/*
 * (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.
 * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
 * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
 *
 * 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 "RenderText.h"

#if HAVE(ACCESSIBILITY)
#include "AXObjectCache.h"
#endif
#include "LineInfo.h"
#include "BreakingContext.h"
#include "BreakLines.h"
#include "CharacterProperties.h"
#include "EllipsisBox.h"
#include "FloatQuad.h"
#include "FontCascade.h"
#include "FrameView.h"
#include "Hyphenation.h"
#include "InlineTextBox.h"
#include "LineLayoutTraversal.h"
#include "Range.h"
#include "RenderBlock.h"
#include "RenderCombineText.h"
#include "RenderElement.h"
#include "RenderInline.h"
#include "RenderLayer.h"
#include "RenderView.h"
#include "Settings.h"
#include "Text.h"
#include "TextResourceDecoder.h"
#include "VisiblePosition.h"
#include <wtf/AlwaysInline.h>
#include <wtf/BitArray.h>
#include <wtf/text/StringBuffer.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/StringView.h>
#include <wtf/text/TextBreakIterator.h>
#include <wtf/unicode/CharacterNames.h>

#if PLATFORM(IOS)
#include "Document.h"
#include "EditorClient.h"
#include "LogicalSelectionOffsetCaches.h"
#include "Page.h"
#include "SelectionRect.h"
#endif

using namespace WTF;
using namespace Unicode;

namespace WebCore {

struct SameSizeAsRenderText : public RenderObject {
    void* pointers[2];
    uint32_t bitfields : 16;
    float widths[2];
    Optional<float> minWidth;
    Optional<float> maxWidth;
    String text;
};

COMPILE_ASSERT(sizeof(RenderText) == sizeof(SameSizeAsRenderText), RenderText_should_stay_small);

class SecureTextTimer;
typedef HashMap<RenderText*, SecureTextTimer*> SecureTextTimerMap;
static SecureTextTimerMap* gSecureTextTimers = 0;

class SecureTextTimer FINAL : public TimerBase {
public:
    SecureTextTimer(RenderText* renderText)
        : m_renderText(renderText)
        , m_lastTypedCharacterOffset(-1)
    {
    }

    void restartWithNewText(unsigned lastTypedCharacterOffset)
    {
        m_lastTypedCharacterOffset = lastTypedCharacterOffset;
        startOneShot(m_renderText->document().settings().passwordEchoDurationInSeconds());
    }
    void invalidate() { m_lastTypedCharacterOffset = -1; }
    unsigned lastTypedCharacterOffset() { return m_lastTypedCharacterOffset; }

private:
    virtual void fired()
    {
        ASSERT(gSecureTextTimers->contains(m_renderText));
        m_renderText->setText(m_renderText->text(), true /* forcing setting text as it may be masked later */);
    }

    RenderText* m_renderText;
    int m_lastTypedCharacterOffset;
};


typedef HashMap<const RenderText*, String> OriginalTextMap;

static OriginalTextMap& originalTextMap()
{
	static NeverDestroyed<OriginalTextMap> map;
    return map;
}

static HashMap<const RenderText*, WeakPtr<RenderInline>>& inlineWrapperForDisplayContentsMap()
{
    static NeverDestroyed<HashMap<const RenderText*, WeakPtr<RenderInline>>> map;
    return map;
}

String capitalize(const String& string, UChar previousCharacter)
{
    // FIXME: Need to change this to use u_strToTitle instead of u_totitle and to consider locale.

    if (string.isNull())
        return string;

    unsigned length = string.length();
    const StringImpl& stringImpl = *string.impl();

    if (length >= std::numeric_limits<unsigned>::max())
        RELEASE_ASSERT_NOT_REACHED();

    StringBuffer<UChar> stringWithPrevious(length + 1);
    stringWithPrevious[0] = previousCharacter == noBreakSpace ? ' ' : previousCharacter;
    for (unsigned i = 1; i < length + 1; i++) {
    	// Replace NO BREAK SPACE with a real space since ICU does not treat it as a word separator.
		if (stringImpl[i - 1] == noBreakSpace)
            stringWithPrevious[i] = ' ';
        else
            stringWithPrevious[i] = stringImpl[i - 1];
    }

    UBreakIterator* boundary = wordBreakIterator(StringView(stringWithPrevious.characters(), length + 1));
    if (!boundary)
        return string;

    StringBuilder result;
    result.reserveCapacity(length);

    int32_t endOfWord;
    int32_t startOfWord = ubrk_first(boundary);
    for (endOfWord = ubrk_next(boundary); endOfWord != UBRK_DONE; startOfWord = endOfWord, endOfWord = ubrk_next(boundary)) {
        if (startOfWord) // Ignore first char of previous string
        	result.appendCharacter(stringImpl[startOfWord - 1] == noBreakSpace ? noBreakSpace : u_totitle(stringWithPrevious[startOfWord]));
		for (int i = startOfWord + 1; i < endOfWord; i++)
			result.append(stringImpl[i - 1]);
	}

	return result.toString();
}

RenderText::RenderText(Text& textNode, const String& text)
    : RenderObject(textNode)
	, m_hasBreakableChar(false)
	, m_hasBreak(false)
	, m_hasTab(false)
	, m_hasBeginWS(false)
	, m_hasEndWS(false)
	, m_linesDirty(false)
	, m_containsReversedText(false)
	, m_isAllASCII(text.containsOnlyASCII())
	, m_knownToHaveNoOverflowAndNoFallbackFonts(false)
	, m_useBackslashAsYenSymbol(false)
	, m_originalTextDiffersFromRendered(false)
	, m_hasInlineWrapperForDisplayContents(false)
	, m_canUseSimplifiedTextMeasuring(false)
	, m_text(text)
{
    ASSERT(!m_text.isNull());
    setIsText();
    m_canUseSimpleFontCodePath = computeCanUseSimpleFontCodePath();
    view().frameView().incrementVisuallyNonEmptyCharacterCount(m_text.length());
}

RenderText::RenderText(Document& document, const String& text)
    : RenderObject(document)
	, m_hasBreakableChar(false)
	, m_hasBreak(false)
    , m_hasTab(false)
	, m_hasBeginWS(false)
	, m_hasEndWS(false)
    , m_linesDirty(false)
    , m_containsReversedText(false)
    , m_isAllASCII(text.containsOnlyASCII())
    , m_knownToHaveNoOverflowAndNoFallbackFonts(false)
    , m_useBackslashAsYenSymbol(false)
	, m_originalTextDiffersFromRendered(false)
	, m_hasInlineWrapperForDisplayContents(false)
	, m_canUseSimplifiedTextMeasuring(false)
#if ENABLE(IOS_TEXT_AUTOSIZING)
    , m_candidateComputedTextSize(0)
#endif
    , m_text(text)
{
    ASSERT(!m_text.isNull());
    setIsText();
    m_canUseSimpleFontCodePath = computeCanUseSimpleFontCodePath();
    view().frameView().incrementVisuallyNonEmptyCharacterCount(m_text.length());
}

