From 79a5e97c13cff6d4b21816f117d3768f938540ec Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Mon, 18 Feb 2019 02:25:54 +0000
Subject: [PATCH] style: Implement scroll-margin parser and serializer.

The reason why we use  RelaxedAtomBool is that
ScrollSnapUtils::GetSnapPointForDestination() is called both from the main and
the compositor threads, and the function will have a branch depending on the
pref value.

Differential Revision: https://phabricator.services.mozilla.com/D20101
---
 components/style/properties/gecko.mako.rs     |  7 ++++-
 .../style/properties/longhands/margin.mako.rs | 15 ++++++++++
 .../properties/shorthands/margin.mako.rs      | 29 +++++++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index cb64a3d1ed0..0260be793f5 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1661,14 +1661,19 @@ fn static_assert() {
     }
 </%self:impl_trait>
 
+<% skip_scroll_margin_longhands = " ".join(["scroll-margin-%s" % x.ident for x in SIDES]) %>
 <% skip_margin_longhands = " ".join(["margin-%s" % x.ident for x in SIDES]) %>
 <%self:impl_trait style_struct_name="Margin"
-                  skip_longhands="${skip_margin_longhands}">
+                  skip_longhands="${skip_margin_longhands}
+                                  ${skip_scroll_margin_longhands}">
 
     % for side in SIDES:
     <% impl_split_style_coord("margin_%s" % side.ident,
                               "mMargin",
                               side.index) %>
+    <% impl_split_style_coord("scroll_margin_%s" % side.ident,
+                              "mScrollMargin",
+                              side.index) %>
     % endfor
 </%self:impl_trait>
 
diff --git a/components/style/properties/longhands/margin.mako.rs b/components/style/properties/longhands/margin.mako.rs
index e5eac633c96..d2a3be11d1d 100644
--- a/components/style/properties/longhands/margin.mako.rs
+++ b/components/style/properties/longhands/margin.mako.rs
@@ -27,3 +27,18 @@
         servo_restyle_damage="reflow"
     )}
 % endfor
+
+% for side in ALL_SIDES:
+    ${helpers.predefined_type(
+        "scroll-margin-%s" % side[0],
+        "Length",
+        "computed::Length::zero()",
+        products="gecko",
+        gecko_pref="layout.css.scroll-snap-v1.enabled",
+        logical=side[1],
+        logical_group="scroll-margin",
+        spec="https://drafts.csswg.org/css-scroll-snap-1/#propdef-scroll-margin-%s" % side[0],
+        flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE",
+        animation_value_type="ComputedValue",
+    )}
+% endfor
diff --git a/components/style/properties/shorthands/margin.mako.rs b/components/style/properties/shorthands/margin.mako.rs
index 8ccd33ebf3b..fd3124a6ae1 100644
--- a/components/style/properties/shorthands/margin.mako.rs
+++ b/components/style/properties/shorthands/margin.mako.rs
@@ -28,3 +28,32 @@ ${helpers.two_properties_shorthand(
     "specified::LengthPercentageOrAuto::parse",
     spec="https://drafts.csswg.org/css-logical/#propdef-margin-inline"
 )}
+
+${helpers.four_sides_shorthand(
+    "scroll-margin",
+    "scroll-margin-%s",
+    "specified::Length::parse",
+    spec="https://drafts.csswg.org/css-scroll-snap-1/#propdef-scroll-margin",
+    products="gecko",
+    gecko_pref="layout.css.scroll-snap-v1.enabled",
+)}
+
+${helpers.two_properties_shorthand(
+    "scroll-margin-block",
+    "scroll-margin-block-start",
+    "scroll-margin-block-end",
+    "specified::Length::parse",
+    spec="https://drafts.csswg.org/css-scroll-snap-1/#propdef-scroll-margin-block",
+    products="gecko",
+    gecko_pref="layout.css.scroll-snap-v1.enabled",
+)}
+
+${helpers.two_properties_shorthand(
+    "scroll-margin-inline",
+    "scroll-margin-inline-start",
+    "scroll-margin-inline-end",
+    "specified::Length::parse",
+    spec="https://drafts.csswg.org/css-scroll-snap-1/#propdef-scroll-margin-inline",
+    products="gecko",
+    gecko_pref="layout.css.scroll-snap-v1.enabled",
+)}