DisplayListSection, StackingLevel, and BackgroundAndBorderLevel all
represent pretty much the same thing, a particular section of the
display list. Instead of maintaining three enums which do the same
thing, just use DisplayListSection everywhere. It's a superset of the
other two and this change will make it easier to flatten the DisplayList
in the future for WebRender.
Correctly handle local sources for CSS3 fonts
Currently, servo panics for me when loading something like this:
```
@font-face {
font-family: "test family";
src: local(test font face);
}
```
That's due to a bug in `FontCacheTask`. `FontCacheTask` tries to get the value for the key
"test font face" from `self.web_families`, but previously initialized a value for the key "test family".
These two commits add an awkward test and fix the bug by not shadowing the variable `family_name`. Since the argument to `local()` should explicitly not be the name of a font family, the previous variable name was wrong and misleading anyways.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/9149)
<!-- Reviewable:end -->
The argument to `local()` is not a font family, but the name of a
»single font face within a larger family« according to
http://www.w3.org/TR/css3-fonts/#src-desc.
The previous implementation of `FontCache::run` would panic if the argument to
`local()` would not be the name of a font family present in `self.web_families`.
That happened since `FontCacheTask` tried to use the argument to `local()` as a
key for `self.web_families`, although it previously correctly initialized a
value for the `family` field of the `AddWebFont` command.
Fix a bunch of clippy lints
This fixes about 130 clippy lints. Let me know if i should split up the commit.
I wasn't sure about some of the changes, especially map_or instead of map(...).unwrap_or(...) and if let instead of single arm match were not always a strict improvement in my opinion, but i'll leave that decision to the reviewer :)
There are about 150 lints left which i thought were clippy bugs or i didn't know how to fix.
cc @Manishearth
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/9123)
<!-- Reviewable:end -->
Enabled use of FontFamily enum type
https://github.com/servo/servo/issues/8371
In addition to replacing loose strings with the FontFamily enum in `font_cache_task.rs`, I also centralized the add_generic_font calls into one single function. If centralizing into one function is not desired or if anything else needs to be changed, please let me know.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8420)
<!-- Reviewable:end -->
This patch does a number of things, unfortunately all at once:
* Hoists a large subset of the layout wrapper functionality into the style system.
* Merges TElementAttributes into the newly-created TElement.
* Reorganizes LayoutData by style vs layout, and removes LayoutDataShared.
* Simplifies the API for borrowing style/layout data.
There's still more to do to make the style system usable standalone, but
this is a good start.
