Convert first letter into a pseudo element.

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 38 matching lines @@
 #include "core/css/resolver/StyleResolverParentScope.h"
 #include "core/dom/Attr.h"
 #include "core/dom/CSSSelectorWatch.h"
 #include "core/dom/ClientRect.h"
 #include "core/dom/ClientRectList.h"
 #include "core/dom/DatasetDOMStringMap.h"
 #include "core/dom/ElementDataCache.h"
 #include "core/dom/ElementRareData.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/FirstLetterPseudoElement.h"
 #include "core/dom/Fullscreen.h"
 #include "core/dom/MutationObserverInterestGroup.h"
 #include "core/dom/MutationRecord.h"
 #include "core/dom/NamedNodeMap.h"
 #include "core/dom/NodeRenderStyle.h"
 #include "core/dom/PresentationAttributeStyle.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/RenderTreeBuilder.h"
 #include "core/dom/ScriptableDocumentParser.h"
 #include "core/dom/SelectorQuery.h"
+#include "core/dom/StyleChangeReason.h"
 #include "core/dom/StyleEngine.h"
 #include "core/dom/Text.h"
 #include "core/dom/custom/CustomElement.h"
 #include "core/dom/custom/CustomElementRegistrationContext.h"
 #include "core/dom/shadow/InsertionPoint.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/TextIterator.h"
 #include "core/editing/htmlediting.h"
 #include "core/editing/markup.h"
@@ skipping 17 matching lines @@
 #include "core/html/HTMLTableRowsCollection.h"
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/page/Chrome.h"
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "core/page/PointerLockController.h"
 #include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderTextFragment.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGElement.h"
 #include "platform/EventDispatchForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/UserGestureIndicator.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "wtf/BitVector.h"
 #include "wtf/HashFunctions.h"
@@ skipping 1225 matching lines @@
 
     // When a shadow root exists, it does the work of attaching the children.
     if (ElementShadow* shadow = this->shadow())
         shadow->attach(context);
 
     ContainerNode::attach(context);
 
     createPseudoElementIfNeeded(AFTER);
     createPseudoElementIfNeeded(BACKDROP);
 
+    // We create the first-letter element after the :before, :after and
+    // children are attached because the first letter text could come
+    // from any of them.
+    createPseudoElementIfNeeded(FIRST_LETTER);
+
     if (hasRareData() && !renderer()) {
         if (ActiveAnimations* activeAnimations = elementRareData()->activeAnimations()) {
             activeAnimations->cssAnimations().cancel();
             activeAnimations->setAnimationStyleChange(false);
         }
     }
 }
 
 void Element::detach(const AttachContext& context)
 {
@@ skipping 139 matching lines @@
             for (ShadowRoot* root = youngestShadowRoot(); root; root = root->olderShadowRoot()) {
                 if (root->shouldCallRecalcStyle(change))
                     root->recalcStyle(change);
             }
             recalcChildStyle(change);
         }
 
         updatePseudoElement(AFTER, change);
         updatePseudoElement(BACKDROP, change);
 
+        // If our children have changed then we need to force the first-letter
+        // checks as we don't know if they effected the first letter or not.
+        // This can be seen when a child transitions from floating to
+        // non-floating we have to take it into account for the first letter.
+        updatePseudoElement(FIRST_LETTER, childNeedsStyleRecalc() ? Force : change);
+
         clearChildNeedsStyleRecalc();
     }
 
     if (hasCustomStyleCallbacks())
         didRecalcStyle(change);
 
     if (change == Reattach)
         reattachWhitespaceSiblings(nextTextSibling);
 }
 
@@ skipping 961 matching lines @@
     // attributes while we are iterating.
     WillBeHeapVector<RefPtrWillBeMember<Attr> > attrNodesCopy(*attrNodes);
     for (size_t i = 0; i < attrNodesCopy.size(); ++i)
         attrNodesCopy[i]->normalize();
 }
 
 void Element::updatePseudoElement(PseudoId pseudoId, StyleRecalcChange change)
 {
     ASSERT(!needsStyleRecalc());
     PseudoElement* element = pseudoElement(pseudoId);
+
     if (element && (change == UpdatePseudoElements || element->shouldCallRecalcStyle(change))) {
+        // If we're updating first letter, and the current first letter renderer
+        // is not the same as the one we're currently using we need to re-create
+        // the first letter renderer.
+        if (pseudoId == FIRST_LETTER) {
+            RenderObject* remainingTextRenderer = FirstLetterPseudoElement::firstLetterTextRenderer(*element);
+            if (!remainingTextRenderer || remainingTextRenderer != toFirstLetterPseudoElement(element)->remainingTextRenderer()

[Julien - ping for review, 2014/10/06 17:47:32]

Wouldn't |element| be an arbitrary Element and not necessarily a
FirstLetterPseudoElement?

