Class: Event

system.events. Event


new Event(type, bubbles, cancelable)

The Event class is used as the base class for the creation of Event objects, which are passed as parameters to event listeners when an event occurs.

Parameters:
Name Type Description
type string

The type of the event.

bubbles boolean

Determines whether the Event object participates in the bubbling stage of the event flow. The default value is false.

cancelable boolean

Determines whether the Event object can be canceled. The default values is false.

See:
Example
var click = function( event )
{
    trace( "click: " + event ) ;
};

var dispatcher = new EventDispatcher() ;

dispatcher.addEventListener( Event.CLICK , click ) ;

dispatcher.dispatchEvent( new Event( Event.CLICK ) ) ;

Members


<static, constant> ACTIVATE

The ACTIVATE constant defines the value of the type property of an activate event object.

See:

<static, constant> ADDED

The Event.ADDED constant defines the value of the type property of an added event object.

See:

<static, constant> ADDED_TO_STAGE

The Event.ADDED_TO_STAGE constant defines the value of the type property of an addedToStage event object.

See:

<static, constant> CANCEL

The Event.CANCEL constant defines the value of the type property of a cancel event object.


<static, constant> CHANGE

The Event.CHANGE constant defines the value of the type property of a change event object.


<static, constant> CLEAR

The Event.CLEAR constant defines the value of the type property of a clear event object.


<static, constant> CLICK

The Event.CLICK constant defines the value of the type property of a click event object.


<static, constant> CLOSE

The Event.CLOSE constant defines the value of the type property of a close event object.


<static, constant> COMPLETE

The Event.COMPLETE constant defines the value of the type property of a complete event object.


<static, constant> CONNECT

The Event.CONNECT constant defines the value of the type property of a connect event object.


<static, constant> COPY

The Event.COPY constant defines the value of the type property of a copy event object.


<static, constant> CUT

The Event.CUT constant defines the value of the type property of a cut event object.


<static, constant> DEACTIVATE

The Event.DEACTIVATE constant defines the value of the type property of a deactivate event object.

See:

<static, constant> FULLSCREEN

The Event.FULLSCREEN constant defines the value of the type property of a fullScreen event object.


<static, constant> INIT

The Event.INIT constant defines the value of the type property of an init event object.


<static, constant> OPEN

The Event.OPEN constant defines the value of the type property of an open event object.


<static, constant> PASTE

The Event.PASTE constant defines the value of the type property of a paste event object.


<static, constant> REMOVED

The Event.REMOVED constant defines the value of the type property of a removed event object.

See:

<static, constant> REMOVED_FROM_STAGE

The Event.REMOVED_FROM_STAGE constant defines the value of the type property of a removedFromStage event object.

See:

<static, constant> RENDER

The Event.RENDER constant defines the value of the type property of a render event object.


<static, constant> RESIZE

The Event.RESIZE constant defines the value of the type property of a resize event object.


<static, constant> SCROLL

The Event.SCROLL constant defines the value of the type property of a scroll event object.


<static, constant> SELECT

The Event.SELECT constant defines the value of the type property of a select event object.


<static, constant> UNLOAD

The Event.UNLOAD constant defines the value of the type property of a unload event object.


bubbles :boolean

Indicates whether an event is a bubbling event. If the event can bubble, this value is true; otherwise it is false.

When an event occurs, it moves through the three phases of the event flow: the capture phase, which flows from the top of the display list hierarchy to the node just before the target node; the target phase, which comprises the target node; and the bubbling phase, which flows from the node subsequent to the target node back up the display list hierarchy.

Some events, such as the activate and unload events, do not have a bubbling phase. The bubbles property has a value of false for events that do not have a bubbling phase.

Type:
  • boolean

cancelable :boolean

Indicates whether the behavior associated with the event can be prevented. If the behavior can be canceled, this value is true; otherwise it is false.

Type:
  • boolean
See:
  • system.events.Event.preventDefault()

currentTarget :Object

The object that is actively processing the Event object with an event listener. For example, if a user clicks an OK button, the current target could be the node containing that button or one of its ancestors that has registered an event listener for that event.

Type:
  • Object

eventPhase :number

The current phase in the event flow. This property can contain the following numeric values:

  • The capture phase (EventPhase.NONE === 0).
  • The capture phase (EventPhase.CAPTURING_PHASE === 1).
  • The target phase (EventPhase.AT_TARGET === 2).
  • The bubbling phase (EventPhase.BUBBLING_PHASE === 3).
Type:
  • number

<constant> target :number

The timestamp at which this event was created.

