C++ LayoutObject::isBR方法代码示例

static bool planCounter(LayoutObject& object, const AtomicString& identifier, bool& isReset, int& value)
{
    // Real text nodes don't have their own style so they can't have counters.
    // We can't even look at their styles or we'll see extra resets and increments!
    if (object.isText() && !object.isBR())
        return false;
    Node* generatingNode = object.generatingNode();
    // We must have a generating node or else we cannot have a counter.
    if (!generatingNode)
        return false;
    const ComputedStyle& style = object.styleRef();

    switch (style.styleType()) {
    case NOPSEUDO:
        // Sometimes nodes have more then one layoutObject. Only the first one gets the counter
        // LayoutTests/http/tests/css/counter-crash.html
        if (generatingNode->layoutObject() != &object)
            return false;
        break;
    case BEFORE:
    case AFTER:
        break;
    default:
        return false; // Counters are forbidden from all other pseudo elements.
    }

    const CounterDirectives directives = style.getCounterDirectives(identifier);
    if (directives.isDefined()) {
        value = directives.combinedValue();
        isReset = directives.isReset();
        return true;
    }

    if (identifier == "list-item") {
        if (object.isListItem()) {
            if (toLayoutListItem(object).hasExplicitValue()) {
                value = toLayoutListItem(object).explicitValue();
                isReset = true;
                return true;
            }
            value = 1;
            isReset = false;
            return true;
        }
        if (Node* e = object.node()) {
            if (isHTMLOListElement(*e)) {
                value = toHTMLOListElement(e)->start();
                isReset = true;
                return true;
            }
            if (isHTMLUListElement(*e) || isHTMLMenuElement(*e) || isHTMLDirectoryElement(*e)) {
                value = 0;
                isReset = true;
                return true;
            }
        }
    }

    return false;
}

static bool blockIsRowOfLinks(const LayoutBlock* block)
{
    // A "row of links" is a block for which:
    //  1. It does not contain non-link text elements longer than 3 characters
    //  2. It contains a minimum of 3 inline links and all links should
    //     have the same specified font size.
    //  3. It should not contain <br> elements.
    //  4. It should contain only inline elements unless they are containers,
    //     children of link elements or children of sub-containers.
    int linkCount = 0;
    LayoutObject* layoutObject = block->firstChild();
    float matchingFontSize = -1;

    while (layoutObject) {
        if (!isPotentialClusterRoot(layoutObject)) {
            if (layoutObject->isText() && toLayoutText(layoutObject)->text().stripWhiteSpace().length() > 3)
                return false;
            if (!layoutObject->isInline() || layoutObject->isBR())
                return false;
        }
        if (layoutObject->style()->isLink()) {
            linkCount++;
            if (matchingFontSize < 0)
                matchingFontSize = layoutObject->style()->specifiedFontSize();
            else if (matchingFontSize != layoutObject->style()->specifiedFontSize())
                return false;

            // Skip traversing descendants of the link.
            layoutObject = layoutObject->nextInPreOrderAfterChildren(block);
            continue;
        }
        layoutObject = layoutObject->nextInPreOrder(block);
    }

    return (linkCount >= 3);
}

Position VisiblePosition::rightVisuallyDistinctCandidate() const
{
    Position p = m_deepPosition;
    if (p.isNull())
        return Position();

    Position downstreamStart = mostForwardCaretPosition(p);
    TextDirection primaryDirection = primaryDirectionOf(*p.anchorNode());

    while (true) {
        InlineBoxPosition boxPosition = computeInlineBoxPosition(p, m_affinity, primaryDirection);
        InlineBox* box = boxPosition.inlineBox;
        int offset = boxPosition.offsetInBox;
        if (!box)
            return primaryDirection == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);

        LayoutObject* layoutObject = &box->layoutObject();

        while (true) {
            if ((layoutObject->isReplaced() || layoutObject->isBR()) && offset == box->caretLeftmostOffset())
                return box->isLeftToRightDirection() ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);

            if (!layoutObject->node()) {
                box = box->nextLeafChild();
                if (!box)
                    return primaryDirection == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);
                layoutObject = &box->layoutObject();
                offset = box->caretLeftmostOffset();
                continue;
            }

            offset = box->isLeftToRightDirection() ? layoutObject->nextOffset(offset) : layoutObject->previousOffset(offset);

            int caretMinOffset = box->caretMinOffset();
            int caretMaxOffset = box->caretMaxOffset();

            if (offset > caretMinOffset && offset < caretMaxOffset)
                break;

            if (box->isLeftToRightDirection() ? offset > caretMaxOffset : offset < caretMinOffset) {
                // Overshot to the right.
                InlineBox* nextBox = box->nextLeafChildIgnoringLineBreak();
                if (!nextBox) {
                    Position positionOnRight = primaryDirection == LTR ? nextVisuallyDistinctCandidate(m_deepPosition) : previousVisuallyDistinctCandidate(m_deepPosition);
                    if (positionOnRight.isNull())
                        return Position();

                    InlineBox* boxOnRight = computeInlineBoxPosition(positionOnRight, m_affinity, primaryDirection).inlineBox;
                    if (boxOnRight && boxOnRight->root() == box->root())
                        return Position();
                    return positionOnRight;
                }

