LibWeb: Derive implicit aria-level for h1–h6 from tag name

Author: https://github.com/Dowsley 🔰
Commit: c6b289c3dc
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6256
Reviewed-by: https://github.com/AtkinsSJ ✅

Libraries/LibWeb/Internals/Internals.cpp

@@ -9,6 +9,8 @@
 #include <LibJS/Runtime/Date.h>
 #include <LibJS/Runtime/VM.h>
 #include <LibUnicode/TimeZone.h>
+#include <LibWeb/ARIA/AriaData.h>
+#include <LibWeb/ARIA/StateAndProperties.h>
 #include <LibWeb/Bindings/InternalsPrototype.h>
 #include <LibWeb/Bindings/Intrinsics.h>
 #include <LibWeb/DOM/Document.h>
@@ -308,6 +310,12 @@ String Internals::get_computed_label(DOM::Element& element)
     return MUST(element.accessible_name(active_document));
 }
 
+String Internals::get_computed_aria_level(DOM::Element& element)
+{
+    auto aria_data = MUST(ARIA::AriaData::build_data(element));
+    return MUST(ARIA::state_or_property_to_string_value(ARIA::StateAndProperties::AriaLevel, *aria_data));
+}
+
 u16 Internals::get_echo_server_port()
 {
     return s_echo_server_port;

Libraries/LibWeb/Internals/Internals.h

@@ -58,6 +58,7 @@ public:
 
     String get_computed_role(DOM::Element& element);
     String get_computed_label(DOM::Element& element);
+    String get_computed_aria_level(DOM::Element& element);
 
     static u16 get_echo_server_port();
     static void set_echo_server_port(u16 port);

Libraries/LibWeb/Internals/Internals.idl

@@ -49,6 +49,7 @@ interface Internals {
 
     DOMString getComputedRole(Element element);
     DOMString getComputedLabel(Element element);
+    DOMString getComputedAriaLevel(Element element);
     unsigned short getEchoServerPort();
 
     undefined setBrowserZoom(double factor);