Source/core/rendering/InlineTextBox.cpp

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This source file includes following definitions.
destroy
markDirty
logicalOverflowRect
setLogicalOverflowRect
baselinePosition
lineHeight
selectionTop
selectionBottom
selectionHeight
isSelected
selectionState
localSelectionRect
deleteLine
extractLine
attachLine
placeEllipsisBox
correctedTextColor
updateGraphicsContext
isLineBreak
nodeAtPoint
paintTextWithShadows
getEmphasisMarkPosition
paint
selectionStartEnd
alignSelectionRectToDevicePixels
paintSelection
paintCompositionBackground
textDecorationStyleToStrokeStyle
computeUnderlineOffset
adjustStepToDecorationLength
strokeWavyTextDecoration
shouldSetDecorationAntialias
shouldSetDecorationAntialias
paintAppliedDecoration
paintDecoration
lineStyleForMarkerType
paintDocumentMarker
paintTextMatchMarker
paintDocumentMarkers
paintCompositionUnderline
caretMinOffset
caretMaxOffset
textPos
offsetForPosition
positionForOffset
containsCaretOffset
characterWidths
constructTextRun
constructTextRun
constructTextRunForInspector
boxName
showBox
/*
 * (C) 1999 Lars Knoll (knoll@kde.org)
 * (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. 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
 * 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 "core/rendering/InlineTextBox.h"

#include "core/dom/Document.h"
#include "core/dom/DocumentMarkerController.h"
#include "core/dom/RenderedDocumentMarker.h"
#include "core/dom/Text.h"
#include "core/editing/Editor.h"
#include "core/editing/InputMethodController.h"
#include "core/frame/LocalFrame.h"
#include "core/page/Page.h"
#include "core/frame/Settings.h"
#include "core/rendering/AbstractInlineTextBox.h"
#include "core/rendering/EllipsisBox.h"
#include "core/rendering/HitTestResult.h"
#include "core/rendering/PaintInfo.h"
#include "core/rendering/RenderBR.h"
#include "core/rendering/RenderBlock.h"
#include "core/rendering/RenderCombineText.h"
#include "core/rendering/RenderRubyRun.h"
#include "core/rendering/RenderRubyText.h"
#include "core/rendering/RenderTheme.h"
#include "core/rendering/style/ShadowList.h"
#include "core/rendering/svg/SVGTextRunRenderingContext.h"
#include "platform/fonts/FontCache.h"
#include "platform/fonts/WidthIterator.h"
#include "platform/graphics/DrawLooperBuilder.h"
#include "platform/graphics/GraphicsContextStateSaver.h"
#include "wtf/Vector.h"
#include "wtf/text/CString.h"
#include "wtf/text/StringBuilder.h"

using namespace std;

namespace WebCore {

struct SameSizeAsInlineTextBox : public InlineBox {
    unsigned variables[1];
    unsigned short variables2[2];
    void* pointers[2];
};

COMPILE_ASSERT(sizeof(InlineTextBox) == sizeof(SameSizeAsInlineTextBox), InlineTextBox_should_stay_small);

typedef WTF::HashMap<const InlineTextBox*, LayoutRect> InlineTextBoxOverflowMap;
static InlineTextBoxOverflowMap* gTextBoxesWithOverflow;

static const int misspellingLineThickness = 3;

void InlineTextBox::destroy()
{
    AbstractInlineTextBox::willDestroy(this);

    if (!knownToHaveNoOverflow() && gTextBoxesWithOverflow)
        gTextBoxesWithOverflow->remove(this);
    InlineBox::destroy();
}

void InlineTextBox::markDirty(bool dirty)
{
    if (dirty) {
        m_len = 0;
        m_start = 0;
    }
    InlineBox::markDirty(dirty);
}

LayoutRect InlineTextBox::logicalOverflowRect() const
{
    if (knownToHaveNoOverflow() || !gTextBoxesWithOverflow)
        return enclosingIntRect(logicalFrameRect());
    return gTextBoxesWithOverflow->get(this);
}

void InlineTextBox::setLogicalOverflowRect(const LayoutRect& rect)
{
    ASSERT(!knownToHaveNoOverflow());
    if (!gTextBoxesWithOverflow)
        gTextBoxesWithOverflow = new InlineTextBoxOverflowMap;
    gTextBoxesWithOverflow->add(this, rect);
}

int InlineTextBox::baselinePosition(FontBaseline baselineType) const
{
    if (!isText() || !parent())
        return 0;
    if (parent()->renderer() == renderer().parent())
        return parent()->baselinePosition(baselineType);
    return toRenderBoxModelObject(renderer().parent())->baselinePosition(baselineType, isFirstLineStyle(), isHorizontal() ? HorizontalLine : VerticalLine, PositionOnContainingLine);
}

LayoutUnit InlineTextBox::lineHeight() const
{
    if (!isText() || !renderer().parent())
        return 0;
    if (renderer().isBR())
        return toRenderBR(renderer()).lineHeight(isFirstLineStyle());
    if (parent()->renderer() == renderer().parent())
        return parent()->lineHeight();
    return toRenderBoxModelObject(renderer().parent())->lineHeight(isFirstLineStyle(), isHorizontal() ? HorizontalLine : VerticalLine, PositionOnContainingLine);
}

LayoutUnit InlineTextBox::selectionTop()
{
    return root().selectionTop();
}

LayoutUnit InlineTextBox::selectionBottom()
{
    return root().selectionBottom();
}

LayoutUnit InlineTextBox::selectionHeight()
{
    return root().selectionHeight();
}

bool InlineTextBox::isSelected(int startPos, int endPos) const
{
    int sPos = max(startPos - m_start, 0);
    // The position after a hard line break is considered to be past its end.
    // See the corresponding code in InlineTextBox::selectionState.
    int ePos = min(endPos - m_start, int(m_len) + (isLineBreak() ? 0 : 1));
    return (sPos < ePos);
}

RenderObject::SelectionState InlineTextBox::selectionState()
{
    RenderObject::SelectionState state = renderer().selectionState();
    if (state == RenderObject::SelectionStart || state == RenderObject::SelectionEnd || state == RenderObject::SelectionBoth) {
        int startPos, endPos;
        renderer().selectionStartEnd(startPos, endPos);
        // The position after a hard line break is considered to be past its end.
        // See the corresponding code in InlineTextBox::isSelected.
        int lastSelectable = start() + len() - (isLineBreak() ? 1 : 0);

        // FIXME: Remove -webkit-line-break: LineBreakAfterWhiteSpace.
        int endOfLineAdjustmentForCSSLineBreak = renderer().style()->lineBreak() == LineBreakAfterWhiteSpace ? -1 : 0;
        bool start = (state != RenderObject::SelectionEnd && startPos >= m_start && startPos <= m_start + m_len + endOfLineAdjustmentForCSSLineBreak);
        bool end = (state != RenderObject::SelectionStart && endPos > m_start && endPos <= lastSelectable);
        if (start && end)
            state = RenderObject::SelectionBoth;
        else if (start)
            state = RenderObject::SelectionStart;
        else if (end)
            state = RenderObject::SelectionEnd;
        else if ((state == RenderObject::SelectionEnd || startPos < m_start) &&
                 (state == RenderObject::SelectionStart || endPos > lastSelectable))
            state = RenderObject::SelectionInside;
        else if (state == RenderObject::SelectionBoth)
            state = RenderObject::SelectionNone;
    }

    // If there are ellipsis following, make sure their selection is updated.
    if (m_truncation != cNoTruncation && root().ellipsisBox()) {
        EllipsisBox* ellipsis = root().ellipsisBox();
        if (state != RenderObject::SelectionNone) {
            int start, end;
            selectionStartEnd(start, end);
            // The ellipsis should be considered to be selected if the end of
            // the selection is past the beginning of the truncation and the
            // beginning of the selection is before or at the beginning of the
            // truncation.
            ellipsis->setSelectionState(end >= m_truncation && start <= m_truncation ?
                RenderObject::SelectionInside : RenderObject::SelectionNone);
        } else
            ellipsis->setSelectionState(RenderObject::SelectionNone);
    }

    return state;
}

LayoutRect InlineTextBox::localSelectionRect(int startPos, int endPos)
{
    int sPos = max(startPos - m_start, 0);
    int ePos = min(endPos - m_start, (int)m_len);

    if (sPos > ePos)
        return LayoutRect();

    FontCachePurgePreventer fontCachePurgePreventer;

