Hi folks,

I'd like to be able to have text shrink to fit a multi-line text box. The box will have a default font (say 20px Sans) and if the text fits in the box it will not adjust the font. However, if the text would overflow, it will reduce the font-size until it no longer overflows.

Just to be clear, I know Inkscape (and SVG in general) doesn't do this by default. However, since I am generating the SVG programatically and then using Inkscape as a converter (to PDF), I believe this is possible if I know the algorithm that Inkscape uses for text flow and how it calculates font-metrics, etc.

So, I suppose my first question is: has anyone done this? I've seen approaches online that use the browser's DOM to do it in Javascript, and I've seen how to do it with ImageMagick. I know that it can be inefficient, but that's not a huge deal for me. Has anyone done something like this Inkscape?

Here's a simple FlowRoot that hold a full alphabet across and is three lines high. Adding even a space to the first line would cause it to wrap to four lines and therefore need to shrink fonts. To make this work, I THINK I would need to do the following:

• Grab the height and widthof the box (applying any scaling in the transform on the FlowRoot, there is none in this example)
• Calculate the number of rows that currently fit with the default font (74.483658 / (20 * 1.25) ~= 3 (oddly, it's just BELOW 3 which means it should wrap... but doesn't - WHY?)
• Count the number of <flowPara> elements in the <flowRoot> since that is the minimum number of rows I'll need.
• For each <flowPara> follow Inkscape's text-wrapping algorithm using the same fontMetrics that it uses [HELP] figuring out how many MORE rows I'll need.
• If that total number of rows is > the number of rows that fit, adjust the font size and re-calculate the split <flowPara>s until it does fit (I will use a Binary Search here starting with the default font and shrinking it.

So, the key things I need to do this are:

• Documentation (or a pointer to code) for Inkscape's Text Wrapping code
• Descriptions of how to calculate the FontMetrics. Specifically, can I use ImageMagick's FontMetrics (which I have in PHP) and get equivalent information? If not, I'd like ideas (fontserver?)
• Explanation of why the text didn't wrap in the example below even though it says it will hold < 3 rows (do I not count line spacing at the top and bottom?)

I'd really appreciate any help on this matter - this would make a huge difference in my project.

Thank you!
Bill

Sample Code