C++ VisiblePosition::affinity方法代码示例

VisibleSelection::VisibleSelection(const VisiblePosition& base, const VisiblePosition& extent)
    : m_base(base.deepEquivalent())
    , m_extent(extent.deepEquivalent())
    , m_affinity(base.affinity())
{
    validate();
}

static VisiblePosition updateAXLineStartForVisiblePosition(const VisiblePosition& visiblePosition)
{
    // A line in the accessibility sense should include floating objects, such as aligned image, as part of a line.
    // So let's update the position to include that.
    VisiblePosition tempPosition;
    VisiblePosition startPosition = visiblePosition;
    Position p;
    RenderObject* renderer;
    while (true) {
        tempPosition = startPosition.previous();
        if (tempPosition.isNull())
            break;
        p = tempPosition.deepEquivalent();
        if (!p.node())
            break;
        renderer = p.node()->renderer();
        if (!renderer || renderer->isRenderBlock() && !p.offset())
            break;
        InlineBox* box;
        int ignoredCaretOffset;
        p.getInlineBoxAndOffset(tempPosition.affinity(), box, ignoredCaretOffset);
        if (box)
            break;
        startPosition = tempPosition;
    }

    return startPosition;
}

VisiblePositionRange AccessibilityObject::visiblePositionRangeForUnorderedPositions(const VisiblePosition& visiblePos1, const VisiblePosition& visiblePos2) const
{
    if (visiblePos1.isNull() || visiblePos2.isNull())
        return VisiblePositionRange();

    VisiblePosition startPos;
    VisiblePosition endPos;
    bool alreadyInOrder;

    // upstream is ordered before downstream for the same position
    if (visiblePos1 == visiblePos2 && visiblePos2.affinity() == UPSTREAM)
        alreadyInOrder = false;

    // use selection order to see if the positions are in order
    else
        alreadyInOrder = Selection(visiblePos1, visiblePos2).isBaseFirst();

    if (alreadyInOrder) {
        startPos = visiblePos1;
        endPos = visiblePos2;
    } else {
        startPos = visiblePos2;
        endPos = visiblePos1;
    }

    return VisiblePositionRange(startPos, endPos);
}

void AXObjectCache::textMarkerDataForVisiblePosition(TextMarkerData& textMarkerData, const VisiblePosition& visiblePos)
{
    // This memory must be bzero'd so instances of TextMarkerData can be tested for byte-equivalence.
    // This also allows callers to check for failure by looking at textMarkerData upon return.
    memset(&textMarkerData, 0, sizeof(TextMarkerData));
    
    if (visiblePos.isNull())
        return;
    
    Position deepPos = visiblePos.deepEquivalent();
    Node* domNode = deepPos.deprecatedNode();
    ASSERT(domNode);
    if (!domNode)
        return;
    
    if (domNode->isHTMLElement()) {
        HTMLInputElement* inputElement = domNode->toInputElement();
        if (inputElement && inputElement->isPasswordField())
            return;
    }
    
    // find or create an accessibility object for this node
    AXObjectCache* cache = domNode->document()->axObjectCache();
    RefPtr<AccessibilityObject> obj = cache->getOrCreate(domNode);
    
    textMarkerData.axID = obj.get()->axObjectID();
    textMarkerData.node = domNode;
    textMarkerData.offset = deepPos.deprecatedEditingOffset();
    textMarkerData.affinity = visiblePos.affinity();   
    
    cache->setNodeInUse(domNode);
}

Selection::Selection(const VisiblePosition& base, const VisiblePosition& extent)
    : m_base(base.deepEquivalent())
    , m_extent(extent.deepEquivalent())
    , m_affinity(base.affinity())
    , m_granularity(CharacterGranularity)
{
    validate();
}

VisibleSelection::VisibleSelection(const VisiblePosition& pos, bool selectOnlyLetters)
    : m_base(pos.deepEquivalent())
    , m_extent(pos.deepEquivalent())
    , m_affinity(pos.affinity())
    , m_selectOnlyLetters(selectOnlyLetters)
{
    validate();
}

VisibleSelection::VisibleSelection(const VisiblePosition& pos, bool isDirectional)
    : m_base(pos.deepEquivalent())
    , m_extent(pos.deepEquivalent())
    , m_affinity(pos.affinity())
    , m_isDirectional(isDirectional)
{
    validate();
}

bool visiblePositionsOnDifferentLines(const VisiblePosition &pos1, const VisiblePosition &pos2)
{
    if (pos1.isNull() || pos2.isNull())
        return false;
    if (pos1 == pos2)
        return false;

    Position p1 = pos1.deepEquivalent();
    Position p2 = pos2.deepEquivalent();
    RenderObject *r1 = p1.node()->renderer();
    RenderObject *r2 = p2.node()->renderer();
    if (r1->isBlockFlow() || r2->isBlockFlow())
        return r1 == r2 ? false : true;
    InlineBox *b1 = r1 ? r1->inlineBox(p1.offset(), pos1.affinity()) : 0;
    InlineBox *b2 = r2 ? r2->inlineBox(p2.offset(), pos2.affinity()) : 0;
    return (b1 && b2 && b1->root() != b2->root());
}

