Hello Kiran,
as far as I know the Alien FFI supports callbacks (http://wiki.squeak.org/squeak/6100). It looks pretty cool, but the wiki page says it supports Mac only, so if you want callbacks in Unix or Windows you may go another way:
Fork a new process that waits on a registered semaphore ('semaIndex := Smalltalk registerExternalObject: (example_semaphore).'). Then write a Squeak plugin that implements the callback you need. Every time your callback is called, signal the registered semaphore ('interpreterProxy->signalSemaphoreWithIndex(semaIndex)') so your Squeak process can do whatever it needs to do.
See http://www.hpi.uni-potsdam.de/hirschfeld/projects/phidgetlab/ for an example of the second way.
I hope that helps ;)
Best regards, Philipp
KiranMutt schrieb:
Hello:
I am working at interfacing an external C library ( static/dynamic ), in that context wanted to know, whether Squeak supports callbacks and any examples on using the same is highly appreciated.
Thanks & Regards Kiran