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

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

<%namespace name="helpers" file="/helpers.mako.rs" />
<% from data import Method, to_camel_case, to_rust_ident, to_camel_case_lower, SYSTEM_FONT_LONGHANDS %>

<% data.new_style_struct("Font", inherited=True) %>

${helpers.predefined_type("font-family",
                          "FontFamily",
                          initial_value="computed::FontFamily::serif()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-family",
                          servo_restyle_damage="rebuild_and_reflow")}

${helpers.predefined_type(
    "font-style",
    "FontStyle",
    initial_value="computed::FontStyle::normal()",
    initial_specified_value="specified::FontStyle::normal()",
    animation_value_type="FontStyle",
    flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
    spec="https://drafts.csswg.org/css-fonts/#propdef-font-style",
    servo_restyle_damage="rebuild_and_reflow",
)}

<% font_variant_caps_custom_consts= { "small-caps": "SMALLCAPS",
                                      "all-small-caps": "ALLSMALL",
                                      "petite-caps": "PETITECAPS",
                                      "all-petite-caps": "ALLPETITE",
                                      "titling-caps": "TITLING" } %>

${helpers.single_keyword_system("font-variant-caps",
                                "normal small-caps",
                                extra_gecko_values="all-small-caps petite-caps all-petite-caps unicase titling-caps",
                                gecko_constant_prefix="NS_FONT_VARIANT_CAPS",
                                gecko_ffi_name="mFont.variantCaps",
                                spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-caps",
                                custom_consts=font_variant_caps_custom_consts,
                                flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                                animation_value_type="discrete",
                                servo_restyle_damage="rebuild_and_reflow")}

${helpers.predefined_type(
    "font-weight",
    "FontWeight",
    initial_value="computed::FontWeight::normal()",
    initial_specified_value="specified::FontWeight::normal()",
    animation_value_type="Number",
    flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
    spec="https://drafts.csswg.org/css-fonts/#propdef-font-weight",
    servo_restyle_damage="rebuild_and_reflow",
)}

${helpers.predefined_type("font-size",
                          "FontSize",
                          initial_value="computed::FontSize::medium()",
                          initial_specified_value="specified::FontSize::medium()",
                          animation_value_type="NonNegativeLength",
                          allow_quirks=True,
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-size",
                          servo_restyle_damage="rebuild_and_reflow")}

${helpers.predefined_type("font-size-adjust",
                          "FontSizeAdjust",
                          products="gecko",
                          initial_value="computed::FontSizeAdjust::none()",
                          initial_specified_value="specified::FontSizeAdjust::none()",
                          animation_value_type="ComputedValue",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-size-adjust")}

${helpers.predefined_type("font-synthesis",
                          "FontSynthesis",
                          products="gecko",
                          initial_value="specified::FontSynthesis::get_initial_value()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-synthesis")}

${helpers.predefined_type(
    "font-stretch",
    "FontStretch",
    initial_value="computed::FontStretch::hundred()",
    initial_specified_value="specified::FontStretch::normal()",
    animation_value_type="Percentage",
    flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
    spec="https://drafts.csswg.org/css-fonts/#propdef-font-stretch",
    servo_restyle_damage="rebuild_and_reflow",
)}

${helpers.single_keyword_system("font-kerning",
                                "auto none normal",
                                products="gecko",
                                gecko_ffi_name="mFont.kerning",
                                gecko_constant_prefix="NS_FONT_KERNING",
                                spec="https://drafts.csswg.org/css-fonts/#propdef-font-kerning",
                                flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                                animation_value_type="discrete")}

${helpers.predefined_type("font-variant-alternates",
                          "FontVariantAlternates",
                          products="gecko",
                          initial_value="computed::FontVariantAlternates::get_initial_value()",
                          initial_specified_value="specified::FontVariantAlternates::get_initial_specified_value()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-alternates")}

${helpers.predefined_type("font-variant-east-asian",
                          "FontVariantEastAsian",
                          products="gecko",
                          initial_value="computed::FontVariantEastAsian::empty()",
                          initial_specified_value="specified::FontVariantEastAsian::empty()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-east-asian")}

