LibWeb/SVG: Implement activation behavior for SVGAElement

This makes navigation work when clicking on SVG `<a>` elements.

Libraries/LibWeb/DOM/Element.cpp

@@ -267,7 +267,7 @@ bool Element::cannot_navigate() const
         return true;
 
     // - element is not an a element and is not connected.
-    return !is_html_anchor_element() && !is_connected();
+    return !(is_html_anchor_element() || is_svg_a_element()) && !is_connected();
 }
 
 // https://html.spec.whatwg.org/multipage/links.html#following-hyperlinks-2
@@ -281,7 +281,7 @@ void Element::follow_the_hyperlink(Optional<String> hyperlink_suffix, HTML::User
     String target_attribute_value;
 
     // 3. If subject is an a or area element, then set targetAttributeValue to the result of getting an element's target given subject.
-    if (is_html_anchor_element() || is_html_area_element())
+    if (is_html_anchor_element() || is_html_area_element() || is_svg_a_element())
         target_attribute_value = get_an_elements_target();
 
     // 4. Let urlRecord be the result of encoding-parsing a URL given subject's href attribute value, relative to subject's node document.

Libraries/LibWeb/SVG/SVGAElement.cpp

@@ -7,8 +7,11 @@
 
 #include <LibWeb/Bindings/SVGAElementPrototype.h>
 #include <LibWeb/DOM/DOMTokenList.h>
+#include <LibWeb/HTML/UserNavigationInvolvement.h>
 #include <LibWeb/Layout/SVGGraphicsBox.h>
+#include <LibWeb/SVG/AttributeNames.h>
 #include <LibWeb/SVG/SVGAElement.h>
+#include <LibWeb/UIEvents/MouseEvent.h>
 
 namespace Web::SVG {
 
@@ -84,4 +87,39 @@ GC::Ptr<Layout::Node> SVGAElement::create_layout_node(GC::Ref<CSS::ComputedPrope
     return heap().allocate<Layout::SVGGraphicsBox>(document(), *this, move(style));
 }
 
+// https://html.spec.whatwg.org/multipage/links.html#links-created-by-a-and-area-elements
+void SVGAElement::activation_behavior(DOM::Event const& event)
+{
+    // The activation behavior of an a or area element element given an event event is:
+
+    // 1. If element has no href attribute, then return.
+    if (href()->base_val().is_empty())
+        return;
+
+    // AD-HOC: Do not activate the element for clicks with the ctrl/cmd modifier present. This lets
+    //         the browser process open the link in a new tab.
+    if (is<UIEvents::MouseEvent>(event)) {
+        auto const& mouse_event = static_cast<UIEvents::MouseEvent const&>(event);
+        if (mouse_event.platform_ctrl_key())
+            return;
+    }
+
+    // 2. Let hyperlinkSuffix be null.
+    Optional<String> hyperlink_suffix {};
+
+    // FIXME: 3. If element is an a element, and event's target is an img with an ismap attribute specified, then:
+
+    // 4. Let userInvolvement be event's user navigation involvement.
+    auto user_involvement = HTML::user_navigation_involvement(event);
+
+    // FIXME: 5. If the user has expressed a preference to download the hyperlink, then set userInvolvement to "browser UI".
+
+    // FIXME: 6. If element has a download attribute, or if the user has expressed a preference to download the
+    //     hyperlink, then download the hyperlink created by element with hyperlinkSuffix set to hyperlinkSuffix and
+    //     userInvolvement set to userInvolvement.
+
+    // 7. Otherwise, follow the hyperlink created by element with hyperlinkSuffix set to hyperlinkSuffix and userInvolvement set to userInvolvement.
+    follow_the_hyperlink(hyperlink_suffix, user_involvement);
+}
+
 }

Libraries/LibWeb/SVG/SVGAElement.h

@@ -39,6 +39,9 @@ private:
     virtual void attribute_changed(FlyString const& name, Optional<String> const& old_value, Optional<String> const& value, Optional<FlyString> const& namespace_) override;
     virtual i32 default_tab_index_value() const override;
 
+    virtual bool has_activation_behavior() const override { return true; }
+    virtual void activation_behavior(DOM::Event const&) override;
+
     GC::Ptr<DOM::DOMTokenList> m_rel_list;
 
     GC::Ptr<SVGAnimatedString> m_target;

Tests/LibWeb/Text/expected/svg-a-element-activation-behavior.txt

@@ -0,0 +1,2 @@
+basic link activated
+target link activated in iframe

Tests/LibWeb/Text/input/svg-a-element-activation-behavior.html

@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<script src="include.js"></script>
+<iframe id="target-frame" name="target-frame"></iframe>
+<svg>
+    <a id="basic-link" href="javascript:println('basic link activated')">
+        <text y="20">Basic Link</text>
+    </a>
+    <a id="target-link" href="javascript:parent.println('target link activated in iframe')" target="target-frame">
+        <text y="40">Target Link</text>
+    </a>
+</svg>
+<script>
+promiseTest(async () => {
+    document.getElementById("basic-link").dispatchEvent(new MouseEvent("click"));
+    await animationFrame();
+
+    document.getElementById("target-link").dispatchEvent(new MouseEvent("click"));
+    await animationFrame();
+});
+</script>