LibWeb: Implement CSS `hypot()`

Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp

@@ -3844,6 +3844,53 @@ ErrorOr<OwnPtr<CalculationNode>> Parser::parse_sqrt_function(Function const& fun
     return TRY(SqrtCalculationNode::create(node.release_nonnull()));
 }
 
+ErrorOr<OwnPtr<CalculationNode>> Parser::parse_hypot_function(Function const& function)
+{
+    TokenStream stream { function.values() };
+    auto parameters = parse_a_comma_separated_list_of_component_values(stream);
+
+    if (parameters.size() == 0) {
+        dbgln_if(CSS_PARSER_DEBUG, "hypot() must have at least 1 parameter"sv);
+        return nullptr;
+    }
+
+    Vector<NonnullOwnPtr<CalculationNode>> calculated_parameters;
+    calculated_parameters.ensure_capacity(parameters.size());
+
+    CalculatedStyleValue::ResolvedType type;
+    bool first = true;
+    for (auto& parameter : parameters) {
+        auto calculation_node = TRY(parse_a_calculation(parameter));
+
+        if (!calculation_node) {
+            dbgln_if(CSS_PARSER_DEBUG, "hypot() parameters must be valid calculations"sv);
+            return nullptr;
+        }
+
+        auto maybe_parameter_type = calculation_node->resolved_type();
+        if (!maybe_parameter_type.has_value()) {
+            dbgln_if(CSS_PARSER_DEBUG, "Failed to resolve type for hypot() parameter #{}"sv, calculated_parameters.size() + 1);
+            return nullptr;
+        }
+
+        auto resolved_type = maybe_parameter_type.value();
+
+        if (first) {
+            type = resolved_type;
+            first = false;
+        }
+
+        if (resolved_type != type) {
+            dbgln_if(CSS_PARSER_DEBUG, "hypot() parameters must all be of the same type"sv);
+            return nullptr;
+        }
+
+        calculated_parameters.append(calculation_node.release_nonnull());
+    }
+
+    return TRY(HypotCalculationNode::create(move(calculated_parameters)));
+}
+
 ErrorOr<RefPtr<StyleValue>> Parser::parse_dynamic_value(ComponentValue const& component_value)
 {
     if (component_value.is_function()) {
@@ -3915,6 +3962,9 @@ ErrorOr<OwnPtr<CalculationNode>> Parser::parse_a_calc_function_node(Function con
     if (function.name().equals_ignoring_ascii_case("sqrt"sv))
         return TRY(parse_sqrt_function(function));
 
+    if (function.name().equals_ignoring_ascii_case("hypot"sv))
+        return TRY(parse_hypot_function(function));
+
     dbgln_if(CSS_PARSER_DEBUG, "We didn't implement `{}` function yet", function.name());
     return nullptr;
 }

Userland/Libraries/LibWeb/CSS/Parser/Parser.h

@@ -304,6 +304,7 @@ private:
     ErrorOr<OwnPtr<CalculationNode>> parse_atan2_function(Function const&);
     ErrorOr<OwnPtr<CalculationNode>> parse_pow_function(Function const&);
     ErrorOr<OwnPtr<CalculationNode>> parse_sqrt_function(Function const&);
+    ErrorOr<OwnPtr<CalculationNode>> parse_hypot_function(Function const&);
     ErrorOr<RefPtr<StyleValue>> parse_dimension_value(ComponentValue const&);
     ErrorOr<RefPtr<StyleValue>> parse_integer_value(TokenStream<ComponentValue>&);
     ErrorOr<RefPtr<StyleValue>> parse_number_value(TokenStream<ComponentValue>&);

Userland/Libraries/LibWeb/CSS/StyleValues/CalculatedStyleValue.cpp

@@ -1344,6 +1344,82 @@ ErrorOr<void> SqrtCalculationNode::dump(StringBuilder& builder, int indent) cons
     return {};
 }
 
