title: How to know that a file was opened ? QT
body: <p>I want to know if a file was opened by user for reading (double click or open with ...), I am coding a <code>C++</code> application with Qt Creator on Windows, after some research  I found  <a href="http://qt-project.org/doc/qt-4.8/qfilesystemwatcher.html" rel="nofollow">QFileSystemWatche</a>, but it let me know only if a change was happened in the specific folder.</p>
  
  <blockquote>
    <p>void QFileSystemWatcher::fileChanged ( const QString &amp; path ) [signal]
    This signal is emitted when the file at the specified path is
    modified, renamed or removed from disk.</p>
  </blockquote>
  
  <p>How to know if the file was opened? or is there a way to modify a file when it is opened or closed?</p>
  
  <p>Any idea please!!!</p>