Convert first letter into a pseudo element.

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. 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
@@ skipping 1363 matching lines @@
             gDelayedUpdateScrollInfoSet->add(this);
         else
             layer()->scrollableArea()->updateAfterLayout();
     }
 }
 
 void RenderBlock::layout()
 {
     OverflowEventDispatcher dispatcher(this);
 
-    // Update our first letter info now.
-    updateFirstLetter();
-
     // Table cells call layoutBlock directly, so don't add any logic here.  Put code into
     // layoutBlock().
     layoutBlock(false);
 
     // It's safe to check for control clip here, since controls can never be table cells.
     // If we have a lightweight clip, there can never be any overflow from children.
     if (hasControlClip() && m_overflow)
         clearLayoutOverflow();
 
     invalidateBackgroundObscurationStatus();
@@ skipping 1579 matching lines @@
 
     int scrollbarWidth = instrinsicScrollbarLogicalWidth();
     maxLogicalWidth += scrollbarWidth;
     minLogicalWidth += scrollbarWidth;
 }
 
 void RenderBlock::computePreferredLogicalWidths()
 {
     ASSERT(preferredLogicalWidthsDirty());
 
-    updateFirstLetter();
-
     m_minPreferredLogicalWidth = 0;
     m_maxPreferredLogicalWidth = 0;
 
     // FIXME: The isFixed() calls here should probably be checking for isSpecified since you
     // should be able to use percentage, calc or viewport relative values for width.
     RenderStyle* styleToUse = style();
     if (!isTableCell() && styleToUse->logicalWidth().isFixed() && styleToUse->logicalWidth().value() >= 0
         && !(isDeprecatedFlexItem() && !styleToUse->logicalWidth().intValue()))
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = adjustContentBoxLogicalWidthForBoxSizing(styleToUse->logicalWidth().value());
     else
@@ skipping 337 matching lines @@
             break;
         firstLineBlock = toRenderBlock(parentBlock);
     }
 
     if (!hasPseudo)
         return 0;
 
