interface HandleDropdownParams { toggle: HTMLElement; menu: HTMLElement; showOnHover?: boolean, onOpen?: Function | undefined; onClose?: Function | undefined; } export function handleDropdown(options: HandleDropdownParams) { const {menu, toggle, onClose, onOpen, showOnHover} = options; let clickListener: Function|null = null; const hide = () => { menu.hidden = true; if (clickListener) { window.removeEventListener('click', clickListener as EventListener); } if (onClose) { onClose(); } }; const show = () => { menu.hidden = false clickListener = (event: MouseEvent) => { if (!toggle.contains(event.target as HTMLElement) && !menu.contains(event.target as HTMLElement)) { hide(); } } window.addEventListener('click', clickListener as EventListener); if (onOpen) { onOpen(); } }; const toggleShowing = (event: MouseEvent) => { menu.hasAttribute('hidden') ? show() : hide(); }; toggle.addEventListener('click', toggleShowing); if (showOnHover) { toggle.addEventListener('mouseenter', toggleShowing); } menu.addEventListener('mouseleave', hide); }