goog.dom.FontSizeMonitor

Provided By	`goog.dom.FontSizeMonitor`
Extends	`goog.events.EventTarget` `goog.Disposable`
All Implemented Interfaces	`goog.disposable.IDisposable` `goog.events.Listenable`

This class can be used to monitor changes in font size. Instances will dispatch a goog.dom.FontSizeMonitor.EventType.CHANGE event. Example usage:

 var fms = new goog.dom.FontSizeMonitor();
 goog.events.listen(fms, goog.dom.FontSizeMonitor.EventType.CHANGE,
     function(e) {
       alert('Font size was changed');
     });

new FontSizeMonitor( `opt_domHelper` )

Parameters

`opt_domHelper`	`(goog.dom.DomHelper\|null)=`
	DOM helper object that is used to determine where to insert the DOM nodes used to determine when the font size changes.

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Instance Methods

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.

Deprecated	Use `#listen` instead, when possible. Otherwise, use `goog.events.listen` if you are passing Object (instead of Function) as handler.

Defined by

goog.events.EventTarget

Parameters

`type`	`(string\|goog.events.EventId)`
	The type of the event to listen for
`handler`	`(function(?): ?\|{handleEvent: function(?): ?}\|null)`
	The function to handle the event. The handler can also be an object that implements the handleEvent method which takes the event object as argument.
`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\|null)=`
	Object in whose scope to call the listener.

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Invokes a callback function when this object is disposed. Callbacks are invoked in the order in which they were added. If a callback is added to an already disposed Disposable, it will be called immediately.

Defined by

goog.Disposable

Parameters

`callback`	`function(): ?`
	The callback function.
`opt_scope`	`(T\|null)=`
	An optional scope to call the callback in.

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Dispatches an event (or event like object) and calls all listeners listening for events of this type. The type of the event is decided by the type property on the event object.

If any of the listeners returns false OR calls preventDefault then this function will return false. If one of the capture listeners calls stopPropagation, then the bubble listeners won't fire.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`e`	`(string\|Object\|null)`
	Event object.

Returns

boolean

If anyone called preventDefault on the event object (or if any of the listeners returns false) this will also return false.

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Disposes of the object and its resources.

Overrides

goog.Disposable

Specified by

goog.disposable.IDisposable

Parameters

None.

Returns

Nothing.

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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.

Overrides	`goog.events.EventTarget`
Parameters	None.

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Fires all registered listeners in this listenable for the given type and capture mode, passing them the given eventObject. This does not perform actual capture/bubble. Only implementors of the interface should be using this.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)`
	The type of the listeners to fire.
`capture`	`boolean`
	The capture mode of the listeners to fire.
`eventObject`	`(EVENTOBJ\|null)`
	The event object to fire.

Returns

boolean

Whether all listeners succeeded without attempting to prevent default behavior. If any listener returns false or called goog.events.Event#preventDefault, this returns false.

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Deprecated	Use `#isDisposed` instead.

Defined by

goog.Disposable

Parameters

None.

Returns

boolean

Whether the object has been disposed of.

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Gets the goog.events.ListenableKey for the event or null if no such listener is in use.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)`
	The name of the event without the 'on' prefix.
`listener`	`function((EVENTOBJ\|null)): (boolean\|undefined)`
	The listener function to get.
`capture`	`boolean`
	Whether the listener is a capturing listener.
`opt_listenerScope`	`(SCOPE\|null)=`
	Object in whose scope to call the listener.

Returns

(goog.events.ListenableKey|null)

the found listener or null if not found.

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Gets all listeners in this listenable for the given type and capture mode.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId)`
	The type of the listeners to fire.
`capture`	`boolean`
	The capture mode of the listeners to fire.

Returns

Array<goog.events.ListenableKey>

An array of registered listeners.

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Returns the parent of this event target to use for capture/bubble mechanism.

NOTE(chrishenry): The name reflects the original implementation of custom event target (goog.events.EventTarget). We decided that changing the name is not worth it.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

None.

Returns

(goog.events.Listenable|null)

The parent EventTarget or null if there is no parent.

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Whether there is any active listeners matching the specified signature. If either the type or capture parameters are unspecified, the function will match on the remaining criteria.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`opt_type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)=`
	Event type.
`opt_capture`	`boolean=`
	Whether to check for capture or bubble listeners.

Returns

boolean

Whether there is any active listeners matching the requested type and/or capture phase.

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Overrides

goog.Disposable

Specified by

goog.disposable.IDisposable

Parameters

None.

Returns

boolean

Whether the object has been disposed of.

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Adds an event listener. A listener can only be added once to an object and if it is added again the key for the listener is returned. Note that if the existing listener is a one-off listener (registered via listenOnce), it will no longer be a one-off listener after a call to listen().

