style: Move system colors to values::specified::color.

This should be an idempotent patch. The way to come up with this patch has been:

 * Run the first script attached to the bug and pipe it to xclip, then paste it
   in color.rs
 * Add the relevant #[derive] annotations and remove the color.mako.rs
   definition.
 * Reorder the values to match the ColorID definition, on which some widget
   prefs and caching stuff relies on.
 * Manually port some documentation from nsLookAndFeel.h
 * Run `rg 'eColorID_' | cut -d : -f 1 | sort | uniq >files`
 * Run the second script attached to the bug.
 * Manually fix usage of `LAST_COLOR` (adding the `End` variant), and adding
   casts to integer as needed.
 * Add an static assert so that people remember to update the prefs, rather than
   a comment on the definition :)

Differential Revision: https://phabricator.services.mozilla.com/D32610

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

@@ -17,114 +17,3 @@ ${helpers.predefined_type(
     ignored_when_colors_disabled="True",
     spec="https://drafts.csswg.org/css-color/#color",
 )}
-
-// FIXME(#15973): Add servo support for system colors
-//
-// FIXME(emilio): Move outside of mako.
-% if product == "gecko":
-pub mod system_colors {
-    <%
-        # These are actually parsed. See nsCSSProps::kColorKTable
-        system_colors = """activeborder activecaption appworkspace background buttonface
-                           buttonhighlight buttonshadow buttontext captiontext graytext highlight
-                           highlighttext inactiveborder inactivecaption inactivecaptiontext
-                           infobackground infotext menu menutext scrollbar threeddarkshadow
-                           threedface threedhighlight threedlightshadow threedshadow window
-                           windowframe windowtext -moz-buttondefault -moz-buttonhoverface
-                           -moz-buttonhovertext -moz-cellhighlight -moz-cellhighlighttext
-                           -moz-eventreerow -moz-field -moz-fieldtext -moz-dialog -moz-dialogtext
-                           -moz-dragtargetzone -moz-gtk-info-bar-text -moz-html-cellhighlight
-                           -moz-html-cellhighlighttext -moz-mac-buttonactivetext
-                           -moz-gtk-buttonactivetext
-                           -moz-mac-chrome-active -moz-mac-chrome-inactive
-                           -moz-mac-defaultbuttontext -moz-mac-focusring -moz-mac-menuselect
-                           -moz-mac-menushadow -moz-mac-menutextdisable -moz-mac-menutextselect
-                           -moz-mac-disabledtoolbartext -moz-mac-secondaryhighlight
-                           -moz-mac-vibrancy-light -moz-mac-vibrancy-dark
-                           -moz-mac-vibrant-titlebar-light -moz-mac-vibrant-titlebar-dark
-                           -moz-mac-menupopup
-                           -moz-mac-menuitem -moz-mac-active-menuitem -moz-mac-source-list
-                           -moz-mac-source-list-selection -moz-mac-active-source-list-selection
-                           -moz-mac-tooltip
-                           -moz-menuhover -moz-menuhovertext -moz-menubartext -moz-menubarhovertext
-                           -moz-oddtreerow -moz-win-mediatext -moz-win-communicationstext
-                           -moz-win-accentcolor -moz-win-accentcolortext
