BETA ActionScript® 3.0 Reference for the Adobe® Flash® Platform
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flash.events 

IEventDispatcher  - AS3

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adobe.utils
air.desktop
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coldfusion.air
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coldfusion.service
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coldfusion.service.mxml
com.adobe.consulting.pst.vo
com.adobe.dct.event
com.adobe.dct.model
com.adobe.dct.service
com.adobe.dct.service.impl
com.adobe.dct.transfer
com.adobe.dct.util
com.adobe.exm.expression
com.adobe.exm.expression.error
com.adobe.exm.expression.event
com.adobe.exm.expression.impl
com.adobe.fiber.runtime.lib
com.adobe.fiber.services
com.adobe.fiber.services.wrapper
com.adobe.fiber.styles
com.adobe.fiber.util
com.adobe.fiber.valueobjects
com.adobe.icc.editors.events
com.adobe.icc.editors.handlers
com.adobe.icc.editors.managers
com.adobe.icc.editors.model
com.adobe.icc.editors.model.el
com.adobe.icc.editors.model.el.operands
com.adobe.icc.editors.model.el.operators
com.adobe.icc.enum
com.adobe.icc.obj
com.adobe.icc.services
com.adobe.icc.services.category
com.adobe.icc.services.config
com.adobe.icc.services.download
com.adobe.icc.services.export
com.adobe.icc.services.external
com.adobe.icc.services.fragmentlayout
com.adobe.icc.services.importexport
com.adobe.icc.services.layout
com.adobe.icc.services.letter
com.adobe.icc.services.locator
com.adobe.icc.services.module
com.adobe.icc.services.render
com.adobe.icc.services.submit
com.adobe.icc.services.user
com.adobe.icc.token
com.adobe.icc.vo
com.adobe.icc.vo.render
com.adobe.icomm.assetplacement.controller
com.adobe.icomm.assetplacement.controller.utils
com.adobe.icomm.assetplacement.model
com.adobe.livecycle.assetmanager.client
com.adobe.livecycle.assetmanager.client.event
com.adobe.livecycle.assetmanager.client.handler
com.adobe.livecycle.assetmanager.client.managers
com.adobe.livecycle.assetmanager.client.model
com.adobe.livecycle.assetmanager.client.model.cms
com.adobe.livecycle.assetmanager.client.service
com.adobe.livecycle.assetmanager.client.service.search
com.adobe.livecycle.assetmanager.client.service.search.cms
com.adobe.livecycle.assetmanager.client.utils
com.adobe.livecycle.rca.model
com.adobe.livecycle.rca.model.constant
com.adobe.livecycle.rca.model.document
com.adobe.livecycle.rca.model.participant
com.adobe.livecycle.rca.model.reminder
com.adobe.livecycle.rca.model.stage
com.adobe.livecycle.rca.service
com.adobe.livecycle.rca.service.core
com.adobe.livecycle.rca.service.core.delegate
com.adobe.livecycle.rca.service.process
com.adobe.livecycle.rca.service.process.delegate
com.adobe.livecycle.rca.token
com.adobe.mosaic.core
com.adobe.mosaic.core.events
com.adobe.mosaic.core.validators
com.adobe.mosaic.om.interfaces
com.adobe.mosaic.skins.aqua
com.adobe.mosaic.skins.aqua.organizer
com.adobe.mosaic.skins.aqua.tile
com.adobe.mosaic.skins.aqua.util
com.adobe.mosaic.skins.aqua.view
com.adobe.mosaic.skins.aqua.viewManager
com.adobe.mosaic.sparklib.editors
com.adobe.mosaic.sparklib.optionMenu
com.adobe.mosaic.sparklib.scrollableMenu
com.adobe.mosaic.sparklib.scrollableMenu.skins
com.adobe.mosaic.sparklib.tabLayout
com.adobe.mosaic.sparklib.tabLayout.events
com.adobe.mosaic.sparklib.tabLayout.layouts
com.adobe.mosaic.sparklib.tabLayout.skins
com.adobe.viewsource
fl.accessibility
fl.containers
fl.controls
fl.controls.dataGridClasses
fl.controls.listClasses
fl.controls.progressBarClasses
fl.core
fl.data
fl.display
fl.events
fl.ik
fl.lang
fl.livepreview
fl.managers
fl.motion
fl.motion.easing
fl.rsl
fl.text
fl.transitions
fl.transitions.easing
fl.video
flash.accessibility
flash.concurrent
flash.crypto
flash.data
flash.desktop
flash.display
flash.display3D
flash.display3D.textures
flash.errors
flash.events
flash.external
flash.filesystem
flash.filters
flash.geom
flash.globalization
flash.html
flash.media
flash.net
flash.net.dns
flash.net.drm
flash.notifications
flash.permissions
flash.printing
flash.profiler
flash.sampler
flash.security
flash.sensors
flash.system
flash.text
flash.text.engine
flash.text.ime
flash.ui
flash.utils
flash.xml
flashx.textLayout
flashx.textLayout.compose
flashx.textLayout.container
flashx.textLayout.conversion
flashx.textLayout.edit
flashx.textLayout.elements
