Re: [jfreechart-dev] Meter Data Set

[David G. <dav...@ob...>]

On Tuesday 09 April 2002 00:44, Bryan Scott wrote:
> Firstly I think the meter data set in 8.1 is great.  I have a couple of
> questions / thoughts?
>
> A. Could MeterDataSet allow the setting of value to be null.  The idea
> being allowing the display to not display the a value under certain
> conditions.  I added a Boolean method isValueValid() to support this. Eg
> when initialised.

Yes, I think null should be valid.  Any plot that uses the dataset should 
check for a null value.

> B. I had started writing a thermometer class for work.  I have modified
> to utilise the MeterDataSet.  I have to maintain this for work anyway
> are you interested in distributing with JFreeChart.

Very interested.  There are probably quite a few people who would find it 
useful.

> C. I would be interested in talking about the range modifiers for this
> meterdataset regarding the disadvantages/advantages of moving these to
> the display class (eg MeterPlot)?

I think there is a good argument for moving them, since they relate more to 
the presentation than the data itself.  Unless there is a situation where the 
range values vary through time as a result of some data calculation...but 
even in that case, there should be a base MeterDataset interface with just a 
single value and then an extended RangeMeterDataset interface or something 
like that.

Hari - I'd be interested in what you think about these changes.  Would you be 
interested in joining the mailing list?  You can sign on at 
http://sourceforge.net/projects/jfreechart by clicking on "Lists"...

Regards,

DG.