Events - MATLAB & Simulink (original) (raw)

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Define and trigger events; create listeners that respond to events

Events are notices broadcast when some change or action occurs involving an object. Listeners define functions that execute when specific events occur. Classes can define and trigger events. MATLAB® can trigger predefined events when code accesses object properties.

Functions

Classes

Topics

Events and Listeners

• Overview Events and Listeners
  Use events and listeners to send and respond to messages.
• Event and Listener Concepts
  Events broadcast notifications to all registered listener and pass event-specific data to listener callback functions.
• Events and Listeners Syntax
  These code examples show how to define events and listeners.
• Event Access List
  Specify a list of classes that can be notified of a specific event.
• Event Attributes
  Control access to events by setting event attributes.

Implementing Listeners

• Listener Callback Syntax
  Specify listener callbacks using function handles.
• Callback Execution
  Errors in listener callbacks do not prevent execution of other listeners. However, the order of listener execution is not defined.
• Listener Lifecycle
  MATLAB manages the lifecycle of listeners. For greater control of listener lifecycle, construct listener objects using the listener method instead of addlistener.
• Determine If Event Has Listeners
  You can determine if there are listeners defined for a specific event and event source.

Property Listeners

• Listen for Changes to Property Values
  MATLAB defines pre and post set and get events for all properties.
• Assignment When Property Value Is Unchanged
  Prevent the triggering of property events when values do not change using the property AbortSet attribute.

Samples of Events and Listeners

• Define Custom Event Data
  Redefine the event data that MATLAB passes to listeners when an event is triggered.
• Observe Changes to Property Values
  Listeners can respond to changes in the value of properties using predefined property events.
• Implement Property Set Listener
  Listeners can respond to changes in property values before or after MATLAB assigns the value.
• Techniques for Using Events and Listeners
  This example shows how to enable and disable listener execution using context menus.