I am just getting started with xcode and cocoa programming. My background is in Windows database products. In the programming environments I am used to, events are provided for placing code to react to things like a window's: onOpen, onGotFocus, onClose, etc. I haven't been able to figure out how to program code that I may want to have happen based on a specific event like a window opening. Seems like something every application would need to do. The only thing I have been able to do is have code respond to a button click. There must be a way to respond to a multitude of other things, but I can't seem to figure out how.