Notify-Mouse
When this style is set, the Bar control fires the following events: MSG-MOUSE-CLICKED, MSG-MOUSE-DBLCLICK, MSG-MOUSE-ENTER, MSG-MOUSE-EXIT.
 
Example - Define a vertical bar in screen section that fires mouse events
screen section.
...
  03 screen-1-br-3 Bar
     line 10.0
     column 5.0
     lines 22.0 
     id 3
     notify-mouse
     height-in-cells
     .