    LayoutUnit selTop = selectionTop();
    LayoutUnit selHeight = selectionHeight();
    RenderStyle* styleToUse = textRenderer().style(isFirstLineStyle());
    const Font& font = styleToUse->font();

    StringBuilder charactersWithHyphen;
    bool respectHyphen = ePos == m_len && hasHyphen();
    TextRun textRun = constructTextRun(styleToUse, font, respectHyphen ? &charactersWithHyphen : 0);

    FloatPoint startingPoint = FloatPoint(logicalLeft(), selTop.toFloat());
    LayoutRect r;
    if (sPos || ePos != static_cast<int>(m_len))
        r = enclosingIntRect(font.selectionRectForText(textRun, startingPoint, selHeight, sPos, ePos));
    else // Avoid computing the font width when the entire line box is selected as an optimization.
        r = enclosingIntRect(FloatRect(startingPoint, FloatSize(m_logicalWidth, selHeight.toFloat())));

    LayoutUnit logicalWidth = r.width();
    if (r.x() > logicalRight())
        logicalWidth  = 0;
    else if (r.maxX() > logicalRight())
        logicalWidth = logicalRight() - r.x();

    LayoutPoint topPoint = isHorizontal() ? LayoutPoint(r.x(), selTop) : LayoutPoint(selTop, r.x());
    LayoutUnit width = isHorizontal() ? logicalWidth : selHeight;
    LayoutUnit height = isHorizontal() ? selHeight : logicalWidth;

    return LayoutRect(topPoint, LayoutSize(width, height));
}

void InlineTextBox::deleteLine()
{
    toRenderText(renderer()).removeTextBox(this);
    destroy();
}

void InlineTextBox::extractLine()
{
    if (extracted())
        return;

    toRenderText(renderer()).extractTextBox(this);
}

void InlineTextBox::attachLine()
{
    if (!extracted())
        return;

    toRenderText(renderer()).attachTextBox(this);
}

float InlineTextBox::placeEllipsisBox(bool flowIsLTR, float visibleLeftEdge, float visibleRightEdge, float ellipsisWidth, float &truncatedWidth, bool& foundBox)
{
    if (foundBox) {
        m_truncation = cFullTruncation;
        return -1;
    }

    // For LTR this is the left edge of the box, for RTL, the right edge in parent coordinates.
    float ellipsisX = flowIsLTR ? visibleRightEdge - ellipsisWidth : visibleLeftEdge + ellipsisWidth;

    // Criteria for full truncation:
    // LTR: the left edge of the ellipsis is to the left of our text run.
    // RTL: the right edge of the ellipsis is to the right of our text run.
    bool ltrFullTruncation = flowIsLTR && ellipsisX <= logicalLeft();
    bool rtlFullTruncation = !flowIsLTR && ellipsisX >= logicalLeft() + logicalWidth();
    if (ltrFullTruncation || rtlFullTruncation) {
        // Too far.  Just set full truncation, but return -1 and let the ellipsis just be placed at the edge of the box.
        m_truncation = cFullTruncation;
        foundBox = true;
        return -1;
    }

    bool ltrEllipsisWithinBox = flowIsLTR && (ellipsisX < logicalRight());
    bool rtlEllipsisWithinBox = !flowIsLTR && (ellipsisX > logicalLeft());
    if (ltrEllipsisWithinBox || rtlEllipsisWithinBox) {
        foundBox = true;

        // The inline box may have different directionality than it's parent.  Since truncation
        // behavior depends both on both the parent and the inline block's directionality, we
        // must keep track of these separately.
        bool ltr = isLeftToRightDirection();
        if (ltr != flowIsLTR) {
            // Width in pixels of the visible portion of the box, excluding the ellipsis.
            int visibleBoxWidth = visibleRightEdge - visibleLeftEdge  - ellipsisWidth;
            ellipsisX = ltr ? logicalLeft() + visibleBoxWidth : logicalRight() - visibleBoxWidth;
        }

        int offset = offsetForPosition(ellipsisX, false);
        if (offset == 0) {
            // No characters should be rendered.  Set ourselves to full truncation and place the ellipsis at the min of our start
            // and the ellipsis edge.
            m_truncation = cFullTruncation;
            truncatedWidth += ellipsisWidth;
            return min(ellipsisX, logicalLeft());
        }

        // Set the truncation index on the text run.
        m_truncation = offset;

        // If we got here that means that we were only partially truncated and we need to return the pixel offset at which
        // to place the ellipsis.
        float widthOfVisibleText = toRenderText(renderer()).width(m_start, offset, textPos(), flowIsLTR ? LTR : RTL, isFirstLineStyle());

        // The ellipsis needs to be placed just after the last visible character.
        // Where "after" is defined by the flow directionality, not the inline
        // box directionality.
        // e.g. In the case of an LTR inline box truncated in an RTL flow then we can
        // have a situation such as |Hello| -> |...He|
        truncatedWidth += widthOfVisibleText + ellipsisWidth;
        if (flowIsLTR)
            return logicalLeft() + widthOfVisibleText;
        else
            return logicalRight() - widthOfVisibleText - ellipsisWidth;
    }
    truncatedWidth += logicalWidth();
    return -1;
}

Color correctedTextColor(Color textColor, Color backgroundColor)
{
    // Adjust the text color if it is too close to the background color,
    // by darkening or lightening it to move it further away.

    int d = differenceSquared(textColor, backgroundColor);
    // semi-arbitrarily chose 65025 (255^2) value here after a few tests;
    if (d > 65025) {
        return textColor;
    }

    int distanceFromWhite = differenceSquared(textColor, Color::white);
    int distanceFromBlack = differenceSquared(textColor, Color::black);

    if (distanceFromWhite < distanceFromBlack) {
        return textColor.dark();
    }

    return textColor.light();
}

void updateGraphicsContext(GraphicsContext* context, const Color& fillColor, const Color& strokeColor, float strokeThickness)
{
    TextDrawingModeFlags mode = context->textDrawingMode();
    if (strokeThickness > 0) {
        TextDrawingModeFlags newMode = mode | TextModeStroke;
        if (mode != newMode) {
            context->setTextDrawingMode(newMode);
            mode = newMode;
        }
    }

    if (mode & TextModeFill && fillColor != context->fillColor())
        context->setFillColor(fillColor);

    if (mode & TextModeStroke) {
        if (strokeColor != context->strokeColor())
            context->setStrokeColor(strokeColor);
        if (strokeThickness != context->strokeThickness())
            context->setStrokeThickness(strokeThickness);
    }
}

bool InlineTextBox::isLineBreak() const
{
    return renderer().isBR() || (renderer().style()->preserveNewline() && len() == 1 && (*textRenderer().text().impl())[start()] == '\n');
}

bool InlineTextBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, LayoutUnit /* lineTop */, LayoutUnit /*lineBottom*/)
{
    if (isLineBreak())
        return false;

    FloatPoint boxOrigin = locationIncludingFlipping();
    boxOrigin.moveBy(accumulatedOffset);
    FloatRect rect(boxOrigin, size());
    if (m_truncation != cFullTruncation && visibleToHitTestRequest(request) && locationInContainer.intersects(rect)) {
        renderer().updateHitTestResult(result, flipForWritingMode(locationInContainer.point() - toLayoutSize(accumulatedOffset)));
        if (!result.addNodeToRectBasedTestResult(renderer().node(), request, locationInContainer, rect))
            return true;
    }
    return false;
}

static void paintTextWithShadows(GraphicsContext* context,
    const RenderObject& renderer, const Font& font, const TextRun& textRun,
    const AtomicString& emphasisMark, int emphasisMarkOffset,
    int startOffset, int endOffset, int truncationPoint,
    const FloatPoint& textOrigin, const FloatRect& boxRect,
    const ShadowList* shadowList, bool stroked, bool horizontal)
{
    // Text shadows are disabled when printing. http://crbug.com/258321
    bool hasShadow = shadowList && !context->printing();

    if (hasShadow) {
        OwnPtr<DrawLooperBuilder> drawLooperBuilder = DrawLooperBuilder::create();
        for (size_t i = shadowList->shadows().size(); i--; ) {
            const ShadowData& shadow = shadowList->shadows()[i];
            float shadowX = horizontal ? shadow.x() : shadow.y();
            float shadowY = horizontal ? shadow.y() : -shadow.x();
            FloatSize offset(shadowX, shadowY);
            drawLooperBuilder->addShadow(offset, shadow.blur(), shadow.color(),
                DrawLooperBuilder::ShadowRespectsTransforms, DrawLooperBuilder::ShadowIgnoresAlpha);
        }
        drawLooperBuilder->addUnmodifiedContent();
        context->setDrawLooper(drawLooperBuilder.release());
    }