RenderText::~RenderText()
{
    // Do not add any code here. Add it to willBeDestroyed() instead.
    ASSERT(!originalTextMap().contains(this));
}

const char* RenderText::renderName() const
{
    return "RenderText";
}

Text* RenderText::textNode() const
{
    return toText(RenderObject::node());
}

bool RenderText::isTextFragment() const
{
    return false;
}

bool RenderText::computeUseBackslashAsYenSymbol() const
{
	auto& style = *this->style();
    const FontDescription& fontDescription = style.font().fontDescription();
    if (style.font().useBackslashAsYenSymbol())
        return true;
    if (fontDescription.isSpecifiedFont())
        return false;
    const TextEncoding* encoding = document().decoder() ? &document().decoder()->encoding() : 0;
    if (encoding && encoding->backslashAsCurrencySymbol() != '\\')
        return true;
    return false;
}

static void initiateFontLoadingByAccessingGlyphDataIfApplicable(const String& textContent, const FontCascade& fontCascade)
{
    // See webkit.org/b/252668
    auto fontVariant = AutoVariant;
#if USE(FONT_VARIANT_VIA_FEATURES)
    if (fontCascade.fontDescription().variantCaps() == FontVariantCaps::Small) {
        // This matches the behavior of ComplexTextController::collectComplexTextRuns(): that function doesn't perform font fallback
        // on the capitalized characters when small caps is enabled, so we shouldn't here either.
        fontVariant = NormalVariant;
    }
#endif// FIXME: Pre-warm glyph loading in FontCascade with the most common range.
    BitArray<256> hasSeen;
    for (UChar32 character : StringView(textContent).codePoints()) {
        if (character < 256) {
            if (hasSeen[character])
                continue;
            hasSeen.set(character);
        }
        fontCascade.glyphDataForCharacter(character, false, fontVariant);
    }
}

void RenderText::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
    // There is no need to ever schedule repaints from a style change of a text run, since
    // we already did this for the parent of the text run.
    // We do have to schedule layouts, though, since a style change can force us to
    // need to relayout.
    if (diff == StyleDifferenceLayout) {
        setNeedsLayoutAndPrefWidthsRecalc();
        m_knownToHaveNoOverflowAndNoFallbackFonts = false;
    }

    auto& newStyle = *style();
    if (!oldStyle)
        initiateFontLoadingByAccessingGlyphDataIfApplicable(m_text, newStyle.fontCascade());

    bool needsResetText = false;
    if (!oldStyle) {
        m_useBackslashAsYenSymbol = computeUseBackslashAsYenSymbol();
        needsResetText = m_useBackslashAsYenSymbol;
        // It should really be computed in the c'tor, but during construction we don't have parent yet -and RenderText style == parent()->style()
		m_canUseSimplifiedTextMeasuring = computeCanUseSimplifiedTextMeasuring();
	} else if (oldStyle->font().useBackslashAsYenSymbol() != newStyle.font().useBackslashAsYenSymbol()) {
    	m_useBackslashAsYenSymbol = computeUseBackslashAsYenSymbol();
        needsResetText = true;
    }

    ETextTransform oldTransform = oldStyle ? oldStyle->textTransform() : TTNONE;
    ETextSecurity oldSecurity = oldStyle ? oldStyle->textSecurity() : TSNONE;
    if (needsResetText || oldTransform != newStyle.textTransform() || oldSecurity != newStyle.textSecurity())
    	 RenderText::setText(originalText(), true);
}

void RenderText::removeAndDestroyTextBoxes()
{
    if (!renderTreeBeingDestroyed())
        m_lineBoxes.removeAllFromParent(*this);
#if !ASSERT_WITH_SECURITY_IMPLICATION_DISABLED
    else
        m_lineBoxes.invalidateParentChildLists();
#endif
    deleteLineBoxes();
}

void RenderText::willBeDestroyed()
{
    if (SecureTextTimer* secureTextTimer = gSecureTextTimers ? gSecureTextTimers->take(this) : nullptr)
        delete secureTextTimer;

    removeAndDestroyTextBoxes();

    if (m_originalTextDiffersFromRendered)
        originalTextMap().remove(this);

    setInlineWrapperForDisplayContents(0);

    RenderObject::willBeDestroyed();
}

String RenderText::originalText() const
{
    return m_originalTextDiffersFromRendered ? originalTextMap().get(this) : m_text;
}

void RenderText::absoluteRects(Vector<IntRect>& rects, const LayoutPoint& accumulatedOffset) const
{
    auto textBoxRange = LineLayoutTraversal::textBoxesFor(*this);
    for (auto it = textBoxRange.begin(); it != textBoxRange.end(); ++it) {
        auto rect = it->rect();
        rects.append(enclosingIntRect(FloatRect(accumulatedOffset + rect.location(), rect.size())));
    }
}

Vector<IntRect> RenderText::absoluteRectsForRange(unsigned start, unsigned end, bool useSelectionHeight, bool* wasFixed) const
{
    const_cast<RenderText&>(*this).ensureLineBoxes();

    // Work around signed/unsigned issues. This function takes unsigneds, and is often passed UINT_MAX
    // to mean "all the way to the end". InlineTextBox coordinates are unsigneds, so changing this 
    // function to take ints causes various internal mismatches. But selectionRect takes ints, and 
    // passing UINT_MAX to it causes trouble. Ideally we'd change selectionRect to take unsigneds, but 
    // that would cause many ripple effects, so for now we'll just clamp our unsigned parameters to INT_MAX.
    ASSERT(end == UINT_MAX || end <= INT_MAX);
    ASSERT(start <= INT_MAX);
    start = min(start, static_cast<unsigned>(INT_MAX));
    end = min(end, static_cast<unsigned>(INT_MAX));

    return m_lineBoxes.absoluteRectsForRange(*this, start, end, useSelectionHeight, wasFixed);
}

#if PLATFORM(IOS)
// This function is similar in spirit to addLineBoxRects, but returns rectangles
// which are annotated with additional state which helps the iPhone draw selections in its unique way.
// Full annotations are added in this class.
void RenderText::collectSelectionRects(Vector<SelectionRect>& rects, unsigned start, unsigned end)
{
    // FIXME: Work around signed/unsigned issues. This function takes unsigneds, and is often passed UINT_MAX
    // to mean "all the way to the end". InlineTextBox coordinates are unsigneds, so changing this
    // function to take ints causes various internal mismatches. But selectionRect takes ints, and
    // passing UINT_MAX to it causes trouble. Ideally we'd change selectionRect to take unsigneds, but
    // that would cause many ripple effects, so for now we'll just clamp our unsigned parameters to INT_MAX.
    ASSERT(end == std::numeric_limits<unsigned>::max() || end <= std::numeric_limits<int>::max());
    ASSERT(start <= std::numeric_limits<int>::max());
    start = std::min(start, static_cast<unsigned>(std::numeric_limits<int>::max()));
    end = std::min(end, static_cast<unsigned>(std::numeric_limits<int>::max()));

    for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
        LayoutRect rect;
        if (start <= box->start() && box->end() <= end)
            rect = box->localSelectionRect(start, end);
        else {
            unsigned realEnd = std::min(box->end(), end);
            rect = box->localSelectionRect(start, realEnd);
            if (rect.isEmpty())
                continue;
        }

        if (box->root().isFirstAfterPageBreak()) {
            if (box->isHorizontal())
                rect.shiftYEdgeTo(box->root().lineTopWithLeading());
            else
                rect.shiftXEdgeTo(box->root().lineTopWithLeading());
        }

