Cocoa Autolayout

In Lion, we revisit the basics of how views are placed in windows for the first time since Mac OS X 10.0. Springs and struts (i.e. autoresizing masks) are out, dashed blue Interface Builder guides are in. Rather than being one-off helpers for setting a frame in IB, guides become persistent objects that maintain a relationship at runtime. Come see what's going on, and what merited such a big change.

WWDC 2011 - macOS