From bbcc5a93321fa34b537e5b635040357c4d49f5d6 Mon Sep 17 00:00:00 2001
From: asynts <asynts@gmail.com>
Date: Tue, 1 Dec 2020 23:35:47 +0100
Subject: [PATCH] LibWeb: Move editing stuff into EditEventHandler.

---
 Base/res/html/misc/contenteditable.html    |  8 +++
 Base/res/html/misc/welcome.html            |  1 +
 Libraries/LibWeb/CMakeLists.txt            |  1 +
 Libraries/LibWeb/DOM/Position.h            |  2 +
 Libraries/LibWeb/Forward.h                 |  1 +
 Libraries/LibWeb/Layout/LayoutPosition.cpp | 10 +++
 Libraries/LibWeb/Layout/LayoutPosition.h   |  6 ++
 Libraries/LibWeb/Page/EditEventHandler.cpp | 71 ++++++++++++++++++++++
 Libraries/LibWeb/Page/EditEventHandler.h   | 49 +++++++++++++++
 Libraries/LibWeb/Page/EventHandler.cpp     | 29 +++------
 Libraries/LibWeb/Page/EventHandler.h       |  5 ++
 11 files changed, 161 insertions(+), 22 deletions(-)
 create mode 100644 Base/res/html/misc/contenteditable.html
 create mode 100644 Libraries/LibWeb/Page/EditEventHandler.cpp
 create mode 100644 Libraries/LibWeb/Page/EditEventHandler.h
diff --git a/Base/res/html/misc/contenteditable.html b/Base/res/html/misc/contenteditable.html
new file mode 100644
index 0000000000..6bc6239f37
--- /dev/null
+++ b/Base/res/html/misc/contenteditable.html
@@ -0,0 +1,8 @@
+<html contenteditable>
+    <body>
+        <h1>Everything on this page should be editable.</h1>
+
+        <p>Here is a paragraph to play with.</p>
+        <p>Another paragraph with a <b>bold</b> element embeded in it.</p>
+    </body>
+</html>
diff --git a/Base/res/html/misc/welcome.html b/Base/res/html/misc/welcome.html
index c976d522d5..51bbae1346 100644
--- a/Base/res/html/misc/welcome.html
+++ b/Base/res/html/misc/welcome.html
@@ -38,6 +38,7 @@ span#loadtime {
     <p>This page loaded in <b><span id="loadtime"></span></b> ms</p>
     <p>Some small test pages:</p>
     <ul>
+        <li><a href="contenteditable.html">contenteditable</a></li>
         <li><a href="clear-1.html">clearing floats</a></li>
         <li><a href="float-1.html">floating boxes</a></li>
         <li><a href="padding-inline.html">inline elements with padding</a></li>
diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 3b6b57dba5..5cfb030bde 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -178,6 +178,7 @@ set(SOURCES
     Namespace.cpp
     OutOfProcessWebView.cpp
     Page/EventHandler.cpp
+    Page/EditEventHandler.cpp
     Page/Frame.cpp
     Page/Page.cpp
     Painting/BorderPainting.cpp
diff --git a/Libraries/LibWeb/DOM/Position.h b/Libraries/LibWeb/DOM/Position.h
index 8794fabb1b..75ef1a2f88 100644
--- a/Libraries/LibWeb/DOM/Position.h
+++ b/Libraries/LibWeb/DOM/Position.h
@@ -27,6 +27,7 @@
 #pragma once
 
 #include <AK/RefPtr.h>
+#include <LibWeb/DOM/Node.h>
 #include <LibWeb/Forward.h>
 
 namespace Web::DOM {
@@ -44,6 +45,7 @@ public:
     const Node* node() const { return m_node; }
 
     unsigned offset() const { return m_offset; }
+    void set_offset(unsigned value) { m_offset = value; }
 
     bool operator==(const Position& other) const
     {
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index 35ff04a815..ec1f5f1569 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -167,6 +167,7 @@ class ReplacedBox;
 
 namespace Web {
 class EventHandler;
+class EditEventHandler;
 class Frame;
 class FrameLoader;
 class InProcessWebView;
diff --git a/Libraries/LibWeb/Layout/LayoutPosition.cpp b/Libraries/LibWeb/Layout/LayoutPosition.cpp
index db0f8f2de1..b2b46b7343 100644
--- a/Libraries/LibWeb/Layout/LayoutPosition.cpp
+++ b/Libraries/LibWeb/Layout/LayoutPosition.cpp
@@ -24,11 +24,21 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <LibWeb/DOM/Position.h>
 #include <LibWeb/Layout/LayoutPosition.h>
 #include <LibWeb/Layout/Node.h>
 
