C++ VisibleSelection::isNone方法代码示例

bool selectionBelongsToObject(AccessibilityObject* coreObject, VisibleSelection& selection)
{
    if (!coreObject || !coreObject->isAccessibilityRenderObject())
        return false;

    if (selection.isNone())
        return false;

    RefPtr<Range> range = selection.toNormalizedRange();
    if (!range)
        return false;

    // We want to check that both the selection intersects the node
    // AND that the selection is not just "touching" one of the
    // boundaries for the selected node. We want to check whether the
    // node is actually inside the region, at least partially.
    auto& node = *coreObject->node();
    auto* lastDescendant = node.lastDescendant();
    unsigned lastOffset = lastOffsetInNode(lastDescendant);
    auto intersectsResult = range->intersectsNode(node);
    return !intersectsResult.hasException()
           && intersectsResult.releaseReturnValue()
           && (&range->endContainer() != &node || range->endOffset())
           && (&range->startContainer() != lastDescendant || range->startOffset() != lastOffset);
}

// Updates |selectionInFlatTree| to match with |selection|.
void SelectionAdjuster::adjustSelectionInFlatTree(
    VisibleSelectionInFlatTree* selectionInFlatTree,
    const VisibleSelection& selection) {
  if (selection.isNone()) {
    *selectionInFlatTree = VisibleSelectionInFlatTree();
    return;
  }

  const PositionInFlatTree& base = toPositionInFlatTree(selection.base());
  const PositionInFlatTree& extent = toPositionInFlatTree(selection.extent());
  const PositionInFlatTree& position1 = toPositionInFlatTree(selection.start());
  const PositionInFlatTree& position2 = toPositionInFlatTree(selection.end());
  position1.anchorNode()->updateDistribution();
  position2.anchorNode()->updateDistribution();
  selectionInFlatTree->m_base = base;
  selectionInFlatTree->m_extent = extent;
  selectionInFlatTree->m_affinity = selection.m_affinity;
  selectionInFlatTree->m_isDirectional = selection.m_isDirectional;
  selectionInFlatTree->m_granularity = selection.m_granularity;
  selectionInFlatTree->m_hasTrailingWhitespace =
      selection.m_hasTrailingWhitespace;
  selectionInFlatTree->m_baseIsFirst =
      base.isNull() || base.compareTo(extent) <= 0;
  if (position1.compareTo(position2) <= 0) {
    selectionInFlatTree->m_start = position1;
    selectionInFlatTree->m_end = position2;
  } else {
    selectionInFlatTree->m_start = position2;
    selectionInFlatTree->m_end = position1;
  }
  selectionInFlatTree->updateSelectionType();
}

static gint webkit_accessible_text_get_n_selections(AtkText* text)
{
    AccessibilityObject* coreObject = core(text);
    VisibleSelection selection = coreObject->selection();

    // We don't support multiple selections for now, so there's only
    // two possibilities
    // Also, we don't want to do anything if the selection does not
    // belong to the currently selected object. We have to check since
    // there's no way to get the selection for a given object, only
    // the global one (the API is a bit confusing)
    return !selectionBelongsToObject(coreObject, selection) || selection.isNone() ? 0 : 1;
}

// This needs to be static so it can be called by canIncreaseSelectionListLevel and canDecreaseSelectionListLevel
static bool getStartEndListChildren(const VisibleSelection& selection, Node*& start, Node*& end)
{
    if (selection.isNone())
        return false;

    // start must be in a list child
    Node* startListChild = enclosingListChild(selection.start().anchorNode());
    if (!startListChild)
        return false;

    // end must be in a list child
    Node* endListChild = selection.isRange() ? enclosingListChild(selection.end().anchorNode()) : startListChild;
    if (!endListChild)
        return false;
    
    // For a range selection we want the following behavior:
    //      - the start and end must be within the same overall list
    //      - the start must be at or above the level of the rest of the range
    //      - if the end is anywhere in a sublist lower than start, the whole sublist gets moved
    // In terms of this function, this means:
    //      - endListChild must start out being be a sibling of startListChild, or be in a
    //         sublist of startListChild or a sibling
    //      - if endListChild is in a sublist of startListChild or a sibling, it must be adjusted
    //         to be the ancestor that is startListChild or its sibling
    while (startListChild->parentNode() != endListChild->parentNode()) {
        endListChild = endListChild->parentNode();
        if (!endListChild)
            return false;
    }
    
    // if the selection ends on a list item with a sublist, include the entire sublist
    if (endListChild->renderer()->isListItem()) {
        RenderObject* r = endListChild->renderer()->nextSibling();
        if (r && isListHTMLElement(r->node()))
            endListChild = r->node();
    }

    start = startListChild;
    end = endListChild;
    return true;
}

VisibleSelection avoidIntersectionWithNode(const VisibleSelection& selection, Node* node)
{
    if (selection.isNone())
        return VisibleSelection(selection);

    VisibleSelection updatedSelection(selection);
    Node* base = selection.base().deprecatedNode();
    Node* extent = selection.extent().deprecatedNode();
    ASSERT(base);
    ASSERT(extent);

    if (base == node || base->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        updatedSelection.setBase(positionInParentBeforeNode(node));
    }

    if (extent == node || extent->isDescendantOf(node)) {
        ASSERT(node->parentNode());
        updatedSelection.setExtent(positionInParentBeforeNode(node));
    }

    return updatedSelection;
}

void TypingCommand::forwardDeleteKeyPressed(TextGranularity granularity, bool killRing)
{
    Frame* frame = document()->frame();
    if (!frame)
        return;

    frame->editor()->updateMarkersForWordsAffectedByEditing(false);