flashx.textLayout.events
flashx.textLayout.factory
flashx.textLayout.formats
flashx.textLayout.operations
flashx.textLayout.utils
flashx.undo
ga.controls
ga.layouts
ga.model
ga.uiComponents
ga.util
ga.views
ga.wrappers
lc.foundation
lc.foundation.domain
lc.foundation.events
lc.foundation.ui
lc.foundation.util
lc.preloader
lc.procmgmt
lc.procmgmt.commands
lc.procmgmt.domain
lc.procmgmt.events
lc.procmgmt.formbridge
lc.procmgmt.impl
lc.procmgmt.ui.attachments
lc.procmgmt.ui.controls
lc.procmgmt.ui.controls.card
lc.procmgmt.ui.controls.renderer
lc.procmgmt.ui.endpoint
lc.procmgmt.ui.help
lc.procmgmt.ui.layout
lc.procmgmt.ui.presentationmodel
lc.procmgmt.ui.process
lc.procmgmt.ui.search
lc.procmgmt.ui.task
lc.procmgmt.ui.task.form
lc.procmgmt.ui.task.form.commands
lc.procmgmt.ui.tracking
mx.accessibility
mx.automation
mx.automation.air
mx.automation.delegates
mx.automation.delegates.advancedDataGrid
mx.automation.delegates.charts
mx.automation.delegates.containers
mx.automation.delegates.controls
mx.automation.delegates.controls.dataGridClasses
mx.automation.delegates.controls.fileSystemClasses
mx.automation.delegates.core
mx.automation.delegates.flashflexkit
mx.automation.events
mx.binding
mx.binding.utils
mx.charts
mx.charts.chartClasses
mx.charts.effects
mx.charts.effects.effectClasses
mx.charts.events
mx.charts.renderers
mx.charts.series
mx.charts.series.items
mx.charts.series.renderData
mx.charts.styles
mx.collections
mx.collections.errors
mx.containers
mx.containers.accordionClasses
mx.containers.dividedBoxClasses
mx.containers.errors
mx.containers.utilityClasses
mx.controls
mx.controls.advancedDataGridClasses
mx.controls.dataGridClasses
mx.controls.listClasses
mx.controls.menuClasses
mx.controls.olapDataGridClasses
mx.controls.scrollClasses
mx.controls.sliderClasses
mx.controls.textClasses
mx.controls.treeClasses
mx.controls.videoClasses
mx.core
mx.core.windowClasses
mx.data
mx.data.crypto
mx.data.errors
mx.data.events
mx.data.messages
mx.data.mxml
mx.data.offline.errors
mx.data.utils
mx.effects
mx.effects.easing
mx.effects.effectClasses
mx.events
mx.filters
mx.flash
mx.formatters
mx.geom
mx.graphics
mx.graphics.codec
mx.graphics.shaderClasses
mx.logging
mx.logging.errors
mx.logging.targets
mx.managers
mx.messaging
mx.messaging.channels
mx.messaging.config
mx.messaging.errors
mx.messaging.events
mx.messaging.management
mx.messaging.messages
mx.modules
mx.netmon
mx.olap
mx.olap.aggregators
mx.preloaders
mx.printing
mx.resources
mx.rpc
mx.rpc.events
mx.rpc.http
mx.rpc.http.mxml
mx.rpc.livecycle
mx.rpc.mxml
mx.rpc.remoting
mx.rpc.remoting.mxml
mx.rpc.soap
mx.rpc.soap.mxml
mx.rpc.wsdl
mx.rpc.xml
mx.skins
mx.skins.halo
mx.skins.spark
mx.skins.wireframe
mx.skins.wireframe.windowChrome
mx.states
mx.styles
mx.utils
mx.validators
org.osmf.containers
org.osmf.display
org.osmf.elements
org.osmf.events
org.osmf.layout
org.osmf.logging
org.osmf.media
org.osmf.metadata
org.osmf.net
org.osmf.net.dvr
org.osmf.net.httpstreaming
org.osmf.net.metrics
org.osmf.net.qos
org.osmf.net.rtmpstreaming
org.osmf.net.rules
org.osmf.traits
org.osmf.utils
spark.accessibility
spark.automation.delegates
spark.automation.delegates.components
spark.automation.delegates.components.gridClasses
spark.automation.delegates.components.mediaClasses
spark.automation.delegates.components.supportClasses
spark.automation.delegates.skins.spark
spark.automation.events
spark.collections
spark.components
spark.components.calendarClasses
spark.components.gridClasses
spark.components.mediaClasses
spark.components.supportClasses
spark.components.windowClasses
spark.core
spark.effects
spark.effects.animation
spark.effects.easing
spark.effects.interpolation
spark.effects.supportClasses
spark.events
spark.filters
spark.formatters
spark.formatters.supportClasses
spark.globalization
spark.globalization.supportClasses
spark.layouts
spark.layouts.supportClasses
spark.managers
spark.modules
spark.preloaders
spark.primitives
spark.primitives.supportClasses
spark.skins
spark.skins.mobile
spark.skins.mobile.supportClasses
spark.skins.spark
spark.skins.spark.mediaClasses.fullScreen
spark.skins.spark.mediaClasses.normal
spark.skins.spark.windowChrome
spark.skins.wireframe
spark.skins.wireframe.mediaClasses
spark.skins.wireframe.mediaClasses.fullScreen
spark.transitions
spark.utils
spark.validators
spark.validators.supportClasses

