query_tooltip
Description:
public virtual signal bool query_tooltip (int x, int y, bool keyboard_mode, Tooltip tooltip)
Emitted when the hover timeout has expired with the cursor hovering above status_icon; or emitted when status_icon 
      got focus in keyboard mode.
Using the given coordinates, the signal handler should determine whether a tooltip should be shown for status_icon. If this is the
       case true should be returned, false otherwise. Note that if 
        keyboard_mode is true, the values of x and y are undefined and should not 
      be used.
The signal handler is free to manipulate tooltip with the therefore destined function calls.
Whether this signal is emitted is platform-dependent. For plain text tooltips, use tooltip_text in preference.
Parameters:
| x | 
           the x coordinate of the cursor position where the request has been  emitted, relative to   | 
      
| y | 
           the y coordinate of the cursor position where the request has been  emitted, relative to   | 
      
| keyboard_mode | 
           true if the tooltip was trigged using the keyboard  | 
      
| tooltip | 
           a Tooltip  | 
      
Returns:
| 
           true if   |