A numeric value corresponding to the time for the specified date according to universal time.

Type:
  • number
Example
var event = new Event( Event.CLICK ) ;
trace( event.timestamp ) ;

target :Object

The event target. This property contains the target node. For example, if a user clicks an OK button, the target node is the display list node containing that button.

Type:
  • Object

type :string

The type of event. The type is case-sensitive.

Type:
  • string

Methods


clone()

Duplicates an instance of an Event subclass.

Returns a new Event object that is a copy of the original instance of the Event object. You do not normally call clone(); the EventDispatcher class calls it automatically when you redispatch an event—that is, when you call dispatchEvent(event) from a handler that is handling event.

The new Event object includes all the properties of the original.

When creating your own custom Event class, you must override the inherited Event.clone() method in order for it to duplicate the properties of your custom class. If you do not set all the properties that you add in your event subclass, those properties will not have the correct values when listeners handle the redispatched event.

In this example, PingEvent is a subclass of Event and therefore implements its own version of clone().

Returns:

A new Event object that is identical to the original.

Example
class UrlEvent extends Event
{
    constructor( type , url , bubbles = false, cancelable = false )
    {
        super( type , bubbles , cancelable ) ;
        this.url = url;
    }

    clone()
    {
        return new UrlEvent( this.type , this.url, this.bubbles, this.cancelable );
    }

    toString()
    {
        return this.formatToString( this.constructor.name , "type", "url" , "bubbles", "cancelable", "eventPhase" );
    }
}

formatToString(className [, rest])

A utility function for implementing the toString() method in custom ActionScript 3.0 Event classes. Overriding the toString() method is recommended, but not required.

Parameters:
Name Type Argument Description
className string

The class name to passed-in the string expression.

rest string <optional>
<repeatable>

rest The properties of the Event class and the properties that you add in your custom Event class.

Example
class UrlEvent extends Event
{
    constructor( type , url , bubbles = false, cancelable = false )
    {
        super( type , bubbles , cancelable ) ;
        this.url = url;
    }

    toString()
    {
        return this.formatToString( this.constructor.name , "type", "url" , "bubbles", "cancelable", "eventPhase" );
    }
}

isDefaultPrevented()

Checks whether the preventDefault() method has been called on the event. If the preventDefault() method has been called, returns true; otherwise, returns false.

See:
  • system.events.Event.preventDefault
Returns:

If preventDefault() has been called, returns true; otherwise, returns false.


isImmediatePropagationStopped()

Check if event.stopImmediatePropagation() was called.


isPropagationStopped()

Check if event.stopPropagation() was called.


preventDefault()

Cancels an event's default behavior if that behavior can be canceled.

Many events have associated behaviors that are carried out by default. For example, if a user types a character into a text field, the default behavior is that the character is displayed in the text field. Because the TextEvent.TEXT_INPUT event's default behavior can be canceled, you can use the preventDefault() method to prevent the character from appearing.

An example of a behavior that is not cancelable is the default behavior associated with the Event.REMOVED event, which is generated whenever Flash Player is about to remove a display object from the display list. The default behavior (removing the element) cannot be canceled, so the preventDefault() method has no effect on this default behavior.

You can use the Event.cancelable property to check whether you can prevent the default behavior associated with a particular event. If the value of Event.cancelable is true, then preventDefault() can be used to cancel the event; otherwise, preventDefault() has no effect.

See:
  • system.events.Event.isDefaultPrevented
  • system.events.Event.cancelable

stopImmediatePropagation()

Prevents processing of any event listeners in the current node and any subsequent nodes in the event flow. This method takes effect immediately, and it affects event listeners in the current node. In contrast, the stopPropagation() method doesn't take effect until all the event listeners in the current node finish processing.

Note: This method does not cancel the behavior associated with this event; see preventDefault() for that functionality.

See:
  • system.events.Event.stopPropagation
  • system.events.Event.preventDefault

stopPropagation()

Prevents processing of any event listeners in nodes subsequent to the current node in the event flow. This method does not affect any event listeners in the current node (currentTarget). In contrast, the stopImmediatePropagation() method prevents processing of event listeners in both the current node and subsequent nodes. Additional calls to this method have no effect. This method can be called in any phase of the event flow.

Note: This method does not cancel the behavior associated with this event; see preventDefault() for that functionality.

See:
  • system.events.Event.stopImmediatePropagation
  • system.events.Event.preventDefault

toString()

Returns the string representation of this instance.

Returns:

the string representation of this instance.