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
.asyncExec( new Runnable( ) {
							public void run( )
							{
								populateAvailableDbObjects( );
							}
						} );
			}
		} );
		setupIdentifierQuoteStringCheckBox( selectTableGroup );
		setRootElement( );
		
		addDragSupportToTree( );
	}
	/*
	 * 
	 * @see org.eclipse.datatools.connectivity.oda.design.internal.ui.DataSetWizardPageCore#collectDataSetDesign(org.eclipse.datatools.connectivity.oda.design.DataSetDesign)
	 */
	protected DataSetDesign collectDataSetDesign( DataSetDesign design )
	{
		if ( this.getControl( ) == null || this.getControl( ).isDisposed( ) )
			return design;
		if ( design != null && doc != null )
			design.setQueryText( doc.get( ) );
		if ( this.shouldUpdateDataSetDesign ||
				!formerQueryTxt.equals( design.getQueryText( ) ) )
		{
			SQLUtility.saveDataSetDesign( design );
			formerQueryTxt = design.getQueryText( );
			this.shouldUpdateDataSetDesign = false;
		}