Language Elements

Global Constants
Global Functions
Operators
Statements, Keywords & Directives
Special Types

Appendixes

What's New
Compiler Errors
Compiler Warnings
Run-Time Errors
Migrating to ActionScript 3
Supported Character Sets
MXML Only Tags
Motion XML Elements
Timed Text Tags
List of deprecated elements
Accessibility Implementation Constants
How to Use ActionScript Examples
Legal notices

Package flash.events

Interfaces
IEventDispatcher
 
Classes
AccelerometerEvent
ActivityEvent
AsyncErrorEvent
AudioOutputChangeEvent
AVDictionaryDataEvent
AVHTTPStatusEvent
AVPauseAtPeriodEndEvent
BrowserInvokeEvent    
ContextMenuEvent
DataEvent
DatagramSocketDataEvent    
DeviceRotationEvent    
DNSResolverEvent    
DRMAuthenticateEvent    
DRMAuthenticationCompleteEvent
DRMAuthenticationErrorEvent
DRMDeviceGroupErrorEvent
DRMDeviceGroupEvent
DRMErrorEvent
DRMLicenseRequestEvent
DRMMetadataEvent
DRMReturnVoucherCompleteEvent
DRMReturnVoucherErrorEvent
DRMStatusEvent
ErrorEvent
Event
EventDispatcher
EventPhase
FileListEvent    
FocusEvent
FullScreenEvent
GameInputEvent    
GeolocationEvent
GestureEvent
GesturePhase
HTMLUncaughtScriptExceptionEvent    
HTTPStatusEvent
IMEEvent
InvokeEvent    
IOErrorEvent
KeyboardEvent
LocationChangeEvent    
MediaEvent    
MouseEvent
NativeDragEvent    
NativeProcessExitEvent    
NativeWindowBoundsEvent    
NativeWindowDisplayStateEvent    
NetDataEvent
NetMonitorEvent
NetStatusEvent
OutputProgressEvent    
PermissionEvent
PressAndTapGestureEvent
ProgressEvent
RemoteNotificationEvent    
SampleDataEvent
ScreenMouseEvent    
SecurityErrorEvent
ServerSocketConnectEvent    
ShaderEvent
SoftKeyboardEvent
SoftKeyboardTrigger
SQLErrorEvent    
SQLEvent    
SQLUpdateEvent    
StageOrientationEvent    
StageVideoAvailabilityEvent
StageVideoEvent
StatusEvent
StorageVolumeChangeEvent    
SyncEvent
TextEvent
ThrottleEvent
ThrottleType
TimerEvent
TouchEvent
TouchEventIntent    
TransformGestureEvent
UncaughtErrorEvent
UncaughtErrorEvents
VideoEvent
VideoTextureEvent
VsyncStateChangeAvailabilityEvent    
(Beta)
Packageflash.events
Interfacepublic interface IEventDispatcher
Implementors AbstractService, AbstractStage, AssetAction, AssetPropertyDescriptor, AssetTypeDescriptor, AttachmentCommand, AttachmentLoader, AuditLevel, BaseUser, BasicService, BindingElement, CDMAssignment, CollectionToken, ContainerLayout, ContextData, CustomAttribute, DataDictionaryElement, DataDictionaryInstance, DataDictionaryReference, DataDictionarySearchFilter, DataDownload, DataManager, DataStoreEventDispatcher, Document, DocumentAssignment, EventDispatcher, FavoritesManager, FileData, FileModel, FlexConfiguration, Folder, InitiateFromStartTaskCommand, LDMAssignment, LinkElement, Message, ModuleAssignment, OLAPCube, ObjectToken, OnDemandEventDispatcher, PDFResponseType, Portfolio, PreferencesManager, Properties, PropertiesNode, Query, QueueBase, QueuesManager, Reminder, ResolvedContent, Review, ReviewContext, ReviewSearchFilter, ReviewTemplateReference, SearchFilter, SearchQuery, SearchTemplateDescriptors, Session, ShaderFilter, Statement, Style, SupportingDocument, SyncManager, TaskAttachmentInfo, TemplateSearchFilter, TextFlow, User, UserPreference, Variable