[Julien - ping for review, 2014/10/06 20:11:45]

Actually nevermind, I thought |element| == this.

[dsinclair, 2014/10/07 19:36:20]

Right, it has to be otherwise something has gone very very very wrong since we
pull it from the pseudoElement() call.

+                || toFirstLetterPseudoElement(element)->isStale()) {
+                // We have to clear out the old first letter here because when it is
+                // disposed it will set the original text back on the remaining text
+                // renderer. If we dispose after creating the new one we will get
+                // incorrect results due to setting the first letter back.
+                elementRareData()->setPseudoElement(FIRST_LETTER, nullptr);
+                createPseudoElementIfNeeded(pseudoId);

[esprehn, 2014/10/07 00:17:40]

You should just reattach the first letter PseudoElement. There's no need to
destroy and recreate the DOM node.

[dsinclair, 2014/10/07 19:36:20]

Done.

I was using FirstLetterPseudoElement::dispose() to put the first letter back
into the remaining text renderer. I've changed that to be ::detach instead.

+                return;
+            }
+        }
 
         // Need to clear the cached style if the PseudoElement wants a recalc so it
         // computes a new style.
         if (element->needsStyleRecalc())
             renderer()->style()->removeCachedPseudoStyle(pseudoId);
 
         // PseudoElement styles hang off their parent element's style so if we needed
         // a style recalc we should Force one on the pseudo.
         // FIXME: We should figure out the right text sibling to pass.
         element->recalcStyle(change == UpdatePseudoElements ? Force : change);
 
         // Wait until our parent is not displayed or pseudoElementRendererIsNeeded
-        // is false, otherwise we could continously create and destroy PseudoElements
+        // is false, otherwise we could continuously create and destroy PseudoElements
         // when RenderObject::isChildAllowed on our parent returns false for the
         // PseudoElement's renderer for each style recalc.
         if (!renderer() || !pseudoElementRendererIsNeeded(renderer()->getCachedPseudoStyle(pseudoId)))
             elementRareData()->setPseudoElement(pseudoId, nullptr);
     } else if (change >= UpdatePseudoElements) {
-        createPseudoElementIfNeeded(pseudoId);
+        // We have a first-letter pseudoElement, but we no longer should have one.
+        // This can happen if we change to a float, for example. We need to cleanup the
+        // first-letter pseudoElement and then fix the text of the original remaining
+        // text renderer.
+        // This can be seen in Test 7 of fast/css/first-letter-removed-added.html
+        if (pseudoId == FIRST_LETTER && element && !FirstLetterPseudoElement::firstLetterTextRenderer(*element))
+            elementRareData()->setPseudoElement(pseudoId, nullptr);

[esprehn, 2014/10/07 00:17:40]

This is in the wrong side of the branch. You should fix the above if statement
instead or add a new case.

[dsinclair, 2014/10/07 19:36:20]

Done? I wasn't quite sure what you meant with the above, but is this what you
were looking for?

+        else
+            createPseudoElementIfNeeded(pseudoId);
     }
 }
 
 void Element::createPseudoElementIfNeeded(PseudoId pseudoId)
 {
     if (isPseudoElement())
         return;
 
     // Document::ensureStyleResolver is not inlined and shows up on profiles, avoid it here.
     StyleEngine* engine = document().styleEngine();
@@ skipping 743 matching lines @@
         return wrapper;
 
     CustomElementBinding* binding = perContextData->customElementBinding(customElementDefinition());
 
     wrapper->SetPrototype(binding->prototype());
 
     return V8DOMWrapper::associateObjectWithWrapperNonTemplate(this, wrapperType, wrapper, isolate);
 }
 
 } // namespace blink