From 422bbe98a56cb80b036b5a969ccce3fc757e8ff1 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 5 Jun 2020 23:36:02 +0200
Subject: [PATCH] LibWeb: Start adding support for the <iframe> element! :^)

This patch introduces a bunch of things:

- Subframes (Web::Frame::create_subframe())
- HTMLIFrameElement (loads and owns the hosted Web::Frame)
- LayoutFrame (layout and rendering of the hosted frame)

There's still a huge number of things missing, like scrolling, overflow
handling, event handling, scripting, etc. But we can make a little
iframe in a document and it actually renders another document there.
I think that's pretty cool! :^)
---
 Base/home/anon/www/iframe-subframe.html    |  2 +
 Base/home/anon/www/iframe.html             |  6 ++
 Base/home/anon/www/welcome.html            |  1 +
 Libraries/LibWeb/CMakeLists.txt            |  2 +
 Libraries/LibWeb/DOM/ElementFactory.cpp    |  3 +
 Libraries/LibWeb/DOM/HTMLIFrameElement.cpp | 96 ++++++++++++++++++++++
 Libraries/LibWeb/DOM/HTMLIFrameElement.h   | 57 +++++++++++++
 Libraries/LibWeb/Frame.cpp                 |  4 +
 Libraries/LibWeb/Frame.h                   |  2 +
 Libraries/LibWeb/Layout/LayoutFrame.cpp    | 88 ++++++++++++++++++++
 Libraries/LibWeb/Layout/LayoutFrame.h      | 57 +++++++++++++
 Libraries/LibWeb/Layout/LayoutNode.h       |  2 +
 Libraries/LibWeb/Layout/LayoutReplaced.h   |  1 +
 13 files changed, 321 insertions(+)
 create mode 100644 Base/home/anon/www/iframe-subframe.html
 create mode 100644 Base/home/anon/www/iframe.html
 create mode 100644 Libraries/LibWeb/DOM/HTMLIFrameElement.cpp
 create mode 100644 Libraries/LibWeb/DOM/HTMLIFrameElement.h
 create mode 100644 Libraries/LibWeb/Layout/LayoutFrame.cpp
 create mode 100644 Libraries/LibWeb/Layout/LayoutFrame.h
diff --git a/Base/home/anon/www/iframe-subframe.html b/Base/home/anon/www/iframe-subframe.html
new file mode 100644
index 00000000000..b6f6111027f
--- /dev/null
+++ b/Base/home/anon/www/iframe-subframe.html
@@ -0,0 +1,2 @@
+This is inside the frame!
+<img src=90s-bg.png>
diff --git a/Base/home/anon/www/iframe.html b/Base/home/anon/www/iframe.html
new file mode 100644
index 00000000000..6b07d626f02
--- /dev/null
+++ b/Base/home/anon/www/iframe.html
@@ -0,0 +1,6 @@
+<body>
+    <p>This page has an iframe in it
+    <p>Cool huh?
+    <iframe width=300 height=200 src="iframe-subframe.html" style="border: 1px solid #444"></iframe>
+    <p><b>this text is after the iframe</b>
+</body>
diff --git a/Base/home/anon/www/welcome.html b/Base/home/anon/www/welcome.html
index 5c6b5b081b8..cfbaca3176c 100644
--- a/Base/home/anon/www/welcome.html
+++ b/Base/home/anon/www/welcome.html
@@ -28,6 +28,7 @@ span#ua {
     <p>Your user agent is: <b><span id="ua"></span></b></p>
     <p>Some small test pages:</p>
     <ul>
+        <li><a href="iframe.html">iframe</a></li>
         <li><a href="many-buggies.html">many buggies</a></li>
         <li><a href="palette.html">system palette color css extension</a></li>
         <li><a href="inline-block-link.html">link inside display: inline-block</a></li>
diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 02b98b3133e..f81bb46086b 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -48,6 +48,7 @@ set(SOURCES
     DOM/HTMLHeadingElement.cpp
     DOM/HTMLHRElement.cpp
     DOM/HTMLHtmlElement.cpp
+    DOM/HTMLIFrameElement.cpp
     DOM/HTMLImageElement.cpp
     DOM/HTMLInputElement.cpp
     DOM/HTMLLinkElement.cpp
@@ -70,6 +71,7 @@ set(SOURCES
     Layout/LayoutBreak.cpp
     Layout/LayoutCanvas.cpp
     Layout/LayoutDocument.cpp
+    Layout/LayoutFrame.cpp
     Layout/LayoutImage.cpp
     Layout/LayoutInline.cpp
     Layout/LayoutListItem.cpp
diff --git a/Libraries/LibWeb/DOM/ElementFactory.cpp b/Libraries/LibWeb/DOM/ElementFactory.cpp
index bb4f13fa006..38fe0f40483 100644
--- a/Libraries/LibWeb/DOM/ElementFactory.cpp
+++ b/Libraries/LibWeb/DOM/ElementFactory.cpp
@@ -36,6 +36,7 @@
 #include <LibWeb/DOM/HTMLHeadElement.h>
 #include <LibWeb/DOM/HTMLHeadingElement.h>
 #include <LibWeb/DOM/HTMLHtmlElement.h>
+#include <LibWeb/DOM/HTMLIFrameElement.h>
 #include <LibWeb/DOM/HTMLImageElement.h>
 #include <LibWeb/DOM/HTMLInputElement.h>