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

The IEventDispatcher interface defines methods for adding or removing event listeners, checks whether specific types of event listeners are registered, and dispatches events.

Event targets are an important part of the Flash® Player and Adobe AIR event model. The event target serves as the focal point for how events flow through the display list hierarchy. When an event such as a mouse click or a keypress occurs, an event object is dispatched into the event flow from the root of the display list. The event object makes a round-trip journey to the event target, which is conceptually divided into three phases: the capture phase includes the journey from the root to the last node before the event target's node; the target phase includes only the event target node; and the bubbling phase includes any subsequent nodes encountered on the return trip to the root of the display list.

In general, the easiest way for a user-defined class to gain event dispatching capabilities is to extend EventDispatcher. If this is impossible (that is, if the class is already extending another class), you can instead implement the IEventDispatcher interface, create an EventDispatcher member, and write simple hooks to route calls into the aggregated EventDispatcher.

View the examples



Public Methods
 MethodDefined By
  
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.
IEventDispatcher
  
Dispatches an event into the event flow.
IEventDispatcher
  
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
IEventDispatcher
  
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
IEventDispatcher
  
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
IEventDispatcher
Method Detail

addEventListener

()method
public function addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event. You can register event listeners on all nodes in the display list for a specific type of event, phase, and priority.

After you successfully register an event listener, you cannot change its priority through additional calls to addEventListener(). To change a listener's priority, you must first call removeEventListener(). Then you can register the listener again with the new priority level.

After the listener is registered, subsequent calls to addEventListener() with a different value for either type or useCapture result in the creation of a separate listener registration. For example, if you first register a listener with useCapture set to true, it listens only during the capture phase. If you call addEventListener() again using the same listener object, but with useCapture set to false, you have two separate listeners: one that listens during the capture phase, and another that listens during the target and bubbling phases.

You cannot register an event listener for only the target phase or the bubbling phase. Those phases are coupled during registration because bubbling applies only to the ancestors of the target node.

When you no longer need an event listener, remove it by calling EventDispatcher.removeEventListener(); otherwise, memory problems might result. Objects with registered event listeners are not automatically removed from memory because the garbage collector does not remove objects that still have references.

Copying an EventDispatcher instance does not copy the event listeners attached to it. (If your newly created node needs an event listener, you must attach the listener after creating the node.) However, if you move an EventDispatcher instance, the event listeners attached to it move along with it.

If the event listener is being registered on a node while an event is also being processed on this node, the event listener is not triggered during the current phase but may be triggered during a later phase in the event flow, such as the bubbling phase.

If an event listener is removed from a node while an event is being processed on the node, it is still triggered by the current actions. After it is removed, the event listener is never invoked again (unless it is registered again for future processing).

Parameters

type:String — The type of event.
 
listener:Function — The listener function that processes the event. This function must accept an event object as its only parameter and must return nothing, as this example shows:

function(evt:Event):void

The function can have any name.
 
useCapture:Boolean (default = false) — Determines whether the listener works in the capture phase or the target and bubbling phases. If useCapture is set to true, the listener processes the event only during the capture phase and not in the target or bubbling phase. If useCapture is false, the listener processes the event only during the target or bubbling phase. To listen for the event in all three phases, call addEventListener() twice, once with useCapture set to true, then again with useCapture set to false.
 
priority:int (default = 0) — The priority level of the event listener. Priorities are designated by a 32-bit integer. The higher the number, the higher the priority. All listeners with priority n are processed before listeners of priority n-1. If two or more listeners share the same priority, they are processed in the order in which they were added. The default priority is 0.
 
useWeakReference:Boolean (default = false) — Determines whether the reference to the listener is strong or weak. A strong reference (the default) prevents your listener from being garbage-collected. A weak reference does not.

