So far, you have seen that a
changed: message causes
messages to be sent. Now, you need to know that such changed messages are
most often sent inside setters, as in the following setters of the
y instance variables. Note that the aspect argument identifies
the instance variablethat is, the aspectthat changes.
ModelSubclass method definition instance setX: value x := value. self changed: #x. ModelSubclass method definition instance setY: value y := value. self changed: #y. Workspace M setX: 0. M setY: 1. Transcript Sample viewer receiving #x update message Sample viewer receiving #y update message