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)`
	The event type id.
`listener`	`function((EVENTOBJ\|null)): (boolean\|undefined)`
	Callback method.
`opt_useCapture`	`boolean=`
	Whether to fire in capture phase (defaults to false).
`opt_listenerScope`	`(SCOPE\|null)=`
	Object in whose scope to call the listener.

Returns

goog.events.ListenableKey

Unique key for the listener.

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Adds an event listener that is removed automatically after the listener fired once.

If an existing listener already exists, listenOnce will do nothing. In particular, if the listener was previously registered via listen(), listenOnce() will not turn the listener into a one-off listener. Similarly, if there is already an existing one-off listener, listenOnce does not modify the listeners (it is still a once listener).

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)`
	The event type id.
`listener`	`function((EVENTOBJ\|null)): (boolean\|undefined)`
	Callback method.
`opt_useCapture`	`boolean=`
	Whether to fire in capture phase (defaults to false).
`opt_listenerScope`	`(SCOPE\|null)=`
	Object in whose scope to call the listener.

Returns

goog.events.ListenableKey

Unique key for the listener.

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Associates a disposable object with this object so that they will be disposed together.

Defined by

goog.Disposable

Parameters

`disposable`	`(goog.disposable.IDisposable\|null)`
	that will be disposed when this object is disposed.

VIEW SOURCE

Removes all listeners from this listenable. If type is specified, it will only remove listeners of the particular type. otherwise all registered listeners will be removed.

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`opt_type`	`(string\|goog.events.EventId)=`
	Type of event to remove, default is to remove all types.

Returns

number

Number of listeners removed.

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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.

Deprecated	Use `#unlisten` instead, when possible. Otherwise, use `goog.events.unlisten` if you are passing Object (instead of Function) as handler.

Defined by

goog.events.EventTarget

Parameters

`type`	`(string\|goog.events.EventId)`
	The type of the event to listen for
`handler`	`(function(?): ?\|{handleEvent: function(?): ?}\|null)`
	The function to handle the event. The handler can also be an object that implements the handleEvent method which takes the event object as argument.
`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\|null)=`
	Object in whose scope to call the listener.

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Sets the parent of this event target to use for capture/bubble mechanism.

Defined by

goog.events.EventTarget

Parameters

`parent`	`(goog.events.EventTarget\|null)`
	Parent listenable (null if none).

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Sets the target to be used for event.target when firing event. Mainly used for testing. For example, see goog.testing.events.mixinListenable.

Defined by

goog.events.EventTarget

Parameters

`target`	`Object`
	The target.

VIEW SOURCE

Removes an event listener which was added with listen() or listenOnce().

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`type`	`(string\|goog.events.EventId<(EVENTOBJ\|null)>)`
	The event type id.
`listener`	`function((EVENTOBJ\|null)): (boolean\|undefined)`
	Callback method.
`opt_useCapture`	`boolean=`
	Whether to fire in capture phase (defaults to false).
`opt_listenerScope`	`(SCOPE\|null)=`
	Object in whose scope to call the listener.

Returns

boolean

Whether any listener was removed.

VIEW SOURCE

Removes an event listener which was added with listen() by the key returned by listen().

Overrides

goog.events.EventTarget

Specified by

goog.events.Listenable

Parameters

`key`	`goog.events.ListenableKey`
	The key returned by listen() or listenOnce().

Returns

boolean

Whether any listener was removed.

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Instance Properties

If monitoring the goog.Disposable instances is enabled, stores the creation stack trace of the Disposable instance.

VIEW SOURCE

No information.

VIEW SOURCE

Static Properties

Constant for the change event.

Deprecated	Use `goog.dom.FontSizeMonitor.EventType.CHANGE` instead.

VIEW SOURCE

Enumerations

FontSizeMonitor.EventType

goog.dom.FontSizeMonitor

new FontSizeMonitor( `opt_domHelper` )

Instance Methods

`this.`addEventListener( `type`, `handler`, `opt_capture`, `opt_handlerScope` ) `→` `void`

`this.`addOnDisposeCallback`<T>`( `callback`, `opt_scope` ) `→` `void`

`this.`dispatchEvent( `e` ) `→` `boolean`

`this.`dispose() `→` `?`

`this.`disposeInternal() `→` `void`

`this.`fireListeners`<EVENTOBJ>`( `type`, `capture`, `eventObject` ) `→` `boolean`

`this.`getDisposed() `→` `boolean`

`this.`getListener`<SCOPE, EVENTOBJ>`( `type`, `listener`, `capture`, `opt_listenerScope` ) `→` `(goog.events.ListenableKey|null)`

`this.`getListeners`<EVENTOBJ>`( `type`, `capture` ) `→` `Array<goog.events.ListenableKey>`