+ErrorOr<NonnullOwnPtr<HypotCalculationNode>> HypotCalculationNode::create(Vector<NonnullOwnPtr<Web::CSS::CalculationNode>> values)
+{
+    return adopt_nonnull_own_or_enomem(new (nothrow) HypotCalculationNode(move(values)));
+}
+
+HypotCalculationNode::HypotCalculationNode(Vector<NonnullOwnPtr<CalculationNode>> values)
+    : CalculationNode(Type::Hypot)
+    , m_values(move(values))
+{
+}
+
+HypotCalculationNode::~HypotCalculationNode() = default;
+
+ErrorOr<String> HypotCalculationNode::to_string() const
+{
+    StringBuilder builder;
+    TRY(builder.try_append("hypot("sv));
+    for (size_t i = 0; i < m_values.size(); ++i) {
+        if (i != 0)
+            TRY(builder.try_append(", "sv));
+        TRY(builder.try_append(TRY(m_values[i]->to_string())));
+    }
+    TRY(builder.try_append(")"sv));
+    return builder.to_string();
+}
+
+Optional<CalculatedStyleValue::ResolvedType> HypotCalculationNode::resolved_type() const
+{
+    // NOTE: We check during parsing that all values have the same type.
+    return m_values[0]->resolved_type();
+}
+
+bool HypotCalculationNode::contains_percentage() const
+{
+    for (auto const& value : m_values) {
+        if (value->contains_percentage())
+            return true;
+    }
+
+    return false;
+}
+
+CalculatedStyleValue::CalculationResult HypotCalculationNode::resolve(Optional<Length::ResolutionContext const&> context, CalculatedStyleValue::PercentageBasis const& percentage_basis) const
+{
+    double square_sum = 0.0;
+
+    for (auto const& value : m_values) {
+        auto child_resolved = value->resolve(context, percentage_basis);
+        auto child_value = resolve_value(child_resolved.value(), context);
+
+        square_sum += child_value * child_value;
+    }
+
+    auto result = sqrt(square_sum);
+
+    return to_resolved_type(resolved_type().value(), result);
+}
+
+ErrorOr<void> HypotCalculationNode::for_each_child_node(Function<ErrorOr<void>(NonnullOwnPtr<CalculationNode>&)> const& callback)
+{
+    for (auto& value : m_values) {
+        TRY(value->for_each_child_node(callback));
+        TRY(callback(value));
+    }
+
+    return {};
+}
+
+ErrorOr<void> HypotCalculationNode::dump(StringBuilder& builder, int indent) const
+{
+    TRY(builder.try_appendff("{: >{}}HYPOT:\n", "", indent));
+    for (auto const& value : m_values)
+        TRY(value->dump(builder, indent + 2));
+    return {};
+}
+
 void CalculatedStyleValue::CalculationResult::add(CalculationResult const& other, Optional<Length::ResolutionContext const&> context, PercentageBasis const& percentage_basis)
 {
     add_or_subtract_internal(SumOperation::Add, other, context, percentage_basis);

Userland/Libraries/LibWeb/CSS/StyleValues/CalculatedStyleValue.h

@@ -568,4 +568,22 @@ private:
     NonnullOwnPtr<CalculationNode> m_value;
 };
 
+class HypotCalculationNode final : public CalculationNode {
+public:
+    static ErrorOr<NonnullOwnPtr<HypotCalculationNode>> create(Vector<NonnullOwnPtr<CalculationNode>>);
+    ~HypotCalculationNode();
+
+    virtual ErrorOr<String> to_string() const override;
+    virtual Optional<CalculatedStyleValue::ResolvedType> resolved_type() const override;
+    virtual bool contains_percentage() const override;
+    virtual CalculatedStyleValue::CalculationResult resolve(Optional<Length::ResolutionContext const&>, CalculatedStyleValue::PercentageBasis const&) const override;
+    virtual ErrorOr<void> for_each_child_node(Function<ErrorOr<void>(NonnullOwnPtr<CalculationNode>&)> const&) override;
+
+    virtual ErrorOr<void> dump(StringBuilder&, int indent) const override;
+
+private:
+    explicit HypotCalculationNode(Vector<NonnullOwnPtr<CalculationNode>>);
+    Vector<NonnullOwnPtr<CalculationNode>> m_values;
+};
+
 }