LibWeb: Implement SVGAnimatedNumber

Author: https://github.com/gmta
Commit: 97fa0be16e
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5389
Reviewed-by: https://github.com/tcl3 ✅

Libraries/LibWeb/SVG/SVGAnimatedNumber.cpp

@@ -1,35 +1,157 @@
 /*
  * Copyright (c) 2023, MacDue <macdue@dueutil.tech>
+ * Copyright (c) 2025, Jelle Raaijmakers <jelle@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/Bindings/SVGAnimatedNumberPrototype.h>
+#include <LibWeb/SVG/AttributeParser.h>
 #include <LibWeb/SVG/SVGAnimatedNumber.h>
 
 namespace Web::SVG {
 
 GC_DEFINE_ALLOCATOR(SVGAnimatedNumber);
 
-GC::Ref<SVGAnimatedNumber> SVGAnimatedNumber::create(JS::Realm& realm, float base_val, float anim_val)
+GC::Ref<SVGAnimatedNumber> SVGAnimatedNumber::create(JS::Realm& realm, GC::Ref<SVGElement> element,
+    FlyString reflected_attribute, float initial_value, SupportsSecondValue supports_second_value,
+    ValueRepresented value_represented)
 {
-    return realm.create<SVGAnimatedNumber>(realm, base_val, anim_val);
+    return realm.create<SVGAnimatedNumber>(realm, element, move(reflected_attribute), initial_value,
+        supports_second_value, value_represented);
 }
 
-SVGAnimatedNumber::SVGAnimatedNumber(JS::Realm& realm, float base_val, float anim_val)
+SVGAnimatedNumber::SVGAnimatedNumber(JS::Realm& realm, GC::Ref<SVGElement> element, FlyString reflected_attribute,
+    float initial_value, SupportsSecondValue supports_second_value, ValueRepresented value_represented)
     : PlatformObject(realm)
-    , m_base_val(base_val)
-    , m_anim_val(anim_val)
+    , m_element(element)
+    , m_reflected_attribute(move(reflected_attribute))
+    , m_initial_value(initial_value)
+    , m_supports_second_value(supports_second_value)
+    , m_value_represented(value_represented)
 {
 }
 
 SVGAnimatedNumber::~SVGAnimatedNumber() = default;
 
+// https://svgwg.org/svg2-draft/types.html#__svg__SVGAnimatedNumber__baseVal
+float SVGAnimatedNumber::base_val() const
+{
+    // On getting baseVal or animVal, the following steps are run:
+    return get_base_or_anim_value();
+}
+
+// // https://svgwg.org/svg2-draft/types.html#__svg__SVGAnimatedNumber__baseVal
+void SVGAnimatedNumber::set_base_val(float new_value)
+{
+    // 1. Let value be the value being assigned to baseVal.
+    auto value = new_value;
+
+    // 2. Let new be a list of numbers.
+    Vector<float, 2> new_;
+
+    // 3. If the reflected attribute is defined to take an number followed by an optional second number, then:
+    if (m_supports_second_value == SupportsSecondValue::Yes) {
+        // 1. Let current be the value of the reflected attribute (using the attribute's initial value if it is not
+        //    present or invalid).
+        auto current = m_element->get_attribute_value(m_reflected_attribute);
+        auto current_values = MUST(current.split(' '));
+
+        // 2. Let first be the first number in current.
+        auto first = current_values.size() > 0 ? parse_value_or_initial(current_values[0]) : m_initial_value;
+
+        // 3. Let second be the second number in current if it has been explicitly specified, and if not, the implicit
+        //    value as described in the definition of the attribute.
+        // LB-NOTE: All known usages of <number-optional-number> specify that a missing second number defaults to the
+        //          value of the first number.
+        auto second = current_values.size() > 1 && !current_values[1].is_empty()
+            ? parse_value_or_initial(current_values[1])
+            : first;
+
+        // 4. If this SVGAnimatedNumber object reflects the first number, then set first to value. Otherwise, set second
+        //    to value.
+        if (m_value_represented == ValueRepresented::First)
+            first = value;
+        else
+            second = value;
+
+        // 5. Append first to new.
+        new_.unchecked_append(first);
+
+        // 6. Append second to new.
+        new_.unchecked_append(second);
+    }
+
+    // 4. Otherwise, the reflected attribute is defined to take a single number value. Append value to new.
+    else {
+        new_.unchecked_append(value);
+    }
+
+    // 5. Set the content attribute to a string consisting of each number in new serialized to an implementation
+    //    specific string that, if parsed as an <number> using CSS syntax, would return the value closest to the number
+    //    (given the implementation's supported Precisionreal number precision), joined and separated by a single U+0020
+    //    SPACE character.
+    auto new_attribute_value = MUST(String::join(' ', new_));
+    m_element->set_attribute_value(m_reflected_attribute, new_attribute_value);
+}
+
+// https://svgwg.org/svg2-draft/types.html#__svg__SVGAnimatedNumber__animVal
+float SVGAnimatedNumber::anim_val() const
+{
+    // On getting baseVal or animVal, the following steps are run:
+    return get_base_or_anim_value();
+}
+
+float SVGAnimatedNumber::parse_value_or_initial(StringView number_value) const
+{
+    auto value = AttributeParser::parse_number_percentage(number_value);
+    if (!value.has_value())
+        return m_initial_value;
+    return value.release_value().value();
+}
+
+// https://svgwg.org/svg2-draft/types.html#__svg__SVGAnimatedNumber__baseVal
+float SVGAnimatedNumber::get_base_or_anim_value() const
+{
+    // 1. Let value be the value of the reflected attribute (using the attribute's initial value if it is not present or
+    //    invalid).
+    auto value = m_element->get_attribute_value(m_reflected_attribute);
+
+    // 2. If the reflected attribute is defined to take an number followed by an optional second number, then:
+    if (m_supports_second_value == SupportsSecondValue::Yes) {
+        // 1. If this SVGAnimatedNumber object reflects the first number, then return the first value in value.
+        auto values = MUST(value.split(' '));
+        if (values.is_empty())
+            return m_initial_value;
+        if (m_value_represented == ValueRepresented::First)
+            return parse_value_or_initial(values[0]);
+
+        // 2. Otherwise, this SVGAnimatedNumber object reflects the second number. Return the second value in value if
+        //    it has been explicitly specified, and if not, return the implicit value as described in the definition of
+        //    the attribute.
+        // LB-NOTE: All known usages of <number-optional-number> specify that a missing second number defaults to the
+        //          value of the first number.
+        VERIFY(m_value_represented == ValueRepresented::Second);
+        if (values.size() > 1 && !values[1].is_empty())
+            return parse_value_or_initial(values[1]);
+        return parse_value_or_initial(values[0]);
+    }
+
+    // 3. Otherwise, the reflected attribute is defined to take a single number value. Return value.
+    return parse_value_or_initial(value);
+}
+
 void SVGAnimatedNumber::initialize(JS::Realm& realm)
 {
     WEB_SET_PROTOTYPE_FOR_INTERFACE(SVGAnimatedNumber);
     Base::initialize(realm);
 }
 
+void SVGAnimatedNumber::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_element);
+}
+
 }