Re: [Swig-devel] SWIG director usage

[William S F. <ws...@fu...>]

Daniele Romagnoli <dany.geotools <at> gmail.com> writes:

> 
> Hi list.I need some assistance on SWIG usage.The
> GDAL library has the "CreateCopy" method which allows to call a
> progress function during writing operations, in order to check the
> percentage of the written image.
> One of the parameter of "CreateCopy" is indeed a function pointer
> which allows to specify which progress function need to be called.When SWIG
> generates java binding for this method, there is no way to exploit
> progress functions by the java method (since there is no concept of
> pointers in java, and thus, no function pointers). The Java "CreateCopy"
method has no parameters related to the management of the writing progress.I
propose my idea and I would let to know if it may be accomplished:
> ---I should patch the cpp source code using a MyProgressFunction as a
parameter of the "CreateCopy".
> Within MyProgressFunction I should call a virtual method like, as an instance,
MyProgress().With SWIG, I can activate Directors and adding a java director
method which will be called by MyProgressFunction.
> ---Is this a reasonable way to solve my problem or there is another one?But
now I have some questions:Directors operates on a specific class (and/or
methods) while the MyProgressFunction is a global method. 
> 
> How can I call the virtual method of the specific class from
MyProgressFunction?What should be the correct sequence of steps to achieve my
task?I'm not really experienced on 
> SWIG directors capabilities and usage.
Write a C++ global progress function and pass this as the the callback for
CreateCopy. Then in the progress function you call a virtual method on a
director class you previously instantiaged.

William