Emphasize arc direction by drawing additional "arrowhead" next to type. [option]

[spyysalo]

Comment from user: in dense dependency annotation, it's hard to see the directions of the dependency arcs. To make this more obvious, we could have an option for toggling an additional "arrowhead" drawn next to the type.

ASCII arc mockup: the "body" of an arc now looks like so

---- subj ----

and would be clearer in cases like so

---- subj>----

[spyysalo]

User mockup with Unicode in labels:

[amadanmath]

Done. A possible further issue is that the smallest arcs don't bear it well; maybe should increase minimal inter-span spacing if arrow at label is on.

[spyysalo]

@amadanmath : thanks, really quick work & looks great! Just one thing: if this is a UI option, we can't control whether this is on or off by default on a collection-by-collection basis, which would be a nice thing to have for online data visualizations (we expect to use this for some datasets, but not all).

I'd suggest to have this under visual.conf control instead, like arrowHead. Would labelArrow do, with a similar syntax as for arrowHead? Serverside at least would be trivial.

[amadanmath]

I suppose it would. Stick it in, then I'll see about cutting away the config option again.

[spyysalo]

Done, you can now have e.g.

ARC_DEFAULT     color:black, dashArray:-, arrowHead:triangle-5, labelArrow:triangle-5

[amadanmath]

Oh, so not just true/false, but also possibly different shape? Hmm, that will require rewriting - I'll see when I have some time, but might not be soon. :(

[spyysalo]

True/false is enough for the use case considered currently, so just use the presence of the attribute to set your true/false flag and open a new issue for cleanup.