Sets the receiver's pull down menu to the argument.
Only <code>CASCADE</code> menu items can have a
pull down menu. The sequence of key strokes, button presses
and/or button releases that are used to request a pull down
menu is platform specific.
<p>
Note: Disposing of a menu item that has a pull down menu
will dispose of the menu. To avoid this behavior, set the
menu to null before the menu item is disposed.
</p>
@param menu the new pull down menu
@exception IllegalArgumentException <ul>
<li>ERROR_MENU_NOT_DROP_DOWN - if the menu is not a drop down menu</li>
<li>ERROR_MENUITEM_NOT_CASCADE - if the menu item is not a <code>CASCADE</code></li>
<li>ERROR_INVALID_ARGUMENT - if the menu has been disposed</li>
<li>ERROR_INVALID_PARENT - if the menu is not in the same widget tree</li>
</ul>
@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 pull down menu to the argument. Only <code>CASCADE</code> menu items can have a pull down menu. The sequence of key strokes, button presses and/or button releases that are used to request a pull down menu is platform specific. <p> Note: Disposing of a menu item that has a pull down menu will dispose of the menu. To avoid this behavior, set the menu to null before the menu item is disposed. </p>
@param menu the new pull down menu
@exception IllegalArgumentException <ul> <li>ERROR_MENU_NOT_DROP_DOWN - if the menu is not a drop down menu</li> <li>ERROR_MENUITEM_NOT_CASCADE - if the menu item is not a <code>CASCADE</code></li> <li>ERROR_INVALID_ARGUMENT - if the menu has been disposed</li> <li>ERROR_INVALID_PARENT - if the menu is not in the same widget tree</li> </ul> @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>