Nested svgs

[rcoreilly]

Structure will need to be modified to deal better with nested SVGs. Currently we have an SVGNode as the Root of the Ki tree, and other SVGNodes can be added as nodes, but they behave just like Groups.

• first todo: modify Render and xform to properly position according to Viewbox.

Apparently, nested svg's render to the same underlying image -- i.e., we still want the outer-most SVG element to be the only one with an actual image.

The only tricky bit is nested <defs> -- apparently it is legal: https://stackoverflow.com/questions/44226035/are-multiple-defs-allowed-in-svg-documents

but the name id's have to be unique across everything (whole html doc, not just svg!)

all of the current url handling is done using top-level SVG. For efficiency, it could cache a list of sub-defs groups and iterate over those.

for grid drawing app, it is almost certainly more robust to import svg integrated into main svg vs. making a sub. check what inkscape does.

• inkscape does support apparently, but has issues: https://gitlab.com/inkscape/inkscape/-/issues/2794

• this claims most editors do not support: https://discourse.elm-lang.org/t/alternative-to-nested-svgs-to-render-properly-outside-the-browser/7097

• flutter_svg does not support: SVG with nested <svg> elements isn't rendering dnfield/flutter_svg#132 -- indicates not super common

links

• https://developer.mozilla.org/en-US/docs/Web/SVG/Element/svg
• https://stackoverflow.com/questions/38959079/svg-nested-svg-vs-group
• https://www.w3.org/TR/SVG/images/coords/PreserveAspectRatio.svg
• https://www.sarasoueidan.com/blog/nesting-svgs/
• https://stackoverflow.com/questions/16890292/why-nest-an-svg-element-inside-another-svg-element