[win32] Drop from other application not working on secondary monitors

[HeikoKlare]

Describe the bug
When using multiple monitors and dropping an element dragged from, e.g., the Windows explorer into a tree viewer, it does only work on specific zoom values of the primary monitor. On secondary monitors, dropping is always forbidden. On the primary monitor, for some zooms the drag position has an offset to the current mouse position.

To Reproduce

• Have at least two monitors at different zooms
• Start an Eclipse SDK
• Drag elements from the Windows explorer into the package explorer

Move the SDK window between the monitors and change the primary monitor zoom to see different effects of forbidden dropping and drop offsets.

Expected behavior
Dropping should work at the exact mouse position on every monitor at every zoom.

Screenshots

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

2. Additional OS info (e.g. OS version, Linux Desktop, etc)
   Windows 11

3. JRE/JDK version
   Eclipse Temurin 21

Version since
Issue can be experienced in Eclipse 2025-06 and still in latest I-Build. I am quite sure this was already fixed for 2025-06 M2.

[akoch-yatta]

Had a short look into it and from the behavior it seems that the used Windows API ScreenToClient is bound to the process DPI awareness, and therefor is System aware in the IDEs. I am a bit confused, if that would be true, because we use this API in multiple places which should lead to issues there as well. I will have a deeper look into it now