bool remove(Page page)

Removes a page from this book, if it is inserted.

Source 

bool remove(Page page) {
  log("removing $page");
  int idx = _pages.indexOf(page);
  if (idx == -1) return false;

  page._display = null;
  if (_active == page) page.onEvent(PageEvent.offScreen, this);

  _pages.removeAt(idx);
  page.onEvent(PageEvent.removed, this);
  page.book = null;
  if (_active == page) {
    if (_pages.isEmpty) {
      _active = null;
      return true;
    }
    // last element wraps around, else move right.
    _active = _pages[idx % _pages.length];
    _active.onEvent(PageEvent.onScreen, this);
  }
  return true;
}