From f7e1f4a15b1c3e1b5086812855672ac3b3f4d49d Mon Sep 17 00:00:00 2001
From: Jelle Raaijmakers <jelle@gmta.nl>
Date: Mon, 26 Aug 2024 14:08:40 +0200
Subject: [PATCH] LibWeb: Propagate input/textarea selection update to document
 selection

Calling `.setSelectionRange()` or `.select()` now updates the document
selection as well, visualizing the text selection.
---
 .../LibWeb/HTML/FormAssociatedElement.cpp     | 21 ++++++++++++-------
 .../LibWeb/HTML/FormAssociatedElement.h       |  2 ++
 .../LibWeb/HTML/HTMLInputElement.cpp          | 10 +++++++++
 .../Libraries/LibWeb/HTML/HTMLInputElement.h  |  3 +++
 .../LibWeb/HTML/HTMLTextAreaElement.cpp       | 10 +++++++++
 .../LibWeb/HTML/HTMLTextAreaElement.h         |  3 +++
 6 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
index 66ba41d91bc74..8e78a8a6dfb0e 100644
--- a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
@@ -411,14 +411,21 @@ void FormAssociatedElement::set_the_selection_range(Optional<WebIDL::UnsignedLon
     //    extent or direction), then queue an element task on the user interaction task source
     //    given the element to fire an event named select at the element, with the bubbles attribute
     //    initialized to true.
-    // AD-HOC: If there is no selection, we do not fire the event. This seems to correspond to how
-    //         other browsers behave.
-    if (was_modified && m_selection_start != m_selection_end) {
+    if (was_modified) {
         auto& html_element = form_associated_element_to_html_element();
-        html_element.queue_an_element_task(Task::Source::UserInteraction, [&html_element] {
-            auto select_event = DOM::Event::create(html_element.realm(), EventNames::select, { .bubbles = true });
-            static_cast<DOM::EventTarget*>(&html_element)->dispatch_event(select_event);
-        });
+
+        // AD-HOC: If there is no selection, we do not fire the event. This seems to correspond to how
+        //         other browsers behave.
+        if (m_selection_start != m_selection_end) {
+            html_element.queue_an_element_task(Task::Source::UserInteraction, [&html_element] {
+                auto select_event = DOM::Event::create(html_element.realm(), EventNames::select, { .bubbles = true });
+                static_cast<DOM::EventTarget*>(&html_element)->dispatch_event(select_event);
+            });
+        }
+
+        // AD-HOC: Notify the element that the selection was changed, so it can perform
+        //         element-specific updates.
+        selection_was_changed();
     }
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
index eea5b700ffdbb..30747c6d92889 100644
--- a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
+++ b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
@@ -137,6 +137,8 @@ class FormAssociatedElement {
     // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#concept-textarea/input-relevant-value
     void relevant_value_was_changed(JS::GCPtr<DOM::Text>);
 
+    virtual void selection_was_changed() { }
+
 private:
     void reset_form_owner();
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
index ada592c5e1dae..59759bcc1ca6d 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.cpp
@@ -45,6 +45,7 @@
 #include <LibWeb/MimeSniff/Resource.h>
 #include <LibWeb/Namespace.h>
 #include <LibWeb/Page/Page.h>
+#include <LibWeb/Selection/Selection.h>
 #include <LibWeb/UIEvents/EventNames.h>
 #include <LibWeb/UIEvents/MouseEvent.h>
 #include <LibWeb/WebIDL/DOMException.h>
@@ -2353,4 +2354,13 @@ HTMLInputElement::ValueAttributeMode HTMLInputElement::value_attribute_mode() co
     VERIFY_NOT_REACHED();
 }
 
+void HTMLInputElement::selection_was_changed()
+{
+    auto selection = document().get_selection();
+    if (!selection || selection->range_count() == 0)
+        return;
+
+    MUST(selection->set_base_and_extent(*m_text_node, selection_start().value(), *m_text_node, selection_end().value()));
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
index 5740e18332c36..9c75cb65c89b2 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
@@ -199,6 +199,9 @@ class HTMLInputElement final
     bool select_applies() const;
     bool selection_or_range_applies() const;
 
+protected:
+    void selection_was_changed() override;
+
 private:
     HTMLInputElement(DOM::Document&, DOM::QualifiedName);
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
index 22c6284beab04..5d3c84248087b 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
@@ -22,6 +22,7 @@
 #include <LibWeb/HTML/Numbers.h>
 #include <LibWeb/Infra/Strings.h>
 #include <LibWeb/Namespace.h>
+#include <LibWeb/Selection/Selection.h>
 
 namespace Web::HTML {
 
@@ -452,4 +453,13 @@ void HTMLTextAreaElement::queue_firing_input_event()
     });
 }
 
+void HTMLTextAreaElement::selection_was_changed()
+{
+    auto selection = document().get_selection();
+    if (!selection || selection->range_count() == 0)
+        return;
+
+    MUST(selection->set_base_and_extent(*m_text_node, selection_start().value(), *m_text_node, selection_end().value()));
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.h b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
index e69fe45abea13..be0d7683e2a09 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLTextAreaElement.h
@@ -114,6 +114,9 @@ class HTMLTextAreaElement final
     String selection_direction_binding() const;
     void set_selection_direction_binding(String direction);
 
+protected:
+    void selection_was_changed() override;
+
 private:
     HTMLTextAreaElement(DOM::Document&, DOM::QualifiedName);