Chart proposal

Hi all,

Here's two proposals for charts:

1) Extend Chart Types

We have already agreed to keep the chart types extensible (with a common 
set of well-known chart types), and I propose to add 'surface' and 
'gantt' to the list of chart type. The former was proposed by Paul 
Langille, the latter by the OOo chart implementers.

2) Move categories to axis

Currently, the plot-area has an (optional) child element categories, 
which contains a sequence of labels for the data points. These 
categories are associated with the first/main axis. I suggest to move 
this element to the axis element, making categories per-axis.

This was suggested by the OOo chart implementers, but it should also 
cover Paul's proposal of adding Y-Axis labels. However, instead of 
introducing a second categories element, it simply makes the categories 
a per-axis item, thus enabling use of categories on the Y-axis as well.

3) Legend expansion

The legend is usually expanded depending on its position (auto-position, 
acutally): A legend on the left would be exanded vertically, a legend on 
the top would be expanded horizontically. The problem is, how to expand 
a legend that has been manually placed, where no 'obvious' expansion can 
be determined?

I propose to add a style attribute legend-expansion with values wide, 
high, balanced and custom, where custom requires an additional 
legen-expansion-aspect-ration attribute. This was proposed by Paul 
(Legend Layout, horizontal, vertical), and two values were added by OOo 
chart people.


Sincerely,
Daniel


Sincerely,
Daniel