Bug 175664 [Mac] Unexpected internal exception occurs when invoke expression builder
Description: There are two problems: 1. "fx" button (Click this button to invoke Expression Builder) could not be displayed correctly, nothing displayed in the button. 2. Click on the button, an unexpected internal exception occurs. Version:2.2.0.v20070205 Steps to reproduce: 1.Insert a Data item to the layout. Click "fx" button to invoke the expression builder, although on Mac "fx" button could not display correctly. Error log: Argument cannot be null Plug-in Provider: Eclipse.org Plug-in Name: BIRT Designer UI Plug-in ID: org.eclipse.birt.report.designer.ui Error Code: Error.GUIException.invokedByUnexpectedException Error Message:Argument cannot be null
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/UIUtil.java
{
		final List list = new ArrayList( ( (StructuredSelection) viewer.getSelection( ) ).toList( ) );
		boolean hasColumnOrRow = false;
		for ( int i = 0; i < list.size( ); i++ )
		{
			if ( list.get( i ) instanceof TableEditPart.DummyRowEditPart
					|| list.get( i ) instanceof TableEditPart.DummyColumnEditPart )
			{
				hasColumnOrRow = true;
				break;
			}
		}
		if ( hasColumnOrRow )
		{
			int selectionType = 0;
			TableEditPart part = null;
			int[] selectContents = new int[0];
			for ( int i = 0; i < list.size( ); i++ )
			{
				Object obj = list.get( i );
				int number = -1;
				if ( obj instanceof TableEditPart.DummyRowEditPart )
				{
					selectionType = 0;
					number = ( (TableEditPart.DummyRowEditPart) obj ).getRowNumber( );
				}
				else if ( obj instanceof TableEditPart.DummyColumnEditPart )
				{
					selectionType = 1;
					number = ( (TableEditPart.DummyColumnEditPart) obj ).getColumnNumber( );