Convert first letter into a pseudo element.

Source/core/dom/PseudoElement.cpp

Index: Source/core/dom/PseudoElement.cpp
diff --git a/Source/core/dom/PseudoElement.cpp b/Source/core/dom/PseudoElement.cpp
index 9e3d981ea39d84921a1f192a096b052e1c2636c4..d38519fd056ce17bef60f7854f954104cd65c696 100644
--- a/Source/core/dom/PseudoElement.cpp
+++ b/Source/core/dom/PseudoElement.cpp
@@ -30,6 +30,7 @@
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/rendering/RenderObject.h"
 #include "core/rendering/RenderQuote.h"
+#include "core/rendering/RenderTextFragment.h"
 #include "core/rendering/style/ContentData.h"
 
 namespace blink {
@@ -49,6 +50,10 @@ const QualifiedName& pseudoElementTagName(PseudoId pseudoId)
         DEFINE_STATIC_LOCAL(QualifiedName, backdrop, (nullAtom, "<pseudo:backdrop>", nullAtom));
         return backdrop;
     }
+    case FIRST_LETTER: {
+        DEFINE_STATIC_LOCAL(QualifiedName, firstLetter, (nullAtom, "<pseudo:first-letter>", nullAtom));
+        return firstLetter;
+    }
     default: {
         ASSERT_NOT_REACHED();
     }
@@ -74,6 +79,7 @@ String PseudoElement::pseudoElementNameForEvents(PseudoId pseudoId)
 PseudoElement::PseudoElement(Element* parent, PseudoId pseudoId)
     : Element(pseudoElementTagName(pseudoId), &parent->document(), CreateElement)
     , m_pseudoId(pseudoId)
+    , m_remainingTextRenderer(nullptr)
 {
     ASSERT(pseudoId != NOPSEUDO);
     setParentOrShadowHostNode(parent);
@@ -94,6 +100,13 @@ void PseudoElement::dispose()
     ASSERT(!nextSibling());
     ASSERT(!previousSibling());
 
+    if (m_remainingTextRenderer && m_remainingTextRenderer->node()) {
+        ASSERT(m_remainingTextRenderer->node()->isTextNode());

[esprehn, 2014/09/30 09:00:30]

toText() already asserts this, and RenderText can only have Text* as the node
anyway, so you don't need this assert.

[dsinclair, 2014/09/30 21:46:33]

Done.

+        Text* textNode = toText(m_remainingTextRenderer->node());
+        m_remainingTextRenderer->setText(textNode->dataImpl(), true);
+    }
+    m_remainingTextRenderer = nullptr;
+
     detach();
     RefPtrWillBeRawPtr<Element> parent = parentOrShadowHostElement();
     setParentOrShadowHostNode(0);
@@ -109,6 +122,15 @@ void PseudoElement::attach(const AttachContext& context)
     RenderObject* renderer = this->renderer();
     if (!renderer)
         return;
+
+    // For a first letter renderer, we remove any current first letter children
+    // and attach new renderers.
+    if (isFirstLetterPseudoElement()) {
+        removeChildren();

[esprehn, 2014/09/30 09:00:30]

This doesn't make sense, PseudoElement never has real DOM children.
removeChildren() doesn't do anything.

[dsinclair, 2014/09/30 21:46:34]

Done.

+        this->attachFirstLetterTextRenderers();

[esprehn, 2014/09/30 09:00:30]

no this->

[dsinclair, 2014/09/30 21:46:34]

Done.

+        return;
+    }
+
     RenderStyle* style = renderer->style();
     if (style->styleType() != BEFORE && style->styleType() != AFTER)
         return;
@@ -125,6 +147,72 @@ void PseudoElement::attach(const AttachContext& context)
     }
 }
 
