C++ SVGInlineTextBox::textFragments方法代码示例

VisiblePosition RenderSVGInlineText::positionForPoint(const LayoutPoint& point)
{
    if (!firstTextBox() || !textLength())
        return createVisiblePosition(0, DOWNSTREAM);

    float baseline = m_scaledFont.fontMetrics().floatAscent();

    RenderBlock* containingBlock = this->containingBlock();
    ASSERT(containingBlock);

    // Map local point to absolute point, as the character origins stored in the text fragments use absolute coordinates.
    FloatPoint absolutePoint(point);
    absolutePoint.moveBy(containingBlock->location());

    float closestDistance = std::numeric_limits<float>::max();
    float closestDistancePosition = 0;
    const SVGTextFragment* closestDistanceFragment = 0;
    SVGInlineTextBox* closestDistanceBox = 0;

    AffineTransform fragmentTransform;
    for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
        if (!box->isSVGInlineTextBox())
            continue;

        SVGInlineTextBox* textBox = toSVGInlineTextBox(box);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();

        unsigned textFragmentsSize = fragments.size();
        for (unsigned i = 0; i < textFragmentsSize; ++i) {
            const SVGTextFragment& fragment = fragments.at(i);
            FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
            fragment.buildFragmentTransform(fragmentTransform);
            if (!fragmentTransform.isIdentity())
                fragmentRect = fragmentTransform.mapRect(fragmentRect);

            float distance = powf(fragmentRect.x() - absolutePoint.x(), 2) +
                             powf(fragmentRect.y() + fragmentRect.height() / 2 - absolutePoint.y(), 2);

            if (distance < closestDistance) {
                closestDistance = distance;
                closestDistanceBox = textBox;
                closestDistanceFragment = &fragment;
                closestDistancePosition = fragmentRect.x();
            }
        }
    }

    if (!closestDistanceFragment)
        return createVisiblePosition(0, DOWNSTREAM);

    int offset = closestDistanceBox->offsetForPositionInFragment(*closestDistanceFragment, absolutePoint.x() - closestDistancePosition, true);
    return createVisiblePosition(offset + closestDistanceBox->start(), offset > 0 ? VP_UPSTREAM_IF_POSSIBLE : DOWNSTREAM);
}

void SVGInlineTextBoxPainter::paintTextMatchMarker(GraphicsContext* context, const LayoutPoint&, DocumentMarker* marker, const ComputedStyle& style, const Font& font)
{
    // SVG is only interested in the TextMatch markers.
    if (marker->type() != DocumentMarker::TextMatch)
        return;

    LayoutSVGInlineText& textLayoutObject = toLayoutSVGInlineText(m_svgInlineTextBox.layoutObject());

    AffineTransform fragmentTransform;
    for (InlineTextBox* box = textLayoutObject.firstTextBox(); box; box = box->nextTextBox()) {
        if (!box->isSVGInlineTextBox())
            continue;

        SVGInlineTextBox* textBox = toSVGInlineTextBox(box);

        int markerStartPosition = std::max<int>(marker->startOffset() - textBox->start(), 0);
        int markerEndPosition = std::min<int>(marker->endOffset() - textBox->start(), textBox->len());

        if (markerStartPosition >= markerEndPosition)
            continue;

        const Vector<SVGTextFragment>& fragments = textBox->textFragments();
        unsigned textFragmentsSize = fragments.size();
        for (unsigned i = 0; i < textFragmentsSize; ++i) {
            const SVGTextFragment& fragment = fragments.at(i);

            int fragmentStartPosition = markerStartPosition;
            int fragmentEndPosition = markerEndPosition;
            if (!textBox->mapStartEndPositionsIntoFragmentCoordinates(fragment, fragmentStartPosition, fragmentEndPosition))
                continue;

            FloatRect fragmentRect = textBox->selectionRectForTextFragment(fragment, fragmentStartPosition, fragmentEndPosition, style);
            fragment.buildFragmentTransform(fragmentTransform);

            // Draw the marker highlight.
            if (m_svgInlineTextBox.layoutObject().frame()->editor().markedTextMatchesAreHighlighted()) {
                Color color = marker->activeMatch() ?
                    LayoutTheme::theme().platformActiveTextSearchHighlightColor() :
                    LayoutTheme::theme().platformInactiveTextSearchHighlightColor();
                GraphicsContextStateSaver stateSaver(*context);
                if (!fragmentTransform.isIdentity())
                    context->concatCTM(fragmentTransform);
                context->setFillColor(color);
                context->fillRect(fragmentRect, color);
            }
        }
    }
}

PositionWithAffinity LayoutSVGInlineText::positionForPoint(const LayoutPoint& point)
{
    if (!hasTextBoxes() || !textLength())
        return createPositionWithAffinity(0);

