title: How to detect Click + [Shift, Ctrl, Alt] in reactjs click event?
body: <p>I want to do some other things when user Click+[Ctrl], but it seems that I could not detect if user press Ctrl when clicking.</p>
  
  <p>I copy the event object infos below.</p>
  
  <pre><code>bubbles    :    false
  cancelBubble    :    false
  cancelable    :    false
  currentTarget    :    react
  defaultPrevented    :    false
  eventPhase    :    2
  isTrusted    :    false
  path    :    Array[1]
  returnValue    :    true
  srcElement    :    react
  target    :    react
  timeStamp    :    5690056.695
  type    :    "react-click"
  </code></pre>
  
  <p>I can see the ctrlKey attribute in the arguments[0]-Proxy Object. But this object is unaccessable('Uncaught illegal access'):</p>
  
  <pre><code>[[Target]]
  :
  SyntheticMouseEvent
  _dispatchInstances:ReactDOMComponent
  _dispatchListeners:(e)
  _targetInst:ReactDOMComponent
  altKey:false
  bubbles:true
  button:0
  buttons:0
  cancelable:true
  clientX:275
  clientY:315
  ctrlKey:false
  </code></pre>