+RenderStyle* PseudoElement::styleForFirstLetter(RenderObject* rendererContainer)
+{
+    if (!rendererContainer)
+        return nullptr;
+
+    RenderObject* styleContainer = parentOrShadowHostElement()->renderer();
+    if (!styleContainer)
+        return nullptr;
+
+    // We always force the pseudo style to recompute as the first-letter style
+    // computed by the style container may not have taken the renderers styles
+    // into account.
+    styleContainer->style()->removeCachedPseudoStyle(FIRST_LETTER);
+
+    RenderStyle* pseudoStyle = styleContainer->getCachedPseudoStyle(FIRST_LETTER, rendererContainer->firstLineStyle());
+    ASSERT(pseudoStyle);
+
+    // Force inline display (except for floating first-letters).
+    pseudoStyle->setDisplay(pseudoStyle->isFloating() ? BLOCK : INLINE);
+
+    // CSS2 says first-letter can't be positioned.
+    pseudoStyle->setPosition(StaticPosition);
+
+    return pseudoStyle;
+}
+
+void PseudoElement::attachFirstLetterTextRenderers()
+{
+    ASSERT(m_pseudoId == FIRST_LETTER);
+
+    RenderObject* nextRenderer = firstLetterTextRenderer();
+    ASSERT(nextRenderer && nextRenderer->isText());
+
+    // The original string is going to be either a generated content string or a DOM node's
+    // string. We want the original string before it got transformed in case first-letter has
+    // no text-transform or a different text-transform applied to it.
+    String oldText = toRenderText(nextRenderer)->isTextFragment() ? toRenderTextFragment(nextRenderer)->completeText() : toRenderText(nextRenderer)->originalText();
+    ASSERT(oldText.impl());
+
+    RenderStyle* pseudoStyle = styleForFirstLetter(nextRenderer->parent());
+    this->renderer()->setStyle(pseudoStyle);

[esprehn, 2014/09/30 09:00:30]

I don't think you need this-> anywhere in here.

[dsinclair, 2014/09/30 21:46:34]

Done.

+
+    // FIXME: This would already have been calculated in firstLetterRenderer. Can we pass the length through?
+    unsigned length = firstLetterLength(oldText);
+
+    // Construct a text fragment for the text after the first letter.
+    // This text fragment might be empty.
+    RenderTextFragment* remainingText =
+        new RenderTextFragment(nextRenderer->node() ? nextRenderer->node() : &nextRenderer->document(), oldText.impl(), length, oldText.length() - length);
+    remainingText->setStyle(nextRenderer->style());
+    if (remainingText->node())
+        remainingText->node()->setRenderer(remainingText);
+    m_remainingTextRenderer = remainingText;
+
+    RenderObject* nextSibling = this->renderer()->nextSibling();
+    this->renderer()->parent()->addChild(remainingText, nextSibling);

[esprehn, 2014/09/30 09:00:30]

Woah this is scary, did you write this stuff or did it already exist?

[dsinclair, 2014/09/30 21:46:34]

I did, the previous version already had the firstLetterContainer and addChild()
to that container.

What would be the better solution here? Use nextSibling->parent()? or do I just
need to if (renderer()->parent()) in case we aren't in the tree for some reason?

+
+    // Construct text fragment for the first letter.
+    RenderTextFragment* letter = new RenderTextFragment(this, oldText.impl(), 0, length);
+    letter->setStyle(pseudoStyle);
+    this->renderer()->addChild(letter);
+
+    nextRenderer->destroy();
+    nextRenderer = remainingText;
+}
+
 bool PseudoElement::rendererIsNeeded(const RenderStyle& style)
 {
     return pseudoElementRendererIsNeeded(&style);
@@ -139,16 +227,31 @@ void PseudoElement::didRecalcStyle(StyleRecalcChange)
     // the style propagated downward manually similar to RenderObject::propagateStyleToAnonymousChildren.
     RenderObject* renderer = this->renderer();
     for (RenderObject* child = renderer->nextInPreOrder(renderer); child; child = child->nextInPreOrder(renderer)) {
-        // We only manage the style for the generated content items.
-        if (!child->isText() && !child->isQuote() && !child->isImage())
+        // We need to re-calculate the correct style for the first letter element
+        // and then apply that to the container and the text fragment inside.
+        if (child->style()->styleType() == FIRST_LETTER && m_remainingTextRenderer) {
+            if (RenderStyle* pseudoStyle = styleForFirstLetter(m_remainingTextRenderer->parent())) {
+                renderer->setStyle(pseudoStyle);

[esprehn, 2014/09/30 09:00:30]

Setting the style on yourself doesn't make sense, it should have already
happened.

[dsinclair, 2014/09/30 21:46:34]

Done.

+                child->setPseudoStyle(pseudoStyle);
+            }
             continue;
+        }
 
-        // The style for the RenderTextFragment for first letter is managed by an enclosing block, not by us.
-        if (child->style()->styleType() == FIRST_LETTER)
+        // We only manage the style for the generated content items.
+        if (!child->isText() && !child->isQuote() && !child->isImage())
             continue;
 
         child->setPseudoStyle(renderer->style());
     }
 }
 
+// A pseudoElement isn't, strictly, in the dom tree, it hands off the parent
+// node. So, we need to have the parent node retrieve its first letter text
+// renderer.
+RenderObject* PseudoElement::firstLetterTextRenderer() const
+{
+    ASSERT(parentOrShadowHostElement());
+    return parentOrShadowHostElement()->firstLetterTextRenderer();
+}
+
 } // namespace