        RenderBlock* containingBlock = this->containingBlock();
        // Map rect, extended left to leftOffset, and right to rightOffset, through transforms to get minX and maxX.
        LogicalSelectionOffsetCaches cache(*containingBlock);
        LayoutUnit leftOffset = containingBlock->logicalLeftSelectionOffset(*containingBlock, box->logicalTop(), cache);
        LayoutUnit rightOffset = containingBlock->logicalRightSelectionOffset(*containingBlock, box->logicalTop(), cache);
        LayoutRect extentsRect = rect;
        if (box->isHorizontal()) {
            extentsRect.setX(leftOffset);
            extentsRect.setWidth(rightOffset - leftOffset);
        } else {
            extentsRect.setY(leftOffset);
            extentsRect.setHeight(rightOffset - leftOffset);
        }
        extentsRect = localToAbsoluteQuad(FloatRect(extentsRect)).enclosingBoundingBox();
        if (!box->isHorizontal())
            extentsRect = extentsRect.transposedRect();
        bool isFirstOnLine = !box->previousOnLineExists();
        bool isLastOnLine = !box->nextOnLineExists();
        if (containingBlock->isRubyBase() || containingBlock->isRubyText())
            isLastOnLine = !containingBlock->containingBlock()->inlineBoxWrapper()->nextOnLineExists();

        bool containsStart = box->start() <= start && box->end() >= start;
        bool containsEnd = box->start() <= end && box->end() >= end;

        bool isFixed = false;
        IntRect absRect = localToAbsoluteQuad(FloatRect(rect), UseTransforms, &isFixed).enclosingBoundingBox();
        bool boxIsHorizontal = !box->isSVGInlineTextBox() ? box->isHorizontal() : !style().isVerticalWritingMode();
        // If the containing block is an inline element, we want to check the inlineBoxWrapper orientation
        // to determine the orientation of the block. In this case we also use the inlineBoxWrapper to
        // determine if the element is the last on the line.
        if (containingBlock->inlineBoxWrapper()) {
            if (containingBlock->inlineBoxWrapper()->isHorizontal() != boxIsHorizontal) {
                boxIsHorizontal = containingBlock->inlineBoxWrapper()->isHorizontal();
                isLastOnLine = !containingBlock->inlineBoxWrapper()->nextOnLineExists();
            }
        }

        rects.append(SelectionRect(absRect, box->direction(), extentsRect.x(), extentsRect.maxX(), extentsRect.maxY(), 0, box->isLineBreak(), isFirstOnLine, isLastOnLine, containsStart, containsEnd, boxIsHorizontal, isFixed, containingBlock->isRubyText(), view().pageNumberForBlockProgressionOffset(absRect.x())));
    }
}
#endif

Vector<FloatQuad> RenderText::absoluteQuadsClippedToEllipsis() const
{
    return m_lineBoxes.absoluteQuads(*this, nullptr, RenderTextLineBoxes::ClipToEllipsis);
}

void RenderText::absoluteQuads(Vector<FloatQuad>& quads, bool* wasFixed) const
{
    quads.appendVector(m_lineBoxes.absoluteQuads(*this, wasFixed, RenderTextLineBoxes::NoClipping));
}

Vector<FloatQuad> RenderText::absoluteQuadsForRange(unsigned start, unsigned end, bool useSelectionHeight, bool ignoreEmptyTextSelections, bool* wasFixed) const
{
    // Work around signed/unsigned issues. This function takes unsigneds, and is often passed UINT_MAX
    // to mean "all the way to the end". InlineTextBox coordinates are unsigneds, so changing this 
    // function to take ints causes various internal mismatches. But selectionRect takes ints, and 
    // passing UINT_MAX to it causes trouble. Ideally we'd change selectionRect to take unsigneds, but 
    // that would cause many ripple effects, so for now we'll just clamp our unsigned parameters to INT_MAX.
    ASSERT(end == UINT_MAX || end <= INT_MAX);
    ASSERT(start <= INT_MAX);
    start = std::min(start, static_cast<unsigned>(INT_MAX));
    end = std::min(end, static_cast<unsigned>(INT_MAX));
    const_cast<RenderText&>(*this).ensureLineBoxes();
    return m_lineBoxes.absoluteQuadsForRange(*this, start, end, useSelectionHeight, ignoreEmptyTextSelections, wasFixed);
}

Position RenderText::positionForPoint(const LayoutPoint& point)
{
    return positionForPoint(point, nullptr).deepEquivalent();
}

VisiblePosition RenderText::positionForPoint(const LayoutPoint& point, const RenderFragmentContainer*)
{
    ensureLineBoxes();
    return m_lineBoxes.positionForPoint(*this, point);
}

static inline Optional<float> combineTextWidth(const RenderText& renderer, const FontCascade& fontCascade, const RenderStyle& style)
{
    if (!style.hasTextCombine() || !renderer.isCombineText())
        return Nullopt;
    auto& combineTextRenderer = toRenderCombineText(renderer);
    return combineTextRenderer.isCombined() ? Optional<float>(combineTextRenderer.combinedTextWidth(fontCascade)) : Optional<float>();
}

ALWAYS_INLINE float RenderText::widthFromCache(const FontCascade& fontCascade, int start, int length, float xPos, HashSet<const Font*>* fallbackFonts, GlyphOverflow* glyphOverflow, const RenderStyle& style) const
{
    if (auto width = combineTextWidth(*this, fontCascade, style))
        return *width;

    TextRun run = RenderBlock::constructTextRun(this, start, length, style);
    run.setCharacterScanForCodePath(!canUseSimpleFontCodePath());
    run.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
    run.setXPos(xPos);
    return fontCascade.width(run, fallbackFonts, glyphOverflow);
}

inline static bool isHangablePunctuationAtLineStart(UChar c)
{
    return U_GET_GC_MASK(c) & (U_GC_PS_MASK | U_GC_PI_MASK | U_GC_PF_MASK);
}

inline static bool isHangablePunctuationAtLineEnd(UChar c)
{
    return U_GET_GC_MASK(c) & (U_GC_PE_MASK | U_GC_PI_MASK | U_GC_PF_MASK);
}

float RenderText::hangablePunctuationStartWidth(unsigned index) const
{
    unsigned len = textLength();
    if (!len || index >= len)
        return 0;

    ASSERT(m_text);
    StringImpl& text = *m_text.impl();

    if (!isHangablePunctuationAtLineStart(text[index]))
        return 0;

    auto& style = *this->style();
    auto& font = style.fontCascade();

    return widthFromCache(font, index, 1, 0, 0, 0, style);
}

float RenderText::hangablePunctuationEndWidth(unsigned index) const
{
    unsigned len = textLength();
    if (!len || index >= len)
        return 0;

    ASSERT(m_text);
    StringImpl& text = *m_text.impl();

    if (!isHangablePunctuationAtLineEnd(text[index]))
        return 0;

    auto& style = *this->style();
    auto& font = style.fontCascade();

    return widthFromCache(font, index, 1, 0, 0, 0, style);
}

bool RenderText::isHangableStopOrComma(UChar c) const
{
    return c == 0x002C || c == 0x002E || c == 0x060C || c == 0x06D4 || c == 0x3001
        || c == 0x3002 || c == 0xFF0C || c == 0xFF0E || c == 0xFE50 || c == 0xFE51
        || c == 0xFE52 || c == 0xFF61 || c == 0xFF64;
}

unsigned RenderText::firstCharacterIndexStrippingSpaces() const
{
    if (!style()->collapseWhiteSpace())
        return 0;

    ASSERT(m_text);
    StringImpl& text = *m_text.impl();

    unsigned i = 0;
    for ( ; i < textLength(); ++i) {
        if (text[i] != ' ' && (text[i] != '\n' || style()->preserveNewline()) && text[i] != '\t')
            break;
    }
    return i;
}

unsigned RenderText::lastCharacterIndexStrippingSpaces() const
{
    if (!textLength())
        return 0;

    if (!style()->collapseWhiteSpace())
        return textLength() - 1;

    ASSERT(m_text);
    StringImpl& text = *m_text.impl();

    int i = textLength() - 1;
    for ( ; i  >= 0; --i) {
        if (text[i] != ' ' && (text[i] != '\n' || style()->preserveNewline()) && text[i] != '\t')
            break;
    }
    return i;
}

