LibWeb: Allow all elements with tabindex attribute to be focusable

Author: https://github.com/lpas
Commit: 3bc061d028
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6780
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/DOM/Element.cpp

@@ -4277,6 +4277,12 @@ bool Element::should_indicate_focus() const
     return false;
 }
 
+// https://html.spec.whatwg.org/multipage/interaction.html#tabindex-value
+bool Element::is_focusable() const
+{
+    return HTML::parse_integer(get_attribute_value(HTML::AttributeNames::tabindex)).has_value();
+}
+
 void Element::set_had_duplicate_attribute_during_tokenization(Badge<HTML::HTMLParser>)
 {
     m_had_duplicate_attribute_during_tokenization = true;

Libraries/LibWeb/DOM/Element.h

@@ -301,6 +301,7 @@ public:
     virtual void did_receive_focus() { }
     virtual void did_lose_focus() { }
     bool should_indicate_focus() const;
+    virtual bool is_focusable() const override;
 
     static GC::Ptr<Layout::NodeWithStyle> create_layout_node_for_display_type(DOM::Document&, CSS::Display const&, GC::Ref<CSS::ComputedProperties>, Element*);
 

Libraries/LibWeb/HTML/HTMLElement.cpp

@@ -149,7 +149,7 @@ void HTMLElement::set_dir(String const& dir)
 
 bool HTMLElement::is_focusable() const
 {
-    return is_editing_host() || get_attribute(HTML::AttributeNames::tabindex).has_value();
+    return Base::is_focusable() || is_editing_host();
 }
 
 // https://html.spec.whatwg.org/multipage/interaction.html#dom-iscontenteditable