    TextRunPaintInfo textRunPaintInfo(textRun);
    textRunPaintInfo.bounds = boxRect;
    if (startOffset <= endOffset) {
        textRunPaintInfo.from = startOffset;
        textRunPaintInfo.to = endOffset;
        if (emphasisMark.isEmpty())
            context->drawText(font, textRunPaintInfo, textOrigin);
        else
            context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
    } else {
        if (endOffset > 0) {
            textRunPaintInfo.from = 0;
            textRunPaintInfo.to = endOffset;
            if (emphasisMark.isEmpty())
                context->drawText(font, textRunPaintInfo, textOrigin);
            else
                context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
        }
        if (startOffset < truncationPoint) {
            textRunPaintInfo.from = startOffset;
            textRunPaintInfo.to = truncationPoint;
            if (emphasisMark.isEmpty())
                context->drawText(font, textRunPaintInfo, textOrigin);
            else
                context->drawEmphasisMarks(font, textRunPaintInfo, emphasisMark, textOrigin + IntSize(0, emphasisMarkOffset));
        }
    }

    if (hasShadow)
        context->clearDrawLooper();
}

bool InlineTextBox::getEmphasisMarkPosition(RenderStyle* style, TextEmphasisPosition& emphasisPosition) const
{
    // This function returns true if there are text emphasis marks and they are suppressed by ruby text.
    if (style->textEmphasisMark() == TextEmphasisMarkNone)
        return false;

    emphasisPosition = style->textEmphasisPosition();
    if (emphasisPosition == TextEmphasisPositionUnder)
        return true; // Ruby text is always over, so it cannot suppress emphasis marks under.

    RenderBlock* containingBlock = renderer().containingBlock();
    if (!containingBlock->isRubyBase())
        return true; // This text is not inside a ruby base, so it does not have ruby text over it.

    if (!containingBlock->parent()->isRubyRun())
        return true; // Cannot get the ruby text.

    RenderRubyText* rubyText = toRenderRubyRun(containingBlock->parent())->rubyText();

    // The emphasis marks over are suppressed only if there is a ruby text box and it not empty.
    return !rubyText || !rubyText->firstLineBox();
}

void InlineTextBox::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset, LayoutUnit /*lineTop*/, LayoutUnit /*lineBottom*/)
{
    if (isLineBreak() || !paintInfo.shouldPaintWithinRoot(&renderer()) || renderer().style()->visibility() != VISIBLE
        || m_truncation == cFullTruncation || paintInfo.phase == PaintPhaseOutline || !m_len)
        return;

    ASSERT(paintInfo.phase != PaintPhaseSelfOutline && paintInfo.phase != PaintPhaseChildOutlines);

    LayoutUnit logicalLeftSide = logicalLeftVisualOverflow();
    LayoutUnit logicalRightSide = logicalRightVisualOverflow();
    LayoutUnit logicalStart = logicalLeftSide + (isHorizontal() ? paintOffset.x() : paintOffset.y());
    LayoutUnit logicalExtent = logicalRightSide - logicalLeftSide;

    LayoutUnit paintEnd = isHorizontal() ? paintInfo.rect.maxX() : paintInfo.rect.maxY();
    LayoutUnit paintStart = isHorizontal() ? paintInfo.rect.x() : paintInfo.rect.y();

    LayoutPoint adjustedPaintOffset = roundedIntPoint(paintOffset);

    if (logicalStart >= paintEnd || logicalStart + logicalExtent <= paintStart)
        return;

    bool isPrinting = textRenderer().document().printing();

    // Determine whether or not we're selected.
    bool haveSelection = !isPrinting && paintInfo.phase != PaintPhaseTextClip && selectionState() != RenderObject::SelectionNone;
    if (!haveSelection && paintInfo.phase == PaintPhaseSelection)
        // When only painting the selection, don't bother to paint if there is none.
        return;

    if (m_truncation != cNoTruncation) {
        if (renderer().containingBlock()->style()->isLeftToRightDirection() != isLeftToRightDirection()) {
            // Make the visible fragment of text hug the edge closest to the rest of the run by moving the origin
            // at which we start drawing text.
            // e.g. In the case of LTR text truncated in an RTL Context, the correct behavior is:
            // |Hello|CBA| -> |...He|CBA|
            // In order to draw the fragment "He" aligned to the right edge of it's box, we need to start drawing
            // farther to the right.
            // NOTE: WebKit's behavior differs from that of IE which appears to just overlay the ellipsis on top of the
            // truncated string i.e.  |Hello|CBA| -> |...lo|CBA|
            LayoutUnit widthOfVisibleText = toRenderText(renderer()).width(m_start, m_truncation, textPos(), isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
            LayoutUnit widthOfHiddenText = m_logicalWidth - widthOfVisibleText;
            // FIXME: The hit testing logic also needs to take this translation into account.
            LayoutSize truncationOffset(isLeftToRightDirection() ? widthOfHiddenText : -widthOfHiddenText, 0);
            adjustedPaintOffset.move(isHorizontal() ? truncationOffset : truncationOffset.transposedSize());
        }
    }

    GraphicsContext* context = paintInfo.context;

    RenderObject& rendererToUse = renderer();
    RenderStyle* styleToUse = rendererToUse.style(isFirstLineStyle());

    adjustedPaintOffset.move(0, styleToUse->isHorizontalWritingMode() ? 0 : -logicalHeight());

    FloatPoint boxOrigin = locationIncludingFlipping();
    // FIXME: Shouldn't these offsets be rounded?
    boxOrigin.move(adjustedPaintOffset.x().toFloat(), adjustedPaintOffset.y().toFloat());
    FloatRect boxRect(boxOrigin, LayoutSize(logicalWidth(), logicalHeight()));

    RenderCombineText* combinedText = styleToUse->hasTextCombine() && textRenderer().isCombineText() && toRenderCombineText(textRenderer()).isCombined() ? &toRenderCombineText(textRenderer()) : 0;

    bool shouldRotate = !isHorizontal() && !combinedText;
    if (shouldRotate)
        context->concatCTM(rotation(boxRect, Clockwise));

    // Determine whether or not we have composition underlines to draw.
    bool containsComposition = renderer().node() && renderer().frame()->inputMethodController().compositionNode() == renderer().node();
    bool useCustomUnderlines = containsComposition && renderer().frame()->inputMethodController().compositionUsesCustomUnderlines();

    // Determine the text colors and selection colors.
    Color textFillColor;
    Color textStrokeColor;
    Color emphasisMarkColor;
    float textStrokeWidth = styleToUse->textStrokeWidth();

    // Text shadows are disabled when printing. http://crbug.com/258321
    const ShadowList* textShadow = (context->printing() || paintInfo.forceBlackText()) ? 0 : styleToUse->textShadow();

    if (paintInfo.forceBlackText()) {
        textFillColor = Color::black;
        textStrokeColor = Color::black;
        emphasisMarkColor = Color::black;
    } else {
        textFillColor = rendererToUse.resolveColor(styleToUse, CSSPropertyWebkitTextFillColor);

        bool forceBackgroundToWhite = false;
        if (isPrinting) {
            if (styleToUse->printColorAdjust() == PrintColorAdjustEconomy)
                forceBackgroundToWhite = true;
            if (textRenderer().document().settings() && textRenderer().document().settings()->shouldPrintBackgrounds())
                forceBackgroundToWhite = false;
        }

        // Make the text fill color legible against a white background
        if (forceBackgroundToWhite)
            textFillColor = correctedTextColor(textFillColor, Color::white);

        textStrokeColor = rendererToUse.resolveColor(styleToUse, CSSPropertyWebkitTextStrokeColor);

        // Make the text stroke color legible against a white background
        if (forceBackgroundToWhite)
            textStrokeColor = correctedTextColor(textStrokeColor, Color::white);

        emphasisMarkColor = rendererToUse.resolveColor(styleToUse, CSSPropertyWebkitTextEmphasisColor);

        // Make the text stroke color legible against a white background
        if (forceBackgroundToWhite)
            emphasisMarkColor = correctedTextColor(emphasisMarkColor, Color::white);
    }

    bool paintSelectedTextOnly = (paintInfo.phase == PaintPhaseSelection);
    bool paintSelectedTextSeparately = false;

