I have an OpenLayers select interaction with an add condition event handler.

const addCondition = (event: MapBrowserEvent):boolean => {

  return true;

In this handler I need to determine if the CTRL key was pressed when the user clicked on a map feature. It does not appear the MapBrowserEvent contains the information to determine if the CTRL key was pressed. Is there a way to do this?

  • 1
    Use ol/events/condition.platformModifierKeyOnly
    – Mike
    Feb 27, 2020 at 19:40
  • I am using platformModifierKeyOnly but the user can still click on the feature or CTRL click. I need to determine whether the CTRL key was pressed when the user clicked.
    – ChrisP
    Feb 27, 2020 at 19:46

1 Answer 1


I'm not familiar with ES6, so this will be old school. You can check individual keys/triggers in the condition function the following way:

function addCondition(mapBrowserEvent) {
  var isClick = ol.events.condition.click(mapBrowserEvent);
  var isCtrl = ol.events.condition.platformModifierKeyOnly(mapBrowserEvent);
  if (isClick) {
    if (isCtrl) {
    else {

You can then return true or false according to your liking.

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