Sends a message to accessible clients indicating that the focus
has changed within a custom control.
@param childID an identifier specifying a child of the control
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li>
</ul>
Sends a message to accessible clients indicating that the focus has changed within a custom control.
@param childID an identifier specifying a child of the control
@exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control</li> </ul>