Inputs to TPAC_2013 technical discussions - Smailus

My comments below are intended to inform the SVG WG about the needs we perceive with respect to technical diagrams rendered in SVG and how we see them being used.

Zoom & Pan
The user needs the ability to rubber band (ideally) zoom in, step zoom out, and pan around a diagram.  The ability to reset the zoom level and center the diagram so the full diagram viewport is shown is an additional use case.
Technical diagrams have a variety of details that only become clear when zoomed in, particularly since SVG diagrams would be viewed in a single pane of a larger viewers display.

>From a user experience perspective, having the existing SVG 1.1 pan/zoom capabilities implemented in viewers may be sufficient.  Adobe's SVG plugin viewer control provided some such functionality.   We are currently implementing our own pan/zoom functionality with embedded code in the diagram, to provide a consistent and browser agnostic pan/zoom system.  That isn't a good long term solution.

A programmatic use case: embedded SVG code would like to be able to specify a coordinate extents rectangle that causes the document viewport to pan and zoom such that the viewer displays the coordinate space of the specified rectangle fully, centered at the center of the specified rectangle.

Load Events / OnLoad
We have found that a viewers' onLoad calls may be happening before the entire diagram and DOM elements are truly available to the script code.  A function call that is guaranteed to not execute until all DOM elements and visual elements have been instantiated is of importance for technical diagrams that interact with backend data systems that would allow embedded code to  insert supplemental 'run-time' information into an SVG diagram.
Thomas
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Thomas Smailus, Ph.D., P.E.
Senior Advanced Information Technologist
Boeing Research & Technology
SVG Forum CoP Lead | Intelligent Graphics SVG lead

EO&T LEAP - 2011 / BR&T HIPO - Cadre 1
Tel: 425/373-2850      Mobile: 347/SMAILUS (non-Boeing)
VTC: thomas.o.smailus@vtc.boeing.com<mailto:thomas.o.smailus@vtc.boeing.com>