[annotator-dev] Request for discussion: non-text annotations?

Thu Nov 22 11:59:28 UTC 2012

Hi Rainer,

On 22.11.12 12:08, Simon Rainer wrote:
> +1 on the 'units' extension. 'fraction' and 'pixel' for the time
> being? (I'm also thinking about our use case with OpenLayers, which
> works with map coordinates. So this might be a nice way to handle
> those cleanly.)

Sounds good to me. So Openlayers uses lat/lon coordinates?

> Regarding shape alternatives: hm. I still need to think through the
> entire case first I guess. But rather than having alternatives, I
> think, I'd simply add extra properties to the shape itself. Say
> something like:
> 
> shape : { type : 'Polygon', geometry : { units : 'pixel',  coords:
> [{x: 10, y: 10}, {x: 100, y: 10}, {x: 100, y: 20}, {x: 10, y: 20}]
> }, anchorPoint: 0 }

Looks Ok to me. A small thing: I would like to use a lower case type
"polygon" similar to the SVG spec.

I like your explicit coordinate pairs for polygon.

> and then 'unaware' clients would simply skip the anchorPoint
> property, dealing only with the raw shape. Or maybe the fact that
> it's (in this case) a "placename annotation" shouldn't be encoded in
> the shape at all, but rather at the level above (as part of the
> annotation). Anyways: still needs more thinking, I guess, and is part
> of another discussion, probably :-)

I think the "anchorPoint" is OK since it enhances the shape. Something
doesn't have to be a place name to have an anchor point. But I agree
that parts specifying the semantics of the annotation should be on the
annotation rather than on the shape.

> Regarding multiple targets: Annotorious doesn't have the necessary UI
> features for handling that use case at the moment. But I agree it's
> something we need to handle in the format sooner rather than later. I
> think I'm going to change my 'shape' field to 'shapes' and then
> simply use a JSON array of shapes, rather than a single object.

Cool, that's what I wanted to do too. And our UI doesn't deal with
multiple targets either...

Cheers
	Robert