The properties of the Event class carry basic information about an event, such as the event's type or whether the event's default behavior can be canceled. For many events, such as the events represented by the Event class constants, this basic information is sufficient. Other events, however, may require more detailed information. Events associated with a mouse click, for example, need to include additional information about the location of the click event and whether any keys were pressed during the click event. You can pass such additional information to event listeners by extending the Event class, which is what the MouseEvent class does. The Flash® Player API defines several Event subclasses for common events that require additional information. Events associated with each of the Event subclasses are described in the documentation for each class.
The methods of the Event class can be used in event listener functions to affect the
behavior of the event object. Some events have an associated default behavior. For example,
the doubleClick event has an associated default behavior that highlights
the word under the mouse pointer at the time of the event. Your event listener can cancel this
behavior by calling the preventDefault() method. You can also make the current
event listener the last one to process an event by calling the stopPropogation()
or stopImmediatePropogation() method.
See also
| Property | Defined by | ||
|---|---|---|---|
| bubbles : Boolean
[read-only]
Indicates whether an event is a bubbling event.
| Event | ||
| cancelable : Boolean
[read-only]
Indicates whether the behavior associated with the event can be prevented.
| Event | ||
 | constructor : Object
A reference to the class object or constructor function for a given object instance.
| Object | |
| currentTarget : Object
[read-only]
The object that is actively processing the Event object with an event listener.
| Event | ||
| eventPhase : uint
[read-only]
The current phase in the event flow.
| Event | ||
| prototype : Object
[static]
A reference to the prototype object of a class or function object.
| Object | |
| target : Object
[read-only]
The event target.
| Event | ||
| type : String
[read-only]
The type of event.
| Event | ||
| Method | Defined by | ||
|---|---|---|---|
|
Creates an Event object to pass as a parameter to event listeners.
| Event | ||
|
Duplicates an instance of an Event subclass.
| Event | ||
|
A utility function for implementing the
toString() method in your custom Event class. | Event | ||
|
Indicates whether an object has a specified property defined.
| Object | |
|
Checks whether
preventDefault() has been called on the event. | Event | ||
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter.
| Object | |
|
Cancels an event's default behavior if that behavior can be canceled.
| Event | ||
|
Indicates whether the specified property exists and is enumerable.
| Object | |
|
Sets the availability of a dynamic property for loop operations.
| Object | |
|
Prevents processing of any event listeners in the current node and any subsequent nodes in
the event flow.
| Event | ||
|
Prevents processing of any event listeners in nodes subsequent to the current node in the
event flow.
| Event | ||
|
Returns a string containing all the properties of the Event object.
| Event | ||
|
Returns the primitive value of the specified object.
| Object | |
| Constant | Defined by | ||
|---|---|---|---|
| ACTIVATE : String = "activate" [static]
Defines the value of the
type property of an activate event object. | Event | ||
| ADDED : String = "added" [static]
Defines the value of the
type property of an added event object. | Event | ||
| CANCEL : String = "cancel" [static]
Defines the value of the
type property of a cancel event object. | Event | ||
| CHANGE : String = "change" [static]
Defines the value of the
type property of a change event object. | Event | ||
| CLOSE : String = "close" [static]
Defines the value of the
type property of a close event object. | Event | ||
| COMPLETE : String = "complete" [static]
Defines the value of the
type property of a complete event object. | Event | ||
| CONNECT : String = "connect" [static]
Defines the value of the
type property of a connect event object. | Event | ||
| DEACTIVATE : String = "deactivate" [static]
Defines the value of the
type property of a deactivate event object. | Event | ||
| ENTER_FRAME : String = "enterFrame" [static]
Defines the value of the
type property of an enterFrame event object. | Event | ||
| ID3 : String = "id3" [static]
Defines the value of the
type property of an id3 event object. | Event | ||
| INIT : String = "init" [static]
Defines the value of the
type property of an init event object. | Event | ||
| MOUSE_LEAVE : String = "mouseLeave" [static]
Defines the value of the
type property of a mouseLeave event object. | Event | ||
| OPEN : String = "open" [static]
Defines the value of the
type property of an open event object. | Event | ||
| REMOVED : String = "removed" [static]
Defines the value of the
type property of a removed event object. | Event | ||
| RENDER : String = "render" [static]
Defines the value of the
type property of a render event object. | Event | ||
| RESIZE : String = "resize" [static]
Defines the value of the
type property of a resize event object. | Event | ||
| SCROLL : String = "scroll" [static]
Defines the value of the
type property of a scroll event object. | Event | ||
| SELECT : String = "select" [static]
Defines the value of the
type property of a select event object. | Event | ||
| SOUND_COMPLETE : String = "soundComplete" [static]
Defines the value of the
type property of a soundComplete event object. | Event | ||
| TAB_CHILDREN_CHANGE : String = "tabChildrenChange" [static]
Defines the value of the
type property of a tabChildrenChange event object. | Event | ||
| TAB_ENABLED_CHANGE : String = "tabEnabledChange" [static]
Defines the value of the
type property of a tabEnabledChange event object. | Event | ||
| TAB_INDEX_CHANGE : String = "tabIndexChange" [static]
Defines the value of the
type property of a tabIndexChange event object. | Event | ||
| UNLOAD : String = "unload" [static]
Defines the value of the
type property of an unload event object. | Event | ||
| bubbles | property |
Hide Inherited Public Properties
Show Inherited Public Propertiesbubbles:Boolean [read-only]
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.