 #include <LibWeb/DOM/HTMLLinkElement.h>
@@ -76,6 +77,8 @@ NonnullRefPtr<Element> create_element(Document& document, const FlyString& tag_n
         return adopt(*new HTMLInputElement(document, lowercase_tag_name));
     if (lowercase_tag_name == "br")
         return adopt(*new HTMLBRElement(document, lowercase_tag_name));
+    if (lowercase_tag_name == "iframe")
+        return adopt(*new HTMLIFrameElement(document, lowercase_tag_name));
     if (lowercase_tag_name == "h1"
         || lowercase_tag_name == "h2"
         || lowercase_tag_name == "h3"
diff --git a/Libraries/LibWeb/DOM/HTMLIFrameElement.cpp b/Libraries/LibWeb/DOM/HTMLIFrameElement.cpp
new file mode 100644
index 00000000000..aab32ea2b59
--- /dev/null
+++ b/Libraries/LibWeb/DOM/HTMLIFrameElement.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCore/ElapsedTimer.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/TextBox.h>
+#include <LibWeb/DOM/Document.h>
+#include <LibWeb/DOM/Event.h>
+#include <LibWeb/DOM/HTMLFormElement.h>
+#include <LibWeb/DOM/HTMLIFrameElement.h>
+#include <LibWeb/Dump.h>
+#include <LibWeb/Frame.h>
+#include <LibWeb/Layout/LayoutFrame.h>
+#include <LibWeb/Layout/LayoutWidget.h>
+#include <LibWeb/Loader/ResourceLoader.h>
+#include <LibWeb/PageView.h>
+#include <LibWeb/Parser/HTMLDocumentParser.h>
+
+namespace Web {
+
+HTMLIFrameElement::HTMLIFrameElement(Document& document, const FlyString& tag_name)
+    : HTMLElement(document, tag_name)
+{
+    m_hosted_frame = Frame::create_subframe();
+}
+
+HTMLIFrameElement::~HTMLIFrameElement()
+{
+}
+
+RefPtr<LayoutNode> HTMLIFrameElement::create_layout_node(const StyleProperties* parent_style) const
+{
+    auto style = document().style_resolver().resolve_style(*this, parent_style);
+    return adopt(*new LayoutFrame(*this, move(style)));
+}
+
+void HTMLIFrameElement::parse_attribute(const FlyString& name, const String& value)
+{
+    HTMLElement::parse_attribute(name, value);
+
+    if (name == HTML::AttributeNames::src) {
+        load_src(value);
+        return;
+    }
+}
+
+void HTMLIFrameElement::load_src(const String& value)
+{
+    dbg() << "Loading iframe document from " << value;
+    auto url = document().complete_url(value);
+    if (!url.is_valid()) {
+        dbg() << "Actually no I'm not, because the URL is not valid :(";
+        return;
+    }
+
+    ResourceLoader::the().load_sync(
+        url,
+        [&](auto& data, auto& headers) {
+            (void)headers;
+            auto html_source = String::copy(data);
+            HTMLDocumentParser parser(html_source, "utf-8");
+            parser.run(url);
+            m_hosted_frame->set_document(&parser.document());
+
+            dbg() << "The hosted frame now has this DOM:";
+            dump_tree(*m_hosted_frame->document());
+        },
+        [&](auto& error) {
+            dbg() << "<iframe> failed to load: " << error;
+        });
+}
+
+}
diff --git a/Libraries/LibWeb/DOM/HTMLIFrameElement.h b/Libraries/LibWeb/DOM/HTMLIFrameElement.h
new file mode 100644
index 00000000000..0a209e2f3fb
--- /dev/null
+++ b/Libraries/LibWeb/DOM/HTMLIFrameElement.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/HTMLElement.h>
+
+namespace Web {
+
+class HTMLIFrameElement : public HTMLElement {
+public:
+    HTMLIFrameElement(Document&, const FlyString& tag_name);
+    virtual ~HTMLIFrameElement() override;
+
+    virtual RefPtr<LayoutNode> create_layout_node(const StyleProperties* parent_style) const override;
+
+    Frame* hosted_frame() { return m_hosted_frame; }
+    const Frame* hosted_frame() const { return m_hosted_frame; }
+
+    virtual void parse_attribute(const FlyString& name, const String& value) override;
+
+private:
+    void load_src(const String&);
+
+    RefPtr<Frame> m_hosted_frame;
+};
+
+template<>
+inline bool is<HTMLIFrameElement>(const Node& node)
+{
+    return is<Element>(node) && to<Element>(node).tag_name().equals_ignoring_case("iframe");
+}
+
+}
diff --git a/Libraries/LibWeb/Frame.cpp b/Libraries/LibWeb/Frame.cpp
index e1d93354e50..3e72cacb998 100644
--- a/Libraries/LibWeb/Frame.cpp
+++ b/Libraries/LibWeb/Frame.cpp
@@ -32,6 +32,10 @@
 
