Allow SVGWriter to avoid having the background element #211
Conversation
barcode/writer.py
Outdated
| } | ||
| _set_attributes(background, **attributes) | ||
| self._group.appendChild(background) | ||
| if self.background and self.background != (255, 255, 255, 0): |
There was a problem hiding this comment.
I think it makes sense to exclude the background rectangle if self.background is None.
But I'm not convinced of excluding it if self.background == (255, 255, 255, 0). Why exclude it instead of respecting the provided input?
Using None sounds like the correct approach for somebody who wants it entirely excluded.
There was a problem hiding this comment.
Actually this derives from my first usages: I wanted to have a transparent background, but using a 4-items tuple resulted in a black background. I did not go deeper in this (maybe there is a need to write background = (255, 255, 255) and then pass opacity 0), but definitely setting background to (255, 255, 255, 0) does not produce a transparent background.
I do, however, agree with you that this is more "sketchy", so maybe leaving only "None" as option and finding the correct way to manage transparency is better
Will you do the modification or I shall modify the PR?
There was a problem hiding this comment.
setting background to (255, 255, 255, 0) does not produce a transparent background.
Do you have a quick example of this? Did you check the background= property on the SVG XML itself? Maybe it was the program that rendered it that didn't handle alpha properly?
I do, however, agree with you that this is more "sketchy", so maybe leaving only "None" as option and finding the correct way to manage transparency is better
Will you do the modification or I shall modify the PR?
Please update the PR.
There was a problem hiding this comment.
Do you have a quick example of this? Did you check the
background=property on the SVG XML itself? Maybe it was the program that rendered it that didn't handle alpha properly?
Honestly I don't know where I got the hint to write (255,255,255,0), since I did it a long time ago, but it appears that CSS (and consequently SVG) do not support that notation.
The library correctly wrote fill:(255, 255, 255, 0), but this is wrong for two reasons: first you must write rgb(r, g, b) if you want to use three separate values, and then the fill parameter does not support alpha channel. The correct way to set transparency is using fill-opacity, so the style for the background rect shall be:
fill:rgb(255, 255, 255);fill-opacity:0
Up to now there is no way to set the fill-opacity parameter (maybe this can be added?), but with this PR maybe it will not be so much necessary.
In any case I'll update the PR
|
Thanks! |
With this PR I modified SVGWriter to be able to avoid having the background element on SVG images
If you set the "background" to None or (255,255,255,0) (i.e. transparent) in the writer_options parameter when calling render then the background will not be written in the SVG (instead of having a rectangle).
This is because transparent background does not seem to work in the current library (it is black)