${helpers.predefined_type("font-variant-ligatures",
                          "FontVariantLigatures",
                          products="gecko",
                          initial_value="computed::FontVariantLigatures::empty()",
                          initial_specified_value="specified::FontVariantLigatures::empty()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-ligatures")}

${helpers.predefined_type("font-variant-numeric",
                          "FontVariantNumeric",
                          products="gecko",
                          initial_value="computed::FontVariantNumeric::empty()",
                          initial_specified_value="specified::FontVariantNumeric::empty()",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-numeric")}

${helpers.single_keyword_system("font-variant-position",
                                "normal sub super",
                                products="gecko",
                                gecko_ffi_name="mFont.variantPosition",
                                gecko_constant_prefix="NS_FONT_VARIANT_POSITION",
                                spec="https://drafts.csswg.org/css-fonts/#propdef-font-variant-position",
                                flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                                animation_value_type="discrete")}

${helpers.predefined_type("font-feature-settings",
                          "FontFeatureSettings",
                          products="gecko",
                          initial_value="computed::FontFeatureSettings::normal()",
                          initial_specified_value="specified::FontFeatureSettings::normal()",
                          extra_prefixes="moz:layout.css.prefixes.font-features",
                          animation_value_type="discrete",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="https://drafts.csswg.org/css-fonts/#propdef-font-feature-settings")}

<%
# This spec link is too long to fit elsewhere
variation_spec = """\
https://drafts.csswg.org/css-fonts-4/#low-level-font-variation-settings-control-the-font-variation-settings-property\
"""
%>

${helpers.predefined_type("font-variation-settings",
                          "FontVariationSettings",
                          products="gecko",
                          gecko_pref="layout.css.font-variations.enabled",
                          initial_value="computed::FontVariationSettings::normal()",
                          initial_specified_value="specified::FontVariationSettings::normal()",
                          animation_value_type="ComputedValue",
                          flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                          spec="${variation_spec}")}

${helpers.predefined_type("font-language-override",
                          "FontLanguageOverride",
                          products="gecko",
                          initial_value="computed::FontLanguageOverride::zero()",
                          initial_specified_value="specified::FontLanguageOverride::normal()",
                          animation_value_type="discrete",
                          extra_prefixes="moz:layout.css.prefixes.font-features",
                          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",
                          initial_value="computed::XLang::get_initial_value()",
                          animation_value_type="none",
                          enabled_in="",
                          spec="Internal (not web-exposed)")}

${helpers.predefined_type("-moz-script-size-multiplier",
                          "MozScriptSizeMultiplier",
                          products="gecko",
                          initial_value="computed::MozScriptSizeMultiplier::get_initial_value()",
                          animation_value_type="none",
                          gecko_ffi_name="mScriptSizeMultiplier",
                          enabled_in="",
                          spec="Internal (not web-exposed)")}

${helpers.predefined_type("-moz-script-level",
                          "MozScriptLevel",
                          0,
                          animation_value_type="none",
                          products="gecko",
                          enabled_in="ua",
                          gecko_ffi_name="mScriptLevel",
                          spec="Internal (not web-exposed)")}

${helpers.single_keyword("-moz-math-display",
                         "inline block",
                         gecko_constant_prefix="NS_MATHML_DISPLAYSTYLE",
                         gecko_ffi_name="mMathDisplay",
                         products="gecko",
                         enabled_in="ua",
                         spec="Internal (not web-exposed)",
                         animation_value_type="none")}

${helpers.single_keyword("-moz-math-variant",
                         """none normal bold italic bold-italic script bold-script
                            fraktur double-struck bold-fraktur sans-serif
                            bold-sans-serif sans-serif-italic sans-serif-bold-italic
                            monospace initial tailed looped stretched""",
                         gecko_constant_prefix="NS_MATHML_MATHVARIANT",
                         gecko_ffi_name="mMathVariant",
                         products="gecko",
                         spec="Internal (not web-exposed)",
                         animation_value_type="none",
                         enabled_in="",
                         needs_conversion=True)}

${helpers.predefined_type("-moz-script-min-size",
                          "MozScriptMinSize",
                          "specified::MozScriptMinSize::get_initial_value()",
                          animation_value_type="none",
                          products="gecko",
                          enabled_in="",
                          gecko_ffi_name="mScriptMinSize",
                          spec="Internal (not web-exposed)")}

