dom.ViewportSizeMonitor Extends goog.events.EventTarget
This class can be used to monitor changes in the viewport size. Instances dispatch a goog.events.EventType.RESIZE event when the viewport size changes. Handlers can call goog.dom.ViewportSizeMonitor#getSize to get the new viewport size. Use this class if you want to execute resize/reflow logic each time the user resizes the browser window. This class is guaranteed to only dispatch RESIZE events when the pixel dimensions of the viewport change. (Internet Explorer fires resize events if any element on the page is resized, even if the viewport dimensions are unchanged, which can lead to infinite resize loops.) Example usage:
   var vsm = new goog.dom.ViewportSizeMonitor();
   goog.events.listen(vsm, goog.events.EventType.RESIZE, function(e) {
     alert('Viewport size changed to ' + vsm.getSize());
   });
 
Manually verified on IE6, IE7, FF2, Opera 11, Safari 4 and Chrome.

Inheritance

Constructor

goog.dom.ViewportSizeMonitor(opt_window)

Parameters

opt_window : Window=
The window to monitor; defaults to the window in which this code is executing.

Instance Methods

Public Protected Private
disposeInternal()
No description.
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getSize() goog.math.Size
Returns the most recently recorded size of the viewport, in pixels. May return null if no window resize event has been handled yet.
Returns: goog.math.Size  The viewport dimensions, in pixels.
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handleResize_(event)
Handles window resize events by measuring the dimensions of the viewport and dispatching a goog.events.EventType.RESIZE event if the current dimensions are different from the previous ones.
Arguments:
event : goog.events.Event
The window resize event to handle.
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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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listenerKey_ :
Event listener key for window the window resize handler, as returned by goog.events.listen.
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size_ : goog.math.Size
The most recently recorded size of the viewport, in pixels.
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window_ :
The window to monitor. Defaults to the window in which the code is running.
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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.dom.ViewportSizeMonitor.getInstanceForWindow(opt_window) !goog.dom.ViewportSizeMonitor
Returns a viewport size monitor for the given window. A new one is created if it doesn't exist already. This prevents the unnecessary creation of multiple spooling monitors for a window.
Arguments:
opt_window : Window=
The window to monitor; defaults to the window in which this code is executing.
Returns: !goog.dom.ViewportSizeMonitor  Monitor for the given window.
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goog.dom.ViewportSizeMonitor.removeInstanceForWindow(opt_window)
Removes and disposes a viewport size monitor for the given window if one exists.
Arguments:
opt_window : Window=
The window whose monitor should be removed; defaults to the window in which this code is executing.
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Static Properties

goog.dom.ViewportSizeMonitor.superClass_ :
No description.
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goog.dom.ViewportSizeMonitor.windowInstanceMap_ :
Map of window hash code to viewport size monitor for that window, if created.
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Package dom

Package Reference