One comment inline. Is is possible to add a test case to WinUserTest that exercises this function?

Where is WinUserTest located? I can't find it in contrib/platform/test/com/sun/jna/platform/win32/

I meant User32Test, sorry, although it's a question of whether it's possible;

If the test relies on user interaction that may not be the case. However, the equivalent keyboard method is exercised in the KeyHook.java demo class. It would be useful to have a similar "MouseHook" class where it can be manually demonstrated/tested.

(Which I belatedly see you commented on in your very first post! So the answer is, yes please!)

It would be useful to have a similar "MouseHook" class where it can be manually demonstrated/tested.

Done.

This looks good to me. Anything missed, @matthiasblaesing ?

It would be great if you could try to keep more of KeyHook untouched. If less of the source is changed, git should be able to pickup the rename. Existing functionality like being able to easily exit would be available then.

It would be great if you could try to keep more of KeyHook untouched. If less of the source is changed, git should be able to pickup the rename. Existing functionality like being able to easily exit would be available then.

So I'll just add this to the KeyHook?

You'll basicly only need:

https://github.com/nordiakt/jna/blob/94f6fa7dc235684adaeef20ca3b823a5df6e8610/contrib/w32windowhooks/com/sun/jna/contrib/demo/WindowHooks.java#L36-L37
https://github.com/nordiakt/jna/blob/94f6fa7dc235684adaeef20ca3b823a5df6e8610/contrib/w32windowhooks/com/sun/jna/contrib/demo/WindowHooks.java#L72-L117

The mainloop is already setup in KeyLoop:

https://github.com/java-native-access/jna/blob/master/contrib/w32keyhook/com/sun/jna/contrib/demo/KeyHook.java#L83-L97

Thank you - merged via e502ea5.