BoundingClientRectCache

Cache for bounding client rectangles. This is useful when cost of HTMLElement.getBoundingClientRect() becomes a problem (it causes browser reflow which in some situations can be very costly). By caching the information from the DOMRect, this cost can be avoided.

Index

Constructors

• constructor

Methods

• getOrAdd

Constructors

constructor

• new BoundingClientRectCache(): BoundingClientRectCache

• Returns BoundingClientRectCache

Methods

publicgetOrAdd

• getOrAdd(element: HTMLElement, timeInMsToNextRefresh?: number): DOMRectCached

• Get or add a DOMRectCached instance for a specified element.

  ---

  Parameters

  • element: HTMLElement

    HTMLElement to get a DOMRectCached instance for.

  • timeInMsToNextRefresh: number = 300

    Optional. Defaults to 300. If the instance, returned by this method, already exists in the cache. Then DomRectCached.refresh method on the instance is called automatically if

    1. timeInMsToNextRefresh = 0. Useful when DomRectCached should be refreshed immediatly.
    2. timeInMsToNextRefresh > 0 && performance.now() - instance.lastRefreshInMs > timeInMsToNextRefresh

    This means that if timeInMsToNextRefresh < 0 then DomRectCached.refresh will never be called. This can be useful when we never want to refresh the DomRectCached instance.

  Returns DOMRectCached

  A DOMRectCached element.