How to define own signals

["tcheer gmx de" <tcheer gmx de>]

Hi all

I am building a gtk application and would like to define my own signals. 
Is it actually possible?
OK, I would like my event not to react to an user action like button 
presed, mouse moved or sth. like that, but it should be emmited to the 
GUI from my controller only when some conditions are true.

Iurgently need some hints, documentation about this, and thank everyone 
for any contribution for this thread.

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Eric Tchepannou