RenderText::Widths RenderText::trimmedPreferredWidths(float leadWidth, bool& stripFrontSpaces)
{
	auto& style = *this->style();
    bool collapseWhiteSpace = style.collapseWhiteSpace();
    if (!collapseWhiteSpace)
        stripFrontSpaces = false;

    if (m_hasTab || preferredLogicalWidthsDirty() || !m_minWidth || !m_maxWidth)
        computePreferredLogicalWidths(leadWidth, !m_minWidth || !m_maxWidth);

    Widths widths;

    widths.beginWS = !stripFrontSpaces && m_hasBeginWS;
    widths.endWS = m_hasEndWS;

    int length = textLength();

    if (!length || (stripFrontSpaces && text()->containsOnlyWhitespace()))
    	return widths;

    widths.endZeroSpace = (*text())[length - 1] == zeroWidthSpace;

    widths.min = m_minWidth.value_or(-1);
    widths.max = m_maxWidth.value_or(-1);

    widths.beginMin = m_beginMinWidth;
    widths.endMin = m_endMinWidth;

    widths.hasBreakableChar = m_hasBreakableChar;
    widths.hasBreak = m_hasBreak;
    widths.endsWithBreak = m_hasBreak && (*text())[length - 1] == '\n';

    ASSERT(m_text);
    StringImpl& text = *m_text.impl();
    if (text[0] == ' ' || (text[0] == '\n' && !style.preserveNewline()) || text[0] == '\t') {
        const FontCascade& font = style.font(); // FIXME: This ignores first-line.
        if (stripFrontSpaces) {
            const UChar space = ' ';
            float spaceWidth = font.width(RenderBlock::constructTextRun(&space, 1, style));
            widths.max -= spaceWidth;
        } else
        	widths.max += font.wordSpacing();
    }

    stripFrontSpaces = collapseWhiteSpace && m_hasEndWS;

    if (!style.autoWrap() || widths.min > widths.max)
    	widths.min = widths.max;

    // Compute our max widths by scanning the string for newlines.
    if (widths.hasBreak) {
        const FontCascade& f = style.font(); // FIXME: This ignores first-line.
        bool firstLine = true;
        widths.beginMax = widths.max;
        widths.endMax = widths.max;
        for (int i = 0; i < length; i++) {
            int linelen = 0;
            while (i + linelen < length && text[i + linelen] != '\n')
                linelen++;

            if (linelen) {
            	widths.endMax = widthFromCache(f, i, linelen, leadWidth + widths.endMax, 0, 0, style);
                if (firstLine) {
                    firstLine = false;
                    leadWidth = 0;
                    widths.beginMax = widths.endMax;
                }
                i += linelen;
            } else if (firstLine) {
            	widths.beginMax = 0;
                firstLine = false;
                leadWidth = 0;
            }

            if (i == length - 1)
                // A <pre> run that ends with a newline, as in, e.g.,
                // <pre>Some text\n\n<span>More text</pre>
            	widths.endMax = 0;
        }
    }

    return widths;
}

static inline bool isSpaceAccordingToStyle(UChar c, const RenderStyle* style)
{
    return c == ' ' || (c == noBreakSpace && style->nbspMode() == SPACE);
}

float RenderText::minLogicalWidth() const
{
    if (preferredLogicalWidthsDirty() || !m_minWidth)
        const_cast<RenderText*>(this)->computePreferredLogicalWidths(0, !preferredLogicalWidthsDirty());

    return *m_minWidth;
}

float RenderText::maxLogicalWidth() const
{
    if (preferredLogicalWidthsDirty() || !m_maxWidth)
        const_cast<RenderText*>(this)->computePreferredLogicalWidths(0, !preferredLogicalWidthsDirty());
        
    return *m_maxWidth;
}

LineBreakIteratorMode mapLineBreakToIteratorMode(LineBreak lineBreak)
{
    switch (lineBreak) {
    case LineBreak::Auto:
    case LineBreak::AfterWhiteSpace:
    case LineBreak::Anywhere:
        return LineBreakIteratorMode::Default;
    case LineBreak::Loose:
        return LineBreakIteratorMode::Loose;
    case LineBreak::Normal:
        return LineBreakIteratorMode::Normal;
    case LineBreak::Strict:
        return LineBreakIteratorMode::Strict;
    }
    return LineBreakIteratorMode::Default;
}

void RenderText::computePreferredLogicalWidths(float leadWidth, bool forcedMinMaxWidthComputation)
{
    HashSet<const Font*> fallbackFonts;
    GlyphOverflow glyphOverflow;
    computePreferredLogicalWidths(leadWidth, fallbackFonts, glyphOverflow, forcedMinMaxWidthComputation);
    if (fallbackFonts.isEmpty() && !glyphOverflow.left && !glyphOverflow.right && !glyphOverflow.top && !glyphOverflow.bottom)
        m_knownToHaveNoOverflowAndNoFallbackFonts = true;
}

static inline float hyphenWidth(const RenderText& renderer, const FontCascade& font)
{
	auto& style = *renderer.style();
    return font.width(RenderBlock::constructTextRun(style.hyphenString().string(), style));
}

float RenderText::maxWordFragmentWidth(const RenderStyle& style, const FontCascade& font, StringView word, unsigned minimumPrefixLength, unsigned minimumSuffixLength, bool currentCharacterIsSpace, unsigned characterIndex, float xPos, float entireWordWidth, WordTrailingSpace& wordTrailingSpace, HashSet<const Font*>& fallbackFonts, GlyphOverflow& glyphOverflow)
{
    unsigned suffixStart = 0;
    if (word.length() <= minimumSuffixLength)
        return entireWordWidth;

    Vector<int, 8> hyphenLocations;
    int hyphenLocation = word.length() - minimumSuffixLength;
    while ((hyphenLocation = lastHyphenLocation(word, hyphenLocation, style.locale())) >= minimumPrefixLength)
        hyphenLocations.append(hyphenLocation);

    if (hyphenLocations.isEmpty())
        return entireWordWidth;

    hyphenLocations.reverse();

    // Consider the word "ABC-DEF-GHI" (where the '-' characters are hyphenation opportunities). We want to measure the width
    // of "ABC-" and "DEF-", but not "GHI-". Instead, we should measure "GHI" the same way we measure regular unhyphenated
    // words (by using wordTrailingSpace). Therefore, this function is split up into two parts - one that measures each prefix,
    // and one that measures the single last suffix.

    // FIXME: Breaking the string at these places in the middle of words doesn't work with complex text.
    float minimumFragmentWidthToConsider = font.size() * 5 / 4 + hyphenWidth(*this, font);
    float maxFragmentWidth = 0;
    for (size_t k = 0; k < hyphenLocations.size(); ++k) {
        int fragmentLength = hyphenLocations[k] - suffixStart;
        StringBuilder fragmentWithHyphen;
        fragmentWithHyphen.append(word.substring(suffixStart, fragmentLength));
        fragmentWithHyphen.append(style.hyphenString());

        TextRun run = RenderBlock::constructTextRun(fragmentWithHyphen.toString(), style);
        run.setCharacterScanForCodePath(!canUseSimpleFontCodePath());
        float fragmentWidth = font.width(run, &fallbackFonts, &glyphOverflow);

