LibWeb/CSS: Remove the "Auto" type from Length

This has always been a bit of a hack. Initially it made sense as a lot
of properties that accept a length also accept `auto`, but while
convenient, that leads to problems: It's easy to forget to check if a
length is `auto`, and places that don't accept it end up with an
invalid state lurking in the type system, which makes things unclear.

Libraries/LibWeb/CSS/CSSStyleProperties.cpp

@@ -321,8 +321,6 @@ WebIDL::ExceptionOr<void> CSSStyleProperties::set_property(PropertyID property_i
 
 static NonnullRefPtr<StyleValue const> style_value_for_length_percentage(LengthPercentage const& length_percentage)
 {
-    if (length_percentage.is_auto())
-        return KeywordStyleValue::create(Keyword::Auto);
     if (length_percentage.is_percentage())
         return PercentageStyleValue::create(length_percentage.percentage());
     if (length_percentage.is_length())

Libraries/LibWeb/CSS/ComputedProperties.cpp

@@ -209,12 +209,8 @@ Size ComputedProperties::size_value(PropertyID id) const
     if (value.is_percentage())
         return Size::make_percentage(value.as_percentage().percentage());
 
-    if (value.is_length()) {
+    if (value.is_length())
-        auto length = value.as_length().length();
+        return Size::make_length(value.as_length().length());
-        if (length.is_auto())
-            return Size::make_auto();
-        return Size::make_length(length);
-    }
 
     // FIXME: Support `anchor-size(..)`
     if (value.is_anchor_size())
@@ -378,11 +374,8 @@ CSSPixels ComputedProperties::compute_line_height(CSSPixelRect const& viewport_r
     if (line_height.is_keyword() && line_height.to_keyword() == Keyword::Normal)
         return CSSPixels { round_to<i32>(font_metrics.font_size * normal_line_height_scale) };
 
-    if (line_height.is_length()) {
+    if (line_height.is_length())
-        auto line_height_length = line_height.as_length().length();
+        return line_height.as_length().length().to_px(viewport_rect, font_metrics, root_font_metrics);
-        if (!line_height_length.is_auto())
-            return line_height_length.to_px(viewport_rect, font_metrics, root_font_metrics);
-    }
 
     if (line_height.is_number())
         return Length(line_height.as_number().number(), Length::Type::Em).to_px(viewport_rect, font_metrics, root_font_metrics);

Libraries/LibWeb/CSS/GridTrackSize.cpp

@@ -96,9 +96,7 @@ bool GridSize::is_intrinsic(Layout::AvailableSize const& available_size) const
 bool GridSize::is_definite() const
 {
     return m_value.visit(
-        [](Size const& size) {
+        [](Size const& size) { return size.is_length_percentage(); },
-            return (size.is_length() && !size.length().is_auto()) || size.is_percentage() || size.is_calculated();
-        },
         [](Flex const&) { return false; });
 }
 

Libraries/LibWeb/CSS/Length.cpp

@@ -38,11 +38,6 @@ Length::Length(double value, Type type)
 }
 Length::~Length() = default;
 
-Length Length::make_auto()
-{
-    return Length(0, Type::Auto);
-}
-
 Length Length::make_px(double value)
 {
     return Length(value, Type::Px);
@@ -55,11 +50,6 @@ Length Length::make_px(CSSPixels value)
 
 Length Length::percentage_of(Percentage const& percentage) const
 {
-    if (is_auto()) {
-        dbgln("Attempting to get percentage of an auto length, this seems wrong? But for now we just return the original length.");
-        return *this;
-    }
-
     return Length { percentage.as_fraction() * raw_value(), m_type };
 }
 
@@ -191,11 +181,6 @@ CSSPixels Length::to_px(ResolutionContext const& context) const
 
 CSSPixels Length::to_px_slow_case(Layout::Node const& layout_node) const
 {
-    if (is_auto()) {
-        // FIXME: We really, really shouldn't end up here, but we do, and so frequently that
-        //        adding a dbgln() here outputs a couple hundred lines loading `welcome.html`.
-        return 0;
-    }
     if (!layout_node.document().browsing_context())
         return 0;
 
@@ -223,9 +208,6 @@ CSSPixels Length::to_px_slow_case(Layout::Node const& layout_node) const
 
 String Length::to_string(SerializationMode serialization_mode) const
 {
-    if (is_auto())
-        return "auto"_string;
-
     // https://drafts.csswg.org/cssom/#serialize-a-css-value
     // -> <length>
     // The <number> component serialized as per <number> followed by the unit in its canonical form as defined in its
@@ -334,8 +316,6 @@ StringView Length::unit_name() const
         return "pc"sv;
     case Type::Px:
         return "px"sv;
-    case Type::Auto:
-        return "auto"sv;
     }
     VERIFY_NOT_REACHED();
 }

