title: How to detect the modifier key on mouse click in Qt
body: <p>I have a <code>QTableWidget</code> and would like that pressing CTRL while clicking on a column header marks the whole column. To get the column index is not a problem since there is a <em>sectionPressed</em> signal which gives me the current index of the column clicked. How can I get the state of any keyboard modifiers when a column is clicked?</p>