        // Narrow prefixes are ignored. See tryHyphenating in RenderBlockLineLayout.cpp.
        if (fragmentWidth <= minimumFragmentWidthToConsider)
            continue;

        suffixStart += fragmentLength;
        maxFragmentWidth = std::max(maxFragmentWidth, fragmentWidth);
    }

    if (!suffixStart) {
        // We didn't find any hyphenation opportunities that we're willing to actually use.
        // Therefore, the width of the maximum fragment is just ... the width of the entire word.
        return entireWordWidth;
    }

    float suffixWidth;
    Optional<float> wordTrailingSpaceWidth;
    if (currentCharacterIsSpace)
        wordTrailingSpaceWidth = wordTrailingSpace.width(fallbackFonts);
    if (wordTrailingSpaceWidth)
        suffixWidth = widthFromCache(font, characterIndex + suffixStart, word.length() - suffixStart + 1, xPos, 0, 0, style) - wordTrailingSpaceWidth.value();
    else
        suffixWidth = widthFromCache(font, characterIndex + suffixStart, word.length() - suffixStart, xPos, 0, 0, style);

    return std::max(maxFragmentWidth, suffixWidth);
}

void RenderText::computePreferredLogicalWidths(float leadWidth, HashSet<const Font*>& fallbackFonts, GlyphOverflow& glyphOverflow, bool forcedMinMaxWidthComputation)
{
	ASSERT_UNUSED(forcedMinMaxWidthComputation, m_hasTab || preferredLogicalWidthsDirty() || forcedMinMaxWidthComputation || !m_knownToHaveNoOverflowAndNoFallbackFonts);

    m_minWidth = 0;
    m_beginMinWidth = 0;
    m_endMinWidth = 0;
    m_maxWidth = 0;

    float currMaxWidth = 0;
    m_hasBreakableChar = false;
    m_hasBreak = false;
    m_hasTab = false;
    m_hasBeginWS = false;
    m_hasEndWS = false;

    auto& style = *this->style();
    auto& font = style.font(); // FIXME: This ignores first-line.
    float wordSpacing = font.wordSpacing();
    auto& string = *text();
    unsigned length = string.length();
    auto iteratorMode = mapLineBreakToIteratorMode(style.lineBreak());
    LazyLineBreakIterator breakIterator(string, style.locale(), iteratorMode);
    bool needsWordSpacing = false;
    bool ignoringSpaces = false;
    bool isSpace = false;
    bool firstWord = true;
    bool firstLine = true;
    Optional<unsigned> nextBreakable;
    unsigned lastWordBoundary = 0;

    // Non-zero only when kerning is enabled, in which case we measure words with their trailing
    // space, then subtract its width.
    WordTrailingSpace wordTrailingSpace(style);
    // If automatic hyphenation is allowed, we keep track of the width of the widest word (or word
    // fragment) encountered so far, and only try hyphenating words that are wider.
    float maxWordWidth = std::numeric_limits<float>::max();
    int minimumPrefixLength = 0;
    int minimumSuffixLength = 0;
    if (style.hyphens() == HyphensAuto && canHyphenate(style.locale())) {
        maxWordWidth = 0;

        // Map 'hyphenate-limit-{before,after}: auto;' to 2.
        minimumPrefixLength = style.hyphenationLimitBefore();
        if (minimumPrefixLength < 0)
            minimumPrefixLength = 2;

        minimumSuffixLength = style.hyphenationLimitAfter();
        if (minimumSuffixLength < 0)
            minimumSuffixLength = 2;
    }

    Optional<int> firstGlyphLeftOverflow;

    bool breakNBSP = style.autoWrap() && style.nbspMode() == SPACE;

    bool breakAnywhere = style.lineBreak() == LineBreak::Anywhere && style.autoWrap();
	// Note the deliberate omission of word-wrap/overflow-wrap's break-word value from this breakAll check.
	// Those do not affect minimum preferred sizes. Note that break-word is a non-standard value for
	// word-break, but we support it as though it means break-all.
	bool breakAll = (style.wordBreak() == WordBreak::BreakAll || style.wordBreak() == WordBreak::BreakWord || style.overflowWrap() == OverflowWrap::Anywhere) && style.autoWrap();
	bool keepAllWords = style.wordBreak() == WordBreak::KeepAll;
    bool canUseLineBreakShortcut = iteratorMode == LineBreakIteratorMode::Default;

    for (unsigned i = 0; i < length; i++) {
        UChar c = string[i];

        bool previousCharacterIsSpace = isSpace;

        bool isNewline = false;
        if (c == '\n') {
            if (style.preserveNewline()) {
                m_hasBreak = true;
                isNewline = true;
                isSpace = false;
            } else
                isSpace = true;
        } else if (c == '\t') {
            if (!style.collapseWhiteSpace()) {
                m_hasTab = true;
                isSpace = false;
            } else
                isSpace = true;
        } else
            isSpace = c == ' ';

        if ((isSpace || isNewline) && !i)
            m_hasBeginWS = true;
        if ((isSpace || isNewline) && i == length - 1)
            m_hasEndWS = true;

        ignoringSpaces |= style.collapseWhiteSpace() && previousCharacterIsSpace && isSpace;
        ignoringSpaces &= isSpace;

        // Ignore spaces and soft hyphens
        if (ignoringSpaces) {
            ASSERT(lastWordBoundary == i);
            lastWordBoundary++;
            continue;
        } else if (c == softHyphen && style.hyphens() != HyphensNone) {
            ASSERT(i >= lastWordBoundary);
            currMaxWidth += widthFromCache(font, lastWordBoundary, i - lastWordBoundary, leadWidth + currMaxWidth, &fallbackFonts, &glyphOverflow, style);
            if (!firstGlyphLeftOverflow)
				firstGlyphLeftOverflow = glyphOverflow.left;
            lastWordBoundary = i + 1;
            continue;
        }

        bool hasBreak = breakAll || isBreakable(breakIterator, i, nextBreakable, breakNBSP, canUseLineBreakShortcut, keepAllWords, breakAnywhere);
        bool betweenWords = true;
        unsigned j = i;
        while (c != '\n' && !isSpaceAccordingToStyle(c, &style) && c != '\t' && c != zeroWidthSpace && (c != softHyphen || style.hyphens() == HyphensNone)) {
        	UChar previousCharacter = c;
			j++;
            if (j == length)
                break;
            c = string[j];
            if (U_IS_LEAD(previousCharacter) && U_IS_TRAIL(c))
                continue;
            if (isBreakable(breakIterator, j, nextBreakable, breakNBSP, canUseLineBreakShortcut, keepAllWords, breakAnywhere) && characterAt(j - 1) != softHyphen)
                break;
            if (breakAll) {
            	// FIXME: This code is ultra wrong.
				// The spec says "word-break: break-all: Any typographic letter units are treated as ID(“ideographic characters”) for the purpose of line-breaking."
				// The spec describes how a "typographic letter unit" is a cluster, not a code point: https://drafts.csswg.org/css-text-3/#typographic-character-unit
				betweenWords = false;
                break;
            }
        }

        unsigned wordLen = j - i;
        if (wordLen) {
            float currMinWidth = 0;
            bool isSpace = (j < length) && isSpaceAccordingToStyle(c, &style);
            float w;
            Optional<float> wordTrailingSpaceWidth;
            if (isSpace)
                wordTrailingSpaceWidth = wordTrailingSpace.width(fallbackFonts);
            if (wordTrailingSpaceWidth)
                w = widthFromCache(font, i, wordLen + 1, leadWidth + currMaxWidth, &fallbackFonts, &glyphOverflow, style) - wordTrailingSpaceWidth.value();
            else {
                w = widthFromCache(font, i, wordLen, leadWidth + currMaxWidth, &fallbackFonts, &glyphOverflow, style);
                if (c == softHyphen && style.hyphens() != HyphensNone)
                    currMinWidth = hyphenWidth(*this, font);
            }

            if (w > maxWordWidth) {
                auto maxFragmentWidth = maxWordFragmentWidth(style, font, StringView(string).substring(i, wordLen), minimumPrefixLength, minimumSuffixLength, isSpace, i, leadWidth + currMaxWidth, w, wordTrailingSpace, fallbackFonts, glyphOverflow);
                currMinWidth += maxFragmentWidth - w; // This, when combined with "currMinWidth += w" below, has the effect of executing "currMinWidth += maxFragmentWidth" instead.
                maxWordWidth = std::max(maxWordWidth, maxFragmentWidth);
            }

            if (!firstGlyphLeftOverflow)
				firstGlyphLeftOverflow = glyphOverflow.left;
            currMinWidth += w;
            if (betweenWords) {
                if (lastWordBoundary == i)
                    currMaxWidth += w;
                else {
                    ASSERT(j >= lastWordBoundary);
                    currMaxWidth += widthFromCache(font, lastWordBoundary, j - lastWordBoundary, leadWidth + currMaxWidth, &fallbackFonts, &glyphOverflow, style);
                }
                lastWordBoundary = j;
            }

            bool isCollapsibleWhiteSpace = (j < length) && style.isCollapsibleWhiteSpace(c);
            if (j < length && style.autoWrap())
                m_hasBreakableChar = true;

