Get the position of a subelement of the SVG file. Do not call from within the size_func callback, because an infinite loop will occur.
A place to store the SVG fragment's position.
An element's id within the SVG, starting with "##", for example, "##layer1"; or %NULL to use the whole SVG.
2.22
See Implementation
Get the position of a subelement of the SVG file. Do not call from within the size_func callback, because an infinite loop will occur.