Visibility API

The Visibility API provides developers a way to observe how much of the player is visible.

Properties

The visibility object provides the following properties:

Property Type Description
visible boolean Indicates whether or not the ratio of visible pixels of the player exceeds the
visible threshold.
ratio number Indicates the ratio of pixels of the player that are within the viewport.
visibleThreshold number Gets or sets the threshold that the ratio must exceed for the player to be visible.

Methods

The visibility object provides the following methods:

Property Type Description
addObserver step : number, callback : function

Adds an observer to monitor the visibility of the player, and returns the created VisibilityObserver.

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.

  • step: The step between every threshold. Must be a number between 0 (exclusive) and 1 (inclusive).
  • callback: The callback to be triggered every time a threshold is crossed.
removeObserver observer : VisibilityObserver Removes a previously created visibility observer.

VisibilityObserver

The VisibilityObserver API enables you to access the thresholds and ratio of a visibility observer.

Properties

The VisibilityObserver object provides the following properties:

Property Type Description
ratio number The ratio of pixels of the player that are within the viewport.
thresholds number[]  The list of thresholds which are monitored by this observer.