Convert first letter into a pseudo element.

Source/core/rendering/RenderTextFragment.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "config.h"
 #include "core/rendering/RenderTextFragment.h"
 
+#include "core/dom/FirstLetterPseudoElement.h"
+#include "core/dom/PseudoElement.h"
+#include "core/dom/StyleChangeReason.h"
 #include "core/dom/Text.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/RenderBlock.h"
 
 namespace blink {
 
 RenderTextFragment::RenderTextFragment(Node* node, StringImpl* str, int startOffset, int length)
     : RenderText(node, str ? str->substring(startOffset, length) : PassRefPtr<StringImpl>(nullptr))
     , m_start(startOffset)
     , m_end(length)
-    , m_firstLetter(nullptr)
+    , m_firstLetterPseudoElement(nullptr)
 {
 }
 
 RenderTextFragment::RenderTextFragment(Node* node, StringImpl* str)
     : RenderText(node, str)
     , m_start(0)
     , m_end(str ? str->length() : 0)
     , m_contentString(str)
-    , m_firstLetter(nullptr)
+    , m_firstLetterPseudoElement(nullptr)
 {
 }
 
 RenderTextFragment::~RenderTextFragment()
 {
+    if (m_firstLetterPseudoElement)
+        m_firstLetterPseudoElement->setRemainingTextRenderer(nullptr);
+    m_firstLetterPseudoElement = nullptr;
 }
 
 void RenderTextFragment::trace(Visitor* visitor)
 {
-    visitor->trace(m_firstLetter);
+    visitor->trace(m_firstLetterPseudoElement);
     RenderText::trace(visitor);
 }
 
-RenderText* RenderTextFragment::firstRenderTextInFirstLetter() const
+PassRefPtr<StringImpl> RenderTextFragment::completeText() const
 {
-    for (RenderObject* current = m_firstLetter; current; current = current->nextInPreOrder(m_firstLetter)) {
-        if (current->isText())
-            return toRenderText(current);
-    }
-    return 0;
+    Text* text = associatedTextNode();
+    return text ? text->dataImpl() : contentString();
 }
 
 PassRefPtr<StringImpl> RenderTextFragment::originalText() const
 {
-    Node* e = node();
-    RefPtr<StringImpl> result = ((e && e->isTextNode()) ? toText(e)->dataImpl() : contentString());
+    RefPtr<StringImpl> result = completeText();
     if (!result)
         return nullptr;
     return result->substring(start(), end());
 }
 
-void RenderTextFragment::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
-{
-    RenderText::styleDidChange(diff, oldStyle);
-
-    if (RenderBlock* block = blockForAccompanyingFirstLetter()) {
-        block->style()->removeCachedPseudoStyle(FIRST_LETTER);
-        block->updateFirstLetter();
-    }
-}
-
-void RenderTextFragment::willBeDestroyed()
-{
-    if (m_firstLetter)
-        m_firstLetter->destroy();
-    RenderText::willBeDestroyed();
-}
-
 void RenderTextFragment::setText(PassRefPtr<StringImpl> text, bool force)
 {
     RenderText::setText(text, force);
 
     m_start = 0;
     m_end = textLength();
-    if (m_firstLetter) {
-        // FIXME: We should not modify the structure of the render tree during
-        // layout. crbug.com/370458
-        DeprecatedDisableModifyRenderTreeStructureAsserts disabler;
 
-        ASSERT(!m_contentString);
-        m_firstLetter->destroy();
-        m_firstLetter = nullptr;
-        if (Node* t = node()) {
-            ASSERT(!t->renderer());
-            t->setRenderer(this);
-        }
+    // If we're the remaining text from a first letter then we have to tell the
+    // first letter pseudo element to reattach itself so it can re-calculate the
+    // correct first-letter settings.
+    if (RenderObject* previous = previousSibling()) {
+        if (!previous->isPseudoElement() || !previous->node()->isFirstLetterPseudoElement())
+            return;
+
+        // Tell the first letter container node, and the first-letter node
+        // that their style may have changed.
+        // e.g. fast/css/first-letter-detach.html
+        toFirstLetterPseudoElement(previous->node())->setNeedsUpdate();
     }
 }
 
 void RenderTextFragment::transformText()
 {
     // Don't reset first-letter here because we are only transforming the truncated fragment.
     if (RefPtr<StringImpl> textToTransform = originalText())
         RenderText::setText(textToTransform.release(), true);
 }
 
 UChar RenderTextFragment::previousCharacter() const
 {
     if (start()) {
-        Node* e = node();
-        StringImpl* original = ((e && e->isTextNode()) ? toText(e)->dataImpl() : contentString());
+        StringImpl* original = completeText().get();
         if (original && start() <= original->length())
             return (*original)[start() - 1];
     }
 
     return RenderText::previousCharacter();
 }
 
-RenderBlock* RenderTextFragment::blockForAccompanyingFirstLetter() const
-{
-    if (!m_firstLetter)
-        return 0;
-    for (RenderObject* block = m_firstLetter->parent(); block; block = block->parent()) {
-        if (block->style()->hasPseudoStyle(FIRST_LETTER) && block->canHaveChildren() && block->isRenderBlock())
-            return toRenderBlock(block);
-    }
-    return 0;
-}
-
 void RenderTextFragment::updateHitTestResult(HitTestResult& result, const LayoutPoint& point)
 {
     if (result.innerNode())
         return;
 
     RenderObject::updateHitTestResult(result, point);
-    if (m_firstLetter || !node())
+    if (!node())
         return;
-    RenderObject* nodeRenderer = node()->renderer();
-    if (!nodeRenderer || !nodeRenderer->isText() || !toRenderText(nodeRenderer)->isTextFragment())
-        return;
+}
 
-    if (isDescendantOf(toRenderTextFragment(nodeRenderer)->m_firstLetter))
-        result.setIsFirstLetter(true);
+// If this is the renderer for a first-letter pseudoNode then we have to look
+// at the node for the remaining text to find our content.
+Text* RenderTextFragment::associatedTextNode() const
+{
+    Node* node = this->node();
+    if (!node)
+        return nullptr;
+
+    if (node->isFirstLetterPseudoElement()) {
+        PseudoElement* pseudo = toPseudoElement(node);

[esprehn, 2014/10/11 04:46:20]

toFirstLetterPseudoElement()

[dsinclair, 2014/10/14 14:31:28]

Done.

+        RenderObject* nextRenderer = FirstLetterPseudoElement::firstLetterTextRenderer(*pseudo);

[esprehn, 2014/10/11 04:46:20]

This should just be a method on FirstLetterPseudoElement.

pseudo->textRenderer(); or something.

[dsinclair, 2014/10/14 14:31:28]

We also call this when we don't have a FirstLetterPseudoElement yet, so it has
to be static. I can make a dummy method on first letter that just calls through
to the static, but the static will need to exist anyway.

+        if (!nextRenderer)
+            return nullptr;
+        node = nextRenderer->node();
+    }
+    return (node && node->isTextNode()) ? toText(node) : nullptr;

[esprehn, 2014/10/11 04:46:20]

How can this ever not be a Text node? RenderTextFragment must be a Text, and the
firstLetterTextRenderer seems like it better return RenderText too, which I
think means it must be a Text node as well.

[dsinclair, 2014/10/14 14:31:28]

This was more to be safe then anything else. It is possible to have a RenderText
that doesn't point to a text node. The first letter renderer for example points
to the FirstLetterPseudoElement instead of the text node (this is because, we'd
end up with two renderers pointed at the same node which causes funkyness when
the renderer or node get destroyed).

 }
 
 } // namespace blink