Custom events to dispatch the various states of the Civic Cookie Control UI (https://www.civicuk.com/cookie-control). I use it to prevent interference with pop-up modals.

cc-extend.js

(function(CookieControl) {

  /**
   * Creating custom events to dispatch the various states of Cookie Control UI.
   */
  CookieControl.loadedEvent = new Event('cc.loaded');
  CookieControl.openedEvent = new Event('cc.open');
  CookieControl.closedEvent = new Event('cc.closed');

  /**
   * MutationObserver callback.
   * Watching: Cookie Control wrapper added.
   */
  CookieControl.isLoadedObserver = new MutationObserver(function(mutations) {
    for (var i=0; i < mutations.length; i++) {
      var mutation = mutations[i];
      if (mutation.addedNodes.length > 0) {
        for (var j=0; j < mutation.addedNodes.length; j++) {
          if (mutation.addedNodes[j].id === 'ccc') {
            // Cookie control wrapper is added to the DOM; it is loaded...
            // Dispatch custom event.
            document.body.dispatchEvent(CookieControl.loadedEvent);
            CookieControl.openStateObserver.observe(document.getElementById('ccc'), { childList: true, subtree: false });
            CookieControl.isLoadedObserver.disconnect();
            return;
          }
        }
      }
    }
  });

  /**
   * MutationObserver callback.
   * Watching: Cookie Control overlay element added or removed, which means the
   * notify bar or panel is open/closed.
   */
  CookieControl.openStateObserver = new MutationObserver(function(mutations) {
    for (var i=0; i < mutations.length; i++) {
      var mutation = mutations[i];
      var nodes = [];
      var eventToDispatch = false;
      if (mutation.addedNodes.length > 0) {
        nodes = mutation.addedNodes;
        eventToDispatch = CookieControl.openedEvent;
      }
      if (mutation.removedNodes.length > 0) {
        nodes = mutation.removedNodes;
        eventToDispatch = CookieControl.closedEvent;
      }
      for (var i=0; i < nodes.length; i++) {
        var node = nodes[i];
        if (node.id === 'ccc-overlay') {
          document.getElementById('ccc').dispatchEvent(eventToDispatch);
          return;
        }
      }
    }
  });

  CookieControl.isLoadedObserver.observe(document.body, { childList: true, subtree: false });

})(CookieControl);

example-usage.js

/**
 * (Example usage)
 * For usability and accessibility, don't allow a pop-up modal to display at the
 * same time as the Cookie Control notify bar or panel.
 */
 
// Listen for the Cookie Control wrapper to be loaded.
document.body.addEventListener('cc.loaded', handleLoadedListener);

var openModal = function() {
  // Continue listening for Cookie Control events in case the user opens the 
  // Cookie Control panel while the modal is still displayed.
}

var closeModal = function() {
  // Once the modal has been closed, we don't need to listen for these events
  // anymore.
  document.getElementById('ccc').removeEventListener('cc.open', handleOpenedListener);
  document.getElementById('ccc').removeEventListener('cc.closed', handleClosedListener);
}

var handleLoadedListener = function() {
  // Listen for cookie control banner or panel to be closed.
  document.getElementById('ccc').addEventListener('cc.closed', handleClosedListener);

  // Listen for cookie control banner or panel to be opened.
  document.getElementById('ccc').addEventListener('cc.open', handleOpenedListener);
}

var handleOpenedListener = function() {
  // Remove cc.loaded listener.
  document.body.removeEventListener('cc.loaded', handleLoadedListener);

  // Close modal...
  closeModal();
}

var handleClosedListener = function() {
  // Remove cc.loaded listener.
  document.body.removeEventListener('cc.loaded', handleLoadedListener);

  window.setTimeout(function() {
    // Open modal after a slight delay...
    openModal();
  }, 1000);
}