Laurent Sansonetti
lsans****@apple*****
Fri Feb 23 03:45:44 JST 2007
Hi guys,
I added some better support for functions/methods dealing with C-array
like arguments and/or return value, whose length isn't fixed and
depend on the context.
Examples:
CGColorRef CGColorCreate ( CGColorSpaceRef colorspace, const float
components[] );
// 'components' length depends on the colorspace (it's the number of
colors + 1)
const float *CGColorGetComponents ( CGColorRef color );
// the return value also depends on the chosen colorspace
Before it was necessary to deal with Array#pack, String#unpack and
OSX::ObjCPtr.
Now you can also write:
components = [0.1, 0.5, 0.9, 0]
color = CGColorCreate(CGColorSpaceCreateDeviceRGB(), components)
# (1)
components2 = CGColorGetComponents(color) # (2)
p components2[0]
Technically,
(1) RubyCocoa is now able to convert a Ruby array to this kind of _C_PTR
(2) RubyCocoa has no way to know the size of the returned array, so it
still returns an OSX::ObjCPtr object. But it's now possible to call
OSX::ObjCPtr#[] to retrieve arbitrary elements from the pointer.
Of course, the user needs to be very careful when writing such code.
Passing a array of non-expected length and/or trying to access an
element at a non-expected index can crash the current application. But
this kind of problems exist in C/ObjC too, and also with the previous
way (using the packing functions).
Laurent