Hi Harold

I've played with it a bit, and am as flummoxed as you. It seems that calling to
setHidden(bool) with true of false will make the return from isHidden() false.

Rococoa does no marshalling in this area - it assumes that you had the signature
right, and lets JNA do the heavy lifting. In fact by the time it gets to a
method invocation, the arguments are all passed to the vargs objc_msgSend
functions, so it's all typeless by then. But in any case, JNA maps Java bool and
Java int to the same type in C.

The other thing that we pass to objc_msgSend is the selector. This is basically
a pointer to the interned method name as a string. That means (I think ;-) that
ObjC classes cannot have a setHidden:(bool) and setHidden:(int) as they will
both have the same selector.

You can see this runtime behaviour if you add

public void setHidden(Object hidden)

to NSView, and then call it

view.setHidden((Object) Integer.valueOf(1)); assertTrue("Should be hidden", view.isHidden()); // ok

view.setHidden((Object) Integer.valueOf(0)); assertFalse("Should be hidden", view.isHidden()); // ok

view.setHidden((Object) Boolean.TRUE); assertTrue("Should be hidden", view.isHidden()); // fails

The code paths in Rococoa are identical for these invocations!

FWIW I have tried this with the current SVN head at Google Code, and the results
are the same. Maybe David and Olivier could try to reproduce with their
auto-generated mappings and report back?

Duncan

On 17 Feb 2010, at 15:25, Harald Kuhr wrote: