Bug 122869 Drag a parameter from data explorer view into a table in library, a new parameter is created automatically.
Description:Drag a parameter from data explorer view into a table in library, a new parameter is created automatically. Steps to reproduce: 1. Add a cascading parameter and a table in a library file. 2. Drag a parameter from data explorer view into a table cell in layout editor. 3. Find that a new parameter was added in data explorer view automatically.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
{
			slotID = CellHandle.CONTENT_SLOT;
		}
		else if ( parent instanceof RowHandle )
		{
			slotID = RowHandle.CONTENT_SLOT;
		}
		else if ( parent instanceof GridHandle )
		{
			slotID = GridHandle.ROW_SLOT;
		}
		else if ( parent instanceof ThemeHandle )
		{
			slotID = ThemeHandle.STYLES_SLOT;
		}
		return slotID;
	}
	/**
	 * Get the slot id of child
	 * 
	 * @param parent
	 * @param child
	 * @return slot ID
	 */
	public static int findSlotID( Object parent, Object child )
	{
		assert parent instanceof DesignElementHandle;
		assert child instanceof DesignElementHandle;
		int slotID = ( (DesignElementHandle) parent )
				.findContentSlot( (DesignElementHandle) child );