Auto merge of #12783 - Wafflespeanut:word_spacing, r=Manishearth

Prefer length and percentage for word spacing

<!-- Please describe your changes on the following line: -->
The goal is to make use of `LengthOrPercentage` for word spacing in `ShapingOptions`, but since it makes use of `f32` which doesn't implement `Hash`, we're going for `NotNan<f32>` from [ordered-float](https://github.com/reem/rust-ordered-float/), which supports hashing. Instead of implementing `Hash` for `LengthOrPercentage` and thereby the inner types like `CSSFloat`, `CalcLengthOrPercentage`, etc., we convert it to `(Au, NotNan<f32>)`.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

<!-- Either: -->
- [ ] There are tests for these changes

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/12783)
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components/gfx/Cargo.toml

@@ -28,6 +28,7 @@ log = "0.3.5"
 mime = "0.2"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
+ordered-float = "0.2.2"
 plugins = {path = "../plugins"}
 profile_traits = {path = "../profile_traits"}
 rand = "0.3"

components/gfx/font.rs

@@ -5,6 +5,7 @@
 use app_units::Au;
 use euclid::{Point2D, Rect, Size2D};
 use font_template::FontTemplateDescriptor;
+use ordered_float::NotNaN;
 use platform::font::{FontHandle, FontTable};
 use platform::font_context::FontContextHandle;
 use platform::font_template::FontTemplateData;
@@ -157,7 +158,7 @@ pub struct ShapingOptions {
     /// NB: You will probably want to set the `IGNORE_LIGATURES_SHAPING_FLAG` if this is non-null.
     pub letter_spacing: Option<Au>,
     /// Spacing to add between each word. Corresponds to the CSS 2.1 `word-spacing` property.
-    pub word_spacing: Au,
+    pub word_spacing: (Au, NotNaN<f32>),
     /// The Unicode script property of the characters in this run.
     pub script: Script,
     /// Various flags.
@@ -225,7 +226,9 @@ impl Font {
 
             let mut advance = Au::from_f64_px(self.glyph_h_advance(glyph_id));
             if character == ' ' {
-                advance += options.word_spacing;
+                // https://drafts.csswg.org/css-text-3/#word-spacing-property
+                let (length, percent) = options.word_spacing;
+                advance = (advance + length) + Au((advance.0 as f32 * percent.into_inner()) as i32);
             }
             if let Some(letter_spacing) = options.letter_spacing {
                 advance += letter_spacing;

components/gfx/lib.rs

@@ -60,6 +60,7 @@ extern crate log;
 extern crate mime;
 extern crate msg;
 extern crate net_traits;
+extern crate ordered_float;
 #[macro_use]
 extern crate profile_traits;
 extern crate rand;

components/gfx/text/shaping/harfbuzz.rs

@@ -403,7 +403,9 @@ impl Shaper {
         // applied. The effect of the property on other word-separator characters is undefined."
         // We elect to only space the two required code points.
         if character == ' ' || character == '\u{a0}' {
-            advance = advance + options.word_spacing
+            // https://drafts.csswg.org/css-text-3/#word-spacing-property
+            let (length, percent) = options.word_spacing;
+            advance = (advance + length) + Au((advance.0 as f32 * percent.into_inner()) as i32);
         }
 
         advance

components/layout/Cargo.toml

@@ -26,6 +26,7 @@ libc = "0.2"
 log = "0.3.5"
 msg = {path = "../msg"}
 net_traits = {path = "../net_traits"}
+ordered-float = "0.2.2"
 plugins = {path = "../plugins"}
 profile_traits = {path = "../profile_traits"}
 range = {path = "../range"}

components/layout/lib.rs

@@ -35,6 +35,7 @@ extern crate libc;
 extern crate log;
 extern crate msg;
 extern crate net_traits;
+extern crate ordered_float;
 #[macro_use]
 #[no_link]
 extern crate plugins as servo_plugins;

components/layout/text.rs

@@ -17,6 +17,7 @@ use gfx::text::text_run::TextRun;
 use gfx::text::util::{self, CompressionMode};
 use inline::{FIRST_FRAGMENT_OF_ELEMENT, InlineFragments, LAST_FRAGMENT_OF_ELEMENT};
 use linked_list::split_off_head;
+use ordered_float::NotNaN;
 use range::Range;
 use std::borrow::ToOwned;
 use std::collections::LinkedList;
@@ -164,7 +165,9 @@ impl TextRunScanner {
                 };
                 text_transform = inherited_text_style.text_transform;
                 letter_spacing = inherited_text_style.letter_spacing.0;
-                word_spacing = inherited_text_style.word_spacing.0.unwrap_or(Au(0));
+                word_spacing = inherited_text_style.word_spacing.0
+                               .map(|lop| lop.to_hash_key())
+                               .unwrap_or((Au(0), NotNaN::new(0.0).unwrap()));
                 text_rendering = inherited_text_style.text_rendering;
             }
 