 namespace Web {
 
+Frame::Frame()
+{
+}
+
 Frame::Frame(PageView& page_view)
     : m_page_view(page_view.make_weak_ptr())
 {
diff --git a/Libraries/LibWeb/Frame.h b/Libraries/LibWeb/Frame.h
index 9d30cdf8a1d..eda008379b1 100644
--- a/Libraries/LibWeb/Frame.h
+++ b/Libraries/LibWeb/Frame.h
@@ -41,6 +41,7 @@ class PageView;
 
 class Frame : public TreeNode<Frame> {
 public:
+    static NonnullRefPtr<Frame> create_subframe() { return adopt(*new Frame); }
     static NonnullRefPtr<Frame> create(PageView& page_view) { return adopt(*new Frame(page_view)); }
     ~Frame();
 
@@ -64,6 +65,7 @@ public:
     void did_scroll(Badge<PageView>);
 
 private:
+    Frame();
     explicit Frame(PageView&);
 
     WeakPtr<PageView> m_page_view;
diff --git a/Libraries/LibWeb/Layout/LayoutFrame.cpp b/Libraries/LibWeb/Layout/LayoutFrame.cpp
new file mode 100644
index 00000000000..288eac3648c
--- /dev/null
+++ b/Libraries/LibWeb/Layout/LayoutFrame.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibGUI/Painter.h>
+#include <LibGUI/ScrollBar.h>
+#include <LibGUI/Widget.h>
+#include <LibGfx/Font.h>
+#include <LibGfx/StylePainter.h>
+#include <LibWeb/DOM/Document.h>
+#include <LibWeb/Frame.h>
+#include <LibWeb/Layout/LayoutDocument.h>
+#include <LibWeb/Layout/LayoutFrame.h>
+#include <LibWeb/PageView.h>
+
+namespace Web {
+
+LayoutFrame::LayoutFrame(const Element& element, NonnullRefPtr<StyleProperties> style)
+    : LayoutReplaced(element, move(style))
+{
+}
+
+LayoutFrame::~LayoutFrame()
+{
+}
+
+void LayoutFrame::layout(LayoutMode layout_mode)
+{
+    set_has_intrinsic_width(true);
+    set_has_intrinsic_height(true);
+    // FIXME: Do proper error checking, etc.
+    bool ok;
+    set_intrinsic_width(node().attribute(HTML::AttributeNames::width).to_int(ok));
+    set_intrinsic_height(node().attribute(HTML::AttributeNames::height).to_int(ok));
+
+    LayoutReplaced::layout(layout_mode);
+}
+
+void LayoutFrame::render(RenderingContext& context)
+{
+    LayoutReplaced::render(context);
+
+    context.painter().save();
+    auto old_viewport_rect = context.viewport_rect();
+
+    context.painter().add_clip_rect(enclosing_int_rect(rect()));
+    context.painter().translate(x(), y());
+
+    context.set_viewport_rect({ {}, node().hosted_frame()->size() });
+    node().hosted_frame()->document()->layout_node()->render(context);
+
+    context.set_viewport_rect(old_viewport_rect);
+    context.painter().restore();
+}
+
+void LayoutFrame::did_set_rect()
+{
+    LayoutReplaced::did_set_rect();
+
+    ASSERT(node().hosted_frame());
+    node().hosted_frame()->set_size(Gfx::Size(rect().width(), rect().height()));