`this.`getParentEventTarget() `→` `(goog.events.Listenable|null)`

`this.`hasListener`<EVENTOBJ>`( `opt_type`, `opt_capture` ) `→` `boolean`

`this.`isDisposed() `→` `boolean`

`this.`listen`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `goog.events.ListenableKey`

`this.`listenOnce`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `goog.events.ListenableKey`

`this.`registerDisposable( `disposable` ) `→` `void`

`this.`removeAllListeners( `opt_type` ) `→` `number`

`this.`removeEventListener( `type`, `handler`, `opt_capture`, `opt_handlerScope` ) `→` `void`

`this.`setParentEventTarget( `parent` ) `→` `void`

`this.`setTargetForTesting( `target` ) `→` `void`

`this.`unlisten`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `boolean`

`this.`unlistenByKey( `key` ) `→` `boolean`

Instance Properties

`this.`creationStack `→` `(string|undefined)`

`this.`resizeTarget_ `→` `(Window|HTMLElement|null)`

Static Properties

FontSizeMonitor.CHANGE_EVENT `→` `string`

Enumerations

goog.dom.FontSizeMonitor

new FontSizeMonitor( opt_domHelper )

Instance Methods

this.addEventListener( type, handler, opt_capture, opt_handlerScope ) → void

this.addOnDisposeCallback<T>( callback, opt_scope ) → void

this.dispatchEvent( e ) → boolean

this.dispose() → ?

this.disposeInternal() → void

this.fireListeners<EVENTOBJ>( type, capture, eventObject ) → boolean

this.getDisposed() → boolean

this.getListener<SCOPE, EVENTOBJ>( type, listener, capture, opt_listenerScope ) → (goog.events.ListenableKey|null)

this.getListeners<EVENTOBJ>( type, capture ) → Array<goog.events.ListenableKey>

this.getParentEventTarget() → (goog.events.Listenable|null)

this.hasListener<EVENTOBJ>( opt_type, opt_capture ) → boolean

this.isDisposed() → boolean

this.listen<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → goog.events.ListenableKey

this.listenOnce<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → goog.events.ListenableKey

this.registerDisposable( disposable ) → void

this.removeAllListeners( opt_type ) → number

this.removeEventListener( type, handler, opt_capture, opt_handlerScope ) → void

this.setParentEventTarget( parent ) → void

this.setTargetForTesting( target ) → void

this.unlisten<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → boolean

this.unlistenByKey( key ) → boolean

Instance Properties

this.creationStack → (string|undefined)

this.resizeTarget_ → (Window|HTMLElement|null)

Static Properties

FontSizeMonitor.CHANGE_EVENT → string

Enumerations

new FontSizeMonitor( `opt_domHelper` )

`this.`addEventListener( `type`, `handler`, `opt_capture`, `opt_handlerScope` ) `→` `void`

`this.`addOnDisposeCallback`<T>`( `callback`, `opt_scope` ) `→` `void`

`this.`dispatchEvent( `e` ) `→` `boolean`

`this.`dispose() `→` `?`

`this.`disposeInternal() `→` `void`

`this.`fireListeners`<EVENTOBJ>`( `type`, `capture`, `eventObject` ) `→` `boolean`

`this.`getDisposed() `→` `boolean`

`this.`getListener`<SCOPE, EVENTOBJ>`( `type`, `listener`, `capture`, `opt_listenerScope` ) `→` `(goog.events.ListenableKey|null)`

`this.`getListeners`<EVENTOBJ>`( `type`, `capture` ) `→` `Array<goog.events.ListenableKey>`

`this.`getParentEventTarget() `→` `(goog.events.Listenable|null)`

`this.`hasListener`<EVENTOBJ>`( `opt_type`, `opt_capture` ) `→` `boolean`

`this.`isDisposed() `→` `boolean`

`this.`listen`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `goog.events.ListenableKey`

`this.`listenOnce`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `goog.events.ListenableKey`

`this.`registerDisposable( `disposable` ) `→` `void`

`this.`removeAllListeners( `opt_type` ) `→` `number`

`this.`removeEventListener( `type`, `handler`, `opt_capture`, `opt_handlerScope` ) `→` `void`

`this.`setParentEventTarget( `parent` ) `→` `void`

`this.`setTargetForTesting( `target` ) `→` `void`

`this.`unlisten`<SCOPE, EVENTOBJ>`( `type`, `listener`, `opt_useCapture`, `opt_listenerScope` ) `→` `boolean`

`this.`unlistenByKey( `key` ) `→` `boolean`

`this.`creationStack `→` `(string|undefined)`

`this.`resizeTarget_ `→` `(Window|HTMLElement|null)`

FontSizeMonitor.CHANGE_EVENT `→` `string`