LibWeb: Return numeric values from Token value getters

This saves user code from having to parse the numbers, as we already did
that while Tokenizing. :^)

As a bonus, we now round extremely large integers to the closest
available value, like the spec tells us to.

1 files changed, 26 insertions, 5 deletions

diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Token.h b/Userland/Libraries/LibWeb/CSS/Parser/Token.h
index b7e2a96480..dcb5bca35d 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Token.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Token.h
@@ -9,6 +9,7 @@
 
 #include <AK/String.h>
 #include <AK/StringBuilder.h>
+#include <math.h>
 
 namespace Web::CSS {
 
@@ -111,10 +112,15 @@ public:
         VERIFY(m_type == Type::Number);
         return m_value.string_view();
     }
+    double number_value() const
+    {
+        VERIFY(m_type == Type::Number);
+        return m_number_value;
+    }
     i64 to_integer() const
     {
         VERIFY(m_type == Type::Number && m_number_type == NumberType::Integer);
-        return number_string_value().to_int<i64>().value();
+        return to_closest_integer(m_number_value);
     }
     bool is_integer_value_signed() const { return number_string_value().starts_with('-') || number_string_value().starts_with('+'); }
 
@@ -123,16 +129,22 @@ public:
         VERIFY(m_type == Type::Dimension);
         return m_unit.string_view();
     }
-    StringView dimension_value() const
+    double dimension_value() const
     {
         VERIFY(m_type == Type::Dimension);
-        return m_value.string_view();
+        return m_number_value;
+    }
+    i64 dimension_value_int() const { return to_closest_integer(dimension_value()); }
+
+    double percentage() const
+    {
+        VERIFY(m_type == Type::Percentage);
+        return m_number_value;
     }
-    i64 dimension_value_int() const { return dimension_value().to_int().value(); }
 
     NumberType number_type() const
     {
-        VERIFY((m_type == Type::Number) || (m_type == Type::Dimension));
+        VERIFY((m_type == Type::Number) || (m_type == Type::Dimension) || (m_type == Type::Percentage));
         return m_number_type;
     }
 
@@ -146,6 +158,15 @@ public:
     Position const& end_position() const { return m_end_position; }
 
 private:
+    static i64 to_closest_integer(double value)
+    {
+        // https://www.w3.org/TR/css-values-4/#numeric-types
+        // When a value cannot be explicitly supported due to range/precision limitations, it must be converted
+        // to the closest value supported by the implementation, but how the implementation defines "closest"
+        // is explicitly undefined as well.
+        return static_cast<i64>(clamp(round(value), NumericLimits<i64>::min(), NumericLimits<i64>::max()));
+    }
+
     Type m_type { Type::Invalid };
 
     StringBuilder m_value;