    ASSERT(m_scalingFactor);
    float baseline = m_scaledFont.getFontMetrics().floatAscent() / m_scalingFactor;

    LayoutBlock* containingBlock = this->containingBlock();
    ASSERT(containingBlock);

    // Map local point to absolute point, as the character origins stored in the text fragments use absolute coordinates.
    FloatPoint absolutePoint(point);
    absolutePoint.moveBy(containingBlock->location());

    float closestDistance = std::numeric_limits<float>::max();
    float closestDistancePosition = 0;
    const SVGTextFragment* closestDistanceFragment = nullptr;
    SVGInlineTextBox* closestDistanceBox = nullptr;

    for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
        if (!box->isSVGInlineTextBox())
            continue;

        SVGInlineTextBox* textBox = toSVGInlineTextBox(box);
        for (const SVGTextFragment& fragment : textBox->textFragments()) {
            FloatRect fragmentRect = fragment.boundingBox(baseline);

            float distance = 0;
            if (!fragmentRect.contains(absolutePoint))
                distance = fragmentRect.squaredDistanceTo(absolutePoint);

            if (distance <= closestDistance) {
                closestDistance = distance;
                closestDistanceBox = textBox;
                closestDistanceFragment = &fragment;
                closestDistancePosition = fragmentRect.x();
            }
        }
    }

    if (!closestDistanceFragment)
        return createPositionWithAffinity(0);

    int offset = closestDistanceBox->offsetForPositionInFragment(*closestDistanceFragment, LayoutUnit(absolutePoint.x() - closestDistancePosition), true);
    return createPositionWithAffinity(offset + closestDistanceBox->start(), offset > 0 ? VP_UPSTREAM_IF_POSSIBLE : TextAffinity::Downstream);
}

void SVGTextLayoutEngine::finalizeTransformMatrices(Vector<SVGInlineTextBox*>& boxes)
{
    unsigned boxCount = boxes.size();
    if (!boxCount)
        return;

    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        SVGInlineTextBox* textBox = boxes.at(boxPosition);
        AffineTransform textBoxTransformation = m_chunkLayoutBuilder.transformationForTextBox(textBox);
        if (textBoxTransformation.isIdentity())
            continue;

        Vector<SVGTextFragment>& fragments = textBox->textFragments();
        unsigned fragmentCount = fragments.size();
        for (unsigned i = 0; i < fragmentCount; ++i) {
            ASSERT(fragments[i].lengthAdjustTransform.isIdentity());
            fragments[i].lengthAdjustTransform = textBoxTransformation;
        }
    }

    boxes.clear();
}

static inline void dumpTextBoxes(Vector<SVGInlineTextBox*>& boxes)
{
    unsigned boxCount = boxes.size();
    fprintf(stderr, "Dumping all text fragments in text sub tree, %i boxes\n", boxCount);

    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        SVGInlineTextBox* textBox = boxes.at(boxPosition);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();
        fprintf(stderr, "-> Box %i: Dumping text fragments for SVGInlineTextBox, textBox=%p, textRenderer=%p\n", boxPosition, textBox, textBox->textRenderer());
        fprintf(stderr, "        textBox properties, start=%i, len=%i, box direction=%i\n", textBox->start(), textBox->len(), textBox->direction());
        fprintf(stderr, "   textRenderer properties, textLength=%i\n", textBox->textRenderer()->textLength());

        const UChar* characters = textBox->textRenderer()->characters();

        unsigned fragmentCount = fragments.size();
        for (unsigned i = 0; i < fragmentCount; ++i) {
            SVGTextFragment& fragment = fragments.at(i);
            String fragmentString(characters + fragment.characterOffset, fragment.length);
            fprintf(stderr, "    -> Fragment %i, x=%lf, y=%lf, width=%lf, height=%lf, characterOffset=%i, length=%i, characters='%s'\n"
                          , i, fragment.x, fragment.y, fragment.width, fragment.height, fragment.characterOffset, fragment.length, fragmentString.utf8().data());
        }
    }
}

void SVGTextChunk::calculateLength(float& length, unsigned& characters) const
{
    SVGTextFragment* lastFragment = 0;

    unsigned boxCount = m_boxes.size();
    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        SVGInlineTextBox* textBox = m_boxes.at(boxPosition);
        Vector<SVGTextFragment>& fragments = textBox->textFragments();

        unsigned size = fragments.size();
        if (!size)
            continue;

        for (unsigned i = 0; i < size; ++i) {
            SVGTextFragment& fragment = fragments.at(i);
            characters += fragment.length;

            if (m_chunkStyle & VerticalText)
                length += fragment.height;
            else
                length += fragment.width;

            if (!lastFragment) {
                lastFragment = &fragment;
                continue;
            }