${helpers.predefined_type("-x-text-zoom",
                          "XTextZoom",
                          "computed::XTextZoom(true)",
                          animation_value_type="none",
                          products="gecko",
                          enabled_in="",
                          spec="Internal (not web-exposed)")}

% if product == "gecko":
    pub mod system_font {
        //! We deal with system fonts here
        //!
        //! System fonts can only be set as a group via the font shorthand.
        //! They resolve at compute time (not parse time -- this lets the
        //! browser respond to changes to the OS font settings).
        //!
        //! While Gecko handles these as a separate property and keyword
        //! values on each property indicating that the font should be picked
        //! from the -x-system-font property, we avoid this. Instead,
        //! each font longhand has a special SystemFont variant which contains
        //! the specified system font. When the cascade function (in helpers)
        //! detects that a value has a system font, it will resolve it, and
        //! cache it on the ComputedValues. After this, it can be just fetched
        //! whenever a font longhand on the same element needs the system font.
        //!
        //! When a longhand property is holding a SystemFont, it's serialized
        //! to an empty string as if its value comes from a shorthand with
        //! variable reference. We may want to improve this behavior at some
        //! point. See also https://github.com/w3c/csswg-drafts/issues/1586.

        use app_units::Au;
        use cssparser::{Parser, ToCss};
        use gecko_bindings::structs::FontFamilyType;
        use properties::longhands;
        use std::fmt;
        use std::hash::{Hash, Hasher};
        use style_traits::ParseError;
        use values::computed::{ToComputedValue, Context};

        <%
            system_fonts = """caption icon menu message-box small-caption status-bar
                              -moz-window -moz-document -moz-workspace -moz-desktop
                              -moz-info -moz-dialog -moz-button -moz-pull-down-menu
                              -moz-list -moz-field""".split()
            kw_font_props = """font_variant_caps
                               font_kerning font_variant_position font_variant_ligatures
                               font_variant_east_asian font_variant_numeric
                               font_optical_sizing""".split()
            kw_cast = """font_variant_caps font_kerning font_variant_position
                         font_optical_sizing""".split()
        %>
        #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq,
                 SpecifiedValueInfo, ToCss)]
        pub enum SystemFont {
            % for font in system_fonts:
                ${to_camel_case(font)},
            % endfor
        }

        // ComputedValues are compared at times
        // so we need these impls. We don't want to
        // add Eq to Number (which contains a float)
        // so instead we have an eq impl which skips the
        // cached values
        impl PartialEq for ComputedSystemFont {
            fn eq(&self, other: &Self) -> bool {
                self.system_font == other.system_font
            }
        }
        impl Eq for ComputedSystemFont {}

        impl Hash for ComputedSystemFont {
            fn hash<H: Hasher>(&self, hasher: &mut H) {
                self.system_font.hash(hasher)
            }
        }

        impl ToComputedValue for SystemFont {
            type ComputedValue = ComputedSystemFont;

            fn to_computed_value(&self, cx: &Context) -> Self::ComputedValue {
                use gecko_bindings::bindings;
                use gecko_bindings::structs::{LookAndFeel_FontID, nsFont};
                use std::mem;
                use values::computed::Percentage;
                use values::computed::font::{FontSize, FontStretch, FontStyle, FontFamilyList};
                use values::generics::NonNegative;

                let id = match *self {
                    % for font in system_fonts:
                        SystemFont::${to_camel_case(font)} => {
                            LookAndFeel_FontID::eFont_${to_camel_case(font.replace("-moz-", ""))}
                        }
                    % endfor
                };

