MATLAB Object-Oriented Programming

Techniques for Using Events and Listeners

In this section...

“Example Overview” on page 11-50

“Techniques Demonstrated in This Example” on page 11-51

“Summary of fcneval Class” on page 11-51

“Summary of fcnview Class” on page 11-52

“Methods Inherited from Handle Class” on page 11-54

“Using the fcneval and fcnview Classes” on page 11-54

“Implement UpdateGraph Event and Listener” on page 11-56

“The PostSet Event Listener” on page 11-60

“Enable and Disable Listeners” on page 11-63

“@fcneval/fcneval.m Class Code” on page 11-64

“@fcnview/fcnview.m Class Code” on page 11-65

Example Overview

This example defines two classes:

• fcneval — The function evaluator class contains a MATLAB expression and evaluates
  this expression over a specified range


• fcnview — The function viewer class contains a fcneval object and displays surface
  graphs of the evaluated expression using the data contained in fcneval.

This class defines two events:

• A class-defined event that occurs when a new value is specified for the MATLAB
  function


• A property event that occurs when the property containing the limits is changed

The following diagram shows the relationship between the two objects. The fcnview

object contains a fcneval object and creates graphs from the data it contains. fcnview

creates listeners to change the graphs if any of the data in the fcneval object change.

11 Events — Sending and Responding to Messages