How does "Cinch App" do it?

If you aren't familiar with Cinch, its an application on Mac App Store that allows you to resize ANY window to half/full screen size if you drag the window to the edge of the screen. Exactly like the functionality in windows 7.

Now my question is, how is it done? I have looked all over cocoa apis looking for notifications/delegate methods for whenever a window is being dragged (ALL windows, not just windows owned by the app from which code is running from) but can't find it. Looked in Core Graphics API...Quartz Display Services....but can't find it.

Any help will be greatly appreciated as I have been looking for the past week....Thanks!

Edit: Resize the window is easy since it can be done through applescript bridge..

Are you developer behind i-Snap or some other Mac App Store clone of Cinch?

I'm the developer behind Cinch, and while I try to maintain an "abundance mentality" which basically says "There's enough out there for everyone", I've been upset by the Mac App Store lowering the barrier for entry to this market which has produced a number of half-backed competitors.

I would be thrilled to see some real innovation around the work I have done, and not just clones looking to make a quick buck.

Anyway, you want to look at the Accessibility APIs. It's a Carbon C API. This is probably your best reference: http://developer.apple.com/library/mac/#samplecode/UIElementInspector/Introduction/Intro.html%23//apple_ref/doc/uid/DTS10000728

I've not used the Cinch app, but if I were to do this I'd expect to be using cocoa events. (Also see here) Specifically the mouse handling events, combined with where the mouse is currently on-screen. They probably set a variable when a window is grabbed and then track the mouse pointer until it hits an edge or until they release the mouse button.

Events are very powerful and provide very low level access to what is happening, but can also be very complex. Good luck!

I'm not sure. Maybe the developers combine apple script and carbon events. You can create carbon events to know when the mouse has been clicked or dragged