Cocoa Programming for OS X: The Big Nerd Ranch Guide

19 Keyboard Events

When the user types, where are the corresponding events sent? First, the window manager gets the event and forwards it to the active application. The active application forwards the keyboard events to the key window. (This window is what most users call the “active window,” but Cocoa developers call it the key window because it receives keyboard events.) The key window forwards the events to the active view.

Which view is the active one? Each window has an outlet called firstResponder that points to one view of that window. That view is the active view for that window. For example, when you click on a text field, it becomes the firstResponder of that window (Figure 19.1).

Figure 19.1  The first responder ...