4 files changed, 17 insertions, 2 deletions
diff --git a/Libraries/LibCore/CEvent.cpp b/Libraries/LibCore/CEvent.cpp
index eacce964c2..ebc9eeff3d 100644
--- a/Libraries/LibCore/CEvent.cpp
+++ b/Libraries/LibCore/CEvent.cpp
@@ -1,9 +1,10 @@
 #include <LibCore/CEvent.h>
 #include <LibCore/CObject.h>
 
-CChildEvent::CChildEvent(Type type, CObject& child)
+CChildEvent::CChildEvent(Type type, CObject& child, CObject* insertion_before_child)
     : CEvent(type)
     , m_child(child.make_weak_ptr())
+    , m_insertion_before_child(insertion_before_child ? insertion_before_child->make_weak_ptr() : nullptr)
 {
 }
 
diff --git a/Libraries/LibCore/CEvent.h b/Libraries/LibCore/CEvent.h
index 8e49c07fd4..28c593be45 100644
--- a/Libraries/LibCore/CEvent.h
+++ b/Libraries/LibCore/CEvent.h
@@ -100,14 +100,18 @@ private:
 
 class CChildEvent final : public CEvent {
 public:
-    CChildEvent(Type, CObject& child);
+    CChildEvent(Type, CObject& child, CObject* insertion_before_child = nullptr);
     ~CChildEvent();
 
     CObject* child() { return m_child.ptr(); }
     const CObject* child() const { return m_child.ptr(); }
 
+    CObject* insertion_before_child() { return m_insertion_before_child.ptr(); }
+    const CObject* insertion_before_child() const { return m_insertion_before_child.ptr(); }
+
 private:
     WeakPtr<CObject> m_child;
+    WeakPtr<CObject> m_insertion_before_child;
 };
 
 class CCustomEvent : public CEvent {
diff --git a/Libraries/LibCore/CObject.cpp b/Libraries/LibCore/CObject.cpp
index 0058de5b39..7de5a5a044 100644
--- a/Libraries/LibCore/CObject.cpp
+++ b/Libraries/LibCore/CObject.cpp
@@ -64,6 +64,15 @@ void CObject::add_child(CObject& object)
     event(*make<CChildEvent>(CEvent::ChildAdded, object));
 }
 
+void CObject::insert_child_before(CObject& new_child, CObject& before_child)
+{
+    // FIXME: Should we support reparenting objects?
+    ASSERT(!new_child.parent() || new_child.parent() == this);
+    new_child.m_parent = this;
+    m_children.insert_before_matching(new_child, [&](auto& existing_child) { return existing_child.ptr() == &before_child; });
+    event(*make<CChildEvent>(CEvent::ChildAdded, new_child, &before_child));
+}
+
 void CObject::remove_child(CObject& object)
 {
     for (int i = 0; i < m_children.size(); ++i) {
diff --git a/Libraries/LibCore/CObject.h b/Libraries/LibCore/CObject.h
index 7a5ce63785..709d2e607e 100644
--- a/Libraries/LibCore/CObject.h
+++ b/Libraries/LibCore/CObject.h
@@ -70,6 +70,7 @@ public:
     bool has_timer() const { return m_timer_id; }
 
     void add_child(CObject&);
+    void insert_child_before(CObject& new_child, CObject& before_child);
     void remove_child(CObject&);
 
     void dump_tree(int indent = 0);