            // Resepect gap between chunks.
            if (m_chunkStyle & VerticalText)
                 length += fragment.y - (lastFragment->y + lastFragment->height);
            else
                 length += fragment.x - (lastFragment->x + lastFragment->width);

            lastFragment = &fragment;
        }
    }
}

void SVGTextChunkBuilder::processTextChunk(const SVGTextChunk& chunk)
{
    bool processTextLength = chunk.hasDesiredTextLength();
    bool processTextAnchor = chunk.hasTextAnchor();
    if (!processTextAnchor && !processTextLength)
        return;

    const Vector<SVGInlineTextBox*>& boxes = chunk.boxes();
    unsigned boxCount = boxes.size();
    if (!boxCount)
        return;

    // Calculate absolute length of whole text chunk (starting from text box 'start', spanning 'length' text boxes).
    float chunkLength = 0;
    unsigned chunkCharacters = 0;
    chunk.calculateLength(chunkLength, chunkCharacters);

    bool isVerticalText = chunk.isVerticalText();
    if (processTextLength) {
        if (chunk.hasLengthAdjustSpacing()) {
            float textLengthShift = (chunk.desiredTextLength() - chunkLength) / chunkCharacters;
            unsigned atCharacter = 0;
            for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
                Vector<SVGTextFragment>& fragments = boxes[boxPosition]->textFragments();
                if (fragments.isEmpty())
                    continue;
                processTextLengthSpacingCorrection(isVerticalText, textLengthShift, fragments, atCharacter);
            }
        } else {
            ASSERT(chunk.hasLengthAdjustSpacingAndGlyphs());
            float textLengthScale = chunk.desiredTextLength() / chunkLength;
            AffineTransform spacingAndGlyphsTransform;

            bool foundFirstFragment = false;
            for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
                SVGInlineTextBox* textBox = boxes[boxPosition];
                Vector<SVGTextFragment>& fragments = textBox->textFragments();
                if (fragments.isEmpty())
                    continue;

                if (!foundFirstFragment) {
                    foundFirstFragment = true;
                    buildSpacingAndGlyphsTransform(isVerticalText, textLengthScale, fragments.first(), spacingAndGlyphsTransform);
                }

                m_textBoxTransformations.set(textBox, spacingAndGlyphsTransform);
            }
        }
    }

    if (!processTextAnchor)
        return;

    // If we previously applied a lengthAdjust="spacing" correction, we have to recalculate the chunk length, to be able to apply the text-anchor shift.
    if (processTextLength && chunk.hasLengthAdjustSpacing()) {
        chunkLength = 0;
        chunkCharacters = 0;
        chunk.calculateLength(chunkLength, chunkCharacters);
    }

    float textAnchorShift = chunk.calculateTextAnchorShift(chunkLength);
    for (unsigned boxPosition = 0; boxPosition < boxCount; ++boxPosition) {
        Vector<SVGTextFragment>& fragments = boxes[boxPosition]->textFragments();
        if (fragments.isEmpty())
            continue;
        processTextAnchorCorrection(isVerticalText, textAnchorShift, fragments);
    }
}

void SVGInlineFlowBox::computeTextMatchMarkerRectForRenderer(RenderSVGInlineText* textRenderer)
{
    ASSERT(textRenderer);

    Node* node = textRenderer->node();
    if (!node || !node->inDocument())
        return;

    RenderStyle* style = textRenderer->style();
    ASSERT(style);

    AffineTransform fragmentTransform;
    Document* document = textRenderer->document();
    Vector<DocumentMarker*> markers = document->markers()->markersFor(textRenderer->node());

    Vector<DocumentMarker*>::iterator markerEnd = markers.end();
    for (Vector<DocumentMarker*>::iterator markerIt = markers.begin(); markerIt != markerEnd; ++markerIt) {
        DocumentMarker* marker = *markerIt;

        // SVG is only interessted in the TextMatch marker, for now.
        if (marker->type() != DocumentMarker::TextMatch)
            continue;

        FloatRect markerRect;
        for (InlineTextBox* box = textRenderer->firstTextBox(); box; box = box->nextTextBox()) {
            if (!box->isSVGInlineTextBox())
                continue;

            SVGInlineTextBox* textBox = static_cast<SVGInlineTextBox*>(box);

            int markerStartPosition = max<int>(marker->startOffset() - textBox->start(), 0);
            int markerEndPosition = min<int>(marker->endOffset() - textBox->start(), textBox->len());

            if (markerStartPosition >= markerEndPosition)
                continue;

            int fragmentStartPosition = 0;
            int fragmentEndPosition = 0;

            const Vector<SVGTextFragment>& fragments = textBox->textFragments();
            unsigned textFragmentsSize = fragments.size();
            for (unsigned i = 0; i < textFragmentsSize; ++i) {
                const SVGTextFragment& fragment = fragments.at(i);

                fragmentStartPosition = markerStartPosition;
                fragmentEndPosition = markerEndPosition;
                if (!textBox->mapStartEndPositionsIntoFragmentCoordinates(fragment, fragmentStartPosition, fragmentEndPosition))
                    continue;

