Support page marks and bleed

[deathowl]

@page {
  size: 159mm 237mm;
  margin: 3mm 3mm 3mm 3mm;
  marks: crop;
}

WARNING: Ignored marks: crop at 4:5, unknown property.

[liZe]

These features should be quite easy to add, using a SVG file for crop marks and another one for crosses, and applying them to the bleed area box.

[dark-light-cz]

Hello!
I know it's nor in standard nor in any draft but can you extend support of bleedbox to be available in 4 sizes. I expect it's not problem and is only extension and does't bkeak anything functional.
Th reason is that i use weasyprint to generate pages for printer working with SRA4(225x320 mm) paper an i need bleed mark to paper A4(210mmx297mm)
I tried to extend the functionality myself but I was unable to find out how adding validators and computers works.

[liZe]

Hi @dark-light-cz!

You want bleed to behave like padding. Good news: it's not that hard 😄.

In validation.py, you can add a decorator for bleed around the expand_four_sides function, and 4 for bleed-left/right/top/bottom around the bleed function.

In properties.py, you can add bleed-left/right/top/bottom where bleed was added in 71d5409.

In css/__init__.py, you can replace bleed by bleed(_(left|right|top|bottom))? (not tested) in RE_INITIAL_NOT_COMPUTED (bleed's initial value is 'auto' where the calculated value depends on the value of marks).

You can then use a list where bleed is used as a single value (for example in document.py), and report these values when creating the bleed box (in pdf.py).

I think that's all! If you have any questions, you can fork and push what you've done even if it doesn't work, I'll help you to solve the problems you meet!

[dark-light-cz]

Hi @liZe

I re-wrote your implementation of bleed as you suggest in my fork in dark-light-cz@05446f5

If you like it I can create pull request.

Only thing I'm not sure with is changes in weasyprint/pdf.py. Can you please take a look at it and tell me whether it is right. I'm not sure why there is dividing by 2 in create of self.BleedBox and I'm not sure if there should be used left or right on x axis and top or bottom on y axis.

If you want my patch to included we propably need some tests. If so, please suggest me how to do it.

[liZe]

@dark-light-cz Sorry for the delay.

Yes, that's cool, thank you, you can create a pull request! I'll merge it and clean a couple of little things later.