From 34d0141da39fef8e0b394622412dcfaa216293ff Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Mon, 14 Dec 2020 13:41:18 +0100
Subject: [PATCH] LibWeb: Simplify <iframe> content frame construction

Now that documents are attached to their frame *before* parsing, we can
create the content frame of <iframe> elements right away, instead of
waiting for the host frame attachment.

Fixes #4408.
---
 Libraries/LibWeb/DOM/Document.cpp           |  9 ---------
 Libraries/LibWeb/DOM/Node.h                 |  3 ---
 Libraries/LibWeb/HTML/HTMLIFrameElement.cpp | 17 ++++++-----------
 Libraries/LibWeb/HTML/HTMLIFrameElement.h   |  3 +--
 4 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
index b8bc63fe3f..a85a23d280 100644
--- a/Libraries/LibWeb/DOM/Document.cpp
+++ b/Libraries/LibWeb/DOM/Document.cpp
@@ -283,20 +283,11 @@ void Document::set_title(const String& title)
 void Document::attach_to_frame(Badge<Frame>, Frame& frame)
 {
     m_frame = frame;
-    for_each_in_subtree([&](auto& node) {
-        node.document_did_attach_to_frame(frame);
-        return IterationDecision::Continue;
-    });
     update_layout();
 }
 
 void Document::detach_from_frame(Badge<Frame>, Frame& frame)
 {
-    for_each_in_subtree([&](auto& node) {
-        node.document_will_detach_from_frame(frame);
-        return IterationDecision::Continue;
-    });
-
     tear_down_layout_tree();
     m_frame = nullptr;
 }
diff --git a/Libraries/LibWeb/DOM/Node.h b/Libraries/LibWeb/DOM/Node.h
index b34a3a1182..7fc2b9bbaa 100644
--- a/Libraries/LibWeb/DOM/Node.h
+++ b/Libraries/LibWeb/DOM/Node.h
@@ -147,9 +147,6 @@ public:
 
     bool is_link() const;
 
-    virtual void document_did_attach_to_frame(Frame&) { }
-    virtual void document_will_detach_from_frame(Frame&) { }
-
     void set_document(Badge<Document>, Document&);
 
     virtual EventTarget* get_parent(const Event&) override;
diff --git a/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp b/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
index b2488620c2..937ca36321 100644
--- a/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLIFrameElement.cpp
@@ -46,6 +46,8 @@ namespace Web::HTML {
 HTMLIFrameElement::HTMLIFrameElement(DOM::Document& document, const QualifiedName& qualified_name)
     : HTMLElement(document, qualified_name)
 {
+    ASSERT(document.frame());
+    m_content_frame = Frame::create_subframe(*this, document.frame()->main_frame());
 }
 
 HTMLIFrameElement::~HTMLIFrameElement()
@@ -58,18 +60,11 @@ RefPtr<Layout::Node> HTMLIFrameElement::create_layout_node(const CSS::StylePrope
     return adopt(*new Layout::FrameBox(document(), *this, move(style)));
 }
 
-void HTMLIFrameElement::document_did_attach_to_frame(Frame& frame)
-{
-    ASSERT(!m_content_frame);
-    m_content_frame = Frame::create_subframe(*this, frame.main_frame());
-    auto src = attribute(HTML::AttributeNames::src);
-    if (src.is_null())
-        return;
-    load_src(src);
-}
-
-void HTMLIFrameElement::document_will_detach_from_frame(Frame&)
+void HTMLIFrameElement::parse_attribute(const FlyString& name, const String& value)
 {
+    HTMLElement::parse_attribute(name, value);
+    if (name == HTML::AttributeNames::src)
+        load_src(value);
 }
 
 void HTMLIFrameElement::load_src(const String& value)
diff --git a/Libraries/LibWeb/HTML/HTMLIFrameElement.h b/Libraries/LibWeb/HTML/HTMLIFrameElement.h
index f3f96d40fb..6688cb0a6c 100644
--- a/Libraries/LibWeb/HTML/HTMLIFrameElement.h
+++ b/Libraries/LibWeb/HTML/HTMLIFrameElement.h
@@ -50,8 +50,7 @@ public:
     void content_frame_did_load(Badge<FrameLoader>);
 
 private:
-    virtual void document_did_attach_to_frame(Frame&) override;
-    virtual void document_will_detach_from_frame(Frame&) override;
+    virtual void parse_attribute(const FlyString& name, const String& value) override;
 
     void load_src(const String&);