    Color selectionFillColor = textFillColor;
    Color selectionStrokeColor = textStrokeColor;
    Color selectionEmphasisMarkColor = emphasisMarkColor;
    float selectionStrokeWidth = textStrokeWidth;
    const ShadowList* selectionShadow = textShadow;
    if (haveSelection) {
        // Check foreground color first.
        Color foreground = paintInfo.forceBlackText() ? Color::black : renderer().selectionForegroundColor();
        if (foreground != selectionFillColor) {
            if (!paintSelectedTextOnly)
                paintSelectedTextSeparately = true;
            selectionFillColor = foreground;
        }

        Color emphasisMarkForeground = paintInfo.forceBlackText() ? Color::black : renderer().selectionEmphasisMarkColor();
        if (emphasisMarkForeground != selectionEmphasisMarkColor) {
            if (!paintSelectedTextOnly)
                paintSelectedTextSeparately = true;
            selectionEmphasisMarkColor = emphasisMarkForeground;
        }

        if (RenderStyle* pseudoStyle = renderer().getCachedPseudoStyle(SELECTION)) {
            // Text shadows are disabled when printing. http://crbug.com/258321
            const ShadowList* shadow = (context->printing() || paintInfo.forceBlackText()) ? 0 : pseudoStyle->textShadow();
            if (shadow != selectionShadow) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionShadow = shadow;
            }

            float strokeWidth = pseudoStyle->textStrokeWidth();
            if (strokeWidth != selectionStrokeWidth) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionStrokeWidth = strokeWidth;
            }

            Color stroke = paintInfo.forceBlackText() ? Color::black : rendererToUse.resolveColor(pseudoStyle, CSSPropertyWebkitTextStrokeColor);
            if (stroke != selectionStrokeColor) {
                if (!paintSelectedTextOnly)
                    paintSelectedTextSeparately = true;
                selectionStrokeColor = stroke;
            }
        }
    }

    // Set our font.
    const Font& font = styleToUse->font();

    FloatPoint textOrigin = FloatPoint(boxOrigin.x(), boxOrigin.y() + font.fontMetrics().ascent());

    if (combinedText)
        combinedText->adjustTextOrigin(textOrigin, boxRect);

    // 1. Paint backgrounds behind text if needed. Examples of such backgrounds include selection
    // and composition underlines.
    if (paintInfo.phase != PaintPhaseSelection && paintInfo.phase != PaintPhaseTextClip && !isPrinting) {

        if (containsComposition && !useCustomUnderlines) {
            paintCompositionBackground(context, boxOrigin, styleToUse, font,
                renderer().frame()->inputMethodController().compositionStart(),
                renderer().frame()->inputMethodController().compositionEnd());
        }

        paintDocumentMarkers(context, boxOrigin, styleToUse, font, true);

        if (haveSelection && !useCustomUnderlines)
            paintSelection(context, boxOrigin, styleToUse, font, selectionFillColor);
    }

    // 2. Now paint the foreground, including text and decorations like underline/overline (in quirks mode only).
    int length = m_len;
    int maximumLength;
    StringView string;
    if (!combinedText) {
        string = textRenderer().text().createView();
        if (static_cast<unsigned>(length) != string.length() || m_start)
            string.narrow(m_start, length);
        maximumLength = textRenderer().textLength() - m_start;
    } else {
        combinedText->getStringToRender(m_start, string, length);
        maximumLength = length;
    }

    StringBuilder charactersWithHyphen;
    TextRun textRun = constructTextRun(styleToUse, font, string, maximumLength, hasHyphen() ? &charactersWithHyphen : 0);
    if (hasHyphen())
        length = textRun.length();

    int sPos = 0;
    int ePos = 0;
    if (paintSelectedTextOnly || paintSelectedTextSeparately)
        selectionStartEnd(sPos, ePos);

    if (m_truncation != cNoTruncation) {
        sPos = min<int>(sPos, m_truncation);
        ePos = min<int>(ePos, m_truncation);
        length = m_truncation;
    }

    int emphasisMarkOffset = 0;
    TextEmphasisPosition emphasisMarkPosition;
    bool hasTextEmphasis = getEmphasisMarkPosition(styleToUse, emphasisMarkPosition);
    const AtomicString& emphasisMark = hasTextEmphasis ? styleToUse->textEmphasisMarkString() : nullAtom;
    if (!emphasisMark.isEmpty())
        emphasisMarkOffset = emphasisMarkPosition == TextEmphasisPositionOver ? -font.fontMetrics().ascent() - font.emphasisMarkDescent(emphasisMark) : font.fontMetrics().descent() + font.emphasisMarkAscent(emphasisMark);

    if (!paintSelectedTextOnly) {
        // For stroked painting, we have to change the text drawing mode.  It's probably dangerous to leave that mutated as a side
        // effect, so only when we know we're stroking, do a save/restore.
        GraphicsContextStateSaver stateSaver(*context, textStrokeWidth > 0);

        updateGraphicsContext(context, textFillColor, textStrokeColor, textStrokeWidth);
        if (!paintSelectedTextSeparately || ePos <= sPos) {
            // FIXME: Truncate right-to-left text correctly.
            paintTextWithShadows(context, rendererToUse, font, textRun, nullAtom, 0, 0, length, length, textOrigin, boxRect, textShadow, textStrokeWidth > 0, isHorizontal());
        } else {
            paintTextWithShadows(context, rendererToUse, font, textRun, nullAtom, 0, ePos, sPos, length, textOrigin, boxRect, textShadow, textStrokeWidth > 0, isHorizontal());
        }

        if (!emphasisMark.isEmpty()) {
            updateGraphicsContext(context, emphasisMarkColor, textStrokeColor, textStrokeWidth);

            DEFINE_STATIC_LOCAL(TextRun, objectReplacementCharacterTextRun, (&objectReplacementCharacter, 1));
            TextRun& emphasisMarkTextRun = combinedText ? objectReplacementCharacterTextRun : textRun;
            FloatPoint emphasisMarkTextOrigin = combinedText ? FloatPoint(boxOrigin.x() + boxRect.width() / 2, boxOrigin.y() + font.fontMetrics().ascent()) : textOrigin;
            if (combinedText)
                context->concatCTM(rotation(boxRect, Clockwise));

            int startOffset = 0;
            int endOffset = length;
            int paintRunLength = length;
            if (combinedText) {
                startOffset = 0;
                endOffset = objectReplacementCharacterTextRun.length();
                paintRunLength = endOffset;
            } else if (paintSelectedTextSeparately && ePos > sPos) {
                startOffset = ePos;
                endOffset = sPos;
            }
            // FIXME: Truncate right-to-left text correctly.
            paintTextWithShadows(context, rendererToUse, combinedText ? combinedText->originalFont() : font, emphasisMarkTextRun, emphasisMark, emphasisMarkOffset, startOffset, endOffset, paintRunLength, emphasisMarkTextOrigin, boxRect, textShadow, textStrokeWidth > 0, isHorizontal());

            if (combinedText)
                context->concatCTM(rotation(boxRect, Counterclockwise));
        }
    }

    if ((paintSelectedTextOnly || paintSelectedTextSeparately) && sPos < ePos) {
        // paint only the text that is selected
        GraphicsContextStateSaver stateSaver(*context, selectionStrokeWidth > 0);

        updateGraphicsContext(context, selectionFillColor, selectionStrokeColor, selectionStrokeWidth);
        paintTextWithShadows(context, rendererToUse, font, textRun, nullAtom, 0, sPos, ePos, length, textOrigin, boxRect, selectionShadow, selectionStrokeWidth > 0, isHorizontal());
        if (!emphasisMark.isEmpty()) {
            updateGraphicsContext(context, selectionEmphasisMarkColor, textStrokeColor, textStrokeWidth);

            DEFINE_STATIC_LOCAL(TextRun, objectReplacementCharacterTextRun, (&objectReplacementCharacter, 1));
            TextRun& emphasisMarkTextRun = combinedText ? objectReplacementCharacterTextRun : textRun;
            FloatPoint emphasisMarkTextOrigin = combinedText ? FloatPoint(boxOrigin.x() + boxRect.width() / 2, boxOrigin.y() + font.fontMetrics().ascent()) : textOrigin;
            if (combinedText)
                context->concatCTM(rotation(boxRect, Clockwise));

            int startOffset = combinedText ? 0 : sPos;
            int endOffset = combinedText ? objectReplacementCharacterTextRun.length() : ePos;
            int paintRunLength = combinedText ? endOffset : length;
            paintTextWithShadows(context, rendererToUse, combinedText ? combinedText->originalFont() : font, emphasisMarkTextRun, emphasisMark, emphasisMarkOffset, startOffset, endOffset, paintRunLength, emphasisMarkTextOrigin, boxRect, selectionShadow, selectionStrokeWidth > 0, isHorizontal());

            if (combinedText)
                context->concatCTM(rotation(boxRect, Counterclockwise));
        }
    }

