Change font size of Canvas without knowing font family

Question

Is there a way to only change the font size of a canvas context without having to know/write the font family.

 var ctx = document.getElementById(\"canvas\").         


        

Answer 1

Update: (from comments) There is no way around specifying font. The Canvas' font is modeled after the short-hand version of font in CSS.

However, there is always a font set on the canvas (or a font type) so what you can do is to first extract the current font by using it like this:

var cFont = ctx.font;

Then replace size arguments and set it back (note that there might be a style parameter there as well).

A simple split for the sake of example:

var fontArgs = ctx.font.split(' ');
var newSize = '12px';
ctx.font = newSize + ' ' + fontArgs[fontArgs.length - 1]; /// using the last part

You will need support for style if needed (IIRC it comes first if used). Notice that font-size is fourth parameter, so this will not work if you will have/not have font-variant(bold,italic,oblique), font-variant(normal, small-caps) and font-weight(bold etc).