title: How can you monitor for click events in Google Apps script for spreadsheets?
body: <p>I'm managing a Google spreadsheet with a script. onEdit is working - I can colour a cell red by putting </p>
  
  <pre><code>SpreadsheetApp.getActiveRange().setBackgroundRGB(255, 0, 0);
  </code></pre>
  
  <p>in the onEdit function. I would like to put the same code in a onClick function, so that when a user clicks on a cell it immediately turns red. Is this possible? I can't find any way to do it in the documentation.</p>