-                           -moz-nativehyperlinktext -moz-comboboxtext -moz-combobox""".split()
-
-        # These are not parsed but must be serialized
-        # They are only ever set directly by Gecko
-        extra_colors = """WindowBackground WindowForeground WidgetBackground WidgetForeground
-                          WidgetSelectBackground WidgetSelectForeground Widget3DHighlight Widget3DShadow
-                          TextBackground TextForeground TextSelectBackground TextSelectForeground
-                          TextSelectForegroundCustom TextSelectBackgroundDisabled TextSelectBackgroundAttention
-                          TextHighlightBackground TextHighlightForeground IMERawInputBackground
-                          IMERawInputForeground IMERawInputUnderline IMESelectedRawTextBackground
-                          IMESelectedRawTextForeground IMESelectedRawTextUnderline
-                          IMEConvertedTextBackground IMEConvertedTextForeground IMEConvertedTextUnderline
-                          IMESelectedConvertedTextBackground IMESelectedConvertedTextForeground
-                          IMESelectedConvertedTextUnderline SpellCheckerUnderline""".split()
-    %>
-    use crate::gecko_bindings::bindings::Gecko_GetLookAndFeelSystemColor;
-    use crate::gecko_bindings::structs::root::mozilla::LookAndFeel_ColorID;
-    use std::fmt::{self, Write};
-    use style_traits::{CssWriter, ToCss};
-    use to_shmem::impl_trivial_to_shmem;
-    use crate::values::computed::{Context, ToComputedValue};
-
-    pub type SystemColor = LookAndFeel_ColorID;
-
-    // It's hard to implement MallocSizeOf for LookAndFeel_ColorID because it
-    // is a bindgen type. So we implement it on the typedef instead.
-    malloc_size_of_is_0!(SystemColor);
-
-    impl_trivial_to_shmem!(SystemColor);
-
-    impl ToCss for SystemColor {
-        fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
-        where
-            W: Write,
-        {
-            let s = match *self {
-                % for color in system_colors + extra_colors:
-                    LookAndFeel_ColorID::eColorID_${to_rust_ident(color)} => "${color}",
-                % endfor
-                LookAndFeel_ColorID::eColorID_LAST_COLOR => unreachable!(),
-            };
-            dest.write_str(s)
-        }
-    }
-
-    impl ToComputedValue for SystemColor {
-        type ComputedValue = u32; // nscolor
-
-        #[inline]
-        fn to_computed_value(&self, cx: &Context) -> Self::ComputedValue {
-            unsafe {
-                Gecko_GetLookAndFeelSystemColor(
-                    *self as i32,
-                    cx.device().document(),
-                )
-            }
-        }
-
-        #[inline]
-        fn from_computed_value(_: &Self::ComputedValue) -> Self {
-            unreachable!()
-        }
-    }
-
-    impl SystemColor {
-        pub fn from_ident<'i, 't>(ident: &str) -> Result<Self, ()> {
-            ascii_case_insensitive_phf_map! {
-                color_name -> SystemColor = {
-                    % for color in system_colors:
-                        "${color}" => LookAndFeel_ColorID::eColorID_${to_rust_ident(color)},
-                    % endfor
-                }
-            }
-
-            color_name(ident).cloned().ok_or(())
-        }
-    }
-}
-% endif