                FloatRect fragmentRect = textBox->selectionRectForTextFragment(fragment, fragmentStartPosition, fragmentEndPosition, style);
                fragment.buildFragmentTransform(fragmentTransform);
                if (!fragmentTransform.isIdentity())
                    fragmentRect = fragmentTransform.mapRect(fragmentRect);

                markerRect.unite(fragmentRect);
            }
        }

        toRenderedDocumentMarker(marker)->setRenderedRect(textRenderer->localToAbsoluteQuad(markerRect).enclosingBoundingBox());
    }
}

void SVGTextChunkBuilder::handleTextChunk(BoxListConstIterator boxStart,
                                          BoxListConstIterator boxEnd) {
  ASSERT(*boxStart);

  const LineLayoutSVGInlineText textLineLayout =
      LineLayoutSVGInlineText((*boxStart)->getLineLayoutItem());
  const ComputedStyle& style = textLineLayout.styleRef();

  // Handle 'lengthAdjust' property.
  float desiredTextLength = 0;
  SVGLengthAdjustType lengthAdjust = SVGLengthAdjustUnknown;
  if (SVGTextContentElement* textContentElement =
          SVGTextContentElement::elementFromLineLayoutItem(
              textLineLayout.parent())) {
    lengthAdjust =
        textContentElement->lengthAdjust()->currentValue()->enumValue();

    SVGLengthContext lengthContext(textContentElement);
    if (textContentElement->textLengthIsSpecifiedByUser())
      desiredTextLength =
          textContentElement->textLength()->currentValue()->value(
              lengthContext);
    else
      desiredTextLength = 0;
  }

  bool processTextLength = desiredTextLength > 0;
  bool processTextAnchor = needsTextAnchorAdjustment(style);
  if (!processTextAnchor && !processTextLength)
    return;

  bool isVerticalText = !style.isHorizontalWritingMode();

  // Calculate absolute length of whole text chunk (starting from text box
  // 'start', spanning 'length' text boxes).
  ChunkLengthAccumulator lengthAccumulator(isVerticalText);
  lengthAccumulator.processRange(boxStart, boxEnd);

  if (processTextLength) {
    float chunkLength = lengthAccumulator.length();
    if (lengthAdjust == SVGLengthAdjustSpacing) {
      float textLengthShift =
          (desiredTextLength - chunkLength) / lengthAccumulator.numCharacters();
      unsigned atCharacter = 0;
      for (auto boxIter = boxStart; boxIter != boxEnd; ++boxIter) {
        Vector<SVGTextFragment>& fragments = (*boxIter)->textFragments();
        if (fragments.isEmpty())
          continue;
        processTextLengthSpacingCorrection(isVerticalText, textLengthShift,
                                           fragments, atCharacter);
      }

      // Fragments have been adjusted, we have to recalculate the chunk
      // length, to be able to apply the text-anchor shift.
      if (processTextAnchor) {
        lengthAccumulator.reset();
        lengthAccumulator.processRange(boxStart, boxEnd);
      }
    } else {
      ASSERT(lengthAdjust == SVGLengthAdjustSpacingAndGlyphs);
      float textLengthScale = desiredTextLength / chunkLength;
      float textLengthBias = 0;

      bool foundFirstFragment = false;
      for (auto boxIter = boxStart; boxIter != boxEnd; ++boxIter) {
        SVGInlineTextBox* textBox = *boxIter;
        Vector<SVGTextFragment>& fragments = textBox->textFragments();
        if (fragments.isEmpty())
          continue;

        if (!foundFirstFragment) {
          foundFirstFragment = true;
          textLengthBias =
              computeTextLengthBias(fragments.first(), textLengthScale);
        }

        applyTextLengthScaleAdjustment(textLengthScale, textLengthBias,
                                       fragments);
      }
    }
  }

  if (!processTextAnchor)
    return;

  float textAnchorShift =
      calculateTextAnchorShift(style, lengthAccumulator.length());
  for (auto boxIter = boxStart; boxIter != boxEnd; ++boxIter) {
    Vector<SVGTextFragment>& fragments = (*boxIter)->textFragments();
    if (fragments.isEmpty())
      continue;
    processTextAnchorCorrection(isVerticalText, textAnchorShift, fragments);
  }
}