events.MouseWheelHandler Extends goog.events.EventTarget
This event handler allows you to catch mouse wheel events in a consistent manner.

Inheritance

Constructor

goog.events.MouseWheelHandler(elementopt_capture)

Parameters

element : Element | Document
The element to listen to the mouse wheel event on.
opt_capture : boolean=
Whether to handle the mouse wheel event in capture phase.

Instance Methods

Public Protected Private
disposeInternal()
No description.
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handleEvent(e)
Handles the events on the element.
Arguments:
e : goog.events.BrowserEvent
The underlying browser event.
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setMaxDeltaX(maxDeltaX)
No description.
Arguments:
maxDeltaX : number
Maximum magnitude for x delta on each mousewheel event. Should be non-negative.
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setMaxDeltaY(maxDeltaY)
No description.
Arguments:
maxDeltaY : number
Maximum magnitude for y delta on each mousewheel event. Should be non-negative.
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addEventListener(typeopt_captureopt_handlerScope)
Use #listen instead, when possible. Otherwise, use goog.events.listen if you are passing Object (instead of Function) as handler. Adds an event listener to the event target. The same handler can only be added once per the type. Even if you add the same handler multiple times using the same type then it will only be called once when the event is dispatched.
Arguments:
type : string
The type of the event to listen for.
: ?function():? | ?{handleEvent:function():?
No description.
opt_capture : boolean=
In DOM-compliant browsers, this determines whether the listener is fired during the capture or bubble phase of the event.
opt_handlerScope : Object=
Object in whose scope to call the listener.
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assertInitialized_()
Asserts that the event target instance is initialized properly.
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dispatchEvent()
No description.
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disposeInternal()
Removes listeners from this object. Classes that extend EventTarget may need to override this method in order to remove references to DOM Elements and additional listeners.
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fireListeners()
No description.
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getListener()
No description.
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getListeners()
No description.
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getParentEventTarget() goog.events.EventTarget
Returns the parent of this event target to use for bubbling.
Returns: goog.events.EventTarget  The parent EventTarget or null if there is no parent.
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hasListener()
No description.
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listen()
No description.
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listenOnce()
No description.
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removeAllListeners()
No description.
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removeEventListener(typeopt_captureopt_handlerScope)
Use #unlisten instead, when possible. Otherwise, use goog.events.unlisten if you are passing Object (instead of Function) as handler. Removes an event listener from the event target. The handler must be the same object as the one added. If the handler has not been added then nothing is done.
Arguments:
type : string
The type of the event to listen for.
: ?function():? | ?{handleEvent:function():?
No description.
opt_capture : boolean=
In DOM-compliant browsers, this determines whether the listener is fired during the capture or bubble phase of the event.
opt_handlerScope : Object=
Object in whose scope to call the listener.
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setParentEventTarget(parent)
Sets the parent of this event target to use for capture/bubble mechanism.
Arguments:
parent : goog.events.EventTarget
Parent listenable (null if none).
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setTargetForTesting(target)
Sets the target to be used for event.target when firing event. Mainly used for testing. For example, see goog.testing.events.mixinListenable.
Arguments:
target : !Object
The target.
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unlisten()
No description.
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unlistenByKey()
No description.
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addOnDisposeCallback(callbackopt_scope)
Invokes a callback function when this object is disposed. Callbacks are invoked in the order in which they were added.
Arguments:
callback : function(this:T):?
The callback function.
opt_scope : T=
An optional scope to call the callback in.
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dispose() void
Disposes of the object. If the object hasn't already been disposed of, calls #disposeInternal. Classes that extend goog.Disposable should override #disposeInternal in order to delete references to COM objects, DOM nodes, and other disposable objects. Reentrant.
Returns: void  Nothing.
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disposeInternal()
Deletes or nulls out any references to COM objects, DOM nodes, or other disposable objects. Classes that extend goog.Disposable should override this method. Not reentrant. To avoid calling it twice, it must only be called from the subclass' disposeInternal method. Everywhere else the public dispose method must be used. For example:
  mypackage.MyClass = function() {
    mypackage.MyClass.base(this, 'constructor');
    // Constructor logic specific to MyClass.
    ...
  };
  goog.inherits(mypackage.MyClass, goog.Disposable);

  mypackage.MyClass.prototype.disposeInternal = function() {
    // Dispose logic specific to MyClass.
    ...
    // Call superclass's disposeInternal at the end of the subclass's, like
    // in C++, to avoid hard-to-catch issues.
    mypackage.MyClass.base(this, 'disposeInternal');
  };
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getDisposed() boolean
Use #isDisposed instead. No description.
Returns: boolean  Whether the object has been disposed of.
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isDisposed() boolean
No description.
Returns: boolean  Whether the object has been disposed of.
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registerDisposable(disposable)
Associates a disposable object with this object so that they will be disposed together.
Arguments:
disposable : goog.disposable.IDisposable
that will be disposed when this object is disposed.
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Instance Properties

constructor :
No description.
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element_ :
This is the element that we will listen to the real mouse wheel events on.
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isRtl_ :
True if the element exists and is RTL, false otherwise.
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listenKey_ :
The key returned from the goog.events.listen.
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maxDeltaX_ :
Optional maximum magnitude for x delta on each mousewheel event.
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maxDeltaY_ :
Optional maximum magnitude for y delta on each mousewheel event.
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actualEventTarget_ : goog.events.EventTarget
The object to use for event.target. Useful when mixing in an EventTarget to another object.
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constructor :
No description.
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eventTargetListeners_ : goog.events.ListenerMap
Maps of event type to an array of listeners.
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parentEventTarget_ : goog.events.EventTarget
Parent event target, used during event bubbling. TODO(user): Change this to goog.events.Listenable. This currently breaks people who expect getParentEventTarget to return goog.events.EventTarget.
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creationStack :
If monitoring the goog.Disposable instances is enabled, stores the creation stack trace of the Disposable instance.
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disposed_ :
Whether the object has been disposed of.
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onDisposeCallbacks_ :
Callbacks to invoke when this object is disposed.
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Static Methods

goog.events.MouseWheelHandler.smartScale_(mouseWheelDeltascaleFactor) number
Helper for scaling down a mousewheel delta by a scale factor, if appropriate.
Arguments:
mouseWheelDelta : number
Delta from a mouse wheel event. Expected to be an integer.
scaleFactor : number
Factor to scale the delta down by. Expected to be an integer.
Returns: number  Scaled-down delta value, or the original delta if the scaleFactor does not appear to be applicable.
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Static Properties

goog.events.MouseWheelHandler.superClass_ :
No description.
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Enumerations

goog.events.MouseWheelHandler.EventType :
Enum type for the events fired by the mouse wheel handler.
Constants:
MOUSEWHEEL
No description.
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Package events

Package Reference