                let mut system: nsFont = unsafe { mem::uninitialized() };
                unsafe {
                    bindings::Gecko_nsFont_InitSystem(
                        &mut system,
                        id as i32,
                        cx.style().get_font().gecko(),
                        cx.device().pres_context()
                    )
                }
                let font_weight = longhands::font_weight::computed_value::T::from_gecko_weight(system.weight);
                let font_stretch = FontStretch(NonNegative(Percentage(unsafe {
                    bindings::Gecko_FontStretch_ToFloat(system.stretch)
                })));
                let font_style = FontStyle::from_gecko(system.style);
                let ret = ComputedSystemFont {
                    font_family: longhands::font_family::computed_value::T(
                        FontFamilyList(
                            unsafe { system.fontlist.mFontlist.mBasePtr.to_safe() }
                        )
                    ),
                    font_size: FontSize {
                        size: Au(system.size).into(),
                        keyword_info: None
                    },
                    font_weight,
                    font_stretch,
                    font_style,
                    font_size_adjust: longhands::font_size_adjust::computed_value
                                               ::T::from_gecko_adjust(system.sizeAdjust),
                    % for kwprop in kw_font_props:
                        ${kwprop}: longhands::${kwprop}::computed_value::T::from_gecko_keyword(
                            system.${to_camel_case_lower(kwprop.replace('font_', ''))}
                            % if kwprop in kw_cast:
                                as u32
                            % endif
                        ),
                    % endfor
                    font_language_override: longhands::font_language_override::computed_value
                                                     ::T(system.languageOverride),
                    font_feature_settings: longhands::font_feature_settings::get_initial_value(),
                    font_variation_settings: longhands::font_variation_settings::get_initial_value(),
                    font_variant_alternates: longhands::font_variant_alternates::get_initial_value(),
                    system_font: *self,
                    default_font_type: system.fontlist.mDefaultFontType,
                };
                unsafe { bindings::Gecko_nsFont_Destroy(&mut system); }
                ret
            }

            fn from_computed_value(_: &ComputedSystemFont) -> Self {
                unreachable!()
            }
        }

        #[inline]
        /// Compute and cache a system font
        ///
        /// Must be called before attempting to compute a system font
        /// specified value
        pub fn resolve_system_font(system: SystemFont, context: &mut Context) {
            // Checking if context.cached_system_font.is_none() isn't enough,
            // if animating from one system font to another the cached system font
            // may change
            if Some(system) != context.cached_system_font.as_ref().map(|x| x.system_font) {
                let computed = system.to_computed_value(context);
                context.cached_system_font = Some(computed);
            }
        }

        #[derive(Clone, Debug)]
        pub struct ComputedSystemFont {
            % for name in SYSTEM_FONT_LONGHANDS:
                pub ${name}: longhands::${name}::computed_value::T,
            % endfor
            pub system_font: SystemFont,
            pub default_font_type: FontFamilyType,
        }

        impl SystemFont {
            pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
                try_match_ident_ignore_ascii_case! { input,
                    % for font in system_fonts:
                        "${font}" => Ok(SystemFont::${to_camel_case(font)}),
                    % endfor
                }
            }
        }

        impl ToCss for SystemFont {
            fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
                // We may want to do something better in the future, see
                // w3c/csswg-drafts#1586.
                dest.write_str("-moz-use-system-font")
            }
        }
    }
% else:
    pub mod system_font {
        use cssparser::Parser;

        // We don't parse system fonts, but in the interest of not littering
        // a lot of code with `if product == gecko` conditionals, we have a
        // dummy system font module that does nothing

        #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, SpecifiedValueInfo, ToCss)]
        #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
        /// void enum for system font, can never exist
        pub enum SystemFont {}
        impl SystemFont {
            pub fn parse(_: &mut Parser) -> Result<Self, ()> {
                Err(())
            }
        }
    }
% endif

${helpers.single_keyword("-moz-osx-font-smoothing",
                         "auto grayscale",
                         gecko_constant_prefix="NS_FONT_SMOOTHING",
                         gecko_ffi_name="mFont.smoothing",
                         gecko_pref="layout.css.osx-font-smoothing.enabled",
                         products="gecko",
                         spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/font-smooth)",
                         flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER",
                         animation_value_type="discrete")}

${helpers.predefined_type("-moz-font-smoothing-background-color",
                          "RGBAColor",
                          "RGBA::transparent()",
                          animation_value_type="AnimatedRGBA",
                          products="gecko",
                          gecko_ffi_name="mFont.fontSmoothingBackgroundColor",
                          enabled_in="chrome",
                          spec="None (Nonstandard internal property)")}

${helpers.predefined_type("-moz-min-font-size-ratio",
                          "Percentage",
                          "computed::Percentage::hundred()",
                          animation_value_type="none",
                          products="gecko",
                          enabled_in="ua",
                          spec="Nonstandard (Internal-only)")}