Also, note that in a 'pure' implementation of the chain-of-responsibility pattern, a processing object may not pass responsibility further down the chain after handling a message.

In object-oriented design, the chain-of-responsibility pattern is a design pattern consisting of a source of command objects and a series of processing objects.

The Cocoa and Cocoa Touch frameworks, used for OS X and iOS applications respectively, actively use the chain-of-responsibility pattern for handling events.

Behavioral patterns (11): Chain-of-responsibility pattern, Command pattern, Interpreter pattern, Iterator pattern, Mediator pattern, Memento pattern, Observer pattern, State pattern, Strategy pattern, Template method pattern, Visitor pattern...