Implement Property Set Listener
This example shows how to define a listener for a property set event. The listener callback
triggers when the value of a specific property changes. The class defined for this example
uses a method for a push-button callback and a static method for the listener callback.
When the push-button callback changes the value of a property, the listener executes its
callback on the PreSet event.This example defines a class (PushButton) with these design elements:- ResultNumber – Observable property
- uicontrol pushbutton – Push-button object used to generate a new graph when its
callback executes - A listener that responds to a change in the observable property
PushButton Class Design
The PushButton class creates figure, uicontrol, axes graphics objects, and a
listener object in the class constructor.The push button's callback is a class method (named pressed). When the push button is
activated, the following sequence occurs:(^1) MATLAB executes the pressed method, which graphs a new set of data and
increments the ResultNumber property.
(^2) Attempting to set the value of the ResultNumber property triggers the PreSet
event, which executes the listener callback before setting the property value.
3 The listener callback uses the event data to obtain the handle of the callback object
(an instance of the PushButton class), which then provides the handle of the axes
object that is stored in its AxHandle property.
(^4) The listener callback updates the axes Title property, after the callback completes
execution, MATLAB sets the ResultsNumber property to its new value.
classdef PushButton < handle
properties (SetObservable)
ResultNumber = 1
end
properties
AxHandle
Implement Property Set Listener