Auto merge of #20187 - emilio:font-optical-sizing, r=emilio

style: Add font-optical-sizing property.

Patch by Jonathan Kew <jkew@mozilla.com>.

Bug: 1435692
Reviewed-by: emilio

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components/style/properties/data.py

@@ -19,7 +19,7 @@ SYSTEM_FONT_LONGHANDS = """font_family font_size font_style
                            font_size_adjust font_variant_alternates
                            font_variant_ligatures font_variant_east_asian
                            font_variant_numeric font_language_override
-                           font_feature_settings""".split()
+                           font_feature_settings font_optical_sizing""".split()
 
 
 def maybe_moz_logical_alias(product, side, prop):

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

@@ -15,15 +15,16 @@ ${helpers.predefined_type("font-family",
                           spec="https://drafts.csswg.org/css-fonts/#propdef-font-family",
                           servo_restyle_damage="rebuild_and_reflow")}
 
-${helpers.single_keyword_system("font-style",
+${helpers.single_keyword_system(
-                                "normal italic oblique",
+    "font-style",
-                                gecko_constant_prefix="NS_FONT_STYLE",
+    "normal italic oblique",
-                                gecko_ffi_name="mFont.style",
+    gecko_constant_prefix="NS_FONT_STYLE",
-                                spec="https://drafts.csswg.org/css-fonts/#propdef-font-style",
+    gecko_ffi_name="mFont.style",
-                                flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
+    spec="https://drafts.csswg.org/css-fonts/#propdef-font-style",
-                                animation_value_type="discrete",
+    flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
-                                servo_restyle_damage="rebuild_and_reflow")}
+    animation_value_type="discrete",
-
+    servo_restyle_damage="rebuild_and_reflow"
+)}
 
 <% font_variant_caps_custom_consts= { "small-caps": "SMALLCAPS",
                                       "all-small-caps": "ALLSMALL",
@@ -180,6 +181,16 @@ ${helpers.predefined_type("font-language-override",
                           flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                           spec="https://drafts.csswg.org/css-fonts-3/#propdef-font-language-override")}
 
+${helpers.single_keyword_system("font-optical-sizing",
+                                "auto none",
+                                products="gecko",
+                                gecko_pref="layout.css.font-variations.enabled",
+                                gecko_ffi_name="mFont.opticalSizing",
+                                gecko_constant_prefix="NS_FONT_OPTICAL_SIZING",
+                                animation_value_type="discrete",
+                                flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
+                                spec="https://www.w3.org/TR/css-fonts-4/#font-optical-sizing-def")}
+
 ${helpers.predefined_type("-x-lang",
                           "XLang",
                           products="gecko",
@@ -278,9 +289,11 @@ ${helpers.predefined_type("-x-text-zoom",
                               -moz-list -moz-field""".split()
             kw_font_props = """font_style font_variant_caps font_stretch
                                font_kerning font_variant_position font_variant_ligatures
-                               font_variant_east_asian font_variant_numeric""".split()
+                               font_variant_east_asian font_variant_numeric
+                               font_optical_sizing""".split()
             kw_cast = """font_style font_variant_caps font_stretch
-                         font_kerning font_variant_position""".split()
+                         font_kerning font_variant_position
+                         font_optical_sizing""".split()
         %>
         #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToCss)]
         pub enum SystemFont {

components/style/properties/shorthand/font.mako.rs

@@ -10,6 +10,7 @@
                                     font-size line-height font-family
                                     ${'font-size-adjust' if product == 'gecko' else ''}
                                     ${'font-kerning' if product == 'gecko' else ''}
+                                    ${'font-optical-sizing' if product == 'gecko' else ''}
                                     ${'font-variant-alternates' if product == 'gecko' else ''}
                                     ${'font-variant-east-asian' if product == 'gecko' else ''}
                                     ${'font-variant-ligatures' if product == 'gecko' else ''}
@@ -30,7 +31,8 @@
         gecko_sub_properties = "kerning language_override size_adjust \
                                 variant_alternates variant_east_asian \
                                 variant_ligatures variant_numeric \
-                                variant_position feature_settings".split()
+                                variant_position feature_settings \
+                                optical_sizing".split()
     %>
     % if product == "gecko":
         % for prop in gecko_sub_properties:
@@ -155,11 +157,19 @@
             % endif
 
             % if product == "gecko":
-                % for name in gecko_sub_properties:
+            if let Some(v) = self.font_optical_sizing {
-                    if self.font_${name} != &font_${name}::get_initial_specified_value() {
+                if v != &font_optical_sizing::get_initial_specified_value() {
-                        return Ok(());
+                    return Ok(());
-                    }
+                }
-                % endfor
+            }
+
+            % for name in gecko_sub_properties:
+            % if name != "optical_sizing":
+            if self.font_${name} != &font_${name}::get_initial_specified_value() {
+                return Ok(());
+            }
+            % endif
+            % endfor
             % endif
 
             // In case of serialization for canvas font, we need to drop
@@ -193,12 +203,22 @@
             let mut all = true;
 
             % for prop in SYSTEM_FONT_LONGHANDS:
-                if let Some(s) = self.${prop}.get_system() {
+            % if prop == "font_optical_sizing":
-                    debug_assert!(sys.is_none() || s == sys.unwrap());
+            if let Some(value) = self.${prop} {
-                    sys = Some(s);
+            % else:
-                } else {
+            {
-                    all = false;
+                let value = self.${prop};
+            % endif
+                match value.get_system() {
+                    Some(s) => {
+                        debug_assert!(sys.is_none() || s == sys.unwrap());
+                        sys = Some(s);
+                    }
+                    None => {
+                        all = false;
+                    }
                 }
+            }
             % endfor
             if self.line_height != &LineHeight::normal() {
                 all = false