title: Get currently pressed keys in inspector
body: <p>I am currently building a simple shortcuts system for my Unity project.</p>
  
  <p>At the moment I am inserting the shortcuts in the inspector by string, for example: "Control+Alt+A". but writing it every time is too annoying.</p>
  
  <p>So I thought about creating a custom editor for it, where the textbox would be filled automatically with the keys the user presses. Unfortunately the only way I found about getting this info is with the OnSceneGUI function, but it requires the scene window to have focus, and if the shortcut is defined in Unity it would fire.</p>
  
  <p>To sum up, How can I read the currently pressed keys and display them with an editor script¿</p>
  
  <p>Edit: <a href="https://forum.unity.com/threads/custom-inspector-to-capture-a-single-key-press.551566/" rel="nofollow noreferrer">this link</a> almost does what I need, but it detects only one key (no combinations), and the Shift key isn't detected at all</p>