The type of event.
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
.
The priority level of the event listener. The priority is designated by a signed 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.
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 garbage-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.
Dispatches an event into the event flow. The event target is the
EventDispatcher object upon which the dispatchEvent()
method
is called.
The Event object that is dispatched into the event flow. If
the event is being redispatched, a clone of the event is
created automatically. After an event is dispatched, its
target
property cannot be changed, so you must
create a new copy of the event for redispatching to work.
A value of true
if the event was successfully
dispatched. A value of false
indicates failure or
that preventDefault()
was called on the event.
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 actually
triggers an event listener, use 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.
When hasEventListener()
is called from a LoaderInfo
object, only the listeners that the caller can access are considered.
The type of event.
A value of true
if a listener of the specified type
is registered; false
otherwise.
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.
The type of event.
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
.
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 the hasEventListener()
and the
willTrigger()
methods is that hasEventListener()
examines only the object to which it belongs, whereas the
willTrigger()
method examines the entire event flow for the
event specified by the type
parameter.
When willTrigger()
is called from a LoaderInfo object,
only the listeners that the caller can access are considered.
The type of event.
A value of true
if a listener of the specified type
will be triggered; false
otherwise.
Generated using TypeDoc
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 callremoveListener()
. Then you can register the listener again with the new priority level.Keep in mind that after the listener is registered, subsequent calls to
addEventListener()
with a differenttype
oruseCapture
value result in the creation of a separate listener registration. For example, if you first register a listener withuseCapture
set totrue
, it listens only during the capture phase. If you calladdEventListener()
again using the same listener object, but withuseCapture
set tofalse
, 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.
If you no longer need an event listener, remove it by calling
removeEventListener()
, or memory problems could result. Event listeners are not automatically removed from memory because the garbage collector does not remove the listener as long as the dispatching object exists(unless theuseWeakReference
parameter is set totrue
).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 being processed on this node, the event listener is not triggered during the current phase but can 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 registered again for future processing).
ArgumentError The
listener
specified is not a function.