Cocoa® Programming

Compound Controls

Compound controls use multiple cells to produce a more complex interface object. They often contain glue code that makes the cells work together in a specific way. Most of these controls still have their own specialized cell subclass. Much of the complexity of managing multiple elements falls to the associated cell class instead of the control object.

Steppers look like a pair of very small buttons with up and down arrows on them. The most complex and most flexible of the compound controls is the NSMatrix, a class for laying out an arbitrary number of cells of arbitrary classes in a uniform way. Forms look like a pair of text fields, one an uneditable label, and the other an editable text field. Forms are usually used in matrices. ...