Convert first letter into a pseudo element.

Source/core/rendering/RenderTextFragment.cpp

Index: Source/core/rendering/RenderTextFragment.cpp
diff --git a/Source/core/rendering/RenderTextFragment.cpp b/Source/core/rendering/RenderTextFragment.cpp
index 20f518f411efb627f41165815671c59eefc80566..92caafc0bb1315b06e47054c078cd956dc7aad85 100644
--- a/Source/core/rendering/RenderTextFragment.cpp
+++ b/Source/core/rendering/RenderTextFragment.cpp
@@ -23,6 +23,9 @@
 #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"
@@ -33,7 +36,7 @@ RenderTextFragment::RenderTextFragment(Node* node, StringImpl* str, int startOff
     : RenderText(node, str ? str->substring(startOffset, length) : PassRefPtr<StringImpl>(nullptr))
     , m_start(startOffset)
     , m_end(length)
-    , m_firstLetter(nullptr)
+    , m_firstLetterPseudoElement(nullptr)
 {
 }
 
@@ -42,73 +45,55 @@ RenderTextFragment::RenderTextFragment(Node* node, StringImpl* 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();
     }
 }
 
@@ -122,8 +107,7 @@ void RenderTextFragment::transformText()
 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];
     }
@@ -131,31 +115,32 @@ UChar RenderTextFragment::previousCharacter() const
     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())
-        return;
-    RenderObject* nodeRenderer = node()->renderer();
-    if (!nodeRenderer || !nodeRenderer->isText() || !toRenderText(nodeRenderer)->isTextFragment())
+    if (!node())
         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