    // Paint decorations
    TextDecoration textDecorations = styleToUse->textDecorationsInEffect();
    if (textDecorations != TextDecorationNone && paintInfo.phase != PaintPhaseSelection) {
        updateGraphicsContext(context, textFillColor, textStrokeColor, textStrokeWidth);
        if (combinedText)
            context->concatCTM(rotation(boxRect, Clockwise));
        paintDecoration(context, boxOrigin, textDecorations, textShadow);
        if (combinedText)
            context->concatCTM(rotation(boxRect, Counterclockwise));
    }

    if (paintInfo.phase == PaintPhaseForeground) {
        paintDocumentMarkers(context, boxOrigin, styleToUse, font, false);

        if (useCustomUnderlines) {
            const Vector<CompositionUnderline>& underlines = renderer().frame()->inputMethodController().customCompositionUnderlines();
            size_t numUnderlines = underlines.size();

            for (size_t index = 0; index < numUnderlines; ++index) {
                const CompositionUnderline& underline = underlines[index];

                if (underline.endOffset <= start())
                    // underline is completely before this run.  This might be an underline that sits
                    // before the first run we draw, or underlines that were within runs we skipped
                    // due to truncation.
                    continue;

                if (underline.startOffset <= end()) {
                    // underline intersects this run.  Paint it.
                    paintCompositionUnderline(context, boxOrigin, underline);
                    if (underline.endOffset > end() + 1)
                        // underline also runs into the next run. Bail now, no more marker advancement.
                        break;
                } else
                    // underline is completely after this run, bail.  A later run will paint it.
                    break;
            }
        }
    }

    if (shouldRotate)
        context->concatCTM(rotation(boxRect, Counterclockwise));
}

void InlineTextBox::selectionStartEnd(int& sPos, int& ePos)
{
    int startPos, endPos;
    if (renderer().selectionState() == RenderObject::SelectionInside) {
        startPos = 0;
        endPos = textRenderer().textLength();
    } else {
        textRenderer().selectionStartEnd(startPos, endPos);
        if (renderer().selectionState() == RenderObject::SelectionStart)
            endPos = textRenderer().textLength();
        else if (renderer().selectionState() == RenderObject::SelectionEnd)
            startPos = 0;
    }

    sPos = max(startPos - m_start, 0);
    ePos = min(endPos - m_start, (int)m_len);
}

void alignSelectionRectToDevicePixels(FloatRect& rect)
{
    float maxX = floorf(rect.maxX());
    rect.setX(floorf(rect.x()));
    rect.setWidth(roundf(maxX - rect.x()));
}

void InlineTextBox::paintSelection(GraphicsContext* context, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, Color textColor)
{
    if (context->paintingDisabled())
        return;

    // See if we have a selection to paint at all.
    int sPos, ePos;
    selectionStartEnd(sPos, ePos);
    if (sPos >= ePos)
        return;

    Color c = renderer().selectionBackgroundColor();
    if (!c.alpha())
        return;

    // If the text color ends up being the same as the selection background, invert the selection
    // background.
    if (textColor == c)
        c = Color(0xff - c.red(), 0xff - c.green(), 0xff - c.blue());

    GraphicsContextStateSaver stateSaver(*context);
    updateGraphicsContext(context, c, c, 0); // Don't draw text at all!

    // If the text is truncated, let the thing being painted in the truncation
    // draw its own highlight.
    int length = m_truncation != cNoTruncation ? m_truncation : m_len;
    StringView string = textRenderer().text().createView();

    if (string.length() != static_cast<unsigned>(length) || m_start)
        string.narrow(m_start, length);

    StringBuilder charactersWithHyphen;
    bool respectHyphen = ePos == length && hasHyphen();
    TextRun textRun = constructTextRun(style, font, string, textRenderer().textLength() - m_start, respectHyphen ? &charactersWithHyphen : 0);
    if (respectHyphen)
        ePos = textRun.length();

    LayoutUnit selectionBottom = root().selectionBottom();
    LayoutUnit selectionTop = root().selectionTopAdjustedForPrecedingBlock();

    int deltaY = roundToInt(renderer().style()->isFlippedLinesWritingMode() ? selectionBottom - logicalBottom() : logicalTop() - selectionTop);
    int selHeight = max(0, roundToInt(selectionBottom - selectionTop));

    FloatPoint localOrigin(boxOrigin.x(), boxOrigin.y() - deltaY);
    FloatRect clipRect(localOrigin, FloatSize(m_logicalWidth, selHeight));
    alignSelectionRectToDevicePixels(clipRect);

    context->clip(clipRect);

    context->drawHighlightForText(font, textRun, localOrigin, selHeight, c, sPos, ePos);
}

void InlineTextBox::paintCompositionBackground(GraphicsContext* context, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, int startPos, int endPos)
{
    int offset = m_start;
    int sPos = max(startPos - offset, 0);
    int ePos = min(endPos - offset, (int)m_len);

    if (sPos >= ePos)
        return;

    GraphicsContextStateSaver stateSaver(*context);

    Color c = Color(225, 221, 85);

    updateGraphicsContext(context, c, c, 0); // Don't draw text at all!

    int deltaY = renderer().style()->isFlippedLinesWritingMode() ? selectionBottom() - logicalBottom() : logicalTop() - selectionTop();
    int selHeight = selectionHeight();
    FloatPoint localOrigin(boxOrigin.x(), boxOrigin.y() - deltaY);
    context->drawHighlightForText(font, constructTextRun(style, font), localOrigin, selHeight, c, sPos, ePos);
}

static StrokeStyle textDecorationStyleToStrokeStyle(TextDecorationStyle decorationStyle)
{
    StrokeStyle strokeStyle = SolidStroke;
    switch (decorationStyle) {
    case TextDecorationStyleSolid:
        strokeStyle = SolidStroke;
        break;
    case TextDecorationStyleDouble:
        strokeStyle = DoubleStroke;
        break;
    case TextDecorationStyleDotted:
        strokeStyle = DottedStroke;
        break;
    case TextDecorationStyleDashed:
        strokeStyle = DashedStroke;
        break;
    case TextDecorationStyleWavy:
        strokeStyle = WavyStroke;
        break;
    }

    return strokeStyle;
}

static int computeUnderlineOffset(const TextUnderlinePosition underlinePosition, const FontMetrics& fontMetrics, const InlineTextBox* inlineTextBox, const float textDecorationThickness)
{
    // Compute the gap between the font and the underline. Use at least one
    // pixel gap, if underline is thick then use a bigger gap.
    const int gap = std::max<int>(1, ceilf(textDecorationThickness / 2.f));

    // FIXME: We support only horizontal text for now.
    switch (underlinePosition) {
    case TextUnderlinePositionAuto:
        return fontMetrics.ascent() + gap; // Position underline near the alphabetic baseline.
    case TextUnderlinePositionUnder: {
        // Position underline relative to the under edge of the lowest element's content box.
        const float offset = inlineTextBox->root().maxLogicalTop() - inlineTextBox->logicalTop();
        if (offset > 0)
            return inlineTextBox->logicalHeight() + gap + offset;
        return inlineTextBox->logicalHeight() + gap;
    }
    }

    ASSERT_NOT_REACHED();
    return fontMetrics.ascent() + gap;
}

static void adjustStepToDecorationLength(float& step, float& controlPointDistance, float length)
{
    ASSERT(step > 0);

    if (length <= 0)
        return;

    unsigned stepCount = static_cast<unsigned>(length / step);

    // Each Bezier curve starts at the same pixel that the previous one
    // ended. We need to subtract (stepCount - 1) pixels when calculating the
    // length covered to account for that.
    float uncoveredLength = length - (stepCount * step - (stepCount - 1));
    float adjustment = uncoveredLength / stepCount;
    step += adjustment;
    controlPointDistance += adjustment;
}

