third_party/WebKit/Source/core/paint/ListMarkerPainter.cpp

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "core/paint/ListMarkerPainter.h"

#include "core/layout/LayoutListItem.h"
#include "core/layout/LayoutListMarker.h"
#include "core/layout/ListMarkerText.h"
#include "core/layout/api/SelectionState.h"
#include "core/paint/BoxPainter.h"
#include "core/paint/LayoutObjectDrawingRecorder.h"
#include "core/paint/PaintInfo.h"
#include "core/paint/TextPainter.h"
#include "platform/geometry/LayoutPoint.h"
#include "platform/graphics/GraphicsContextStateSaver.h"

namespace blink {

static inline void paintSymbol(GraphicsContext& context,
                               const Color& color,
                               const IntRect& marker,
                               EListStyleType listStyle) {
  context.setStrokeColor(color);
  context.setStrokeStyle(SolidStroke);
  context.setStrokeThickness(1.0f);
  switch (listStyle) {
    case Disc:
      context.fillEllipse(marker);
      break;
    case Circle:
      context.strokeEllipse(marker);
      break;
    case Square:
      context.fillRect(marker);
      break;
    default:
      ASSERT_NOT_REACHED();
      break;
  }
}

void ListMarkerPainter::paint(const PaintInfo& paintInfo,
                              const LayoutPoint& paintOffset) {
  if (paintInfo.phase != PaintPhaseForeground)
    return;

  if (m_layoutListMarker.style()->visibility() != EVisibility::Visible)
    return;

  if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(
          paintInfo.context, m_layoutListMarker, paintInfo.phase))
    return;

  LayoutPoint boxOrigin(paintOffset + m_layoutListMarker.location());
  LayoutRect overflowRect(m_layoutListMarker.visualOverflowRect());
  overflowRect.moveBy(boxOrigin);

  IntRect pixelSnappedOverflowRect = pixelSnappedIntRect(overflowRect);
  if (!paintInfo.cullRect().intersectsCullRect(overflowRect))
    return;

  LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutListMarker,
                                       paintInfo.phase,
                                       pixelSnappedOverflowRect);

  LayoutRect box(boxOrigin, m_layoutListMarker.size());

  IntRect marker = m_layoutListMarker.getRelativeMarkerRect();
  marker.moveBy(roundedIntPoint(boxOrigin));

  GraphicsContext& context = paintInfo.context;

  if (m_layoutListMarker.isImage()) {
    context.drawImage(m_layoutListMarker.image()
                          ->image(m_layoutListMarker, marker.size(),
                                  m_layoutListMarker.styleRef().effectiveZoom())
                          .get(),
                      marker);
    if (m_layoutListMarker.getSelectionState() != SelectionNone) {
      LayoutRect selRect = m_layoutListMarker.localSelectionRect();
      selRect.moveBy(boxOrigin);
      context.fillRect(
          pixelSnappedIntRect(selRect),
          m_layoutListMarker.listItem()->selectionBackgroundColor());
    }
    return;
  }

  LayoutListMarker::ListStyleCategory styleCategory =
      m_layoutListMarker.getListStyleCategory();
  if (styleCategory == LayoutListMarker::ListStyleCategory::None)
    return;

  Color color(m_layoutListMarker.resolveColor(CSSPropertyColor));

  if (BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(
          m_layoutListMarker.styleRef(),
          m_layoutListMarker.listItem()->document()))
    color = TextPainter::textColorForWhiteBackground(color);

  // Apply the color to the list marker text.
  context.setFillColor(color);

  const EListStyleType listStyle = m_layoutListMarker.style()->listStyleType();
  if (styleCategory == LayoutListMarker::ListStyleCategory::Symbol) {
    paintSymbol(context, color, marker, listStyle);
    return;
  }

  if (m_layoutListMarker.text().isEmpty())
    return;

  const Font& font = m_layoutListMarker.style()->font();
  TextRun textRun = constructTextRun(font, m_layoutListMarker.text(),
                                     m_layoutListMarker.styleRef());

  GraphicsContextStateSaver stateSaver(context, false);
  if (!m_layoutListMarker.style()->isHorizontalWritingMode()) {
    marker.moveBy(roundedIntPoint(-boxOrigin));
    marker = marker.transposedRect();
    marker.moveBy(
        IntPoint(roundToInt(box.x()),
                 roundToInt(box.y() - m_layoutListMarker.logicalHeight())));
    stateSaver.save();
    context.translate(marker.x(), marker.maxY());
    context.rotate(static_cast<float>(deg2rad(90.)));
    context.translate(-marker.x(), -marker.maxY());
  }

  TextRunPaintInfo textRunPaintInfo(textRun);
  textRunPaintInfo.bounds = marker;
  IntPoint textOrigin = IntPoint(
      marker.x(),
      marker.y() + m_layoutListMarker.style()->getFontMetrics().ascent());

  // Text is not arbitrary. We can judge whether it's RTL from the first
  // character, and we only need to handle the direction RightToLeft for now.
  bool textNeedsReversing =
      WTF::Unicode::direction(m_layoutListMarker.text()[0]) ==
      WTF::Unicode::RightToLeft;
  StringBuilder reversedText;
  if (textNeedsReversing) {
    unsigned length = m_layoutListMarker.text().length();
    reversedText.reserveCapacity(length);
    for (int i = length - 1; i >= 0; --i)
      reversedText.append(m_layoutListMarker.text()[i]);
    ASSERT(reversedText.length() == length);
    textRun.setText(reversedText.toString());
  }

  const UChar suffix =
      ListMarkerText::suffix(listStyle, m_layoutListMarker.listItem()->value());
  UChar suffixStr[2] = {suffix, static_cast<UChar>(' ')};
  TextRun suffixRun =
      constructTextRun(font, suffixStr, 2, m_layoutListMarker.styleRef(),
                       m_layoutListMarker.style()->direction());
  TextRunPaintInfo suffixRunInfo(suffixRun);
  suffixRunInfo.bounds = marker;

  if (m_layoutListMarker.style()->isLeftToRightDirection()) {
    context.drawText(font, textRunPaintInfo, textOrigin);
    context.drawText(font, suffixRunInfo,
                     textOrigin + IntSize(font.width(textRun), 0));
  } else {
    context.drawText(font, suffixRunInfo, textOrigin);
    context.drawText(font, textRunPaintInfo,
                     textOrigin + IntSize(font.width(suffixRun), 0));
  }
}

}  // namespace blink