            // Add in wordSpacing to our currMaxWidth, but not if this is the last word on a line or the
            // last word in the run.
            if ((isSpace || isCollapsibleWhiteSpace) && !containsOnlyWhitespace(j, length-j))
                currMaxWidth += wordSpacing;

            if (firstWord) {
                firstWord = false;
                // If the first character in the run is breakable, then we consider ourselves to have a beginning
                // minimum width of 0, since a break could occur right before our run starts, preventing us from ever
                // being appended to a previous text run when considering the total minimum width of the containing block.
                if (hasBreak)
                    m_hasBreakableChar = true;
                m_beginMinWidth = hasBreak ? 0 : currMinWidth;
            }
            m_endMinWidth = currMinWidth;

            m_minWidth = std::max(currMinWidth, *m_minWidth);

            i += wordLen - 1;
        } else {
            // Nowrap can never be broken, so don't bother setting the
            // breakable character boolean. Pre can only be broken if we encounter a newline.
            if (style.autoWrap() || isNewline)
                m_hasBreakableChar = true;

            if (isNewline) { // Only set if preserveNewline was true and we saw a newline.
                if (firstLine) {
                    firstLine = false;
                    leadWidth = 0;
                    if (!style.autoWrap())
                        m_beginMinWidth = currMaxWidth;
                }

                if (currMaxWidth > *m_maxWidth)
                    m_maxWidth = currMaxWidth;
                currMaxWidth = 0;
            } else {
                TextRun run = RenderBlock::constructTextRun(this, i, 1, style);
                run.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
                run.setXPos(leadWidth + currMaxWidth);

                currMaxWidth += font.width(run, &fallbackFonts);
                glyphOverflow.right = 0;
                needsWordSpacing = isSpace && !previousCharacterIsSpace && i == length - 1;
            }
            ASSERT(lastWordBoundary == i);
            lastWordBoundary++;
        }
    }

    glyphOverflow.left = firstGlyphLeftOverflow.value_or(glyphOverflow.left);

    if ((needsWordSpacing && length > 1) || (ignoringSpaces && !firstWord))
        currMaxWidth += wordSpacing;

    m_maxWidth = std::max(currMaxWidth, *m_maxWidth);

    if (!style.autoWrap())
        m_minWidth = m_maxWidth;

    if (style.whiteSpace() == WhiteSpace::Pre) {
        if (firstLine)
            m_beginMinWidth = *m_maxWidth;
        m_endMinWidth = currMaxWidth;
    }

    setPreferredLogicalWidthsDirty(false);
}

template<typename CharacterType> static inline bool isAllCollapsibleWhitespace(const CharacterType* characters, unsigned length, const RenderStyle& style)
{
    for (unsigned i = 0; i < length; ++i) {
        if (!style.isCollapsibleWhiteSpace(characters[i]))
            return false;
    }
    return true;
}

bool RenderText::isAllCollapsibleWhitespace() const
{
	auto& text = *this->text();
    if (text.is8Bit())
        return WebCore::isAllCollapsibleWhitespace(text.characters8(), text.length(), *style());
    return WebCore::isAllCollapsibleWhitespace(text.characters16(), text.length(), *style());
}

template<typename CharacterType> static inline bool isAllPossiblyCollapsibleWhitespace(const CharacterType* characters, unsigned length)
{
    for (unsigned i = 0; i < length; ++i) {
        if (!(characters[i] == '\n' || characters[i] == ' ' || characters[i] == '\t'))
            return false;
    }
    return true;
}

bool RenderText::containsOnlyWhitespace(unsigned from, unsigned length) const
{
    ASSERT(from <= text().length());
    ASSERT(length <= text().length());
    ASSERT(from + length <= text().length());
	auto& text = *this->text();
    if (text.is8Bit())
        return isAllPossiblyCollapsibleWhitespace(text.characters8() + from, length);
    return isAllPossiblyCollapsibleWhitespace(text.characters16() + from, length);
}

IntPoint RenderText::firstRunLocation() const
{
    auto first = LineLayoutTraversal::firstTextBoxFor(*this);
    if (!first)
        return IntPoint();
    return IntPoint(first->rect().location());
}
    
void RenderText::setSelectionState(SelectionState state)
{
    if (state != SelectionNone)
        ensureLineBoxes();

    RenderObject::setSelectionState(state);

    if (canUpdateSelectionOnRootLineBoxes())
        m_lineBoxes.setSelectionState(*this, state);

    // The containing block can be null in case of an orphaned tree.
    RenderBlock* containingBlock = this->containingBlock();
    if (containingBlock && !containingBlock->isRenderView())
        containingBlock->setSelectionState(state);
}

void RenderText::setTextWithOffset(const String& text, unsigned offset, unsigned length, bool force)
{
    if (!force && m_text == text)
        return;

    int delta = text.length() - textLength();
    unsigned end = offset + length;

    m_linesDirty = m_lineBoxes.dirtyRange(*this, offset, end, delta);

    setText(text, force || m_linesDirty);
}

static inline bool isInlineFlowOrEmptyText(const RenderObject* o)
{
    if (o->isRenderInline())
        return true;
    if (!o->isText())
        return false;
    StringImpl* text = toRenderText(o)->text();
    if (!text)
        return true;
    return !text->length();
}

UChar RenderText::previousCharacter() const
{
    const RenderObject* previousText = this;
    while ((previousText = previousText->previousInPreOrder())) {
        if (!previousText->isInFlow())
            continue;
        if (!isInlineFlowOrEmptyText(previousText))
            break;
    }
    UChar prev = ' ';
    if (previousText && previousText->isText())
        if (StringImpl* previousString = toRenderText(previousText)->text())
            prev = (*previousString)[previousString->length() - 1];
    return prev;
}

LayoutUnit RenderText::topOfFirstText() const
{
    return firstTextBox()->root()->lineTop();
}

String applyTextTransform(const RenderStyle& style, const String& text, UChar previousCharacter)
{
    switch (style.textTransform()) {
    case TTNONE:
        return text;
    case CAPITALIZE:
        return capitalize(text, previousCharacter); // FIXME: Need to take locale into account.
    case UPPERCASE:
        return text.convertToUppercaseWithLocale(style.locale());
    case LOWERCASE:
        return text.convertToLowercaseWithLocale(style.locale());
    }
    ASSERT_NOT_REACHED();
    return text;
}

void RenderText::setRenderedText(const String& text)
{
    ASSERT(!text.isNull());

    String originalText = this->originalText();

    m_text = text;

    if (m_useBackslashAsYenSymbol)
        m_text.replace('\\', yenSign);