components/style/values/specified/color.rs

@@ -8,8 +8,6 @@ use super::AllowQuirks;
 #[cfg(feature = "gecko")]
 use crate::gecko_bindings::structs::nscolor;
 use crate::parser::{Parse, ParserContext};
-#[cfg(feature = "gecko")]
-use crate::properties::longhands::system_colors::SystemColor;
 use crate::values::computed::{Color as ComputedColor, Context, ToComputedValue};
 use crate::values::generics::color::{Color as GenericColor, ColorOrAuto as GenericColorOrAuto};
 use crate::values::specified::calc::CalcNode;
@@ -35,7 +33,6 @@ pub enum Color {
     },
     /// A complex color value from computed value
     Complex(ComputedColor),
-
     /// A system color
     #[cfg(feature = "gecko")]
     System(SystemColor),
@@ -47,6 +44,215 @@ pub enum Color {
     InheritFromBodyQuirk,
 }
 
+/// System colors.
+#[allow(missing_docs)]
+#[cfg(feature = "gecko")]
+#[derive(Copy, Clone, Debug, MallocSizeOf, Parse, PartialEq, ToCss, ToShmem)]
+#[repr(u8)]
+pub enum SystemColor {
+    #[css(skip)]
+    WindowBackground,
+    #[css(skip)]
+    WindowForeground,
+    #[css(skip)]
+    WidgetBackground,
+    #[css(skip)]
+    WidgetForeground,
+    #[css(skip)]
+    WidgetSelectBackground,
+    #[css(skip)]
+    WidgetSelectForeground,
+    #[css(skip)]
+    Widget3DHighlight,
+    #[css(skip)]
+    Widget3DShadow,
+    #[css(skip)]
+    TextBackground,
+    #[css(skip)]
+    TextForeground,
+    #[css(skip)]
+    TextSelectBackground,
+    #[css(skip)]
+    TextSelectForeground,
+    #[css(skip)]
+    TextSelectForegroundCustom,
+    #[css(skip)]
+    TextSelectBackgroundDisabled,
+    #[css(skip)]
+    TextSelectBackgroundAttention,
+    #[css(skip)]
+    TextHighlightBackground,
+    #[css(skip)]
+    TextHighlightForeground,
+    #[css(skip)]
+    IMERawInputBackground,
+    #[css(skip)]
+    IMERawInputForeground,
+    #[css(skip)]
+    IMERawInputUnderline,
+    #[css(skip)]
+    IMESelectedRawTextBackground,
+    #[css(skip)]
+    IMESelectedRawTextForeground,
+    #[css(skip)]
+    IMESelectedRawTextUnderline,
+    #[css(skip)]
+    IMEConvertedTextBackground,
+    #[css(skip)]
+    IMEConvertedTextForeground,
+    #[css(skip)]
+    IMEConvertedTextUnderline,
+    #[css(skip)]
+    IMESelectedConvertedTextBackground,
+    #[css(skip)]
+    IMESelectedConvertedTextForeground,
+    #[css(skip)]
+    IMESelectedConvertedTextUnderline,
+    #[css(skip)]
+    SpellCheckerUnderline,
+    Activeborder,
+    Activecaption,
+    Appworkspace,
+    Background,
+    Buttonface,
+    Buttonhighlight,
+    Buttonshadow,
+    Buttontext,
+    Captiontext,
+    Graytext,
+    Highlight,
+    Highlighttext,
+    Inactiveborder,
+    Inactivecaption,
+    Inactivecaptiontext,
+    Infobackground,
+    Infotext,
+    Menu,
+    Menutext,
+    Scrollbar,
+    Threeddarkshadow,
+    Threedface,
+    Threedhighlight,
+    Threedlightshadow,
+    Threedshadow,
+    Window,
+    Windowframe,
+    Windowtext,
+    MozButtondefault,
+    MozField,
+    MozFieldtext,
+    MozDialog,
+    MozDialogtext,
+    /// Used to highlight valid regions to drop something onto.
+    MozDragtargetzone,
+    /// Used for selected but not focused cell backgrounds.
+    MozCellhighlight,
+    /// Used for selected but not focused cell text.
+    MozCellhighlighttext,
+    /// Used for selected but not focused html cell backgrounds.
+    MozHtmlCellhighlight,
+    /// Used for selected but not focused html cell text.
+    MozHtmlCellhighlighttext,
+    /// Used to button text background when hovered.
+    MozButtonhoverface,
+    /// Used to button text color when hovered.
+    MozButtonhovertext,
+    /// Used for menu item backgrounds when hovered.
+    MozMenuhover,
+    /// Used for menu item text when hovered.
+    MozMenuhovertext,
+    /// Used for menubar item text.
+    MozMenubartext,
+    /// Used for menubar item text when hovered.
+    MozMenubarhovertext,
+
+    /// On platforms where these colors are the same as -moz-field, use
+    /// -moz-fieldtext as foreground color
+    MozEventreerow,
+    MozOddtreerow,
+
+    /// Used for button text when pressed.
+    MozGtkButtonactivetext,
+
+    /// Used for button text when pressed.
+    MozMacButtonactivetext,
+    /// Background color of chrome toolbars in active windows.
+    MozMacChromeActive,
+    /// Background color of chrome toolbars in inactive windows.
+    MozMacChromeInactive,
+    /// Foreground color of default buttons.
+    MozMacDefaultbuttontext,
+    /// Ring color around text fields and lists.
+    MozMacFocusring,
+    /// Color used when mouse is over a menu item.
+    MozMacMenuselect,
+    /// Color used to do shadows on menu items.
