HasChangeHandlers abstract class / dart_web_toolkit_event Library / API Reference / Dart Web Toolkit

HasChangeHandlers abstract class

A widget that implements this interface provides registration for {@link ChangeHandler} instances.

abstract class HasChangeHandlers extends HasHandlers {

 /**
  * Adds a {@link ChangeEvent} handler.
  *
  * @param handler the change handler
  * @return {@link HandlerRegistration} used to remove this handler
  */
 HandlerRegistration addChangeHandler(ChangeHandler handler);
}

Extends

HasHandlers > HasChangeHandlers

Subclasses

FileUpload, ListBox, ValueBoxBase<T>

Methods

abstract HandlerRegistration addChangeHandler(ChangeHandler handler) #

Adds a {@link ChangeEvent} handler.

@param handler the change handler @return {@link HandlerRegistration} used to remove this handler

abstract void fireEvent(DwtEvent event) #

inherited from HasHandlers

Fires the given event to the handlers listening to the event's type.

Any exceptions thrown by handlers will be bundled into a UmbrellaException and then re-thrown after all handlers have completed. An exception thrown by a handler will not prevent other handlers from executing.

@param event the event