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
public void handleEvent( final Event event )
			{
				TreeItem item = (TreeItem) event.item;
				BusyIndicator.showWhile( item.getDisplay( ), new Runnable( ) {
					/*
					 * @see java.lang.Runnable#run()
					 */
					public void run( )
					{
						showTable( event );
					}
				} );
			}
			/**
			 * @param event
			 */
			private void showTable( Event event )
			{
				TreeItem item = (TreeItem) event.item;
				if ( item == null )
					return;
				if ( item == rootNode )
					return;
				if ( isSchemaNode( item ) )
				{
					populateTableList( item.getText( ), item );
					return;
				}
				String tableName = Utility.getTreeItemsName( item );
				String catalogName = metaDataProvider.getCatalog( );