Displaying cumulative exposure time and area covered for a selection

[Remco Slijkhuis]

The following would be nice to see:

You select some observations and for that selection (when you get that 'selection layer') you see the sum of the exposure times and the area covered.

- It seems to be expected for exposure time per filter (of course all zero at the moment, but we know that). The area would be a new thing.
- And, which I think is not done right now, it should be split by type (so, area/exposure time for OBs, for raw files, for data products if all of these were part of the selection).

[Fabien Chéreau (xalioth)]

First, you can achieve what you need just by creating a layer for each data type. If it's not enough, I am not sure I understand everything:
 - do you want to split area information by filter like what is done for exp time?
 - you want all of this info split again per metadata type?

If it's what you want, we need to split by [metadata type/filter]. This creates quite a lot of new combination, and this is has to be treated pretty much statically in SVMT, so not so clean to code :(

[Remco Slijkhuis (rslijkhuis)]

About creating a layer for each data type:
  Ah yes, this would probably achieve a similar effect.
  Just, for this to work conveniently, it would be good when one of Alberto's suggestions was implemented, namely, when creating a new layer, to take over the constraints from the previous layer.

In fact, I just realized that the purpose of all this is actually for comparing, so maybe it's more a job for the compare window (what is the proper name for this btw?).

So then there is not much need for splitting by metadata type.

But splitting the area covered by filter would actually be a necessary thing when comparing/producing statistics.
For displaying the area in the 'selection layer', maybe you can get away with not splitting by filter, but I think it would be better to do it there as well (or start with the total area and at some later point add a splitting by filter).