    ASSERT(m_text);

    const auto& style = *this->style();
    if (style.textTransform() != TTNONE)
        m_text = applyTextTransform(style, m_text, previousCharacter());

	// We use the same characters here as for list markers.
	// See the listMarkerText function in RenderListMarker.cpp.
	switch (style.textSecurity()) {
	case TSNONE:
		break;
	case TSCIRCLE:
#if PLATFORM(IOS)
		secureText(blackCircle);
#else
		secureText(whiteBullet);
#endif
		break;
case TSDISC:
#if PLATFORM(IOS)
		secureText(blackCircle);
#else
		secureText(bullet);
#endif
		break;
case TSSQUARE:
#if PLATFORM(IOS)
		secureText(blackCircle);
#else
		secureText(blackSquare);
#endif
	}

    ASSERT(!m_text.isNull());

    m_isAllASCII = m_text.containsOnlyASCII();
    m_canUseSimpleFontCodePath = computeCanUseSimpleFontCodePath();
    m_canUseSimplifiedTextMeasuring = computeCanUseSimplifiedTextMeasuring();

    if (m_text != originalText) {
        originalTextMap().set(this, originalText);
        m_originalTextDiffersFromRendered = true;
    } else if (m_originalTextDiffersFromRendered) {
        originalTextMap().remove(this);
        m_originalTextDiffersFromRendered = false;
    }
}

void RenderText::secureText(UChar mask)
{
    if (!m_text.length())
        return;

    int lastTypedCharacterOffsetToReveal = -1;
    String revealedText;
    SecureTextTimer* secureTextTimer = gSecureTextTimers ? gSecureTextTimers->get(this) : 0;
    if (secureTextTimer && secureTextTimer->isActive()) {
        lastTypedCharacterOffsetToReveal = secureTextTimer->lastTypedCharacterOffset();
        if (lastTypedCharacterOffsetToReveal >= 0)
            revealedText.append(m_text[lastTypedCharacterOffsetToReveal]);
    }

    m_text.fill(mask);
    if (lastTypedCharacterOffsetToReveal >= 0) {
        m_text.replace(lastTypedCharacterOffsetToReveal, 1, revealedText);
        // m_text may be updated later before timer fires. We invalidate the lastTypedCharacterOffset to avoid inconsistency.
        secureTextTimer->invalidate();
    }
}

bool RenderText::computeCanUseSimplifiedTextMeasuring() const
{
    if (!m_canUseSimpleFontCodePath)
        return false;

    auto& font = style()->font();
    if (font.wordSpacing() || font.letterSpacing())
        return false;

    // Additional check on the font codepath.
    TextRun run(m_text);
    run.setCharacterScanForCodePath(false);
    if (font.codePath(run) != FontCascade::Simple)
        return false;

    auto whitespaceIsCollapsed = style()->collapseWhiteSpace();
    for (unsigned i = 0; i < m_text.length(); ++i) {
        if ((!whitespaceIsCollapsed && m_text[i] == '\t') || m_text[i] == noBreakSpace || m_text[i] >= HiraganaLetterSmallA)
            return false;
    }
    return true;
}

void RenderText::setText(const String& text, bool force)
{
    ASSERT(!text.isNull());

    if (!force && text == originalText())
        return;

    m_text = text;
    if (m_originalTextDiffersFromRendered) {
        originalTextMap().remove(this);
        m_originalTextDiffersFromRendered = false;
    }

    setRenderedText(text);

    setNeedsLayoutAndPrefWidthsRecalc();
    m_knownToHaveNoOverflowAndNoFallbackFonts = false;

    if (parent() && parent()->isRenderBlockFlow())
        toRenderBlockFlow(parent())->invalidateLineLayoutPath();

#if HAVE(ACCESSIBILITY)
    AXObjectCache* axObjectCache = document().axObjectCache();
    if (axObjectCache->accessibilityEnabled())
        axObjectCache->contentChanged(this);
#endif
}

String RenderText::textWithoutConvertingBackslashToYenSymbol() const
{
    if (!m_useBackslashAsYenSymbol || style()->textSecurity() != TSNONE)
        return text();

    if (style()->textTransform() == TTNONE)
        return originalText();

    return applyTextTransform(*style(), originalText(), previousCharacter());
}

void RenderText::dirtyLineBoxes(bool fullLayout)
{
    if (fullLayout)
        deleteLineBoxes();
    else if (!m_linesDirty)
        m_lineBoxes.dirtyAll();
    m_linesDirty = false;
}

void RenderText::deleteLineBoxes()
{
    m_lineBoxes.deleteAll();
}

PassOwnPtr<InlineTextBox> RenderText::createTextBox()
{
    return adoptPtr(new InlineTextBox(*this));
}

void RenderText::positionLineBox(InlineTextBox& textBox)
{
    if (!textBox.hasTextContent())
        return;
    m_containsReversedText |= !textBox.isLeftToRightDirection();
}

void RenderText::ensureLineBoxes()
{
    if (!parent()->isRenderBlockFlow())
        return;
    toRenderBlockFlow(parent())->ensureLineBoxes();
}

float RenderText::width(unsigned from, unsigned len, float xPos, bool firstLine, HashSet<const Font*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
{
    if (from >= textLength())
        return 0;

    if (from + len > textLength())
        len = textLength() - from;

    auto& lineStyle = firstLine ? *firstLineStyle() : *style();
    return width(from, len, lineStyle.font(), xPos, fallbackFonts, glyphOverflow);
}

float RenderText::width(unsigned from, unsigned length, const FontCascade& fontCascade, float xPos, HashSet<const Font*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
{
    ASSERT(from + length <= textLength());
    if (!textLength() || !length)
        return 0.f;

    auto& style = *this->style();
    if (auto width = combineTextWidth(*this, fontCascade, style))
        return *width;

    if (length == 1 && (characterAt(from) == space))
        return canUseSimplifiedTextMeasuring() ? fontCascade.primaryFont()->spaceWidth() : fontCascade.widthOfSpaceString();

    float width = 0.f;
    if (&fontCascade == &style.fontCascade()) {
        if (!style.preserveNewline() && !from && length == text()->length() && (!glyphOverflow || !glyphOverflow->computeBounds)) {
            if (fallbackFonts) {
                ASSERT(glyphOverflow);
                if (preferredLogicalWidthsDirty() || !m_knownToHaveNoOverflowAndNoFallbackFonts) {
                	const_cast<RenderText*>(this)->computePreferredLogicalWidths(0, *fallbackFonts, *glyphOverflow);
                    if (fallbackFonts->isEmpty() && !glyphOverflow->left && !glyphOverflow->right && !glyphOverflow->top && !glyphOverflow->bottom)
                        m_knownToHaveNoOverflowAndNoFallbackFonts = true;
                }
                // The rare case of when we switch between IFC and legacy preferred width computation.
                if (!m_maxWidth)
                    width = maxLogicalWidth();
                width = *m_maxWidth;
            } else
            	width = maxLogicalWidth();
        } else
        	width = widthFromCache(fontCascade, from, length, xPos, fallbackFonts, glyphOverflow, style);
    } else {
        TextRun run = RenderBlock::constructTextRun(this, from, length, style);
        run.setCharacterScanForCodePath(!canUseSimpleFontCodePath());
        run.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
        run.setXPos(xPos);
        width = fontCascade.width(run, fallbackFonts, glyphOverflow);
    }

    return clampTo<float>(width, 0.f);
}

IntRect RenderText::linesBoundingBox() const
{
    auto first = LineLayoutTraversal::firstTextBoxFor(*this);
    if (!first)
        return IntRect();

    auto boundingBox = first->rect();
    for (auto box = first; ++box;)
        boundingBox.uniteEvenIfEmpty(box->rect());

    return enclosingIntRect(boundingBox);
}

LayoutRect RenderText::clippedOverflowRectForRepaint(RenderLayerModelObject* repaintContainer) const
{
    RenderObject* rendererToRepaint = containingBlock();

