Bug 192349 The column selected disappears when you reclick the downward arrow [0001]
Description: The column selected disappears when you reclick the downward arrow. Build number: 2.2.0.v20070613-1211 Steps to reproduce: 1, New a table binding to a data set, add an Aggregation, select one column from the "Data Field" dropdown list, click the downward arrow again. Expected result: The column selected is still there. Actual result: The column selected disappears. Error log: N/A
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/dialogs/BindingDialogHelper.java
cmbGroup.setEnabled( false );
			btnTable.setSelection( true );
		}
	}
	private String[] getGroups( )
	{
		if ( getBindingHolder( ) instanceof ListingHandle )
		{
			ListingHandle listingHandle = (ListingHandle) getBindingHolder( );
			String[] groups = new String[listingHandle.getGroups( ).getCount( )];
			for ( int i = 0; i < groups.length; i++ )
			{
				groups[i] = ( (GroupHandle) listingHandle.getGroups( ).get( i ) ).getName( );
			}
			return groups;
		}
		return new String[0];
	}
	private void setDataFieldExpression( String expression )
	{
		this.expression = expression;
		if ( expression != null )
		{
			if ( cmbDataField != null && !cmbDataField.isDisposed( ) )
			{
				cmbDataField.setText( expression );
			}
			if ( txtExpression != null && !txtExpression.isDisposed( ) )
			{
				txtExpression.setText( expression );