Controls how text, images and arrows will be displayed
in the receiver. The argument should be one of
<code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code>
unless the receiver is an <code>ARROW</code> button, in
which case, the argument indicates the direction of
the arrow (one of <code>LEFT</code>, <code>RIGHT</code>,
<code>UP</code> or <code>DOWN</code>).
@param alignment the new alignment
@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>
Controls how text, images and arrows will be displayed in the receiver. The argument should be one of <code>LEFT</code>, <code>RIGHT</code> or <code>CENTER</code> unless the receiver is an <code>ARROW</code> button, in which case, the argument indicates the direction of the arrow (one of <code>LEFT</code>, <code>RIGHT</code>, <code>UP</code> or <code>DOWN</code>).
@param alignment the new alignment
@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>