                // Reposition at the other logical position corresponding to our edge's visual position and go for another round.
                box = nextBox;
                layoutObject = &box->layoutObject();
                offset = nextBox->caretLeftmostOffset();
                continue;
            }

            ASSERT(offset == box->caretRightmostOffset());

            unsigned char level = box->bidiLevel();
            InlineBox* nextBox = box->nextLeafChild();

            if (box->direction() == primaryDirection) {
                if (!nextBox) {
                    InlineBox* logicalEnd = 0;
                    if (primaryDirection == LTR ? box->root().getLogicalEndBoxWithNode(logicalEnd) : box->root().getLogicalStartBoxWithNode(logicalEnd)) {
                        box = logicalEnd;
                        layoutObject = &box->layoutObject();
                        offset = primaryDirection == LTR ? box->caretMaxOffset() : box->caretMinOffset();
                    }
                    break;
                }

                if (nextBox->bidiLevel() >= level)
                    break;

                level = nextBox->bidiLevel();

                InlineBox* prevBox = box;
                do {
                    prevBox = prevBox->prevLeafChild();
                } while (prevBox && prevBox->bidiLevel() > level);

                if (prevBox && prevBox->bidiLevel() == level) // For example, abc FED 123 ^ CBA
                    break;

                // For example, abc 123 ^ CBA or 123 ^ CBA abc
                box = nextBox;
                layoutObject = &box->layoutObject();
                offset = box->caretLeftmostOffset();
                if (box->direction() == primaryDirection)
                    break;
                continue;
            }

            while (nextBox && !nextBox->layoutObject().node())
                nextBox = nextBox->nextLeafChild();
//.........这里部分代码省略.........

Position VisiblePosition::leftVisuallyDistinctCandidate() const
{
    Position p = m_deepPosition;
    if (p.isNull())
        return Position();

    Position downstreamStart = p.downstream();
    TextDirection primaryDirection = p.primaryDirection();

    while (true) {
        InlineBox* box;
        int offset;
        p.getInlineBoxAndOffset(m_affinity, primaryDirection, box, offset);
        if (!box)
            return primaryDirection == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);

        LayoutObject* layoutObject = &box->layoutObject();

        while (true) {
            if ((layoutObject->isReplaced() || layoutObject->isBR()) && offset == box->caretRightmostOffset())
                return box->isLeftToRightDirection() ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);

            if (!layoutObject->node()) {
                box = box->prevLeafChild();
                if (!box)
                    return primaryDirection == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);
                layoutObject = &box->layoutObject();
                offset = box->caretRightmostOffset();
                continue;
            }

            offset = box->isLeftToRightDirection() ? layoutObject->previousOffset(offset) : layoutObject->nextOffset(offset);

            int caretMinOffset = box->caretMinOffset();
            int caretMaxOffset = box->caretMaxOffset();

            if (offset > caretMinOffset && offset < caretMaxOffset)
                break;

            if (box->isLeftToRightDirection() ? offset < caretMinOffset : offset > caretMaxOffset) {
                // Overshot to the left.
                InlineBox* prevBox = box->prevLeafChildIgnoringLineBreak();
                if (!prevBox) {
                    Position positionOnLeft = primaryDirection == LTR ? previousVisuallyDistinctCandidate(m_deepPosition) : nextVisuallyDistinctCandidate(m_deepPosition);
                    if (positionOnLeft.isNull())
                        return Position();

                    InlineBox* boxOnLeft;
                    int offsetOnLeft;
                    positionOnLeft.getInlineBoxAndOffset(m_affinity, primaryDirection, boxOnLeft, offsetOnLeft);
                    if (boxOnLeft && boxOnLeft->root() == box->root())
                        return Position();
                    return positionOnLeft;
                }

                // Reposition at the other logical position corresponding to our edge's visual position and go for another round.
                box = prevBox;
                layoutObject = &box->layoutObject();
                offset = prevBox->caretRightmostOffset();
                continue;
            }

            ASSERT(offset == box->caretLeftmostOffset());

            unsigned char level = box->bidiLevel();
            InlineBox* prevBox = box->prevLeafChild();

            if (box->direction() == primaryDirection) {
                if (!prevBox) {
                    InlineBox* logicalStart = 0;
                    if (primaryDirection == LTR ? box->root().getLogicalStartBoxWithNode(logicalStart) : box->root().getLogicalEndBoxWithNode(logicalStart)) {
                        box = logicalStart;
                        layoutObject = &box->layoutObject();
                        offset = primaryDirection == LTR ? box->caretMinOffset() : box->caretMaxOffset();
                    }
                    break;
                }
                if (prevBox->bidiLevel() >= level)
                    break;

                level = prevBox->bidiLevel();

                InlineBox* nextBox = box;
                do {
                    nextBox = nextBox->nextLeafChild();
                } while (nextBox && nextBox->bidiLevel() > level);

                if (nextBox && nextBox->bidiLevel() == level)
                    break;

                box = prevBox;
                layoutObject = &box->layoutObject();
                offset = box->caretRightmostOffset();
                if (box->direction() == primaryDirection)
                    break;
                continue;
            }

            while (prevBox && !prevBox->layoutObject().node())
                prevBox = prevBox->prevLeafChild();
//.........这里部分代码省略.........