Bug 168808 Display text is lost after launching import values dialog
Steps to reproduce: 1.new a parameter; 2.select list box control type; 3.press "Import Values" button to import some values; 4.assign display texts for the imported values; 5.press "Import Values" button to launch import values dialog again; 6.press ok button on dialog; Expected result: The previous assigned display texts are remained. Actual result: The previous display texts are lost.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
				text = choice.getValue( );
			}
			else if ( columnIndex == valueIndex + 1 )
			{
				text = choice.getLabel( );
				if ( text == null )
				{
					text = format( choice.getValue( ) );
				}
			}
			if ( text == null )
			{
				text = ""; 
			}
			return text;
		}
		public void addListener( ILabelProviderListener listener )
		{
		}
		public void dispose( )
		{
		}
		public boolean isLabelProperty( Object element, String property )
		{
			return false;
		}
		public void removeListener( ILabelProviderListener listener )
		{
		}