Move painting code from InlineTextBox to InlineTextBoxPainter.

Source/core/rendering/InlineTextBox.cpp

 /*
  * (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.
  *
@@ skipping 15 matching lines @@
 #include "core/dom/Document.h"
 #include "core/dom/DocumentMarkerController.h"
 #include "core/dom/RenderedDocumentMarker.h"
 #include "core/dom/Text.h"
 #include "core/editing/CompositionUnderline.h"
 #include "core/editing/CompositionUnderlineRangeFilter.h"
 #include "core/editing/Editor.h"
 #include "core/editing/InputMethodController.h"
 #include "core/frame/LocalFrame.h"
 #include "core/page/Page.h"
-#include "core/paint/BoxPainter.h"
+#include "core/paint/InlineTextBoxPainter.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"
@@ skipping 17 matching lines @@
     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;
 
-typedef WTF::HashMap<const InlineTextBox*, TextBlobPtr> InlineTextBoxBlobCacheMap;
-static InlineTextBoxBlobCacheMap* gTextBlobCache;
-
-static const int misspellingLineThickness = 3;
 
 void InlineTextBox::destroy()
 {
     AbstractInlineTextBox::willDestroy(this);
 
     if (!knownToHaveNoOverflow() && gTextBoxesWithOverflow)
         gTextBoxesWithOverflow->remove(this);
-    if (gTextBlobCache)
-        gTextBlobCache->remove(this);
+    InlineTextBoxPainter::removeFromTextBlobCache(*this);
     InlineBox::destroy();
 }
 
 void InlineTextBox::markDirty()
 {
     // FIXME: Is it actually possible to try and paint a dirty InlineTextBox?
-    if (gTextBlobCache)
-        gTextBlobCache->remove(this);
+    InlineTextBoxPainter::removeFromTextBlobCache(*this);
 
     m_len = 0;
     m_start = 0;
     InlineBox::markDirty();
 }
 
 LayoutRect InlineTextBox::logicalOverflowRect() const
 {
     if (knownToHaveNoOverflow() || !gTextBoxesWithOverflow)
         return enclosingIntRect(logicalFrameRect());
@@ skipping 21 matching lines @@
 {
     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 = std::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 = std::min(endPos - m_start, int(m_len) + (isLineBreak() ? 0 : 1));
     return (sPos < ePos);
 }
 
 RenderObject::SelectionState InlineTextBox::selectionState() const
@@ skipping 45 matching lines @@
 LayoutRect InlineTextBox::localSelectionRect(int startPos, int endPos)
 {
     int sPos = std::max(startPos - m_start, 0);
     int ePos = std::min(endPos - m_start, (int)m_len);
 
     if (sPos > ePos)
         return LayoutRect();
 
     FontCachePurgePreventer fontCachePurgePreventer;
 