 namespace Web::Layout {
 
+DOM::Position LayoutPosition::to_dom_position() const
+{
+    if (!layout_node)
+        return {};
+
+    // FIXME: Verify that there are no shenanigans going on.
+    return { const_cast<DOM::Node&>(*layout_node->dom_node()), (unsigned)index_in_node };
+}
+
 LayoutRange LayoutRange::normalized() const
 {
     if (!is_valid())
diff --git a/Libraries/LibWeb/Layout/LayoutPosition.h b/Libraries/LibWeb/Layout/LayoutPosition.h
index fa132c7ee6..5a7819e81c 100644
--- a/Libraries/LibWeb/Layout/LayoutPosition.h
+++ b/Libraries/LibWeb/Layout/LayoutPosition.h
@@ -27,6 +27,8 @@
 #pragma once
 
 #include <AK/RefPtr.h>
+#include <LibWeb/Forward.h>
+#include <LibWeb/Layout/Node.h>
 
 namespace Web::Layout {
 
@@ -35,6 +37,8 @@ class Node;
 struct LayoutPosition {
     RefPtr<Node> layout_node;
     int index_in_node { 0 };
+
+    DOM::Position to_dom_position() const;
 };
 
 class LayoutRange {
@@ -58,7 +62,9 @@ public:
     void set_end(const LayoutPosition& end) { m_end = end; }
 
     const LayoutPosition& start() const { return m_start; }
+    LayoutPosition& start() { return m_start; }
     const LayoutPosition& end() const { return m_end; }
+    LayoutPosition& end() { return m_end; }
 
     LayoutRange normalized() const;
 
diff --git a/Libraries/LibWeb/Page/EditEventHandler.cpp b/Libraries/LibWeb/Page/EditEventHandler.cpp
new file mode 100644
index 0000000000..e823892788
--- /dev/null
+++ b/Libraries/LibWeb/Page/EditEventHandler.cpp
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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 <AK/StringBuilder.h>
+#include <LibWeb/DOM/Position.h>
+#include <LibWeb/DOM/Text.h>
+#include <LibWeb/Layout/LayoutPosition.h>
+#include <LibWeb/Page/Frame.h>
+
+#include "EditEventHandler.h"
+
+namespace Web {
+
+void EditEventHandler::handle_delete(DOM::Position position)
+{
+    if (position.offset() == 0)
+        TODO();
+
+    if (is<DOM::Text>(*position.node())) {
+        auto& node = downcast<DOM::Text>(*position.node());
+        StringBuilder builder;
+        builder.append(node.data().substring_view(0, position.offset() - 1));
+        builder.append(node.data().substring_view(position.offset()));
+        node.set_data(builder.to_string());
+
+        m_frame.cursor_position().set_offset(m_frame.cursor_position().offset() - 1);
+        node.invalidate_style();
+    }
+}
+
+void EditEventHandler::handle_insert(DOM::Position position, u32 code_point)
+{
+    // FIXME: Unicode fiasco.
+
+    if (is<DOM::Text>(*position.node())) {
+        auto& node = downcast<DOM::Text>(*position.node());
+        StringBuilder builder;
+        builder.append(node.data().substring_view(0, position.offset()));
+        builder.append_code_point(code_point);
+        builder.append(node.data().substring_view(position.offset()));
+        node.set_data(builder.to_string());
+
+        m_frame.cursor_position().set_offset(m_frame.cursor_position().offset() + 1);
+        node.invalidate_style();
+    }
+}
+
+}
diff --git a/Libraries/LibWeb/Page/EditEventHandler.h b/Libraries/LibWeb/Page/EditEventHandler.h
new file mode 100644
index 0000000000..bb3c2c7a48
--- /dev/null
+++ b/Libraries/LibWeb/Page/EditEventHandler.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ * 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/Forward.h>
+
+namespace Web {
+
+class EditEventHandler {
+public:
+    explicit EditEventHandler(Frame& frame)
+        : m_frame(frame)
+    {
+    }
+
+    virtual ~EditEventHandler() = default;
+
+    virtual void handle_delete(DOM::Position);
+    virtual void handle_insert(DOM::Position, u32 code_point);
+
+private:
+    Frame& m_frame;
+};
+
+}
diff --git a/Libraries/LibWeb/Page/EventHandler.cpp b/Libraries/LibWeb/Page/EventHandler.cpp
index 0f2ef8951f..3f50cbbd7f 100644
--- a/Libraries/LibWeb/Page/EventHandler.cpp
+++ b/Libraries/LibWeb/Page/EventHandler.cpp
@@ -52,6 +52,7 @@ static Gfx::IntPoint compute_mouse_event_offset(const Gfx::IntPoint& position, c
 