public function get bubbles():Boolean
See also
| cancelable | property |
cancelable:Boolean [read-only]
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.
public function get cancelable():Boolean
See also
| currentTarget | property |
currentTarget:Object [read-only]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.
Implementation public function get currentTarget():Object
See also
| eventPhase | property |
eventPhase:uint [read-only]The current phase in the event flow. This property can contain the following numeric values:
EventPhase.CAPTURING_PHASE).EventPhase.AT_TARGET).EventPhase.BUBBLING_PHASE). public function get eventPhase():uint
See also
| target | property |
target:Object [read-only]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.
Implementation public function get target():Object
See also
| type | property |
type:String [read-only]The type of event. The type is case-sensitive.
Implementation public function get type():String
See also
| Event | () | constructor |
public function Event(type:String, bubbles:Boolean = false, cancelable:Boolean = false)Creates an Event object to pass as a parameter to event listeners.
Parameterstype:String — The type of the event, accessible as Event.type.
|
|
bubbles:Boolean (default = false)false.
|
|
cancelable:Boolean (default = false)false.
|
| clone | () | method |
public function clone():EventDuplicates 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().
class PingEvent extends Event {
var URL:String;
public override function clone():Event {
return new PingEvent(type, bubbles, cancelable, URL);
}
}
Returns
Event —
A new Event object that is identical to the original.
|
See also
| formatToString | () | method |
public function formatToString(className:String, ... arguments):String
A utility function for implementing the
toString() method in your custom Event class. Overriding the
toString() method is recommended, but not required.
class PingEvent extends Event {
var URL:String;
public override function toString():String {
return formatToString("PingEvent", "type", "bubbles", "cancelable", "eventPhase", "URL");
}
}
Parameters
className:String — The name of your custom Event class. In the previous example,
the className parameter is PingEvent.
|
|
... arguments — The properties of the Event class and the properties that you add in
your custom Event class. In the previous example, the ...arguments parameter
includes type, bubbles, cancelable, eventPhase, and URL.
|
String —
The name of your custom Event class and the String value of your ...arguments
parameter.
|
| isDefaultPrevented | () | method |
public function isDefaultPrevented():Boolean
Checks whether preventDefault() has been called on the event. If
preventDefault() has been called,
returns true; otherwise, returns false.
Boolean —
If preventDefault() has been called, returns true; otherwise,
returns false.
|
See also
| preventDefault | () | method |
public function preventDefault():voidCancels an event's default behavior if that behavior can be canceled.
Many events have associated behaviors that Flash Player carries 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 also
| stopImmediatePropagation | () | method |
public function stopImmediatePropagation():void
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 also
| stopPropagation | () | method |
public function stopPropagation():void
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 also
| toString | () | method |
public function toString():String
Returns a string containing all the properties of the Event object. The string is in the following format:
[Event type=value bubbles=value cancelable=value]
ReturnsString —
A string containing all the properties of the Event object.