+    MozMacMenushadow,
+    /// Color used to display text for disabled menu items.
+    MozMacMenutextdisable,
+    /// Color used to display text while mouse is over a menu item.
+    MozMacMenutextselect,
+    /// Text color of disabled text on toolbars.
+    MozMacDisabledtoolbartext,
+    /// Inactive light hightlight
+    MozMacSecondaryhighlight,
+
+    /// Font smoothing background colors needed by the Mac OS X theme, based on
+    /// -moz-appearance names.
+    MozMacVibrancyLight,
+    MozMacVibrancyDark,
+    MozMacVibrantTitlebarLight,
+    MozMacVibrantTitlebarDark,
+    MozMacMenupopup,
+    MozMacMenuitem,
+    MozMacActiveMenuitem,
+    MozMacSourceList,
+    MozMacSourceListSelection,
+    MozMacActiveSourceListSelection,
+    MozMacTooltip,
+
+    /// Accent color for title bar.
+    MozWinAccentcolor,
+    /// Color from drawing text over the accent color.
+    MozWinAccentcolortext,
+    /// Media rebar text.
+    MozWinMediatext,
+    /// Communications rebar text.
+    MozWinCommunicationstext,
+
+    /// Hyperlink color extracted from the system, not affected by the
+    /// browser.anchor_color user pref.
+    ///
+    /// There is no OS-specified safe background color for this text, but it is
+    /// used regularly within Windows and the Gnome DE on Dialog and Window
+    /// colors.
+    MozNativehyperlinktext,
+
+    /// Combobox widgets
+    MozComboboxtext,
+    MozCombobox,
+
+    MozGtkInfoBarText,
+
+    #[css(skip)]
+    End, // Just for array-indexing purposes.
+}
+
+#[cfg(feature = "gecko")]
+impl SystemColor {
+    #[inline]
+    fn compute(&self, cx: &Context) -> ComputedColor {
+        use crate::gecko_bindings::bindings;
+        unsafe {
+            convert_nscolor_to_computedcolor(bindings::Gecko_GetLookAndFeelSystemColor(
+                *self as i32,
+                cx.device().document(),
+            ))
+        }
+    }
+}
+
+
 #[cfg(feature = "gecko")]
 mod gecko {
     #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss, ToShmem)]
@@ -340,32 +546,29 @@ impl Color {
     /// If `context` is `None`, and the specified color requires data from
     /// the context to resolve, then `None` is returned.
     pub fn to_computed_color(&self, _context: Option<&Context>) -> Option<ComputedColor> {
-        match *self {
-            Color::CurrentColor => Some(ComputedColor::currentcolor()),
-            Color::Numeric { ref parsed, .. } => Some(ComputedColor::rgba(*parsed)),
-            Color::Complex(ref complex) => Some(*complex),
+        Some(match *self {
+            Color::CurrentColor => ComputedColor::currentcolor(),
+            Color::Numeric { ref parsed, .. } => ComputedColor::rgba(*parsed),
+            Color::Complex(ref complex) => *complex,
             #[cfg(feature = "gecko")]
-            Color::System(system) => _context
-                .map(|context| convert_nscolor_to_computedcolor(system.to_computed_value(context))),
+            Color::System(system) => system.compute(_context?),
             #[cfg(feature = "gecko")]
             Color::Special(special) => {
                 use self::gecko::SpecialColorKeyword as Keyword;
-                _context.map(|context| {
-                    let prefs = context.device().pref_sheet_prefs();
-                    convert_nscolor_to_computedcolor(match special {
-                        Keyword::MozDefaultColor => prefs.mDefaultColor,
-                        Keyword::MozDefaultBackgroundColor => prefs.mDefaultBackgroundColor,
-                        Keyword::MozHyperlinktext => prefs.mLinkColor,
-                        Keyword::MozActivehyperlinktext => prefs.mActiveLinkColor,
-                        Keyword::MozVisitedhyperlinktext => prefs.mVisitedLinkColor,
-                    })
+                let prefs = _context?.device().pref_sheet_prefs();
+                convert_nscolor_to_computedcolor(match special {
+                    Keyword::MozDefaultColor => prefs.mDefaultColor,
+                    Keyword::MozDefaultBackgroundColor => prefs.mDefaultBackgroundColor,
+                    Keyword::MozHyperlinktext => prefs.mLinkColor,
+                    Keyword::MozActivehyperlinktext => prefs.mActiveLinkColor,
+                    Keyword::MozVisitedhyperlinktext => prefs.mVisitedLinkColor,
                 })
             },
             #[cfg(feature = "gecko")]
             Color::InheritFromBodyQuirk => {
-                _context.map(|context| ComputedColor::rgba(context.device().body_text_color()))
+                ComputedColor::rgba(_context?.device().body_text_color())
             },
-        }
+        })
     }
 }