title: Menu item enable/disable in Qt
body: <p>In the below code i want to ,
  If i select / click Patient Type button. them in the menu "xmenumain" "Pediatric ECG" item should be disabled (it should list in the menu list but coloured in faded grey) . how do i achieve it ?</p>
  
  <pre><code>void MyMenu::cppSlot()
      {
       xmenumain = new QMenu;
  
      xmenumain-&gt;addAction("                   X",this, SLOT (call_exit(xmenumain)));
      xmenumain-&gt;addAction ( "Edit User Settings" , this , SLOT (call_a()) );
      xmenumain-&gt;addAction ( "Parameters" , this , SLOT (call_b()) );
      xmenumain-&gt;addAction ( "Sound Adjust" , this , SLOT (call_c()) );
      xmenumain-&gt;addAction ( "Patient Type" , this , SLOT (call_d()) );
      xmenumain-&gt;addAction ( "Pediatric ECG" , this , SLOT (call_d()) );
      xmenumain-&gt;addAction ( "Data Output" , this , SLOT (call_d()) );
      xmenumain-&gt;addAction ( "Set Time &amp; Date" , this , SLOT (call_d()) );
      xmenumain-&gt;addAction ( "Sweepspeed" , this , SLOT (call_d()) );
      xmenumain-&gt;addAction ( "Respspeed" , this , SLOT (call_d()) );
  
      //xmenumain-&gt;popup( QCursor::pos() );
      //Change font and width
  
      xmenumain-&gt;setFont(QFont ("Courier", 13));
      xmenumain-&gt;setFixedWidth(250);
      //Colour setting
      QPalette palette=xmenumain-&gt;palette();
      palette.setColor(QPalette::Background, Qt::darkGray);
      xmenumain-&gt;setPalette(palette);
      //xmenumain-&gt;languageChange();
  
  
      //xmenumain-&gt;setAutoFillBackground(true);
  
  
      // Align the menu coordinates
      xmenumain-&gt;move(940,370);
      xmenumain-&gt;show();
      /*if(!(xmenumain-&gt;isEnabled()))
      {
          xmenumain-&gt;show();
      }*/
  }
  </code></pre>