Convert first letter into a pseudo element.

Source/core/editing/TextIterator.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov.
  *
  * 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
@@ skipping 741 matching lines @@
     }
     if (!m_textBox && m_remainingTextBox) {
         m_textBox = m_remainingTextBox;
         m_remainingTextBox = 0;
         m_firstLetterText = nullptr;
         m_offset = 0;
         handleTextBox();
     }
 }
 
-static inline RenderText* firstRenderTextInFirstLetter(RenderBoxModelObject* firstLetter)
+static RenderObject* firstLetterPseudoElement(RenderObject* fragment)
 {
-    if (!firstLetter)
-        return 0;
-
-    // FIXME: Should this check descendent objects?
-    for (RenderObject* current = firstLetter->slowFirstChild(); current; current = current->nextSibling()) {
-        if (current->isText())
-            return toRenderText(current);
-    }
-    return 0;
+    RenderObject* previousSibling = fragment->previousSibling();
+    if (previousSibling && previousSibling->isPseudoElement() && previousSibling->node()->isFirstLetterPseudoElement())

[Julien - ping for review, 2014/10/06 17:47:33]

Isn't the previousSibling->isPseudoElement() call redundant with
isFirstLetterPseudoElement()? (I haven't repeated this comment to other similar
patterns)

Also it's weird that this code doesn't use firstLetterPseudoElement like the
rest of the code.

[dsinclair, 2014/10/07 19:36:21]

No. I don't know if I have a node() unless I know if I'm a pseudoElement. It's
possible for previousSibling->node() to return a nullptr.
The firstLetterPseudoElement didn't exist on RenderTextFragment when I wrote
this code. Fixed.

+        return previousSibling;
+    return nullptr;
 }
 
 void TextIterator::handleTextNodeFirstLetter(RenderTextFragment* renderer)
 {
-    if (renderer->firstLetter()) {
-        RenderBoxModelObject* r = renderer->firstLetter();
-        if (r->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility)
+    RenderObject* pseudoElement = firstLetterPseudoElement(renderer);
+    if (pseudoElement) {
+        if (pseudoElement->style()->visibility() != VISIBLE && !m_ignoresStyleVisibility)
             return;
-        if (RenderText* firstLetter = firstRenderTextInFirstLetter(r)) {
+        // First letter pseudo elements only have one child which is the text.
+        if (RenderObject* firstLetter = pseudoElement->slowFirstChild()) {
+            ASSERT(firstLetter->isText());

[Julien - ping for review, 2014/10/06 17:47:33]

This ASSERT is redundant with the toRenderText below *and* is disabled in
Release contrary to toRenderText.

[dsinclair, 2014/10/07 19:36:21]

Done.

             m_handledFirstLetter = true;
             m_remainingTextBox = m_textBox;
-            m_textBox = firstLetter->firstTextBox();
+            m_textBox = toRenderText(firstLetter)->firstTextBox();
             m_sortedTextBoxes.clear();
-            m_firstLetterText = firstLetter;
+            m_firstLetterText = toRenderText(firstLetter);
         }
     }
     m_handledFirstLetter = true;
 }
 
 bool TextIterator::handleReplacedElement()
 {
     if (m_fullyClippedStack.top())
         return false;
 
@@ skipping 45 matching lines @@
     m_lastCharacter = 0;
 
     return true;
 }
 
 bool TextIterator::hasVisibleTextNode(RenderText* renderer)
 {
     if (renderer->style()->visibility() == VISIBLE)
         return true;
     if (renderer->isTextFragment()) {
-        RenderTextFragment* fragment = toRenderTextFragment(renderer);
-        if (fragment->firstLetter() && fragment->firstLetter()->style()->visibility() == VISIBLE)
+        RenderObject* pseudoElement = firstLetterPseudoElement(renderer);
+        if (pseudoElement && pseudoElement->style()->visibility() == VISIBLE)
             return true;
     }
     return false;
 }
 
 static bool shouldEmitTabBeforeNode(Node* node)
 {
     RenderObject* r = node->renderer();
 
     // Table cells are delimited by tabs.
@@ skipping 655 matching lines @@
     }
 
     if (!m_shouldHandleFirstLetter && offsetAfterFirstLetter < m_offset) {
         m_shouldHandleFirstLetter = true;
         offsetInNode = offsetAfterFirstLetter;
         return renderer;
     }
 
     m_shouldHandleFirstLetter = false;
     offsetInNode = 0;
-    RenderText* firstLetterRenderer = firstRenderTextInFirstLetter(fragment->firstLetter());
+
+    RenderObject* pseudoElement = firstLetterPseudoElement(fragment);
+    ASSERT(pseudoElement && pseudoElement->slowFirstChild());
+    RenderText* firstLetterRenderer = toRenderText(pseudoElement->slowFirstChild());
 
     m_offset = firstLetterRenderer->caretMaxOffset();
     m_offset += collapsedSpaceLength(firstLetterRenderer, m_offset);
 
     return firstLetterRenderer;
 }
 
 bool SimplifiedBackwardsTextIterator::handleReplacedElement()
 {
     unsigned index = m_node->nodeIndex();
@@ skipping 879 matching lines @@
             resultEnd = collapseTo;
             return;
         }
     }
 
     CharacterIterator computeRangeIterator(inputStart, inputEnd, iteratorFlagsForFindPlainText);
     calculateCharacterSubrange(computeRangeIterator, matchStart, matchLength, resultStart, resultEnd);
 }
 
 }