    // Do not cross self-painting layer boundaries.
    auto& enclosingLayerRenderer = enclosingLayer()->renderer();
    if (&enclosingLayerRenderer != rendererToRepaint && !rendererToRepaint->isDescendantOf(enclosingLayerRenderer))
        rendererToRepaint = &enclosingLayerRenderer;

    // The renderer we chose to repaint may be an ancestor of repaintContainer, but we need to do a repaintContainer-relative repaint.
    if (repaintContainer && repaintContainer != rendererToRepaint && !rendererToRepaint->isDescendantOf(*repaintContainer))
        return repaintContainer->clippedOverflowRectForRepaint(repaintContainer);

    return rendererToRepaint->clippedOverflowRectForRepaint(repaintContainer);
}

LayoutRect RenderText::selectionRectForRepaint(RenderLayerModelObject* repaintContainer, bool clipToVisibleContent)
{
    ASSERT(!needsLayout());

    if (selectionState() == SelectionNone)
        return LayoutRect();
    if (!containingBlock())
        return LayoutRect();

    // Now calculate startPos and endPos for painting selection.
    // We include a selection while endPos > 0
    unsigned startPos;
    unsigned endPos;
    if (selectionState() == SelectionInside) {
        // We are fully selected.
        startPos = 0;
        endPos = textLength();
    } else {
        startPos = view().selection().startPosition();
        endPos = view().selection().endPosition();
        if (selectionState() == SelectionStart)
            endPos = textLength();
        else if (selectionState() == SelectionEnd)
            startPos = 0;
    }

    if (startPos == endPos)
        return IntRect();

    LayoutRect rect = m_lineBoxes.selectionRectForRange(startPos, endPos);

    if (clipToVisibleContent)
        return computeRectForRepaint(rect, repaintContainer);

	return localToContainerQuad(FloatRect(rect), repaintContainer).enclosingBoundingBox();
}

int RenderText::caretMinOffset() const
{
    auto first = LineLayoutTraversal::firstTextBoxFor(*this);
    if (!first)
        return 0;

    int minOffset = first->localStartOffset();
    for (auto box = first; ++box;)
        minOffset = std::min<int>(minOffset, box->localStartOffset());

    return minOffset;
}

int RenderText::caretMaxOffset() const
{
    auto first = LineLayoutTraversal::firstTextBoxFor(*this);
    if (!first)
        return text()->length();

    int maxOffset = first->localEndOffset();
    for (auto box = first; ++box;)
        maxOffset = std::max<int>(maxOffset, box->localEndOffset());

    return maxOffset;
}

unsigned RenderText::countRenderedCharacterOffsetsUntil(unsigned offset) const
{
    unsigned result = 0;
	auto textBoxRange = LineLayoutTraversal::textBoxesFor(*this);
	for (auto it = textBoxRange.begin(); it != textBoxRange.end(); ++it) {
		auto& box = *it;
        auto start = box.localStartOffset();
        auto length = box.length();
        if (offset < start)
            return result;
        if (offset <= start + length) {
            result += offset - start;
            return result;
        }
        result += length;
    }
    return result;
}

enum class OffsetType { Character, Caret };
static inline bool containsOffset(const RenderText& text, unsigned offset, OffsetType type)
{
    for (auto box = LineLayoutTraversal::firstTextBoxInTextOrderFor(text); box; box.traverseNextInTextOrder()) {
        auto start = box->localStartOffset();
        if (offset < start)
            return false;
        unsigned end = box->localEndOffset();
        if (offset >= start && offset <= end) {
            if (offset == end && (type == OffsetType::Character || box->isLineBreak()))
                continue;
            if (type == OffsetType::Character)
                return true;
            // Return false for offsets inside composed characters.
            return !offset || offset == static_cast<unsigned>(text.nextOffset(text.previousOffset(offset)));
        }
    }
    return false;
}

bool RenderText::containsRenderedCharacterOffset(unsigned offset) const
{
    return containsOffset(*this, offset, OffsetType::Character);
}

bool RenderText::containsCaretOffset(unsigned offset) const
{
    return containsOffset(*this, offset, OffsetType::Caret);
}

bool RenderText::hasRenderedText() const
{
	auto textBoxRange = LineLayoutTraversal::textBoxesFor(*this);
	for (auto it = textBoxRange.begin(); it != textBoxRange.end(); ++it) {
		auto& box = *it;
        if (box.length())
            return true;
    }
    return false;
}

int RenderText::previousOffset(int current) const
{
    if (isAllASCII() || m_text.is8Bit())
        return current - 1;

    CachedTextBreakIterator iterator(m_text, TextBreakIterator::Mode::Caret, nullAtom);
    return iterator.preceding(current).value_or(current - 1);
}

int RenderText::previousOffsetForBackwardDeletion(int current) const
{
    ASSERT(!m_text.isNull());

    CachedTextBreakIterator iterator(m_text, TextBreakIterator::Mode::Delete, nullAtom);
    return iterator.preceding(current).value_or(0);
}

int RenderText::nextOffset(int current) const
{
    if (isAllASCII() || m_text.is8Bit())
        return current + 1;

    CachedTextBreakIterator iterator(m_text, TextBreakIterator::Mode::Caret, nullAtom);
    return iterator.following(current).value_or(current + 1);
}

bool RenderText::computeCanUseSimpleFontCodePath() const
{
    if (isAllASCII() || m_text.is8Bit())
        return true;
    return FontCascade::characterRangeCodePath(text()->characters16(), length()) == FontCascade::Simple;
}

void RenderText::momentarilyRevealLastTypedCharacter(unsigned lastTypedCharacterOffset)
{
    if (!gSecureTextTimers)
        gSecureTextTimers = new SecureTextTimerMap;

    SecureTextTimer* secureTextTimer = gSecureTextTimers->get(this);
    if (!secureTextTimer) {
        secureTextTimer = new SecureTextTimer(this);
        gSecureTextTimers->add(this, secureTextTimer);
    }
    secureTextTimer->restartWithNewText(lastTypedCharacterOffset);
}

StringView RenderText::stringView(unsigned start, Optional<unsigned> stop) const
{
    unsigned destination = stop.valueOr(text()->length());
    ASSERT(start <= length());
    ASSERT(destination <= length());
    ASSERT(start <= destination);
    if (text()->is8Bit())
        return StringView(text()->characters8() + start, destination - start);
    return StringView(text()->characters16() + start, destination - start);
}

RenderInline* RenderText::inlineWrapperForDisplayContents()
{
    ASSERT(m_hasInlineWrapperForDisplayContents == inlineWrapperForDisplayContentsMap().contains(this));

    if (!m_hasInlineWrapperForDisplayContents)
        return 0;
    return inlineWrapperForDisplayContentsMap().get(this).get();
}

void RenderText::setInlineWrapperForDisplayContents(RenderInline* wrapper)
{
    ASSERT(m_hasInlineWrapperForDisplayContents == inlineWrapperForDisplayContentsMap().contains(this));

    if (!wrapper) {
        if (!m_hasInlineWrapperForDisplayContents)
            return;
        inlineWrapperForDisplayContentsMap().remove(this);
        m_hasInlineWrapperForDisplayContents = false;
        return;
    }
    inlineWrapperForDisplayContentsMap().add(this, makeWeakPtr(wrapper));
    m_hasInlineWrapperForDisplayContents = true;
}

} // namespace WebCore
