Sets the receiver's spacing. Spacing specifies the number of pixels allocated around
each item.
@param spacing the spacing around each item
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
</ul>
Sets the receiver's spacing. Spacing specifies the number of pixels allocated around each item.
@param spacing the spacing around each item
@exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>