|
See also
| ACTIVATE | constant |
public static const ACTIVATE:String = "activate"
Defines the value of the type property of an activate event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | Any DisplayObject instance with a listener registered for the ACTIVATE event.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| ADDED | constant |
public static const ADDED:String = "added"
Defines the value of the type property of an added event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The DisplayObject instance being added to the display list.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| CANCEL | constant |
public static const CANCEL:String = "cancel"
Defines the value of the type property of a cancel event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | A reference to the object on which the operation is canceled. |
See also
| CHANGE | constant |
public static const CHANGE:String = "change"
Defines the value of the type property of a change event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object that has had its value modified.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| CLOSE | constant |
public static const CLOSE:String = "close"
Defines the value of the type property of a close event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object whose connection has been closed. |
See also
| COMPLETE | constant |
public static const COMPLETE:String = "complete"
Defines the value of the type property of a complete event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The network object that has completed loading.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| CONNECT | constant |
public static const CONNECT:String = "connect"
Defines the value of the type property of a connect event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The Socket or XMLSocket object that has established a network connection. |
See also
| DEACTIVATE | constant |
public static const DEACTIVATE:String = "deactivate"
Defines the value of the type property of a deactivate event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | Any DisplayObject instance with a listener registered for the DEACTIVATE event.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| ENTER_FRAME | constant |
public static const ENTER_FRAME:String = "enterFrame"
Defines the value of the type property of an enterFrame event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | Any DisplayObject instance with a listener registered for the ENTER_FRAME event.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| ID3 | constant |
public static const ID3:String = "id3"
Defines the value of the type property of an id3 event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The Sound object loading the MP3 for which ID3 data is now available.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| INIT | constant |
public static const INIT:String = "init"
Defines the value of the type property of an init event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The LoaderInfo object associated with the SWF file being loaded. |
See also
| MOUSE_LEAVE | constant |
public static const MOUSE_LEAVE:String = "mouseLeave"
Defines the value of the type property of a mouseLeave event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The Stage object.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| OPEN | constant |
public static const OPEN:String = "open"
Defines the value of the type property of an open event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The network object that has opened a connection. |
See also
| REMOVED | constant |
public static const REMOVED:String = "removed"
Defines the value of the type property of a removed event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The DisplayObject instance to be removed from the display list.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| RENDER | constant |
public static const RENDER:String = "render"
Defines the value of the type property of a render event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; the default behavior cannot be canceled. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | Any DisplayObject instance with a listener registered for the RENDER event.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| RESIZE | constant |
public static const RESIZE:String = "resize"
Defines the value of the type property of a resize event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The Stage object. |
See also
| SCROLL | constant |
public static const SCROLL:String = "scroll"
Defines the value of the type property of a scroll event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The TextField object that has been scrolled.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| SELECT | constant |
public static const SELECT:String = "select"
Defines the value of the type property of a select event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The FileReference object on which an item has been selected. |
See also
| SOUND_COMPLETE | constant |
public static const SOUND_COMPLETE:String = "soundComplete"
Defines the value of the type property of a soundComplete event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The Sound object on which a sound has finished playing. |
See also
| TAB_CHILDREN_CHANGE | constant |
public static const TAB_CHILDREN_CHANGE:String = "tabChildrenChange"
Defines the value of the type property of a tabChildrenChange event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object whose tabChildren flag has changed.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| TAB_ENABLED_CHANGE | constant |
public static const TAB_ENABLED_CHANGE:String = "tabEnabledChange"
Defines the value of the type property of a tabEnabledChange event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The InteractiveObject whose tabEnabled flag has changed.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| TAB_INDEX_CHANGE | constant |
public static const TAB_INDEX_CHANGE:String = "tabIndexChange"
Defines the value of the type property of a tabIndexChange event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object whose tabIndex has changed.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
See also
| UNLOAD | constant |
public static const UNLOAD:String = "unload"
Defines the value of the type property of an unload event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The LoaderInfo object associated with the SWF file being unloaded or replaced. |
See also
EventExample class and the
Square custom class to demonstrate how to manage event bubbling.
package {
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
public class EventExample extends Sprite {
public function EventExample() {
var square_0:Square = new Square(300, 0x336633);
addChild(square_0);
var square_1:Square = new Square(250, 0x669966);
square_0.addChild(square_1);
var square_2:Square = new Square(200, 0x66CC66);
square_1.addChild(square_2);
var square_3:Square = new Square(150, 0xAA0000);
square_3.shouldBubble = false;
square_2.addChild(square_3);
var square_4:Square = new Square(100, 0x66FF66);
square_3.addChild(square_4);
var square_5:Square = new Square(50, 0xCC0000);
square_5.shouldBubble = false;
square_4.addChild(square_5);
this.addEventListener(MouseEvent.CLICK, clickHandler);
}
private function clickHandler(e:Event):void {
trace(">> stage: " + e.type + " event from " + e.target.name + " called on " + this.name);
trace(">> --------------------------------------------");
}
}
}
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
class Square extends Sprite {
private var sideLen:int;
private var color:Number;
public var shouldBubble:Boolean = true;
public function Square(sideLen:int, color:Number) {
this.sideLen = sideLen;
this.color = color;
init();
draw();
}
private function init():void {
buttonMode = true;
this.addEventListener(MouseEvent.CLICK, firstClickHandler);
this.addEventListener(MouseEvent.CLICK, secondClickHandler);
this.addEventListener(MouseEvent.CLICK, thirdClickHandler);
}
private function draw():void {
this.graphics.beginFill(color);
this.graphics.drawRect(0, 0, sideLen, sideLen);
}
private function firstClickHandler(e:Event):void {
trace(">> 1e: " + e.type + " event from " + e.target.name + " called on " + this.name);
if(!shouldBubble) {
e.stopPropagation();
}
}
private function secondClickHandler(e:Event):void {
trace(">> 2e: " + e.type + " event from " + e.target.name + " called on " + this.name);
if(!shouldBubble) {
e.stopImmediatePropagation();
trace(">> --------------------------------------------");
}
}
private function thirdClickHandler(e:Event):void {
trace(">> 3e: " + e.type + " event from " + e.target.name + " called on " + this.name);
}
}
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Current page: http://livedocs.adobe.com/flex/2/langref/flash/events/Event.html
Comments
jeb1138 said on Jul 3, 2006 at 3:33 PM :