Bokeh: Adding label for Span

[abdelwahed]

I would like to see the option of adding label to vertical/horizontal "Span"s (the solid and dashed green and red lines in the attached figure)
perhaps
redspan.label = "breathing rate"

[bryevdv]

Is there a reason existing Label or LabelSet will not work? In general we are in a mode of trying to pare down and simplify things, so if this would duplicate functionality that can be accomplished another way then I'd probably -1 on it.

[mattpap]

I think the problem is that currently we can't attach an annotation to another annotation, only to canvas, frame and panels. I would like to implement this at some point, as part of layout work.

[abdelwahed]

@bryevdv A label (with render mode "css") would looks like the figure attached below:

• can the label be aligned vertically parallel to the corresponding line?
• for a simple label, having it as a span's property would take less coding (rather than creating Label object)

[jasonsross]

vertical and horizontal lines with labels showing up IN the appropriate axis are very common practice in engineering situations. They are know as chart limits or generally "reference" lines. It looks like span already accomplishes the line itself with relative ease, so it would be extremely convenient to specify a label for a span which will by default appear within the axis, not within the plotting area. Since we are already specifying the location for the span, it seems redundant to then specify the location again for the label of the span. Hope you can consider supporting this.