-    LayoutUnit selTop = selectionTop();
-    LayoutUnit selHeight = selectionHeight();
+    LayoutUnit selTop = root().selectionTop();
+    LayoutUnit selHeight = root().selectionHeight();
     RenderStyle* styleToUse = renderer().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))
@@ skipping 143 matching lines @@
         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);
-
-    LayoutRect logicalVisualOverflow = logicalOverflowRect();
-    LayoutUnit logicalStart = logicalVisualOverflow.x() + (isHorizontal() ? paintOffset.x() : paintOffset.y());
-    LayoutUnit logicalExtent = logicalVisualOverflow.width();
-
-    LayoutUnit paintEnd = isHorizontal() ? paintInfo.rect.maxX() : paintInfo.rect.maxY();
-    LayoutUnit paintStart = isHorizontal() ? paintInfo.rect.x() : paintInfo.rect.y();
-
-    // When subpixel font scaling is enabled text runs are positioned at
-    // subpixel boundaries on the x-axis and thus there is no reason to
-    // snap the x value. We still round the y-axis to ensure consistent
-    // line heights.
-    LayoutPoint adjustedPaintOffset = RuntimeEnabledFeatures::subpixelFontScalingEnabled()
-        ? LayoutPoint(paintOffset.x(), paintOffset.y().round())
-        : roundedIntPoint(paintOffset);
-
-    if (logicalStart >= paintEnd || logicalStart + logicalExtent <= paintStart)
-        return;
-
-    bool isPrinting = renderer().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 = 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;
-    RenderStyle* styleToUse = renderer().style(isFirstLineStyle());
-
-    adjustedPaintOffset.move(0, styleToUse->isHorizontalWritingMode() ? 0 : -logicalHeight());
-
-    FloatPoint boxOrigin = locationIncludingFlipping();
-    boxOrigin.move(adjustedPaintOffset.x().toFloat(), adjustedPaintOffset.y().toFloat());
-    FloatRect boxRect(boxOrigin, LayoutSize(logicalWidth(), logicalHeight()));
-
-    RenderCombineText* combinedText = styleToUse->hasTextCombine() && renderer().isCombineText() && toRenderCombineText(renderer()).isCombined() ? &toRenderCombineText(renderer()) : 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 text colors.
-    TextPainter::Style textStyle = TextPainter::textPaintingStyle(renderer(), styleToUse, paintInfo.forceBlackText(), isPrinting);
-    TextPainter::Style selectionStyle = TextPainter::selectionPaintingStyle(renderer(), haveSelection, paintInfo.forceBlackText(), isPrinting, textStyle);
-    bool paintSelectedTextOnly = (paintInfo.phase == PaintPhaseSelection);
-    bool paintSelectedTextSeparately = !paintSelectedTextOnly && textStyle != selectionStyle;
-
-    // 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 highlights.
-    if (paintInfo.phase != PaintPhaseSelection && paintInfo.phase != PaintPhaseTextClip && !isPrinting) {
-        if (containsComposition) {
-            paintCompositionBackgrounds(context, boxOrigin, styleToUse, font, useCustomUnderlines);
-        }
-
-        paintDocumentMarkers(context, boxOrigin, styleToUse, font, true);
-
-        if (haveSelection && !useCustomUnderlines)
-            paintSelection(context, boxOrigin, styleToUse, font, selectionStyle.fillColor);
-    }
-
-    // 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 = renderer().text().createView();
-        if (static_cast<unsigned>(length) != string.length() || m_start)
-            string.narrow(m_start, length);
-        maximumLength = renderer().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 selectionStart = 0;
-    int selectionEnd = 0;
-    if (paintSelectedTextOnly || paintSelectedTextSeparately)
