Collection of UI elements that behave as popovers

For simple menus, create a single instance of Menu, and reuse it for potentially many open/close calls. This is a good and simple pattern for a static menu.

const menu = new Menu(...);
setPopupToOpen(triggerElem, menu, options);

You can create a new Menu instance on every open, and destroy it on close. This should be preferred if the menu changes depending on context, or if its content subscribes to outside changes (which is wasteful when the menu is not shown).

setPopupToCreate(triggerElem, () => new Menu(...), options);

You can use an existing DOM element to attach/detach on open/close, e.g. a tooltip:

const myDom = document.querySelector('.my-tooltip');
setPopupToAttach(triggerElem, myDom, options);

You can define a custom popup class. It can then be used for either the static or dynamic usage pattern.

class SpecialMenu implements IPopupContent {
  constructor() { ... }
  openPopup(ctl) { ...; return content; };
  closePopup() { ... };
  dispose() { ... }  // Only needed for setPopupToCreate() usage.
}

// Calls .openPopup() on open, .closePopup() on close.
setPopupToOpen(triggerElem, new SpecialMenu(...), options);

// Calls constructor and .openPopup() on open; .closePopup() and .dispose() on close.
setPopupToCreate(triggerElem, () => new SpecialMenu(...), options);

You can use a low-level function-based interface to create a custom popup. It's the basis for all the more convenient interfaces above, and you may use it e.g. to create adapters for other libraries. See popupFunc() documentation for an example.

setPopupToFunc(triggerElem, (ctl) => {
  return () => { content, dispose };
}, options);