 EventHandler::EventHandler(Badge<Frame>, Frame& frame)
     : m_frame(frame)
+    , m_edit_event_handler(make<EditEventHandler>(frame))
 {
 }
 
@@ -344,34 +345,18 @@ bool EventHandler::handle_keydown(KeyCode key, unsigned modifiers, u32 code_poin
             return focus_next_element();
     }
 
-    if (m_frame.cursor_position().node() && m_frame.cursor_position().node()->is_editable()) {
-        // FIXME: Support backspacing across DOM node boundaries.
-        if (key == KeyCode::Key_Backspace && m_frame.cursor_position().offset() > 0) {
-            auto& text_node = downcast<DOM::Text>(*m_frame.cursor_position().node());
-            StringBuilder builder;
-            builder.append(text_node.data().substring_view(0, m_frame.cursor_position().offset() - 1));
-            builder.append(text_node.data().substring_view(m_frame.cursor_position().offset(), text_node.data().length() - m_frame.cursor_position().offset()));
-            text_node.set_data(builder.to_string());
-            m_frame.set_cursor_position({ *m_frame.cursor_position().node(), m_frame.cursor_position().offset() - 1 });
-            // FIXME: This should definitely use incremental layout invalidation instead!
-            text_node.document().force_layout();
+    if (m_frame.cursor_position().is_valid() && m_frame.cursor_position().node()->is_editable()) {
+        if (key == KeyCode::Key_Backspace) {
+            m_edit_event_handler->handle_delete(m_frame.cursor_position());
             return true;
         }
 
-        if (code_point && m_frame.cursor_position().is_valid() && is<DOM::Text>(*m_frame.cursor_position().node())) {
-            auto& text_node = downcast<DOM::Text>(*m_frame.cursor_position().node());
-            StringBuilder builder;
-            builder.append(text_node.data().substring_view(0, m_frame.cursor_position().offset()));
-            builder.append_code_point(code_point);
-            builder.append(text_node.data().substring_view(m_frame.cursor_position().offset(), text_node.data().length() - m_frame.cursor_position().offset()));
-            text_node.set_data(builder.to_string());
-            // FIXME: This will advance the cursor incorrectly when inserting multiple whitespaces (DOM vs layout whitespace collapse difference.)
-            m_frame.set_cursor_position({ *m_frame.cursor_position().node(), m_frame.cursor_position().offset() + 1 });
-            // FIXME: This should definitely use incremental layout invalidation instead!
-            text_node.document().force_layout();
+        if (code_point) {
+            m_edit_event_handler->handle_insert(m_frame.cursor_position(), code_point);
             return true;
         }
     }
+
     return false;
 }
 
diff --git a/Libraries/LibWeb/Page/EventHandler.h b/Libraries/LibWeb/Page/EventHandler.h
index 65acfbdbe1..09334a5d44 100644
--- a/Libraries/LibWeb/Page/EventHandler.h
+++ b/Libraries/LibWeb/Page/EventHandler.h
@@ -32,6 +32,7 @@
 #include <LibGUI/Forward.h>
 #include <LibGfx/Forward.h>
 #include <LibWeb/Forward.h>
+#include <LibWeb/Page/EditEventHandler.h>
 
 namespace Web {
 
@@ -50,6 +51,8 @@ public:
 
     void set_mouse_event_tracking_layout_node(Layout::Node*);
 
+    void set_edit_event_handler(NonnullOwnPtr<EditEventHandler> value) { m_edit_event_handler = move(value); }
+
 private:
     bool focus_next_element();
     bool focus_previous_element();
@@ -64,6 +67,8 @@ private:
     bool m_in_mouse_selection { false };
 
     WeakPtr<Layout::Node> m_mouse_event_tracking_layout_node;
+
+    NonnullOwnPtr<EditEventHandler> m_edit_event_handler;
 };
 
 }