VisibleSelection::VisibleSelection(const VisiblePosition& base, const VisiblePosition& extent, bool isDirectional)
    : m_base(base.deepEquivalent())
    , m_extent(extent.deepEquivalent())
    , m_affinity(base.affinity())
    , m_changeObserver(nullptr)
    , m_isDirectional(isDirectional)
{
    validate();
}

void setAffinityUsingLinePosition(VisiblePosition &pos)
{
    // When not moving across line wrap, make sure to end up with DOWNSTREAM affinity.
    if (pos.isNotNull() && pos.affinity() == UPSTREAM) {
        VisiblePosition temp(pos);
        temp.setAffinity(DOWNSTREAM);
        if (!visiblePositionsOnDifferentLines(temp, pos))
            pos.setAffinity(DOWNSTREAM);
    }
}

void SelectionController::moveTo(const VisiblePosition &pos)
{
    setSelection(Selection(pos.deepEquivalent(), pos.deepEquivalent(), pos.affinity()));
    m_needsLayout = true;
}

void SelectionController::setExtent(const VisiblePosition &pos)
{
    setSelection(Selection(m_sel.base(), pos.deepEquivalent(), pos.affinity()));
    m_needsLayout = true;
}

RenderedPosition::RenderedPosition(const VisiblePosition& position)
    : RenderedPosition(position.deepEquivalent(), position.affinity())
{
}

SelectionController::SelectionController(const VisiblePosition &visiblePos)
    : m_needsLayout(true)
    , m_modifyBiasSet(false)
{
    setSelection(Selection(visiblePos.deepEquivalent(), visiblePos.deepEquivalent(), visiblePos.affinity()));
}

void DeleteSelectionCommand::initializePositionData()
{
    initializeStartEnd();
    
    Node* startCell = enclosingTableCell(m_upstreamStart.node());
    Node* endCell = enclosingTableCell(m_downstreamEnd.node());
    // Don't move content between parts of a table or between table and non-table content.
    // FIXME: This isn't right.  A borderless table with two rows and a single column would appear as two paragraphs.
    if ((startCell || endCell) && endCell != startCell)
        m_mergeBlocksAfterDelete = false;
    
    // Usually the start and the end of the selection to delete are pulled together as a result of the deletion.
    // Sometimes they aren't (like when no merge is requested), so we must choose one position to hold the caret 
    // and receive the placeholder after deletion.
    VisiblePosition visibleEnd(m_downstreamEnd);
    if (m_mergeBlocksAfterDelete && !isEndOfParagraph(visibleEnd))
        m_endingPosition = m_downstreamEnd;
    else
        m_endingPosition = m_downstreamStart;

    // Handle leading and trailing whitespace, as well as smart delete adjustments to the selection
    m_leadingWhitespace = m_upstreamStart.leadingWhitespacePosition(m_selectionToDelete.affinity());
    m_trailingWhitespace = m_downstreamEnd.trailingWhitespacePosition(VP_DEFAULT_AFFINITY);

    if (m_smartDelete) {
    
        // skip smart delete if the selection to delete already starts or ends with whitespace
        Position pos = VisiblePosition(m_upstreamStart, m_selectionToDelete.affinity()).deepEquivalent();
        bool skipSmartDelete = pos.trailingWhitespacePosition(VP_DEFAULT_AFFINITY, true).isNotNull();
        if (!skipSmartDelete)
            skipSmartDelete = m_downstreamEnd.leadingWhitespacePosition(VP_DEFAULT_AFFINITY, true).isNotNull();

        // extend selection upstream if there is whitespace there
        bool hasLeadingWhitespaceBeforeAdjustment = m_upstreamStart.leadingWhitespacePosition(m_selectionToDelete.affinity(), true).isNotNull();
        if (!skipSmartDelete && hasLeadingWhitespaceBeforeAdjustment) {
            VisiblePosition visiblePos = VisiblePosition(m_upstreamStart, VP_DEFAULT_AFFINITY).previous();
            pos = visiblePos.deepEquivalent();
            // Expand out one character upstream for smart delete and recalculate
            // positions based on this change.
            m_upstreamStart = pos.upstream();
            m_downstreamStart = pos.downstream();
            m_leadingWhitespace = m_upstreamStart.leadingWhitespacePosition(visiblePos.affinity());
        }
        
        // trailing whitespace is only considered for smart delete if there is no leading
        // whitespace, as in the case where you double-click the first word of a paragraph.
        if (!skipSmartDelete && !hasLeadingWhitespaceBeforeAdjustment && m_downstreamEnd.trailingWhitespacePosition(VP_DEFAULT_AFFINITY, true).isNotNull()) {
            // Expand out one character downstream for smart delete and recalculate
            // positions based on this change.
            pos = VisiblePosition(m_downstreamEnd, VP_DEFAULT_AFFINITY).next().deepEquivalent();
            m_upstreamEnd = pos.upstream();
            m_downstreamEnd = pos.downstream();
            m_trailingWhitespace = m_downstreamEnd.trailingWhitespacePosition(VP_DEFAULT_AFFINITY);
        }
    }
    
    //
    // Handle setting start and end blocks and the start node.
    //
    m_startBlock = m_downstreamStart.node()->enclosingBlockFlowOrTableElement();
    m_endBlock = m_upstreamEnd.node()->enclosingBlockFlowOrTableElement();
}