Creates a new <code>DragSource</code> to handle dragging from the specified <code>Control</code>.
Creating an instance of a DragSource may cause system resources to be allocated depending on the platform.
It is therefore mandatory that the DragSource instance be disposed when no longer required.
@param control the <code>Control</code> that the user clicks on to initiate the drag
@param style the bitwise OR'ing of allowed operations; this may be a combination of any of
DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK
@exception SWTException <ul>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li>
<li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li>
</ul>
@exception SWTError <ul>
<li>ERROR_CANNOT_INIT_DRAG - unable to initiate drag source; this will occur if more than one
drag source is created for a control or if the operating system will not allow the creation
of the drag source</li>
</ul>
<p>NOTE: ERROR_CANNOT_INIT_DRAG should be an SWTException, since it is a
recoverable error, but can not be changed due to backward compatibility.</p>
Creates a new <code>DragSource</code> to handle dragging from the specified <code>Control</code>. Creating an instance of a DragSource may cause system resources to be allocated depending on the platform. It is therefore mandatory that the DragSource instance be disposed when no longer required.
@param control the <code>Control</code> that the user clicks on to initiate the drag @param style the bitwise OR'ing of allowed operations; this may be a combination of any of DND.DROP_NONE, DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK
@exception SWTException <ul> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent</li> <li>ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass</li> </ul> @exception SWTError <ul> <li>ERROR_CANNOT_INIT_DRAG - unable to initiate drag source; this will occur if more than one drag source is created for a control or if the operating system will not allow the creation of the drag source</li> </ul>
<p>NOTE: ERROR_CANNOT_INIT_DRAG should be an SWTException, since it is a recoverable error, but can not be changed due to backward compatibility.</p>
@see Widget#dispose @see DragSource#checkSubclass @see DND#DROP_NONE @see DND#DROP_COPY @see DND#DROP_MOVE @see DND#DROP_LINK