components/servo/Cargo.lock

@@ -766,6 +766,7 @@ dependencies = [
  "mime 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1124,6 +1125,7 @@ dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "range 0.0.1",
@@ -1606,6 +1608,15 @@ dependencies = [
  "openssl 0.7.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ordered-float"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unreachable 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "osmesa-sys"
 version = "0.0.5"
@@ -2193,6 +2204,7 @@ dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2361,6 +2373,14 @@ dependencies = [
  "harfbuzz-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "unreachable"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "void 0.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unreachable"
 version = "0.1.1"
@@ -2453,6 +2473,11 @@ dependencies = [
  "pkg-config 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "void"
+version = "0.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "void"
 version = "1.0.2"

components/style/Cargo.toml

@@ -34,6 +34,7 @@ lazy_static = "0.2"
 log = "0.3.5"
 matches = "0.1"
 num-traits = "0.1.32"
+ordered-float = "0.2.2"
 rand = "0.3"
 rustc-serialize = "0.3"
 selectors = "0.7"

components/style/lib.rs

@@ -57,6 +57,7 @@ extern crate log;
 #[macro_use]
 extern crate matches;
 extern crate num_traits;
+extern crate ordered_float;
 extern crate rand;
 extern crate rustc_serialize;
 extern crate selectors;

components/style/properties/longhand/inherited_text.mako.rs

@@ -285,7 +285,7 @@
     #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
     pub enum SpecifiedValue {
         Normal,
-        Specified(specified::Length),  // FIXME(SimonSapin) support percentages
+        Specified(specified::LengthOrPercentage),
     }
 
     impl ToCss for SpecifiedValue {
@@ -298,10 +298,10 @@
     }
 
     pub mod computed_value {
-        use app_units::Au;
+        use values::computed::LengthOrPercentage;
         #[derive(Debug, Clone, PartialEq)]
         #[cfg_attr(feature = "servo", derive(HeapSizeOf))]
-        pub struct T(pub Option<Au>);
+        pub struct T(pub Option<LengthOrPercentage>);
     }
 
     impl ToCss for computed_value::T {
@@ -326,7 +326,7 @@
             match *self {
                 SpecifiedValue::Normal => computed_value::T(None),
                 SpecifiedValue::Specified(l) =>
-                    computed_value::T(Some(l.to_computed_value(context)))
+                    computed_value::T(Some(l.to_computed_value(context))),
             }
         }
     }
@@ -335,7 +335,8 @@
         if input.try(|input| input.expect_ident_matching("normal")).is_ok() {
             Ok(SpecifiedValue::Normal)
         } else {
-            specified::Length::parse_non_negative(input).map(SpecifiedValue::Specified)
+            specified::LengthOrPercentage::parse_non_negative(input)
+                                          .map(SpecifiedValue::Specified)
         }
     }
 </%helpers:longhand>

components/style/values/computed/mod.rs

@@ -4,6 +4,7 @@
 
 use app_units::Au;
 use euclid::size::Size2D;
+use ordered_float::NotNaN;
 use properties::ComputedValues;
 use std::fmt;
 use super::LocalToCss;
@@ -241,6 +242,15 @@ impl LengthOrPercentage {
             Length(_) | Percentage(_) | Calc(_) => false
         }
     }
+
+    pub fn to_hash_key(&self) -> (Au, NotNaN<f32>) {
+        use self::LengthOrPercentage::*;
+        match *self {
+            Length(l) => (l, NotNaN::new(0.0).unwrap()),
+            Percentage(p) => (Au(0), NotNaN::new(p).unwrap()),
+            Calc(c) => (c.length(), NotNaN::new(c.percentage()).unwrap()),
+        }
+    }
 }
 
 impl fmt::Debug for LengthOrPercentage {

ports/cef/Cargo.lock

@@ -684,6 +684,7 @@ dependencies = [
  "mime 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1033,6 +1034,7 @@ dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "msg 0.0.1",
  "net_traits 0.0.1",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "range 0.0.1",
@@ -1480,6 +1482,15 @@ dependencies = [
  "openssl 0.7.14 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ordered-float"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unreachable 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "osmesa-sys"
 version = "0.0.5"
@@ -2078,6 +2089,7 @@ dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2230,6 +2242,14 @@ dependencies = [
  "harfbuzz-sys 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "unreachable"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "void 0.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unreachable"
 version = "0.1.1"
@@ -2315,6 +2335,11 @@ dependencies = [
  "pkg-config 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "void"
+version = "0.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "void"
 version = "1.0.2"

ports/geckolib/Cargo.lock

@@ -214,6 +214,33 @@ dependencies = [
  "libc 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "num"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-iter 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num-iter"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.1.32"
@@ -227,6 +254,15 @@ dependencies = [
  "libc 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "ordered-float"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unreachable 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "quickersort"
 version = "2.0.1"
@@ -325,6 +361,7 @@ dependencies = [
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "ordered-float 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "selectors 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -386,6 +423,14 @@ name = "unicode-normalization"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "unreachable"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "void 0.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "unreachable"
 version = "0.1.1"
@@ -425,6 +470,11 @@ dependencies = [
  "xdg 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "void"
+version = "0.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "void"
 version = "1.0.2"

python/tidy/servo_tidy/tidy.py

@@ -261,7 +261,7 @@ def check_lock(file_name, contents):
         raise StopIteration
 
     # package names to be neglected (as named by cargo)
-    exceptions = ["lazy_static"]
+    exceptions = ["lazy_static", "unreachable", "void"]
 
     import toml
     content = toml.loads(contents)