-        selectionStartEnd(selectionStart, selectionEnd);
-
-    bool respectHyphen = selectionEnd == m_len && hasHyphen();
-    if (respectHyphen)
-        selectionEnd = textRun.length();
-
-    if (m_truncation != cNoTruncation) {
-        selectionStart = std::min<int>(selectionStart, m_truncation);
-        selectionEnd = std::min<int>(selectionEnd, m_truncation);
-        length = m_truncation;
-    }
-
-    TextPainter textPainter(context, font, textRun, textOrigin, boxRect, isHorizontal());
-    TextEmphasisPosition emphasisMarkPosition;
-    bool hasTextEmphasis = getEmphasisMarkPosition(styleToUse, emphasisMarkPosition);
-    if (hasTextEmphasis)
-        textPainter.setEmphasisMark(styleToUse->textEmphasisMarkString(), emphasisMarkPosition);
-    if (combinedText)
-        textPainter.setCombinedText(combinedText);
-
-    if (!paintSelectedTextOnly) {
-        // FIXME: Truncate right-to-left text correctly.
-        int startOffset = 0;
-        int endOffset = length;
-        if (paintSelectedTextSeparately && selectionStart < selectionEnd) {
-            startOffset = selectionEnd;
-            endOffset = selectionStart;
-        }
-
-        // FIXME: This cache should probably ultimately be held somewhere else.
-        // A hashmap is convenient to avoid a memory hit when the
-        // RuntimeEnabledFeature is off.
-        bool textBlobIsCacheable = RuntimeEnabledFeatures::textBlobEnabled() && startOffset == 0 && endOffset == length;
-        TextBlobPtr* cachedTextBlob = 0;
-        if (textBlobIsCacheable) {
-            if (!gTextBlobCache)
-                gTextBlobCache = new InlineTextBoxBlobCacheMap;
-            cachedTextBlob = &gTextBlobCache->add(this, nullptr).storedValue->value;
-        }
-        textPainter.paint(startOffset, endOffset, length, textStyle, cachedTextBlob);
-    }
-
-    if ((paintSelectedTextOnly || paintSelectedTextSeparately) && selectionStart < selectionEnd) {
-        // paint only the text that is selected
-        textPainter.paint(selectionStart, selectionEnd, length, selectionStyle);
-    }
-
-    // Paint decorations
-    TextDecoration textDecorations = styleToUse->textDecorationsInEffect();
-    if (textDecorations != TextDecorationNone && !paintSelectedTextOnly) {
-        GraphicsContextStateSaver stateSaver(*context, false);
-        TextPainter::updateGraphicsContext(context, textStyle, isHorizontal(), stateSaver);
-        if (combinedText)
-            context->concatCTM(rotation(boxRect, Clockwise));
-        paintDecoration(context, boxOrigin, textDecorations);
-        if (combinedText)
-            context->concatCTM(rotation(boxRect, Counterclockwise));
-    }
-
-    if (paintInfo.phase == PaintPhaseForeground) {
-        paintDocumentMarkers(context, boxOrigin, styleToUse, font, false);
-
-        // Paint custom underlines for compositions.
-        if (useCustomUnderlines) {
-            const Vector<CompositionUnderline>& underlines = renderer().frame()->inputMethodController().customCompositionUnderlines();
-            CompositionUnderlineRangeFilter filter(underlines, start(), end());
-            for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
-                if (it->color == Color::transparent)
-                    continue;
-                paintCompositionUnderline(context, boxOrigin, *it);
-            }
-        }
-    }
-
-    if (shouldRotate)
-        context->concatCTM(rotation(boxRect, Counterclockwise));
+    InlineTextBoxPainter(*this).paint(paintInfo, paintOffset);
 }
 
