktop/unix/native/common/awt/systemscale/systemScale.c#L41-L52

If scaling is now detected correctly on JDK 17+ the extra launcher logic should be probably removed. There are going to be some edge cases with multi screen setups where not all screens need scaling etc. If it turns out that it is still needed, we might have to set -Dsun.java2d.uiScale.enabled=false too whenever GDK_SCALE is set to prevent double scaling issues.

btw NetBeans is currently only tested on OpenJDK re-distributions, experience may vary if you run it on forks