nsISupports
Last changed in Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4)Implemented by: @mozilla.org/eventlistenerservice;1
. To create an instance, use:
var eventListenerService = Components.classes["@mozilla.org/eventlistenerservice;1"]
.getService(Components.interfaces.nsIEventListenerService);
UniversalXPConnect privileges are required to use this service.
Method overview
void getEventTargetChainFor(in nsIDOMEventTarget aEventTarget, [optional] out unsigned long aCount, [retval, array, size_is(aCount)] out nsIDOMEventTarget aOutArray); |
void getListenerInfoFor(in nsIDOMEventTarget aEventTarget, [optional] out unsigned long aCount, [retval, array, size_is(aCount)] out nsIEventListenerInfo aOutArray); |
boolean hasListenersFor(in nsIDOMEventTarget aEventTarget, in DOMString aType); |
void addSystemEventListener(in nsIDOMEventTarget target, in DOMString type, in nsIDOMEventListener listener, in boolean useCapture); |
void removeSystemEventListener(in nsIDOMEventTarget target, in DOMString type, in nsIDOMEventListener listener, in boolean useCapture); |
Attributes
Attribute | Type | Description |
systemEventGroup |
|
Returns system event group. Read only. Obsolete since Gecko 7.0 |
Methods
getEventTargetChainFor()
Returns an array of event targets indicating all the targets that will receive the same events that are delivered to the specified target. aEventTarget
will be at index 0. The objects are the ones that would be used as event.currentTarget
while dispatching an event to aEventTarget
.
void getEventTargetChainFor( in nsIDOMEventTarget aEventTarget, [optional] out unsigned long aCount, [retval, array, size_is(aCount)] out nsIDOMEventTarget aOutArray );
Parameters
-
aEventTarget
-
The
nsIDOMEventTarget
for which to return the event target chain. -
aCount
- On return, contains the number of elements in the returned array.
-
aOutArray
- The array into which to store the event targets.
getListenerInfoFor()
Returns an array of nsIEventListenerInfo
objects describing everyone listening to the specified event target. If aEventTarget
doesn't have any listeners, this returns null
.
void getListenerInfoFor( in nsIDOMEventTarget aEventTarget, [optional] out unsigned long aCount, [retval, array, size_is(aCount)] out nsIEventListenerInfo aOutArray );
Parameters
-
aEventTarget
-
The
nsIEventTarget
for which to obtain a list of listeners. -
aCount
- On return, the number of returned listener descriptors.
-
aOutArray
-
An array of
nsIEventListenerInfo
objects describing the listeners.
hasListenersFor()
Returns true if a event target has any listener for the given type.
boolean hasListenersFor( in nsIDOMEventTarget aEventTarget, in DOMString aType );
Parameters
-
aEventTarget
-
The
nsIDOMEventTarget
for which to check if this has any listener for aType. -
aType
- An event name.
addSystemEventListener()
Add a system-group eventlistener to a event target.
System-group eventlisteners are called after all eventlisteners in default-group handle the events. So, system-group eventlisteners can implement the default action of the event. Even if an event is stopped its propagation in default-group, the event will be fired again in system-group.
void addSystemEventListener(
in nsIDOMEventTarget target,
in DOMString type,
in nsIDOMEventListener listener,
in boolean useCapture
);
Parameters
-
target
-
The
nsIDOMEventTarget
for the event target to listen an event. -
type
- The event name to listen.
-
listener
-
The
nsIDOMEventListener
which listens the event. -
useCapture
- True if to listen the event in capture phase, otherwise, false.
removeSystemEventListener()
Remove a system-group eventlistener from a event target.
void removeSystemEventListener( in nsIDOMEventTarget target, in DOMString type, in nsIDOMEventListener listener, in boolean useCapture );
Parameters
-
target
-
The
nsIDOMEventTarget
for the event target listening the event. -
type
- The listening event name.
-
listener
-
The
nsIDOMEventListener
which is listening the event. -
useCapture
- True if listening the events in capture phase, otherwise, false.
Remarks
nsIEventListenerService
was introduced with bug 448602.