OptionalanchorOptionaldismissClose on Escape. Default true.
OptionaldismissClose on a press outside the panel and its anchor. Default: not modal.
OptionaledgeA second element the panel should clear when placed beside (the rail, not just the button in it).
OptionalinitialWhere focus lands: an element, null to leave focus where it is, or the first control (default).
OptionalmodalDraw a scrim and refuse outside dismissal. Default false; center placement implies it.
OptionalonOptionalplacementWhere the panel goes relative to the anchor. Default below; center ignores the anchor.
OptionalrestoreGive focus back to the opener on close. Default true.
The control the panel opens from; positions the panel and keeps a click on it from counting as outside.