/*
 * Draw one cubic Bezier curve and repeat the same pattern long the the decoration's axis.
 * The start point (p1), controlPoint1, controlPoint2 and end point (p2) of the Bezier curve
 * form a diamond shape:
 *
 *                              step
 *                         |-----------|
 *
 *                   controlPoint1
 *                         +
 *
 *
 *                  . .
 *                .     .
 *              .         .
 * (x1, y1) p1 +           .            + p2 (x2, y2) - <--- Decoration's axis
 *                          .         .               |
 *                            .     .                 |
 *                              . .                   | controlPointDistance
 *                                                    |
 *                                                    |
 *                         +                          -
 *                   controlPoint2
 *
 *             |-----------|
 *                 step
 */
static void strokeWavyTextDecoration(GraphicsContext* context, FloatPoint p1, FloatPoint p2, float strokeThickness)
{
    context->adjustLineToPixelBoundaries(p1, p2, strokeThickness, context->strokeStyle());

    Path path;
    path.moveTo(p1);

    // Distance between decoration's axis and Bezier curve's control points.
    // The height of the curve is based on this distance. Use a minimum of 6 pixels distance since
    // the actual curve passes approximately at half of that distance, that is 3 pixels.
    // The minimum height of the curve is also approximately 3 pixels. Increases the curve's height
    // as strockThickness increases to make the curve looks better.
    float controlPointDistance = 3 * max<float>(2, strokeThickness);

    // Increment used to form the diamond shape between start point (p1), control
    // points and end point (p2) along the axis of the decoration. Makes the
    // curve wider as strockThickness increases to make the curve looks better.
    float step = 2 * max<float>(2, strokeThickness);

    bool isVerticalLine = (p1.x() == p2.x());

    if (isVerticalLine) {
        ASSERT(p1.x() == p2.x());

        float xAxis = p1.x();
        float y1;
        float y2;

        if (p1.y() < p2.y()) {
            y1 = p1.y();
            y2 = p2.y();
        } else {
            y1 = p2.y();
            y2 = p1.y();
        }

        adjustStepToDecorationLength(step, controlPointDistance, y2 - y1);
        FloatPoint controlPoint1(xAxis + controlPointDistance, 0);
        FloatPoint controlPoint2(xAxis - controlPointDistance, 0);

        for (float y = y1; y + 2 * step <= y2;) {
            controlPoint1.setY(y + step);
            controlPoint2.setY(y + step);
            y += 2 * step;
            path.addBezierCurveTo(controlPoint1, controlPoint2, FloatPoint(xAxis, y));
        }
    } else {
        ASSERT(p1.y() == p2.y());

        float yAxis = p1.y();
        float x1;
        float x2;

        if (p1.x() < p2.x()) {
            x1 = p1.x();
            x2 = p2.x();
        } else {
            x1 = p2.x();
            x2 = p1.x();
        }

        adjustStepToDecorationLength(step, controlPointDistance, x2 - x1);
        FloatPoint controlPoint1(0, yAxis + controlPointDistance);
        FloatPoint controlPoint2(0, yAxis - controlPointDistance);

        for (float x = x1; x + 2 * step <= x2;) {
            controlPoint1.setX(x + step);
            controlPoint2.setX(x + step);
            x += 2 * step;
            path.addBezierCurveTo(controlPoint1, controlPoint2, FloatPoint(x, yAxis));
        }
    }

    context->setShouldAntialias(true);
    context->strokePath(path);
}

static bool shouldSetDecorationAntialias(TextDecorationStyle decorationStyle)
{
    return decorationStyle == TextDecorationStyleDotted || decorationStyle == TextDecorationStyleDashed;
}

static bool shouldSetDecorationAntialias(TextDecorationStyle underline, TextDecorationStyle overline, TextDecorationStyle linethrough)
{
    return shouldSetDecorationAntialias(underline) || shouldSetDecorationAntialias(overline) || shouldSetDecorationAntialias(linethrough);
}

static void paintAppliedDecoration(GraphicsContext* context, FloatPoint start, float width, float doubleOffset, int wavyOffsetFactor,
    RenderObject::AppliedTextDecoration decoration, float thickness, bool antialiasDecoration, bool isPrinting)
{
    context->setStrokeStyle(textDecorationStyleToStrokeStyle(decoration.style));
    context->setStrokeColor(decoration.color);

    switch (decoration.style) {
    case TextDecorationStyleWavy:
        strokeWavyTextDecoration(context, start + FloatPoint(0, doubleOffset * wavyOffsetFactor), start + FloatPoint(width, doubleOffset * wavyOffsetFactor), thickness);
        break;
    case TextDecorationStyleDotted:
    case TextDecorationStyleDashed:
        context->setShouldAntialias(antialiasDecoration);
        // Fall through
    default:
        context->drawLineForText(start, width, isPrinting);

        if (decoration.style == TextDecorationStyleDouble)
            context->drawLineForText(start + FloatPoint(0, doubleOffset), width, isPrinting);
    }
}

void InlineTextBox::paintDecoration(GraphicsContext* context, const FloatPoint& boxOrigin, TextDecoration deco, const ShadowList* shadowList)
{
    GraphicsContextStateSaver stateSaver(*context);

    if (m_truncation == cFullTruncation)
        return;

    FloatPoint localOrigin = boxOrigin;

    float width = m_logicalWidth;
    if (m_truncation != cNoTruncation) {
        width = toRenderText(renderer()).width(m_start, m_truncation, textPos(), isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
        if (!isLeftToRightDirection())
            localOrigin.move(m_logicalWidth - width, 0);
    }

    // Get the text decoration colors.
    RenderObject::AppliedTextDecoration underline, overline, linethrough;

    renderer().getTextDecorations(deco, underline, overline, linethrough, true);
    if (isFirstLineStyle())
        renderer().getTextDecorations(deco, underline, overline, linethrough, true, true);

    // Use a special function for underlines to get the positioning exactly right.
    bool isPrinting = textRenderer().document().printing();

    bool linesAreOpaque = !isPrinting && (!(deco & TextDecorationUnderline) || underline.color.alpha() == 255) && (!(deco & TextDecorationOverline) || overline.color.alpha() == 255) && (!(deco & TextDecorationLineThrough) || linethrough.color.alpha() == 255);

    RenderStyle* styleToUse = renderer().style(isFirstLineStyle());
    int baseline = styleToUse->fontMetrics().ascent();

    size_t shadowCount = shadowList ? shadowList->shadows().size() : 0;
    // Set the thick of the line to be 10% (or something else ?)of the computed font size and not less than 1px.
    // Using computedFontSize should take care of zoom as well.

    // Update Underline thickness, in case we have Faulty Font Metrics calculating underline thickness by old method.
    float textDecorationThickness = styleToUse->fontMetrics().underlineThickness();
    int fontHeightInt  = (int)(styleToUse->fontMetrics().floatHeight() + 0.5);
    if ((textDecorationThickness == 0.f) || (textDecorationThickness >= (fontHeightInt >> 1)))
        textDecorationThickness = std::max(1.f, styleToUse->computedFontSize() / 10.f);

    context->setStrokeThickness(textDecorationThickness);

    bool antialiasDecoration = shouldSetDecorationAntialias(overline.style, underline.style, linethrough.style)
        && RenderBoxModelObject::shouldAntialiasLines(context);

    float extraOffset = 0;
    if (!linesAreOpaque && shadowCount > 1) {
        FloatRect clipRect(localOrigin, FloatSize(width, baseline + 2));
        for (size_t i = shadowCount; i--; ) {
            const ShadowData& s = shadowList->shadows()[i];
            FloatRect shadowRect(localOrigin, FloatSize(width, baseline + 2));
            shadowRect.inflate(s.blur());
            float shadowX = isHorizontal() ? s.x() : s.y();
            float shadowY = isHorizontal() ? s.y() : -s.x();
            shadowRect.move(shadowX, shadowY);
            clipRect.unite(shadowRect);
            extraOffset = max(extraOffset, max(0.0f, shadowY) + s.blur());
        }
        context->clip(clipRect);
        extraOffset += baseline + 2;
        localOrigin.move(0, extraOffset);
    }

    for (size_t i = max(static_cast<size_t>(1), shadowCount); i--; ) {
        // Even if we have no shadows, we still want to run the code below this once.
        if (i < shadowCount) {
            if (!i) {
                // The last set of lines paints normally inside the clip.
                localOrigin.move(0, -extraOffset);
                extraOffset = 0;
            }
            const ShadowData& shadow = shadowList->shadows()[i];
            float shadowX = isHorizontal() ? shadow.x() : shadow.y();
            float shadowY = isHorizontal() ? shadow.y() : -shadow.x();
            context->setShadow(FloatSize(shadowX, shadowY - extraOffset), shadow.blur(), shadow.color());
        }

