[Mapcss] How to Style Arrows

[Paul Hartmann]

On 05/19/2013 08:24 PM, william skora wrote:
> Hi,
>
> I was wondering if there is any current capability to control the styling
> of arrows that appears on ways in JOSM. Specifically, I'm interested in
> capability to control the size of the arrows, their color, and how often
> they appear.
>
> If so, could you share some syntax as well of how to do this ?
>
> I've searched through the mail archives and didn't find anything.

You can draw the arrows with repeated images along the line 
(repeat-image, since v. 5801). Instead of including a png file, you can 
also include svg or embed it inline:

way[oneway=yes]::arrows {
   repeat-image: "data:image/svg+xml,<svg><path d='M 0 0 L 10 5 L 0 10 
z' fill='white' stroke='blue'/></svg>";
   repeat-image-spacing: 30;
   major-z-index: 3.1;
}

One problem is to get rid of the default arrows, currently there is no 
direct way to turn them off in your style sheet. As a workaround, you 
could hide the line style on the default layer (opacity 0.0) and draw 
another line on a different layer. I admit this is not very practical, 
but at least it's possible.

way[oneway=yes] {
   opacity: 0.0;
}
way[oneway=yes]::snd {
   width: 3;
   color: blue;
}

The more specific the questions get for JOSM, the more you might 
consider to ask on the JOSM mailing list, or open a ticket on 
josm.openstreetmap.de directly.

Paul