THEOplayer > Visibility

Visibility interface

The visibility API.

Signature:

export interface Visibility 

Properties

Property	Type	Description
ratio	number	The ratio of pixels of the player that are within the viewport.
visible	boolean	Whether the Visibility.ratio of visible pixels is exceeded.
visibleThreshold	number	The threshold that the ratio must exceed for the player to be visible.

Methods

Method	Description
addObserver​(step: number, callback: VisibilityObserverCallback): VisibilityObserver	Add a visibility observer to monitor the player.
removeObserver​(observer: VisibilityObserver): void	Remove a visibility observer. The observer will stop monitoring player visibility, and will no longer trigger its callback.

Property Details

ratio

The ratio of pixels of the player that are within the viewport.

Signature:

readonly ratio: number;

visible

Whether the Visibility.ratio of visible pixels is exceeded.

Signature:

readonly visible: boolean;

visibleThreshold

The threshold that the ratio must exceed for the player to be visible.

Signature:

visibleThreshold: number;

Remarks

- This number is in the range of [0, 1].

Method Details

addObserver

Add a visibility observer to monitor the player.

Signature:

addObserver(step: number, callback: VisibilityObserverCallback): VisibilityObserver;

Parameters

Parameter	Type	Description
step	number	The step between every threshold. This number is in the range of ]0, 1].
callback	VisibilityObserverCallback	The callback to be triggered every time a threshold is crossed.

Returns

A new visibility observer.

Remarks

- The callback is triggered every time the ratio of visible pixels crosses a threshold, and receives the ratio of visible pixels as first argument.
- The list of thresholds is evenly distributed between 0 and 1, with the distance between every two consecutive thresholds determined by the given step.

removeObserver

Remove a visibility observer.

The observer will stop monitoring player visibility, and will no longer trigger its callback.

Signature:

removeObserver(observer: VisibilityObserver): void;

Parameters

Parameter	Type	Description
observer	VisibilityObserver	The observer to remove.