+
+    node().hosted_frame()->document()->layout();
+}
+
+}
diff --git a/Libraries/LibWeb/Layout/LayoutFrame.h b/Libraries/LibWeb/Layout/LayoutFrame.h
new file mode 100644
index 00000000000..d7e2015f68c
--- /dev/null
+++ b/Libraries/LibWeb/Layout/LayoutFrame.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibWeb/Layout/LayoutReplaced.h>
+#include <LibWeb/DOM/HTMLIFrameElement.h>
+
+namespace Web {
+
+class LayoutFrame final : public LayoutReplaced {
+public:
+    LayoutFrame(const Element&, NonnullRefPtr<StyleProperties>);
+    virtual ~LayoutFrame() override;
+
+    virtual void render(RenderingContext&) override;
+    virtual void layout(LayoutMode) override;
+
+    const HTMLIFrameElement& node() const { return static_cast<const HTMLIFrameElement&>(LayoutReplaced::node()); }
+    HTMLIFrameElement& node() { return static_cast<HTMLIFrameElement&>(LayoutReplaced::node()); }
+
+private:
+    virtual bool is_frame() const final { return true; }
+    virtual const char* class_name() const override { return "LayoutFrame"; }
+    virtual void did_set_rect() override;
+};
+
+template<>
+inline bool is<LayoutFrame>(const LayoutNode& node)
+{
+    return node.is_frame();
+}
+
+}
diff --git a/Libraries/LibWeb/Layout/LayoutNode.h b/Libraries/LibWeb/Layout/LayoutNode.h
index 8c31244e9c6..dc46e6019be 100644
--- a/Libraries/LibWeb/Layout/LayoutNode.h
+++ b/Libraries/LibWeb/Layout/LayoutNode.h
@@ -60,6 +60,7 @@ public:
 
     bool is_anonymous() const { return !m_node; }
     const Node* node() const { return m_node; }
+    Node* node() { return const_cast<Node*>(m_node); }
 
     Document& document();
     const Document& document() const;
@@ -87,6 +88,7 @@ public:
     virtual bool is_block() const { return false; }
     virtual bool is_replaced() const { return false; }
     virtual bool is_widget() const { return false; }
+    virtual bool is_frame() const { return false; }
     virtual bool is_image() const { return false; }
     virtual bool is_canvas() const { return false; }
     virtual bool is_box() const { return false; }
diff --git a/Libraries/LibWeb/Layout/LayoutReplaced.h b/Libraries/LibWeb/Layout/LayoutReplaced.h
index 99450b3a794..f3e9669f3b7 100644
--- a/Libraries/LibWeb/Layout/LayoutReplaced.h
+++ b/Libraries/LibWeb/Layout/LayoutReplaced.h
@@ -37,6 +37,7 @@ public:
     virtual ~LayoutReplaced() override;
 
     const Element& node() const { return to<Element>(*LayoutNode::node()); }
+    Element& node() { return to<Element>(*LayoutNode::node()); }
 
     virtual bool is_replaced() const final { return true; }
 
