Returns the amount that the receiver's value will be
modified by when the up/down (or right/left) arrows
are pressed.
@return the increment
@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>
Returns the amount that the receiver's value will be modified by when the up/down (or right/left) arrows are pressed.
@return the increment
@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>