Add support for the !important attribute

[LaurenzV]

This solves the problem I had where I wanted to achieve that I can override all styles in the SVG via stylesheet injection. I tested it with rsvg-convert and it works in the same way, so it would be great to have this merged. :)

[RazrFalcon]

Are you sure !important shouldn't be handled on the simplecss side? I genuinely have no idea how it suppose to work.

[LaurenzV]

Are you sure !important shouldn't be handled on the simplecss side? I genuinely have no idea how it suppose to work.

I think simplecss is low-level enough that it's enough if it provides the information whether an attribute has the important value or not, which is what it currently does. And since style deduplication is handled on the resvg side right now, we have to do it there anyway.

[RazrFalcon]

Looks good to me.

[RazrFalcon]

#252

[LaurenzV]

Will try it.

[LaurenzV]

Seems to work as intended. :)

Before:

After:

[LaurenzV]

I just noticed this, though:

When a declaration is important, the order of precedence is reversed. Declarations marked as important in the user-agent style sheets override all important declarations in the user style sheets. Similarly, all important declarations in the user style sheets override all important declarations in the author's style sheets. Finally, all important declarations take precedence over all animations.

So I think I need to adapt the swapping condition a bit. Will do so a bit later.

[LaurenzV]

The condition should probably be:

• Existing is not important, new is not important -> swap
• Existing is important, new is not important -> don't swap
• Existing is not important, new is important -> swap
• Existing is important, new is important -> don't swap (since the order is reversed, so existing important attributes take precedence over new important attributes)

Will adapt it and extend the test cases.

[LaurenzV]

Should be good now.