macOS References to icon objects...

This is a wierd question to ask, so let me try to do the best I can...

Seeings that Xcode pushes a lot of Object-Oriented design, and OS X is developed around a lot of objects, it seems that one could potentially get a reference to and change-enhance these objects.

Something I am interested in doing is changing/enhancing icons. Is there a framework or information somewhere that shows how one can "grab" reference to and modify objects like an icon representation? For instance, making the iTunes icon have a small indicator showing if its playing or not, or adding a tag to a subfolder that shows how many items are in the folder.

If someone could point the way, that would be awesome.

robbieduncan said:

You cannot easily do either of those things as your code would have to access the private memory space of another process. You could use mach-inject or something to break into the other app but that's not easy to get right.

Click to expand...

Is this how applications like DriveGuage work? Perhaps there is something at the system level, like what ShapeShifter is doing for replacing window draws.

What I need is some books on advanced OS X topics like this that are up-to-date. These exist for Windows, but I guess in the mac world the market share isn't large enough for someone in the "know" to write and maintain a book. Add to that the break-neck speed that Apple is on for OS X releases compared to the M$ world, I guess its just not cost-effective. Most of the books I have are either decent but cover older versions of OS X, or cover newer versions and suck.