     return firstLineBlock;
 }
 
-static RenderStyle* styleForFirstLetter(RenderObject* firstLetterBlock, RenderObject* firstLetterContainer)
-{
-    RenderStyle* pseudoStyle = firstLetterBlock->getCachedPseudoStyle(FIRST_LETTER, firstLetterContainer->firstLineStyle());
-    // 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;
-}
-
-// CSS 2.1 http://www.w3.org/TR/CSS21/selector.html#first-letter
-// "Punctuation (i.e, characters defined in Unicode [UNICODE] in the "open" (Ps), "close" (Pe),
-// "initial" (Pi). "final" (Pf) and "other" (Po) punctuation classes), that precedes or follows the first letter should be included"
-static inline bool isPunctuationForFirstLetter(UChar c)
-{
-    CharCategory charCategory = category(c);
-    return charCategory == Punctuation_Open
-        || charCategory == Punctuation_Close
-        || charCategory == Punctuation_InitialQuote
-        || charCategory == Punctuation_FinalQuote
-        || charCategory == Punctuation_Other;
-}
-
-static inline bool isSpaceForFirstLetter(UChar c)
-{
-    return isSpaceOrNewline(c) || c == noBreakSpace;
-}
-
-static inline RenderObject* findFirstLetterBlock(RenderBlock* start)
-{
-    RenderObject* firstLetterBlock = start;
-    while (true) {
-        bool canHaveFirstLetterRenderer = firstLetterBlock->style()->hasPseudoStyle(FIRST_LETTER)
-            && firstLetterBlock->canHaveGeneratedChildren()
-            && isRenderBlockFlowOrRenderButton(firstLetterBlock);
-        if (canHaveFirstLetterRenderer)
-            return firstLetterBlock;
-
-        RenderObject* parentBlock = firstLetterBlock->parent();
-        if (firstLetterBlock->isReplaced() || !parentBlock
-            || !isRenderBlockFlowOrRenderButton(parentBlock)) {
-            return 0;
-        }
-        ASSERT(parentBlock->isRenderBlock());
-        if (toRenderBlock(parentBlock)->firstChild() != firstLetterBlock)
-            return 0;
-        firstLetterBlock = parentBlock;
-    }
-
-    return 0;
-}
-
-void RenderBlock::updateFirstLetterStyle(RenderObject* firstLetterBlock, RenderObject* currentChild)
-{
-    RenderObject* firstLetter = currentChild->parent();
-    RenderObject* firstLetterContainer = firstLetter->parent();
-    RenderStyle* pseudoStyle = styleForFirstLetter(firstLetterBlock, firstLetterContainer);
-    ASSERT(firstLetter->isFloating() || firstLetter->isInline());
-
-    if (RenderStyle::stylePropagationDiff(firstLetter->style(), pseudoStyle) == Reattach) {
-        // The first-letter renderer needs to be replaced. Create a new renderer of the right type.
-        RenderBoxModelObject* newFirstLetter;
-        if (pseudoStyle->display() == INLINE)
-            newFirstLetter = RenderInline::createAnonymous(&document());
-        else
-            newFirstLetter = RenderBlockFlow::createAnonymous(&document());
-        newFirstLetter->setStyle(pseudoStyle);
-
-        // Move the first letter into the new renderer.
-        while (RenderObject* child = firstLetter->slowFirstChild()) {
-            if (child->isText())
-                toRenderText(child)->removeAndDestroyTextBoxes();
-            firstLetter->removeChild(child);
-            newFirstLetter->addChild(child, 0);
-        }
-
-        RenderObject* nextSibling = firstLetter->nextSibling();
-        if (RenderTextFragment* remainingText = toRenderBoxModelObject(firstLetter)->firstLetterRemainingText()) {
-            ASSERT(remainingText->isAnonymous() || remainingText->node()->renderer() == remainingText);
-            // Replace the old renderer with the new one.
-            remainingText->setFirstLetter(newFirstLetter);
-            newFirstLetter->setFirstLetterRemainingText(remainingText);
-        }
-        // To prevent removal of single anonymous block in RenderBlock::removeChild and causing
-        // |nextSibling| to go stale, we remove the old first letter using removeChildNode first.
-        firstLetterContainer->virtualChildren()->removeChildNode(firstLetterContainer, firstLetter);
-        firstLetter->destroy();
-        firstLetter = newFirstLetter;
-        firstLetterContainer->addChild(firstLetter, nextSibling);
-    } else {
-        firstLetter->setStyle(pseudoStyle);
-    }
-
-    for (RenderObject* genChild = firstLetter->slowFirstChild(); genChild; genChild = genChild->nextSibling()) {
-        if (genChild->isText())
-            genChild->setStyle(pseudoStyle);
-    }
-}
-
-static inline unsigned firstLetterLength(const String& text)
-{
-    unsigned length = 0;
-    unsigned textLength = text.length();
-
-    if (textLength == 0)
-        return length;
-
-    // Account for leading spaces first.
-    while (length < textLength && isSpaceForFirstLetter(text[length]))
-        length++;
-
-    // Now account for leading punctuation.
-    while (length < textLength && isPunctuationForFirstLetter(text[length]))
-        length++;
-
-    // Bail if we didn't find a letter before the end of the text or before a space.
-    if (isSpaceForFirstLetter(text[length]) || length == textLength)
-        return 0;
-
-    // Account the next character for first letter.
-    length++;
-
-    // Keep looking allowed punctuation for the :first-letter.
-    for (unsigned scanLength = length; scanLength < textLength; ++scanLength) {
-        UChar c = text[scanLength];
-
-        if (!isPunctuationForFirstLetter(c))
-            break;
-
-        length = scanLength + 1;
-    }
-    return length;
-}
-
-void RenderBlock::createFirstLetterRenderer(RenderObject* firstLetterBlock, RenderText& currentChild, unsigned length)
