Bug 199021 Error message pops up several times when click an invalid dataset
Description: There is a sqlserver datasource and dataset, remove the jtds driver to let the dataset invalid. Double click on the dataset, the error message will pop up serveral times. Build version:2.2.0.v20070807-0630 Steps to reproduce: 1. Create a sqlserver datasource and dataset. 2. Remove the jtds driver, and the dataset will be invalid. 3. Double click on the dataset. Expect result: Error message pops up once to indicate the problem. Actual result: Error message pops up serveral times.
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
type = DbType.PROCEDURE_STRING;
					break;
			}
		}
		return type;
	}
	/**
	 * @param item A tree Item which has to be tested
	 * @return if the TreeItem represents a Schema node
	 */
	protected boolean isSchemaNode( TreeItem item )
	{
		if ( item != null && isSchemaSupported )
		{
			if ( item.getParentItem( ) == rootNode )
			{
				return true;
			}
		}
		return false;
	}
	/**
	 * refresh page
	 * 
	 */
	private void refreshPage( )
	{
		
		DataSourceDesign curDataSourceDesign = this.getDataSetDesign( )
				.getDataSourceDesign( );