style: Introduce a concept of logical group.

Bug: 1473180
Reviewed-by: emilio
MozReview-Commit-ID: GXlf8JNML4N

components/style/properties/data.py

@@ -168,7 +168,7 @@ class Longhand(object):
                  enabled_in="content", need_index=False,
                  gecko_ffi_name=None,
                  allowed_in_keyframe_block=True, cast_type='u8',
-                 logical=False, alias=None, extra_prefixes=None, boxed=False,
+                 logical=False, logical_group=None, alias=None, extra_prefixes=None, boxed=False,
                  flags=None, allowed_in_page_rule=False, allow_quirks=False,
                  ignored_when_colors_disabled=False,
                  vector=False, servo_restyle_damage="repaint"):
@@ -196,6 +196,9 @@ class Longhand(object):
         self.gecko_ffi_name = gecko_ffi_name or "m" + self.camel_case
         self.cast_type = cast_type
         self.logical = arg_to_bool(logical)
+        self.logical_group = logical_group
+        if self.logical:
+            assert logical_group, "Property " + name + " must have a logical group"
         self.alias = parse_property_aliases(alias)
         self.extra_prefixes = parse_property_aliases(extra_prefixes)
         self.boxed = arg_to_bool(boxed)

components/style/properties/longhands/border.mako.rs

@@ -27,6 +27,7 @@
         spec=maybe_logical_spec(side, "color"),
         animation_value_type="AnimatedColor",
         logical=is_logical,
+        logical_group="border-color",
         allow_quirks=not is_logical,
         flags="APPLIES_TO_FIRST_LETTER",
         ignored_when_colors_disabled=True,
@@ -40,6 +41,7 @@
         flags="APPLIES_TO_FIRST_LETTER",
         animation_value_type="discrete" if not is_logical else "none",
         logical=is_logical,
+        logical_group="border-style",
         needs_context=False,
     )}
 
@@ -52,6 +54,7 @@
         spec=maybe_logical_spec(side, "width"),
         animation_value_type="NonNegativeLength",
         logical=is_logical,
+        logical_group="border-width",
         flags="APPLIES_TO_FIRST_LETTER GETCS_NEEDS_LAYOUT_FLUSH",
         allow_quirks=not is_logical,
         servo_restyle_damage="reflow rebuild_and_reflow_inline"

components/style/properties/longhands/margin.mako.rs

@@ -20,6 +20,7 @@
         allow_quirks=not side[1],
         animation_value_type="ComputedValue",
         logical=side[1],
+        logical_group="margin",
         spec=spec,
         flags="APPLIES_TO_FIRST_LETTER GETCS_NEEDS_LAYOUT_FLUSH",
         allowed_in_page_rule=True,

components/style/properties/longhands/padding.mako.rs

@@ -21,6 +21,7 @@
         alias=maybe_moz_logical_alias(product, side, "-moz-padding-%s"),
         animation_value_type="NonNegativeLengthOrPercentage",
         logical=side[1],
+        logical_group="padding",
         spec=spec,
         flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_PLACEHOLDER GETCS_NEEDS_LAYOUT_FLUSH",
         allow_quirks=not side[1],

components/style/properties/longhands/position.mako.rs

@@ -18,7 +18,8 @@
         flags="GETCS_NEEDS_LAYOUT_FLUSH",
         animation_value_type="ComputedValue",
         allow_quirks=True,
-        servo_restyle_damage="reflow_out_of_flow"
+        servo_restyle_damage="reflow_out_of_flow",
+        logical_group="inset",
     )}
 % endfor
 // inset-* logical properties, map to "top" / "left" / "bottom" / "right"
@@ -32,6 +33,7 @@
         alias="offset-%s:layout.css.offset-logical-properties.enabled" % side,
         animation_value_type="ComputedValue",
         logical=True,
+        logical_group="inset",
     )}
 % endfor
 
@@ -221,6 +223,7 @@ ${helpers.predefined_type(
             "computed::MozLength::auto()",
             parse_function,
             logical=logical,
+            logical_group="size",
             allow_quirks=not logical,
             spec=spec % size,
             animation_value_type="MozLength",
@@ -234,6 +237,7 @@ ${helpers.predefined_type(
             "computed::MozLength::auto()",
             parse_function,
             logical=logical,
+            logical_group="min-size",
             allow_quirks=not logical,
             spec=spec % size,
             animation_value_type="MozLength",
@@ -245,6 +249,7 @@ ${helpers.predefined_type(
             "computed::MaxLength::none()",
             parse_function,
             logical=logical,
+            logical_group="max-size",
             allow_quirks=not logical,
             spec=spec % size,
             animation_value_type="MaxLength",

components/style/properties/properties.mako.rs

@@ -56,6 +56,7 @@ use style_adjuster::StyleAdjuster;
 pub use self::declaration_block::*;
 
 <%!
+    from collections import defaultdict
     from data import Method, Keyword, to_rust_ident, to_camel_case, SYSTEM_FONT_LONGHANDS
     import os.path
 %>
@@ -841,6 +842,29 @@ bitflags! {
     }
 }
 
+<%
+    logical_groups = defaultdict(list)
+    for prop in data.longhands:
+        if prop.logical_group:
+            logical_groups[prop.logical_group].append(prop)
+
+    for group, props in logical_groups.iteritems():
+        logical_count = sum(1 for p in props if p.logical)
+        if logical_count * 2 != len(props):
+            raise RuntimeError("Logical group {} has ".format(group) +
+                               "unbalanced logical / physical properties")
+%>
+
+/// A group for properties which may override each other
+/// via logical resolution.
+#[derive(Clone, Copy, Eq, Hash, PartialEq)]
+pub enum LogicalGroup {
+    % for group in logical_groups.iterkeys():
+    /// ${group}
+    ${to_camel_case(group)},
+    % endfor
+}
+
 /// An identifier for a given longhand property.
 #[derive(Clone, Copy, Eq, Hash, MallocSizeOf, PartialEq)]
 #[repr(u16)]
@@ -993,9 +1017,15 @@ impl LonghandId {
         match *self {
             % for property in data.longhands:
             % if property.logical:
+                <% logical_group = property.logical_group %>
                 LonghandId::${property.camel_case} => {
                     <%helpers:logical_setter_helper name="${property.name}">
                     <%def name="inner(physical_ident)">
+                        <%
+                            physical_name = physical_ident.replace("_", "-")
+                            physical_property = data.longhands_by_name[physical_name]
+                            assert logical_group == physical_property.logical_group
+                        %>
                         LonghandId::${to_camel_case(physical_ident)}
                     </%def>
                     </%helpers:logical_setter_helper>
@@ -1006,6 +1036,20 @@ impl LonghandId {
         }
     }
 
+    /// Return the logical group of this longhand property.
+    pub fn logical_group(&self) -> Option<LogicalGroup> {
+        const LOGICAL_GROUPS: [Option<LogicalGroup>; ${len(data.longhands)}] = [
+            % for prop in data.longhands:
+            % if prop.logical_group:
+            Some(LogicalGroup::${to_camel_case(prop.logical_group)}),
+            % else:
+            None,
+            % endif
+            % endfor
+        ];
+        LOGICAL_GROUPS[*self as usize]
+    }
+
     /// Returns PropertyFlags for given longhand property.
     pub fn flags(&self) -> PropertyFlags {
         match *self {