Libraries/LibWeb/CSS/Length.h

@@ -68,9 +68,6 @@ public:
         Pt,
         Pc,
         Px,
-
-        // FIXME: Remove auto somehow
-        Auto,
     };
 
     struct FontMetrics {
@@ -90,12 +87,10 @@ public:
     Length(double value, Type type);
     ~Length();
 
-    static Length make_auto();
     static Length make_px(double value);
     static Length make_px(CSSPixels value);
     Length percentage_of(Percentage const&) const;
 
-    bool is_auto() const { return m_type == Type::Auto; }
     bool is_px() const { return m_type == Type::Px; }
 
     bool is_absolute() const
@@ -185,8 +180,6 @@ public:
 
     ALWAYS_INLINE CSSPixels to_px(CSSPixelRect const& viewport_rect, FontMetrics const& font_metrics, FontMetrics const& root_font_metrics) const
     {
-        if (is_auto())
-            return 0;
         if (is_absolute())
             return absolute_length_to_px();
         if (is_font_relative())
@@ -254,11 +247,8 @@ private:
 class LengthOrAuto {
 public:
     LengthOrAuto(Length length)
+        : m_length(move(length))
     {
-        if (length.is_auto())
-            m_length = {};
-        else
-            m_length = move(length);
     }
 
     static LengthOrAuto make_auto() { return LengthOrAuto { OptionalNone {} }; }

Libraries/LibWeb/CSS/Parser/ValueParsing.cpp

@@ -3173,7 +3173,6 @@ RefPtr<FitContentStyleValue const> Parser::parse_fit_content_value(TokenStream<C
     if (component_value.is_ident("fit-content"sv)) {
         transaction.commit();
         return FitContentStyleValue::create();
-        return nullptr;
     }
 
     if (!component_value.is_function())
@@ -3192,8 +3191,6 @@ RefPtr<FitContentStyleValue const> Parser::parse_fit_content_value(TokenStream<C
         return nullptr;
 
     transaction.commit();
-    if (maybe_length->is_auto())
-        return FitContentStyleValue::create();
     return FitContentStyleValue::create(maybe_length.release_value());
 }
 

Libraries/LibWeb/CSS/PercentageOr.h

@@ -208,8 +208,6 @@ class LengthPercentage : public PercentageOr<Length, LengthPercentage> {
 public:
     using PercentageOr<Length, LengthPercentage>::PercentageOr;
 
-    bool is_auto() const { return is_length() && length().is_auto(); }
-
     bool is_length() const { return is_t(); }
     Length const& length() const { return get_t(); }
 };
@@ -217,19 +215,13 @@ public:
 class LengthPercentageOrAuto {
 public:
     LengthPercentageOrAuto(LengthPercentage length_percentage)
+        : m_length_percentage(move(length_percentage))
     {
-        if (length_percentage.is_auto())
-            m_length_percentage = {};
-        else
-            m_length_percentage = move(length_percentage);
     }
 
     LengthPercentageOrAuto(Length length)
+        : m_length_percentage(move(length))
     {
-        if (length.is_auto())
-            m_length_percentage = {};
-        else
-            m_length_percentage = move(length);
     }
 
     LengthPercentageOrAuto(Percentage percentage)

Libraries/LibWeb/CSS/Size.cpp

@@ -48,8 +48,6 @@ Size Size::make_calculated(NonnullRefPtr<CalculatedStyleValue const> calculated)
 
 Size Size::make_length_percentage(LengthPercentage const& length_percentage)
 {
-    if (length_percentage.is_auto())
-        return make_auto();
     if (length_percentage.is_length())
         return make_length(length_percentage.length());
     if (length_percentage.is_percentage())

Libraries/LibWeb/CSS/StyleValues/CalculatedStyleValue.cpp

@@ -2807,9 +2807,6 @@ CalculatedStyleValue::CalculationResult CalculatedStyleValue::CalculationResult:
         [](Frequency const& frequency) { return frequency.to_hertz(); },
         [&context](Length const& length) {
             // Handle some common cases first, so we can resolve more without a context
-            if (length.is_auto())
-                return 0.0;
-
             if (length.is_absolute())
                 return length.absolute_length_to_px_without_rounding();
 

Libraries/LibWeb/CSS/StyleValues/LengthStyleValue.cpp

@@ -13,7 +13,6 @@ namespace Web::CSS {
 
 ValueComparingNonnullRefPtr<LengthStyleValue const> LengthStyleValue::create(Length const& length)
 {
-    VERIFY(!length.is_auto());
     if (length.is_px()) {
         if (length.raw_value() == 0) {
             static auto value = adopt_ref(*new (nothrow) LengthStyleValue(CSS::Length::make_px(0)));