Class-level member functions are not subject to garbage collection, so you can set useWeakReference to true for class-level member functions without subjecting them to garbage collection. If you set useWeakReference to true for a listener that is a nested inner function, the function will be garbge-collected and no longer persistent. If you create references to the inner function (save it in another variable) then it is not garbage-collected and stays persistent.

dispatchEvent

()method 
public function dispatchEvent(event:Event):Boolean

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

Dispatches an event into the event flow. The event target is the EventDispatcher object upon which dispatchEvent() is called.

Parameters

event:Event — The event object dispatched into the event flow.

Returns
Boolean — A value of true unless preventDefault() is called on the event, in which case it returns false.

hasEventListener

()method 
public function hasEventListener(type:String):Boolean

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

Checks whether the EventDispatcher object has any listeners registered for a specific type of event. This allows you to determine where an EventDispatcher object has altered handling of an event type in the event flow hierarchy. To determine whether a specific event type will actually trigger an event listener, use IEventDispatcher.willTrigger().

The difference between hasEventListener() and willTrigger() is that hasEventListener() examines only the object to which it belongs, whereas willTrigger() examines the entire event flow for the event specified by the type parameter.

Parameters

type:String — The type of event.

Returns
Boolean — A value of true if a listener of the specified type is registered; false otherwise.

Related API Elements

removeEventListener

()method 
public function removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

Removes a listener from the EventDispatcher object. If there is no matching listener registered with the EventDispatcher object, a call to this method has no effect.

Parameters

type:String — The type of event.
 
listener:Function — The listener object to remove.
 
useCapture:Boolean (default = false) — Specifies whether the listener was registered for the capture phase or the target and bubbling phases. If the listener was registered for both the capture phase and the target and bubbling phases, two calls to removeEventListener() are required to remove both: one call with useCapture set to true, and another call with useCapture set to false.

willTrigger

()method 
public function willTrigger(type:String):Boolean

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9, Flash Lite 4

Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. This method returns true if an event listener is triggered during any phase of the event flow when an event of the specified type is dispatched to this EventDispatcher object or any of its descendants.

The difference between hasEventListener() and willTrigger() is that hasEventListener() examines only the object to which it belongs, whereas willTrigger() examines the entire event flow for the event specified by the type parameter.

Parameters

type:String — The type of event.

Returns
Boolean — A value of true if a listener of the specified type will be triggered; false otherwise.
IEventDispatcherExample.as

The following example uses the IEventDispatcherExample and DecoratedDispatcher sample classes to show how the IEventDispatcher class can be implemented and used. The example accomplishes this by implementing each method of DecoratedDispatcher in the same manner as in EventDispatcher. Within the constructor for IEventDispatcherExample, a new instance (named decorDispatcher) of the DecoratedDispatcher class is constructed and the decorDispatcher variable is used to call addEventListener() with the custom event doSomething, which is then handled by didSomething(), which prints a line of text using trace().
 
package {
        import flash.events.Event;
        import flash.display.Sprite;
       
        public class IEventDispatcherExample extends Sprite {
                public function IEventDispatcherExample() {
                        var decorDispatcher:DecoratedDispatcher = new DecoratedDispatcher();
                        decorDispatcher.addEventListener("doSomething", didSomething);
                        decorDispatcher.dispatchEvent(new Event("doSomething"));
                }
               
                public function didSomething(evt:Event):void {
                        trace(">> didSomething");
                }
        }
}

import flash.events.IEventDispatcher;
import flash.events.EventDispatcher;
import flash.events.Event;
               
class DecoratedDispatcher implements IEventDispatcher {       
    private var dispatcher:EventDispatcher;
               
    public function DecoratedDispatcher() {
        dispatcher = new EventDispatcher(this);
    }
           
    public function addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void{
        dispatcher.addEventListener(type, listener, useCapture, priority);
    }
           
    public function dispatchEvent(evt:Event):Boolean{
        return dispatcher.dispatchEvent(evt);
    }
    
    public function hasEventListener(type:String):Boolean{
        return dispatcher.hasEventListener(type);
    }
    
    public function removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void{
        dispatcher.removeEventListener(type, listener, useCapture);
    }
                   
    public function willTrigger(type:String):Boolean {
        return dispatcher.willTrigger(type);
    }
}