Changing font functionality #104

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opened 2021-01-27 15:07:54 +01:00 by jkissl · 1 comment

jkissl commented

2021-01-27 15:07:54 +01:00

(Migrated from github.com)

Looking through the documentation and the code in I found the font_path argument that either defaults to a supplied font or can be passed a path to a different font. I've tried several different variations of passing a font to it and even modified writer.py directly to use a different font. Neither of those had any effect on the font that appears below the barcode. Can you provide an example of changing the font?

kmBlaine commented

2021-01-29 23:33:20 +01:00

(Migrated from github.com)

I encountered this as well behavior as well. It only applies if you are writing SVGs though. If you write raster files (PNGs, JPGs, etc), the font_path option does exactly what you expect.

Looking at the SVGWriter class in class in barcode/writer.py it's pretty obvious why:

class SVGWriter(BaseWriter):
    # ...
    def _create_text(self, xpos, ypos):
        # ...
            attributes = {
                "x": SIZE.format(xpos),
                "y": SIZE.format(ypos),

                #
                # the 'font-family' attribute used by XHTML docs to render font is not set
                #
                "style": "fill:{};font-size:{}pt;text-anchor:middle;".format(
                    self.foreground,
                    self.font_size,
                ),
            }

As hacky workaround since in my use case I needed bunch of arbitrarily scalable barcodes with non-ambiguous font (a lot of fonts 0 and capitol O look identical), I just had it write the font_path option as the XHTML font-family option:

class SVGWriter(BaseWriter):
    # ...
    def _create_text(self, xpos, ypos):
        # ...
            attributes = {
                "x": SIZE.format(xpos),
                "y": SIZE.format(ypos),
                "style": "fill:{};font-size:{}pt;text-anchor:middle;font-family:'{}'".format(
                    self.foreground,
                    self.font_size,
                    self.font_path
                ),
            }

CAUTION: I am not clear on how that would interact with the SVG sizing system in the package so I didn't commit and PR this change. I wanted to take a closer look and do this more smartly if need be. Regardless, I am more than happy to work with the team on giving SVG barcodes font customizability.

I encountered this as well behavior as well. It only applies if you are writing SVGs though. If you write raster files (PNGs, JPGs, etc), the `font_path` option does exactly what you expect. Looking at the `SVGWriter` class in class in [barcode/writer.py](https://github.com/WhyNotHugo/python-barcode/blob/master/barcode/writer.py) it's pretty obvious why: ``` class SVGWriter(BaseWriter): # ... def _create_text(self, xpos, ypos): # ... attributes = { "x": SIZE.format(xpos), "y": SIZE.format(ypos), # # the 'font-family' attribute used by XHTML docs to render font is not set # "style": "fill:{};font-size:{}pt;text-anchor:middle;".format( self.foreground, self.font_size, ), } ``` As hacky workaround since in my use case I needed bunch of arbitrarily scalable barcodes with non-ambiguous font (a lot of fonts `0` and capitol `O` look identical), I just had it write the `font_path` option as the XHTML `font-family` option: ``` class SVGWriter(BaseWriter): # ... def _create_text(self, xpos, ypos): # ... attributes = { "x": SIZE.format(xpos), "y": SIZE.format(ypos), "style": "fill:{};font-size:{}pt;text-anchor:middle;font-family:'{}'".format( self.foreground, self.font_size, self.font_path ), } ``` CAUTION: I am not clear on how that would interact with the SVG sizing system in the package so I didn't commit and PR this change. I wanted to take a closer look and do this more smartly if need be. Regardless, I am more than happy to work with the team on giving SVG barcodes font customizability.