LibWeb: Add Range::for_each_contained()

This centralizes the logic for iterating over a Range's contained nodes.

Libraries/LibWeb/DOM/Range.cpp

@@ -578,10 +578,11 @@ String Range::to_string() const
     }
 
     // 4. Append the concatenation of the data of all Text nodes that are contained in this, in tree order, to s.
-    for (GC::Ptr<Node> node = start_container(); node != end_container()->next_sibling(); node = node->next_in_pre_order()) {
-        if (is<Text>(*node) && contains_node(*node))
+    for_each_contained([&](GC::Ref<DOM::Node> node) {
+        if (is<Text>(*node))
             builder.append(static_cast<Text const&>(*node).data());
-    }
+        return IterationDecision::Continue;
+    });
 
     // 5. If this’s end node is a Text node, then append the substring of that node’s data from its start until this’s end offset to s.
     if (is<Text>(*end_container())) {

Libraries/LibWeb/DOM/Range.h

@@ -2,7 +2,7 @@
  * Copyright (c) 2020, the SerenityOS developers.
  * Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
  * Copyright (c) 2022-2023, Andreas Kling <andreas@ladybird.org>
- * Copyright (c) 2024, Jelle Raaijmakers <jelle@ladybird.org>
+ * Copyright (c) 2024-2025, Jelle Raaijmakers <jelle@ladybird.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -10,6 +10,7 @@
 #pragma once
 
 #include <LibWeb/DOM/AbstractRange.h>
+#include <LibWeb/DOM/Node.h>
 #include <LibWeb/Selection/Selection.h>
 #include <LibWeb/WebIDL/Types.h>
 
@@ -98,6 +99,29 @@ public:
 
     WebIDL::ExceptionOr<GC::Ref<DocumentFragment>> create_contextual_fragment(String const& fragment);
 
+    template<typename Callback>
+    void for_each_contained(Callback callback) const
+    {
+        return const_cast<Range*>(this)->for_each_contained(move(callback));
+    }
+
+    template<typename Callback>
+    void for_each_contained(Callback callback)
+    {
+        GC::Ptr<Node> end = m_end_container;
+        while (end && !end->next_sibling())
+            end = end->parent();
+        if (end)
+            end = end->next_sibling();
+
+        for (GC::Ptr<Node> node = m_start_container; node && node != end; node = node->next_in_pre_order()) {
+            if (contains_node(*node)) {
+                if (callback(*node) == IterationDecision::Break)
+                    return;
+            }
+        }
+    }
+
 private:
     explicit Range(Document&);
     Range(GC::Ref<Node> start_container, WebIDL::UnsignedLong start_offset, GC::Ref<Node> end_container, WebIDL::UnsignedLong end_offset);

Libraries/LibWeb/Editing/Commands.cpp

@@ -551,12 +551,12 @@ bool command_insert_paragraph_action(DOM::Document& document, String const&)
 
         // 4. Append to node list the first node in tree order that is contained in new range and is an allowed child of
         //    "p", if any.
-        new_range->start_container()->for_each_in_inclusive_subtree([&](DOM::Node& node) {
-            if (is_allowed_child_of_node(GC::Ref { node }, HTML::TagNames::p) && new_range->contains_node(node)) {
+        new_range->for_each_contained([&node_list](GC::Ref<DOM::Node> node) {
+            if (is_allowed_child_of_node(node, HTML::TagNames::p)) {
                 node_list.append(node);
-                return TraversalDecision::Break;
+                return IterationDecision::Break;
             }
-            return TraversalDecision::Continue;
+            return IterationDecision::Continue;
         });
 
         // 5. If node list is empty:
@@ -725,14 +725,10 @@ bool command_insert_paragraph_action(DOM::Document& document, String const&)
     container->parent()->insert_before(*new_container, container->next_sibling());
 
     // 26. Let contained nodes be all nodes contained in new line range.
-    // FIXME: this is probably wildly inefficient
     Vector<GC::Ref<DOM::Node>> contained_nodes;
-    auto common_ancestor = new_line_range->common_ancestor_container();
-    common_ancestor->for_each_in_subtree([&](GC::Ref<DOM::Node> child_node) {
-        if (!new_line_range->contains_node(child_node))
-            return TraversalDecision::SkipChildrenAndContinue;
-        contained_nodes.append(child_node);
-        return TraversalDecision::Continue;
+    new_line_range->for_each_contained([&contained_nodes](GC::Ref<DOM::Node> node) {
+        contained_nodes.append(node);
+        return IterationDecision::Continue;
     });
 
     // 27. Let frag be the result of calling extractContents() on new line range.

Libraries/LibWeb/Editing/Internal/Algorithms.cpp

@@ -590,21 +590,17 @@ void delete_the_selection(Selection& selection, bool block_merging, bool strip_w
 
     // 24. For each node contained in the active range, append node to node list if the last member of node list (if
     //     any) is not an ancestor of node; node is editable; and node is not a thead, tbody, tfoot, tr, th, or td.
-    auto common_ancestor = active_range()->common_ancestor_container();
-    common_ancestor->for_each_in_subtree([&](GC::Ref<DOM::Node> node) {
-        if (!active_range()->contains_node(node))
-            return TraversalDecision::SkipChildrenAndContinue;
-
+    active_range()->for_each_contained([&node_list](GC::Ref<DOM::Node> node) {
         if (!node_list.is_empty() && node_list.last()->is_ancestor_of(node))
-            return TraversalDecision::SkipChildrenAndContinue;
+            return IterationDecision::Continue;
 
         if (!node->is_editable())
-            return TraversalDecision::Continue;
+            return IterationDecision::Continue;
 
         if (!is<HTML::HTMLTableSectionElement>(*node) && !is<HTML::HTMLTableRowElement>(*node) && !is<HTML::HTMLTableCellElement>(*node))
             node_list.append(node);
 
-        return TraversalDecision::Continue;
+        return IterationDecision::Continue;
     });
 
     // 25. For each node in node list:

Libraries/LibWeb/HTML/Navigable.cpp

@@ -2186,10 +2186,11 @@ static String visible_text_in_range(DOM::Range const& range)
     if (is<DOM::Text>(*range.start_container()) && range.start_container()->layout_node())
         builder.append(static_cast<DOM::Text const&>(*range.start_container()).data().bytes_as_string_view().substring_view(range.start_offset()));
 
-    for (GC::Ptr<DOM::Node> node = range.start_container(); node != range.end_container()->next_sibling(); node = node->next_in_pre_order()) {
-        if (is<DOM::Text>(*node) && range.contains_node(*node) && node->layout_node())
+    range.for_each_contained([&](GC::Ref<DOM::Node> node) {
+        if (is<DOM::Text>(*node) && node->layout_node())
             builder.append(static_cast<DOM::Text const&>(*node).data());
-    }
+        return IterationDecision::Continue;
+    });
 
     if (is<DOM::Text>(*range.end_container()) && range.end_container()->layout_node())
         builder.append(static_cast<DOM::Text const&>(*range.end_container()).data().bytes_as_string_view().substring_view(0, range.end_offset()));