SVG - resize tspan to fill all available space
===

I have `tspan` element with some text in it. I specified some `font-size` for it as well. In addition I have parent's box size, i.e. width and height. So now I'd like my text to fit the box with the specified width and height.

One of the options I have is manually calculate string `width` and `height` (but it became more complicated in case of different fonts and browsers).

So is there any other way in SVG to resize `tspan` to necessary sizes? Please note that I want text font size to be changed properly, i.e. so text will be displayed in **max** font size and any single char from it will be visible.