-{
-    ASSERT(length);
-
-    RenderObject* firstLetterContainer = currentChild.parent();
-    RenderStyle* pseudoStyle = styleForFirstLetter(firstLetterBlock, firstLetterContainer);
-    RenderBoxModelObject* firstLetter = 0;
-    if (pseudoStyle->display() == INLINE)
-        firstLetter = RenderInline::createAnonymous(&document());
-    else
-        firstLetter = RenderBlockFlow::createAnonymous(&document());
-    firstLetter->setStyle(pseudoStyle);
-
-    // FIXME: The first letter code should not modify the render tree during
-    // layout. crbug.com/370458
-    DeprecatedDisableModifyRenderTreeStructureAsserts disabler;
-
-    firstLetterContainer->addChild(firstLetter, &currentChild);
-
-    // 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 = currentChild.originalText();
-    ASSERT(oldText.impl());
-
-    // Construct a text fragment for the text after the first letter.
-    // This text fragment might be empty.
-    RenderTextFragment* remainingText =
-        new RenderTextFragment(currentChild.node() ? currentChild.node() : &currentChild.document(), oldText.impl(), length, oldText.length() - length);
-    remainingText->setStyle(currentChild.style());
-    if (remainingText->node())
-        remainingText->node()->setRenderer(remainingText);
-
-    firstLetterContainer->addChild(remainingText, &currentChild);
-    firstLetterContainer->removeChild(&currentChild);
-    remainingText->setFirstLetter(firstLetter);
-    firstLetter->setFirstLetterRemainingText(remainingText);
-
-    // construct text fragment for the first letter
-    RenderTextFragment* letter =
-        new RenderTextFragment(remainingText->node() ? remainingText->node() : &remainingText->document(), oldText.impl(), 0, length);
-    letter->setStyle(pseudoStyle);
-    firstLetter->addChild(letter);
-
-    currentChild.destroy();
-}
-
-// Once we see any of these renderers we can stop looking for first-letter as
-// they signal the end of the first line of text.
-bool RenderBlock::isInvalidFirstLetterRenderer(RenderObject* obj) const
-{
-    return (obj->isBR() || (obj->isText() && toRenderText(obj)->isWordBreak()));
-}
-
-void RenderBlock::updateFirstLetter()
-{
-    if (!document().styleEngine()->usesFirstLetterRules())
-        return;
-    // Don't recur
-    if (style()->styleType() == FIRST_LETTER)
-        return;
-
-    // FIXME: We need to destroy the first-letter object if it is no longer the first child. Need to find
-    // an efficient way to check for that situation though before implementing anything.
-    RenderObject* firstLetterBlock = findFirstLetterBlock(this);
-    if (!firstLetterBlock)
-        return;
-
-    // Drill into inlines looking for our first text child.
-    RenderObject* currChild = firstLetterBlock->slowFirstChild();
-    unsigned length = 0;
-    while (currChild) {
-        if (currChild->isText()) {
-            // FIXME: If there is leading punctuation in a different RenderText than
-            // the first letter, we'll not apply the correct style to it.
-            length = firstLetterLength(toRenderText(currChild)->originalText());
-            if (length || isInvalidFirstLetterRenderer(currChild))
-                break;
-            currChild = currChild->nextSibling();
-        } else if (currChild->isListMarker()) {
-            currChild = currChild->nextSibling();
-        } else if (currChild->isFloatingOrOutOfFlowPositioned()) {
-            if (currChild->style()->styleType() == FIRST_LETTER) {
-                currChild = currChild->slowFirstChild();
-                break;
-            }
-            currChild = currChild->nextSibling();
-        } else if (currChild->isReplaced() || currChild->isRenderButton() || currChild->isMenuList()) {
-            break;
-        } else if (currChild->isFlexibleBoxIncludingDeprecated() || currChild->isRenderGrid()) {
-            return;
-        } else if (currChild->style()->hasPseudoStyle(FIRST_LETTER) && currChild->canHaveGeneratedChildren())  {
-            // We found a lower-level node with first-letter, which supersedes the higher-level style
-            firstLetterBlock = currChild;
-            currChild = currChild->slowFirstChild();
-        } else {
-            currChild = currChild->slowFirstChild();
-        }
-    }
-
-    if (!currChild)
-        return;
-
-    // If the child already has style, then it has already been created, so we just want
-    // to update it.
-    if (currChild->parent()->style()->styleType() == FIRST_LETTER) {
-        updateFirstLetterStyle(firstLetterBlock, currChild);
-        return;
-    }
-
-    // FIXME: This black-list of disallowed RenderText subclasses is fragile.
-    // Should counter be on this list? What about RenderTextFragment?
-    if (!currChild->isText() || isInvalidFirstLetterRenderer(currChild))
-        return;
-
-    createFirstLetterRenderer(firstLetterBlock, toRenderText(*currChild), length);
-}
-
 // Helper methods for obtaining the last line, computing line counts and heights for line counts
 // (crawling into blocks).
 static bool shouldCheckLines(RenderObject* obj)
 {
     return !obj->isFloatingOrOutOfFlowPositioned()
         && obj->isRenderBlock() && obj->style()->height().isAuto()
         && (!obj->isDeprecatedFlexibleBox() || obj->style()->boxOrient() == VERTICAL);
 }
 
 static int getHeightForLineCount(RenderBlock* block, int l, bool includeBottom, int& count)
@@ skipping 576 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink