goog.labs.style.PixelDensityMonitor
| Provided By | |
|---|---|
| Extends | |
| All Implemented Interfaces |
Monitors the window for changes to the ratio between device and screen pixels, e.g. when the user moves the window from a high density screen to a screen with normal density. Dispatches goog.labs.style.PixelDensityMonitor.EventType.CHANGE events when the density changes between the two predefined values NORMAL and HIGH.
This class uses the window.devicePixelRatio value which is supported in WebKit and FF18. If the value does not exist, it will always return a NORMAL density. It requires support for MediaQueryList to detect changes to the devicePixelRatio.
new PixelDensityMonitor( opt_domHelper )
| Parameters |
|
|---|
Instance Methods
this.addEventListener( type, handler, opt_capture, opt_handlerScope ) → void
voidAdds 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.
| warning Deprecated | Use |
|---|
| Defined by | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Parameters |
|
this.addOnDisposeCallback<T>( callback, opt_scope ) → void
voidInvokes 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 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Parameters |
|
this.dispatchEvent( e ) → boolean
booleanDispatches 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 | |||||
|---|---|---|---|---|---|
| Specified by | |||||
| Parameters |
| ||||
| Returns |
|
this.dispose() → ?
?Disposes of the object and its resources.
| Overrides | ||
|---|---|---|
| Specified by | ||
| Parameters | None. | |
| Returns |
|
this.disposeInternal() → void
voidRemoves 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 | |
|---|---|
| Parameters | None. |
this.fireListeners<EVENTOBJ>( type, capture, eventObject ) → boolean
booleanFires 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 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||||||
| Parameters |
| ||||||||||||
| Returns |
|
this.getDensity() → goog.labs.style.PixelDensityMonitor.Density
goog.labs.style.PixelDensityMonitor.Density| Parameters | None. | ||
|---|---|---|---|
| Returns |
|
this.getDisposed() → boolean
boolean| warning Deprecated | Use |
|---|
| Defined by | |||
|---|---|---|---|
| Parameters | None. | ||
| Returns |
|
this.getListener<SCOPE, EVENTOBJ>( type, listener, capture, opt_listenerScope ) → (goog.events.ListenableKey|null)
(goog.events.ListenableKey|null)Gets the goog.events.ListenableKey for the event or null if no such listener is in use.
| Overrides | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||||||||||
| Parameters |
| ||||||||||||||||
| Returns |
|
this.getListeners<EVENTOBJ>( type, capture ) → Array<goog.events.ListenableKey>
Array<goog.events.ListenableKey>Gets all listeners in this listenable for the given type and capture mode.
| Overrides | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||
| Parameters |
| ||||||||
| Returns |
|
this.getParentEventTarget() → (goog.events.Listenable|null)
(goog.events.Listenable|null)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 | |||
|---|---|---|---|
| Specified by | |||
| Parameters | None. | ||
| Returns |
|
this.hasListener<EVENTOBJ>( opt_type, opt_capture ) → boolean
booleanWhether 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 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||
| Parameters |
| ||||||||
| Returns |
|
this.isDisposed() → boolean
boolean| Overrides | |||
|---|---|---|---|
| Specified by | |||
| Parameters | None. | ||
| Returns |
|
this.listen<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → goog.events.ListenableKey
goog.events.ListenableKeyAdds 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 | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||||||||||
| Parameters |
| ||||||||||||||||
| Returns |
|
this.listenOnce<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → goog.events.ListenableKey
goog.events.ListenableKeyAdds 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 | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||||||||||
| Parameters |
| ||||||||||||||||
| Returns |
|
this.registerDisposable( disposable ) → void
voidAssociates a disposable object with this object so that they will be disposed together.
| Defined by | |||||
|---|---|---|---|---|---|
| Parameters |
|
this.removeAllListeners( opt_type ) → number
numberRemoves 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 | |||||
|---|---|---|---|---|---|
| Specified by | |||||
| Parameters |
| ||||
| Returns |
|
this.removeEventListener( type, handler, opt_capture, opt_handlerScope ) → void
voidRemoves 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.
| warning Deprecated | Use |
|---|
| Defined by | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Parameters |
|
this.setParentEventTarget( parent ) → void
voidSets the parent of this event target to use for capture/bubble mechanism.
| Defined by | |||||
|---|---|---|---|---|---|
| Parameters |
|
this.setTargetForTesting( target ) → void
voidSets the target to be used for event.target when firing
event. Mainly used for testing. For example, see
goog.testing.events.mixinListenable.
| Defined by | |||||
|---|---|---|---|---|---|
| Parameters |
|
this.start() → void
voidStarts monitoring for changes in pixel density.
this.unlisten<SCOPE, EVENTOBJ>( type, listener, opt_useCapture, opt_listenerScope ) → boolean
booleanRemoves an event listener which was added with listen() or listenOnce().
| Overrides | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specified by | |||||||||||||||||
| Parameters |
| ||||||||||||||||
| Returns |
|
this.unlistenByKey( key ) → boolean
booleanRemoves an event listener which was added with listen() by the key returned by listen().
| Overrides | |||||
|---|---|---|---|---|---|
| Specified by | |||||
| Parameters |
| ||||
| Returns |
|
Instance Properties
this.creationStack → (string|undefined)
(string|undefined)If monitoring the goog.Disposable instances is enabled, stores the creation stack trace of the Disposable instance.