 void InlineTextBox::selectionStartEnd(int& sPos, int& ePos) const
 {
     int startPos, endPos;
     if (renderer().selectionState() == RenderObject::SelectionInside) {
         startPos = 0;
         endPos = renderer().textLength();
     } else {
         renderer().selectionStartEnd(startPos, endPos);
         if (renderer().selectionState() == RenderObject::SelectionStart)
             endPos = renderer().textLength();
         else if (renderer().selectionState() == RenderObject::SelectionEnd)
             startPos = 0;
     }
 
     sPos = std::max(startPos - m_start, 0);
     ePos = std::min(endPos - m_start, (int)m_len);
 }
 
-void InlineTextBox::paintSelection(GraphicsContext* context, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, Color textColor)
-{
-    // 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());
-
-    // 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 = renderer().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, renderer().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 = std::max(0, roundToInt(selectionBottom - selectionTop));
-
-    FloatPoint localOrigin(boxOrigin.x(), boxOrigin.y() - deltaY);
-    FloatRect clipRect(localOrigin, FloatSize(m_logicalWidth, selHeight));
-
-    GraphicsContextStateSaver stateSaver(*context);
-    context->clip(clipRect);
-    context->drawHighlightForText(font, textRun, localOrigin, selHeight, c, sPos, ePos);
-}
-
-unsigned InlineTextBox::underlinePaintStart(const CompositionUnderline& underline)
-{
-    return std::max(static_cast<unsigned>(m_start), underline.startOffset);
-}
-
-unsigned InlineTextBox::underlinePaintEnd(const CompositionUnderline& underline)
-{
-    unsigned paintEnd = std::min(end() + 1, underline.endOffset); // end() points at the last char, not past it.
-    if (m_truncation != cNoTruncation)
-        paintEnd = std::min(paintEnd, static_cast<unsigned>(m_start + m_truncation));
-    return paintEnd;
-}
-
-void InlineTextBox::paintSingleCompositionBackgroundRun(GraphicsContext* context, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, Color backgroundColor, int startPos, int endPos)
-{
-    int sPos = std::max(startPos - m_start, 0);
-    int ePos = std::min(endPos - m_start, static_cast<int>(m_len));
-    if (sPos >= ePos)
-        return;
-
-    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, backgroundColor, 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.
-    int gap = 0;
-
-    // Underline position of zero means draw underline on Baseline Position,
-    // in Blink we need at least 1-pixel gap to adding following check.
-    // Positive underline Position means underline should be drawn above baselin e
-    // and negative value means drawing below baseline, negating the value as in Blink
-    // downward Y-increases.
-
-    if (fontMetrics.underlinePosition())
-        gap = -fontMetrics.underlinePosition();
-    else
-        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 * std::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 * std::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)
-{
-    GraphicsContextStateSaver stateSaver(*context);
-
-    if (m_truncation == cFullTruncation)
-        return;
-
-    FloatPoint localOrigin = boxOrigin;
-
-    float width = m_logicalWidth;
-    if (m_truncation != cNoTruncation) {
-        width = 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 = renderer().document().printing();
-
-    RenderStyle* styleToUse = renderer().style(isFirstLineStyle());
-    int baseline = styleToUse->fontMetrics().ascent();
-
-    // 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)
-        && BoxPainter::shouldAntialiasLines(context);
-
-    // 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 (renderer().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 = std::max<int>(marker->startOffset() - m_start, 0);
-        int endPosition = std::min<int>(marker->endOffset() - m_start, m_len);
-
-        if (m_truncation != cNoTruncation)
-            endPosition = std::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()));
+    InlineTextBoxPainter(*this).paintDocumentMarker(pt, boxOrigin, marker, style, font, grammar);
 }
 
 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 = std::max(marker->startOffset() - m_start, (unsigned)0);
-    int ePos = std::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);
-        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::paintCompositionBackgrounds(GraphicsContext* pt, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, bool useCustomUnderlines)
-{
-    if (useCustomUnderlines) {
-        // Paint custom background highlights for compositions.
-        const Vector<CompositionUnderline>& underlines = renderer().frame()->inputMethodController().customCompositionUnderlines();
-        CompositionUnderlineRangeFilter filter(underlines, start(), end());
-        for (CompositionUnderlineRangeFilter::ConstIterator it = filter.begin(); it != filter.end(); ++it) {
-            if (it->backgroundColor == Color::transparent)
-                continue;
-            paintSingleCompositionBackgroundRun(pt, boxOrigin, style, font, it->backgroundColor, underlinePaintStart(*it), underlinePaintEnd(*it));
-        }
-
-    } else {
-        paintSingleCompositionBackgroundRun(pt, boxOrigin, style, font, RenderTheme::theme().platformDefaultCompositionBackgroundColor(),
-            renderer().frame()->inputMethodController().compositionStart(),
-            renderer().frame()->inputMethodController().compositionEnd());
-    }
-}
-
-void InlineTextBox::paintDocumentMarkers(GraphicsContext* pt, const FloatPoint& boxOrigin, RenderStyle* style, const Font& font, bool background)
-{
-    if (!renderer().node())
-        return;
-
-    DocumentMarkerVector markers = renderer().document().markers().markersFor(renderer().node());
-    DocumentMarkerVector::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;
-
-    unsigned paintStart = underlinePaintStart(underline);
-    unsigned paintEnd = underlinePaintEnd(underline);
-
-    // start of line to draw, relative to paintOffset.
-    float start = paintStart == static_cast<unsigned>(m_start) ? 0 :
-        renderer().width(m_start, paintStart - m_start, textPos(), isLeftToRightDirection() ? LTR : RTL, isFirstLineStyle());
-    // how much line to draw
-    float width = (paintStart == static_cast<unsigned>(m_start) && paintEnd == static_cast<unsigned>(end()) + 1) ? m_logicalWidth :
-        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, renderer().document().printing());
+    InlineTextBoxPainter(*this).paintTextMatchMarker(pt, boxOrigin, marker, style, font);
 }
 
 int InlineTextBox::caretMinOffset() const
 {
     return m_start;
 }
 
 int InlineTextBox::caretMaxOffset() const
 {
     return m_start + m_len;
@@ skipping 156 matching lines @@
     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 blink