Bug 162365 [Regression]Can't drag any item from library to another library
Description: Can't drag any item from library to another library Step to reproduce: 1. new a library and insert several items in it 2. new another one 3. drag the items form first library to the second Actual result: Can't drag.
UI/org.eclipse.birt.report.designer.ui.lib/src/org/eclipse/birt/report/designer/internal/lib/views/outline/LibraryOutlinePage.java
ScalarParameterHandle targetParameter = (ScalarParameterHandle) target;
					if ( targetParameter.getContainer( ) instanceof CascadingParameterGroupHandle )
						return RESULT_NO;
				}
				return RESULT_UNKNOW;
			}
		} );
		
		
		IDropConstraint cascadingParameterGroupChildrenConstraint = new IDropConstraint( ) {
			public int validate( Object transfer, Object target )
			{
				if ( transfer instanceof Object[] && ((Object[])transfer).length>0 && ((Object[])transfer)[0] instanceof ScalarParameterHandle)
				{
					ScalarParameterHandle transferParameter = (ScalarParameterHandle) ((Object[])transfer)[0];
					if ( transferParameter.getContainer( ) instanceof CascadingParameterGroupHandle )
						return RESULT_NO;
				}
				return RESULT_UNKNOW;
			}
		};
		
		dropListener.addDropConstraint( ScalarParameterHandle.class, cascadingParameterGroupChildrenConstraint );
		dropListener.addDropConstraint( ParameterGroupHandle.class, cascadingParameterGroupChildrenConstraint );
		dropListener.addDropConstraint( ReportElementModel.class, cascadingParameterGroupChildrenConstraint );
		
		getTreeViewer( ).addDropSupport( ops, transfers, dropListener );
	}
}