        // Offset between lines - always non-zero, so lines never cross each other.
        float doubleOffset = textDecorationThickness + 1.f;

        if (deco & TextDecorationUnderline) {
            const int underlineOffset = computeUnderlineOffset(styleToUse->textUnderlinePosition(), styleToUse->fontMetrics(), this, textDecorationThickness);
            paintAppliedDecoration(context, localOrigin + FloatPoint(0, underlineOffset), width, doubleOffset, 1, underline, textDecorationThickness, antialiasDecoration, isPrinting);
        }
        if (deco & TextDecorationOverline) {
            paintAppliedDecoration(context, localOrigin, width, -doubleOffset, 1, overline, textDecorationThickness, antialiasDecoration, isPrinting);
        }
        if (deco & TextDecorationLineThrough) {
            const float lineThroughOffset = 2 * baseline / 3;
            paintAppliedDecoration(context, localOrigin + FloatPoint(0, lineThroughOffset), width, doubleOffset, 0, linethrough, textDecorationThickness, antialiasDecoration, isPrinting);
        }
    }
}

static GraphicsContext::DocumentMarkerLineStyle lineStyleForMarkerType(DocumentMarker::MarkerType markerType)
{
    switch (markerType) {
    case DocumentMarker::Spelling:
        return GraphicsContext::DocumentMarkerSpellingLineStyle;
    case DocumentMarker::Grammar:
        return GraphicsContext::DocumentMarkerGrammarLineStyle;
    default:
        ASSERT_NOT_REACHED();
        return GraphicsContext::DocumentMarkerSpellingLineStyle;
    }
}

void InlineTextBox::paintDocumentMarker(GraphicsContext* pt, const FloatPoint& boxOrigin, DocumentMarker* marker, RenderStyle* style, const Font& font, bool grammar)
{
    // Never print spelling/grammar markers (5327887)
    if (textRenderer().document().printing())
        return;

    if (m_truncation == cFullTruncation)
        return;

    float start = 0; // start of line to draw, relative to tx
    float width = m_logicalWidth; // how much line to draw

    // Determine whether we need to measure text
    bool markerSpansWholeBox = true;
    if (m_start <= (int)marker->startOffset())
        markerSpansWholeBox = false;
    if ((end() + 1) != marker->endOffset()) // end points at the last char, not past it
        markerSpansWholeBox = false;
    if (m_truncation != cNoTruncation)
        markerSpansWholeBox = false;

    if (!markerSpansWholeBox || grammar) {
        int startPosition = max<int>(marker->startOffset() - m_start, 0);
        int endPosition = min<int>(marker->endOffset() - m_start, m_len);

        if (m_truncation != cNoTruncation)
            endPosition = min<int>(endPosition, m_truncation);

        // Calculate start & width
        int deltaY = renderer().style()->isFlippedLinesWritingMode() ? selectionBottom() - logicalBottom() : logicalTop() - selectionTop();
        int selHeight = selectionHeight();
        FloatPoint startPoint(boxOrigin.x(), boxOrigin.y() - deltaY);
        TextRun run = constructTextRun(style, font);

        // FIXME: Convert the document markers to float rects.
        IntRect markerRect = enclosingIntRect(font.selectionRectForText(run, startPoint, selHeight, startPosition, endPosition));
        start = markerRect.x() - startPoint.x();
        width = markerRect.width();

        // Store rendered rects for bad grammar markers, so we can hit-test against it elsewhere in order to
        // display a toolTip. We don't do this for misspelling markers.
        if (grammar) {
            markerRect.move(-boxOrigin.x(), -boxOrigin.y());
            markerRect = renderer().localToAbsoluteQuad(FloatRect(markerRect)).enclosingBoundingBox();
            toRenderedDocumentMarker(marker)->setRenderedRect(markerRect);
        }
    }

    // IMPORTANT: The misspelling underline is not considered when calculating the text bounds, so we have to
    // make sure to fit within those bounds.  This means the top pixel(s) of the underline will overlap the
    // bottom pixel(s) of the glyphs in smaller font sizes.  The alternatives are to increase the line spacing (bad!!)
    // or decrease the underline thickness.  The overlap is actually the most useful, and matches what AppKit does.
    // So, we generally place the underline at the bottom of the text, but in larger fonts that's not so good so
    // we pin to two pixels under the baseline.
    int lineThickness = misspellingLineThickness;
    int baseline = renderer().style(isFirstLineStyle())->fontMetrics().ascent();
    int descent = logicalHeight() - baseline;
    int underlineOffset;
    if (descent <= (2 + lineThickness)) {
        // Place the underline at the very bottom of the text in small/medium fonts.
        underlineOffset = logicalHeight() - lineThickness;
    } else {
        // In larger fonts, though, place the underline up near the baseline to prevent a big gap.
        underlineOffset = baseline + 2;
    }
    pt->drawLineForDocumentMarker(FloatPoint(boxOrigin.x() + start, boxOrigin.y() + underlineOffset), width, lineStyleForMarkerType(marker->type()));
}

void InlineTextBox::paintTextMatchMarker(GraphicsContext* pt, const FloatPoint& boxOrigin, DocumentMarker* marker, RenderStyle* style, const Font& font)
{
    // Use same y positioning and height as for selection, so that when the selection and this highlight are on
    // the same word there are no pieces sticking out.
    int deltaY = renderer().style()->isFlippedLinesWritingMode() ? selectionBottom() - logicalBottom() : logicalTop() - selectionTop();
    int selHeight = selectionHeight();

    int sPos = max(marker->startOffset() - m_start, (unsigned)0);
    int ePos = min(marker->endOffset() - m_start, (unsigned)m_len);
    TextRun run = constructTextRun(style, font);

    // Always compute and store the rect associated with this marker. The computed rect is in absolute coordinates.
    IntRect markerRect = enclosingIntRect(font.selectionRectForText(run, IntPoint(x(), selectionTop()), selHeight, sPos, ePos));
    markerRect = renderer().localToAbsoluteQuad(FloatRect(markerRect)).enclosingBoundingBox();
    toRenderedDocumentMarker(marker)->setRenderedRect(markerRect);

    // Optionally highlight the text
    if (renderer().frame()->editor().markedTextMatchesAreHighlighted()) {
        Color color = marker->activeMatch() ?
            RenderTheme::theme().platformActiveTextSearchHighlightColor() :
            RenderTheme::theme().platformInactiveTextSearchHighlightColor();
        GraphicsContextStateSaver stateSaver(*pt);
        updateGraphicsContext(pt, color, color, 0); // Don't draw text at all!
        pt->clip(FloatRect(boxOrigin.x(), boxOrigin.y() - deltaY, m_logicalWidth, selHeight));
        pt->drawHighlightForText(font, run, FloatPoint(boxOrigin.x(), boxOrigin.y() - deltaY), selHeight, color, sPos, ePos);
    }
}

void InlineTextBox::paintDocumentMarkers(GraphicsContext* pt, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, bool background)
{
    if (!renderer().node())
        return;

    Vector<DocumentMarker*> markers = renderer().document().markers().markersFor(renderer().node());
    Vector<DocumentMarker*>::const_iterator markerIt = markers.begin();

    // Give any document markers that touch this run a chance to draw before the text has been drawn.
    // Note end() points at the last char, not one past it like endOffset and ranges do.
    for ( ; markerIt != markers.end(); ++markerIt) {
        DocumentMarker* marker = *markerIt;

        // Paint either the background markers or the foreground markers, but not both
        switch (marker->type()) {
            case DocumentMarker::Grammar:
            case DocumentMarker::Spelling:
                if (background)
                    continue;
                break;
            case DocumentMarker::TextMatch:
                if (!background)
                    continue;
                break;
            default:
                continue;
        }

        if (marker->endOffset() <= start())
            // marker is completely before this run.  This might be a marker that sits before the
            // first run we draw, or markers that were within runs we skipped due to truncation.
            continue;

        if (marker->startOffset() > end())
            // marker is completely after this run, bail.  A later run will paint it.
            break;

        // marker intersects this run.  Paint it.
        switch (marker->type()) {
            case DocumentMarker::Spelling:
                paintDocumentMarker(pt, boxOrigin, marker, style, font, false);
                break;
            case DocumentMarker::Grammar:
                paintDocumentMarker(pt, boxOrigin, marker, style, font, true);
                break;
            case DocumentMarker::TextMatch:
                paintTextMatchMarker(pt, boxOrigin, marker, style, font);
                break;
            default:
                ASSERT_NOT_REACHED();
        }

