KeyedViewBitmapCache

public class KeyedViewBitmapCache : ViewBitmapCache

A specialization of ViewBitmapCache that supports storing hashable metadata that can be used to invalidate the contents of the cache by comparing the current values with the values present the previous time the cache was rendered.

  • Updates the key for this bitmap cache to be a ordered-set of the given hashable values.

    The next time cachingOrRendering is invoked, if the contents of the latest updateKeys up to before the method is invoked is different from the contents of the last time cachingOrRendering was invoked, the bitmap cache is invalidated and is re-rendered.

    Declaration

    Swift

    public func updateKeys(_ keys: AnyHashable...)

  • Performs a deferred rendering operation that either redraws the cache bitmap if it’s been invalidated through closure and then draws it on renderer, or if a cached bitmap is already present, draws the cached bitmap to renderer and skips invoking closure.

    If the latest updateKeys invocation does not match the keys present when the last cachingOrRendering call was made, the contents of the cache are erased and re-rendered.

    Declaration

    Swift

    public override func cachingOrRendering(
    _ renderer: any Renderer,
    _ closure: (any Renderer) -> Void
)