Bug 312859 The list of operator for Chart filter does not provide 30 visible items
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/dialogs/ChartCubeFilterConditionBuilder.java
expressionValue2.setVisible( true );
				andLable.setVisible( true );
				andLable.setEnabled( true );
			}
			updateButtons( );
		}
		public void widgetDefaultSelected( SelectionEvent e )
		{
		}
	};
	protected Listener comboModifyListener = new Listener( ) {
		public void handleEvent( Event e )
		{
			Assert.isLegal( e.widget instanceof Combo );
			Combo combo = (Combo) e.widget;
			String newValue = combo.getText( );
			String value = DEUtil.getExpression( getResultSetColumn( newValue ) );
			if ( value != null )
				newValue = value;
			combo.setText( newValue );
			updateButtons( );
		}
	};
	protected Composite createDummy( Composite parent, int colSpan )
	{
		Composite dummy = new Composite( parent, SWT.NONE );
		GridData gdata = new GridData( );
		gdata.widthHint = 22;
		gdata.horizontalSpan = colSpan;
		gdata.heightHint = 10;