[Lazarus] Dockable IDE

[Hans-Peter Diettrich]

On Tue, Jun 1, 2010 at 22:53, Rick <rick at sloservers.com> wrote:
> I was able to use axis transformations/linear offset to stack several series
> vertically as we discussed.
> I discovered an issue with area series and linear transformation, however.
> I expected area series to shade the area between the horizontal axis and
> graph.  Instead, it appears to
> fill the area between the bottom of the chart and the graph.  It doesn't
> respect the linear transformation.
> Try making an area series and then shifting it up 10.  It'll draw all the
> way down to -10 on its axis.

Well, that's kind-of as-designed, I think. At least it was that way
before I started maintaining TAChart, and I suspect it was done intentionally.
But you are right that drawing to zero level deserves at least an option.
There are some tricky corner cases -- e.g. drawing series with both positive
and negative values, but it is doable.

> Also, I think somebody asked about this before but it would be nice if there
> was an area series that would
> draw an outline but not the vertical lines at each data point.  That looks
> like it'll be a pain in the butt to
> implement, but if you ever find yourself needing to kill a little time ;)
>  It would make for prettier stairstep
> graphs that don't have the area shaded, IMHO.

Yes, that is a long standing feature request.

On the whole, the area series needs a serious amount of work.
It currently does not support two other important features --
3d look and rotation.
So if I have time, I will just rewrite area drawing, taking into
account all these changes.

Meanwhile, the patches are very welcome ;-).

BTW, did you test events for TDataPointDragTool?
I have implemented a different set of events than
you suggested -- are they enough for your use case?

-- 
Alexander S. Klenin