<html><head></head><body><div class="ydp252f382eyahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false"><div>Hi,<br><br>I use cairo to make maps from Vitalnet C application that I write and maintain. Historically, I made PNG and PDF maps (which are great). I recently modified the Vitalnet source code to also produce SVG maps. It works fine, the SVG maps look great.<br><br>I would like to allow panning / zooming the SVG maps. I know that to do that requires javascript coding, and an id within the SVG code. I'm comfortable with that.<br><br>https://www.petercollingridge.co.uk/tutorials/svg/interactive/pan-and-zoom/ is an article I found.<br><br>https://github.com/ariutta/svg-pan-zoom is a library I found.<br><br>///////////////// My question<br><br>When I make the cairo SVG map, <g id="surface6"> is always generated so far. Can I count on surface6 id not changing? Is it hard-coded, or might change (eg, surface7)? What is significance (if any) to surface6 id, or just hard-coded arbitrary id?<br><br>Thanks,<br>Daniel<br><br>PS - I am not asking for help with javascript coding. Mostly want to clarify significance of surface6 id, and if might change.<br></div><br></div></div></body></html>