Event handlers and execution options to be monitored.
Function that returns the element's absolute boundaries (start/end) relative to the document. This is executed when the layout changes (e.g., window resize).
OptionaloffsetAn optional symmetrical padding (in pixels) added to both the top and bottom of the element's boundary box for triggering events earlier/later.
OptionalonCallback executed when the node is successfully removed from monitoring.
A unique reference object (e.g., the HTMLElement itself) used as a key for tracking the node and responding to remove requests.
Configuration options required to register a new element for scroll/viewport monitoring.