    }
}

void InlineTextBox::paintCompositionUnderline(GraphicsContext* ctx, const FloatPoint& boxOrigin, const CompositionUnderline& underline)
{
    if (m_truncation == cFullTruncation)
        return;

    float start = 0; // start of line to draw, relative to tx
    float width = m_logicalWidth; // how much line to draw
    bool useWholeWidth = true;
    unsigned paintStart = m_start;
    unsigned paintEnd = end() + 1; // end points at the last char, not past it
    if (paintStart <= underline.startOffset) {
        paintStart = underline.startOffset;
        useWholeWidth = false;
        start = toRenderText(renderer()).width(m_start, paintStart - m_start, textPos(), isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
    }
    if (paintEnd != underline.endOffset) {      // end points at the last char, not past it
        paintEnd = min(paintEnd, (unsigned)underline.endOffset);
        useWholeWidth = false;
    }
    if (m_truncation != cNoTruncation) {
        paintEnd = min(paintEnd, (unsigned)m_start + m_truncation);
        useWholeWidth = false;
    }
    if (!useWholeWidth) {
        width = toRenderText(renderer()).width(paintStart, paintEnd - paintStart, textPos() + start, isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
    }

    // Thick marked text underlines are 2px thick as long as there is room for the 2px line under the baseline.
    // All other marked text underlines are 1px thick.
    // If there's not enough space the underline will touch or overlap characters.
    int lineThickness = 1;
    int baseline = renderer().style(isFirstLineStyle())->fontMetrics().ascent();
    if (underline.thick && logicalHeight() - baseline >= 2)
        lineThickness = 2;

    // We need to have some space between underlines of subsequent clauses, because some input methods do not use different underline styles for those.
    // We make each line shorter, which has a harmless side effect of shortening the first and last clauses, too.
    start += 1;
    width -= 2;

    ctx->setStrokeColor(underline.color);
    ctx->setStrokeThickness(lineThickness);
    ctx->drawLineForText(FloatPoint(boxOrigin.x() + start, boxOrigin.y() + logicalHeight() - lineThickness), width, textRenderer().document().printing());
}

int InlineTextBox::caretMinOffset() const
{
    return m_start;
}

int InlineTextBox::caretMaxOffset() const
{
    return m_start + m_len;
}

float InlineTextBox::textPos() const
{
    // When computing the width of a text run, RenderBlock::computeInlineDirectionPositionsForLine() doesn't include the actual offset
    // from the containing block edge in its measurement. textPos() should be consistent so the text are rendered in the same width.
    if (logicalLeft() == 0)
        return 0;
    return logicalLeft() - root().logicalLeft();
}

int InlineTextBox::offsetForPosition(float lineOffset, bool includePartialGlyphs) const
{
    if (isLineBreak())
        return 0;

    if (lineOffset - logicalLeft() > logicalWidth())
        return isLeftToRightDirection() ? len() : 0;
    if (lineOffset - logicalLeft() < 0)
        return isLeftToRightDirection() ? 0 : len();

    FontCachePurgePreventer fontCachePurgePreventer;

    RenderText& text = toRenderText(renderer());
    RenderStyle* style = text.style(isFirstLineStyle());
    const Font& font = style->font();
    return font.offsetForPosition(constructTextRun(style, font), lineOffset - logicalLeft(), includePartialGlyphs);
}

float InlineTextBox::positionForOffset(int offset) const
{
    ASSERT(offset >= m_start);
    ASSERT(offset <= m_start + m_len);

    if (isLineBreak())
        return logicalLeft();

    FontCachePurgePreventer fontCachePurgePreventer;

    RenderText& text = toRenderText(renderer());
    RenderStyle* styleToUse = text.style(isFirstLineStyle());
    ASSERT(styleToUse);
    const Font& font = styleToUse->font();
    int from = !isLeftToRightDirection() ? offset - m_start : 0;
    int to = !isLeftToRightDirection() ? m_len : offset - m_start;
    // FIXME: Do we need to add rightBearing here?
    return font.selectionRectForText(constructTextRun(styleToUse, font), IntPoint(logicalLeft(), 0), 0, from, to).maxX();
}

bool InlineTextBox::containsCaretOffset(int offset) const
{
    // Offsets before the box are never "in".
    if (offset < m_start)
        return false;

    int pastEnd = m_start + m_len;

    // Offsets inside the box (not at either edge) are always "in".
    if (offset < pastEnd)
        return true;

    // Offsets outside the box are always "out".
    if (offset > pastEnd)
        return false;

    // Offsets at the end are "out" for line breaks (they are on the next line).
    if (isLineBreak())
        return false;

    // Offsets at the end are "in" for normal boxes (but the caller has to check affinity).
    return true;
}

void InlineTextBox::characterWidths(Vector<float>& widths) const
{
    FontCachePurgePreventer fontCachePurgePreventer;

    RenderStyle* styleToUse = textRenderer().style(isFirstLineStyle());
    const Font& font = styleToUse->font();

    TextRun textRun = constructTextRun(styleToUse, font);

    GlyphBuffer glyphBuffer;
    WidthIterator it(&font, textRun);
    float lastWidth = 0;
    widths.resize(m_len);
    for (unsigned i = 0; i < m_len; i++) {
        it.advance(i + 1, &glyphBuffer);
        widths[i] = it.m_runWidthSoFar - lastWidth;
        lastWidth = it.m_runWidthSoFar;
    }
}

TextRun InlineTextBox::constructTextRun(RenderStyle* style, const Font& font, StringBuilder* charactersWithHyphen) const
{
    ASSERT(style);
    ASSERT(textRenderer().text());

    StringView string = textRenderer().text().createView();
    unsigned startPos = start();
    unsigned length = len();

    if (string.length() != length || startPos)
        string.narrow(startPos, length);

    return constructTextRun(style, font, string, textRenderer().textLength() - startPos, charactersWithHyphen);
}

TextRun InlineTextBox::constructTextRun(RenderStyle* style, const Font& font, StringView string, int maximumLength, StringBuilder* charactersWithHyphen) const
{
    ASSERT(style);

    if (charactersWithHyphen) {
        const AtomicString& hyphenString = style->hyphenString();
        charactersWithHyphen->reserveCapacity(string.length() + hyphenString.length());
        charactersWithHyphen->append(string);
        charactersWithHyphen->append(hyphenString);
        string = charactersWithHyphen->toString().createView();
        maximumLength = string.length();
    }

    ASSERT(maximumLength >= static_cast<int>(string.length()));

    TextRun run(string, textPos(), expansion(), expansionBehavior(), direction(), dirOverride() || style->rtlOrdering() == VisualOrder, !textRenderer().canUseSimpleFontCodePath());
    run.setTabSize(!style->collapseWhiteSpace(), style->tabSize());
    run.setCharacterScanForCodePath(!textRenderer().canUseSimpleFontCodePath());
    if (textRunNeedsRenderingContext(font))
        run.setRenderingContext(SVGTextRunRenderingContext::create(&textRenderer()));

    // Propagate the maximum length of the characters buffer to the TextRun, even when we're only processing a substring.
    run.setCharactersLength(maximumLength);
    ASSERT(run.charactersLength() >= run.length());
    return run;
}

TextRun InlineTextBox::constructTextRunForInspector(RenderStyle* style, const Font& font) const
{
    return InlineTextBox::constructTextRun(style, font);
}

#ifndef NDEBUG

const char* InlineTextBox::boxName() const
{
    return "InlineTextBox";
}

void InlineTextBox::showBox(int printedCharacters) const
{
    const RenderText& obj = toRenderText(renderer());
    String value = obj.text();
    value = value.substring(start(), len());
    value.replaceWithLiteral('\\', "\\\\");
    value.replaceWithLiteral('\n', "\\n");
    printedCharacters += fprintf(stderr, "%s\t%p", boxName(), this);
    for (; printedCharacters < showTreeCharacterOffset; printedCharacters++)
        fputc(' ', stderr);
    printedCharacters = fprintf(stderr, "\t%s %p", obj.renderName(), &obj);
    const int rendererCharacterOffset = 24;
    for (; printedCharacters < rendererCharacterOffset; printedCharacters++)
        fputc(' ', stderr);
    fprintf(stderr, "(%d,%d) \"%s\"\n", start(), start() + len(), value.utf8().data());
}

#endif

} // namespace WebCore
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root/Source/core/rendering/InlineTextBox.cpp

DEFINITIONS