    VisibleSelection selectionToDelete;
    VisibleSelection selectionAfterUndo;

    switch (endingSelection().selectionType()) {
    case VisibleSelection::RangeSelection:
        selectionToDelete = endingSelection();
        selectionAfterUndo = selectionToDelete;
        break;
    case VisibleSelection::CaretSelection: {
        m_smartDelete = false;

        // Handle delete at beginning-of-block case.
        // Do nothing in the case that the caret is at the start of a
        // root editable element or at the start of a document.
        FrameSelection selection;
        selection.setSelection(endingSelection());
        selection.modify(FrameSelection::AlterationExtend, DirectionForward, granularity);
        if (killRing && selection.isCaret() && granularity != CharacterGranularity)
            selection.modify(FrameSelection::AlterationExtend, DirectionForward, CharacterGranularity);

        Position downstreamEnd = endingSelection().end().downstream();
        VisiblePosition visibleEnd = endingSelection().visibleEnd();
        Node* enclosingTableCell = enclosingNodeOfType(visibleEnd.deepEquivalent(), &isTableCell);
        if (enclosingTableCell && visibleEnd == lastPositionInNode(enclosingTableCell))
            return;
        if (visibleEnd == endOfParagraph(visibleEnd))
            downstreamEnd = visibleEnd.next(CannotCrossEditingBoundary).deepEquivalent().downstream();
        // When deleting tables: Select the table first, then perform the deletion
        if (downstreamEnd.containerNode() && downstreamEnd.containerNode()->renderer() && downstreamEnd.containerNode()->renderer()->isTable()
            && downstreamEnd.computeOffsetInContainerNode() <= caretMinOffset(downstreamEnd.containerNode())) {
            setEndingSelection(VisibleSelection(endingSelection().end(), positionAfterNode(downstreamEnd.containerNode()), DOWNSTREAM, endingSelection().isDirectional()));
            typingAddedToOpenCommand(ForwardDeleteKey);
            return;
        }

        // deleting to end of paragraph when at end of paragraph needs to merge the next paragraph (if any)
        if (granularity == ParagraphBoundary && selection.selection().isCaret() && isEndOfParagraph(selection.selection().visibleEnd()))
            selection.modify(FrameSelection::AlterationExtend, DirectionForward, CharacterGranularity);

        selectionToDelete = selection.selection();
        if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start())
            selectionAfterUndo = selectionToDelete;
        else {
            // It's a little tricky to compute what the starting selection would have been in the original document.
            // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
            // the current state of the document and we'll get the wrong result.
            Position extent = startingSelection().end();
            if (extent.containerNode() != selectionToDelete.end().containerNode())
                extent = selectionToDelete.extent();
            else {
                int extraCharacters;
                if (selectionToDelete.start().containerNode() == selectionToDelete.end().containerNode())
                    extraCharacters = selectionToDelete.end().computeOffsetInContainerNode() - selectionToDelete.start().computeOffsetInContainerNode();
                else
                    extraCharacters = selectionToDelete.end().computeOffsetInContainerNode();
                extent = Position(extent.containerNode(), extent.computeOffsetInContainerNode() + extraCharacters, Position::PositionIsOffsetInAnchor);
            }
            selectionAfterUndo.setWithoutValidation(startingSelection().start(), extent);
        }
        break;
    }
    case VisibleSelection::NoSelection:
        ASSERT_NOT_REACHED();
        break;
    }
    
    ASSERT(!selectionToDelete.isNone());
    if (selectionToDelete.isNone())
        return;
    
    if (selectionToDelete.isCaret() || !frame->selection()->shouldDeleteSelection(selectionToDelete))
        return;
        
    if (killRing)
        frame->editor()->addToKillRing(selectionToDelete.toNormalizedRange().get(), false);
    // make undo select what was deleted
    setStartingSelection(selectionAfterUndo);
    CompositeEditCommand::deleteSelection(selectionToDelete, m_smartDelete);
    setSmartDelete(false);
    typingAddedToOpenCommand(ForwardDeleteKey);
}

void TypingCommand::deleteKeyPressed(TextGranularity granularity, bool killRing)
{
    Frame* frame = document()->frame();
    if (!frame)
        return;

    frame->editor()->updateMarkersForWordsAffectedByEditing(false);

    VisibleSelection selectionToDelete;
    VisibleSelection selectionAfterUndo;

    switch (endingSelection().selectionType()) {
    case VisibleSelection::RangeSelection:
        selectionToDelete = endingSelection();
        selectionAfterUndo = selectionToDelete;
        break;
    case VisibleSelection::CaretSelection: {
        // After breaking out of an empty mail blockquote, we still want continue with the deletion
        // so actual content will get deleted, and not just the quote style.
        if (breakOutOfEmptyMailBlockquotedParagraph())
            typingAddedToOpenCommand(DeleteKey);

        m_smartDelete = false;

        FrameSelection selection;
        selection.setSelection(endingSelection());
        selection.modify(FrameSelection::AlterationExtend, DirectionBackward, granularity);
        if (killRing && selection.isCaret() && granularity != CharacterGranularity)
            selection.modify(FrameSelection::AlterationExtend, DirectionBackward, CharacterGranularity);

        if (endingSelection().visibleStart().previous(CannotCrossEditingBoundary).isNull()) {
            // When the caret is at the start of the editable area in an empty list item, break out of the list item.
            if (breakOutOfEmptyListItem()) {
                typingAddedToOpenCommand(DeleteKey);
                return;
            }
            // When there are no visible positions in the editing root, delete its entire contents.
            if (endingSelection().visibleStart().next(CannotCrossEditingBoundary).isNull() && makeEditableRootEmpty()) {
                typingAddedToOpenCommand(DeleteKey);
                return;
            }
        }

        VisiblePosition visibleStart(endingSelection().visibleStart());
        // If we have a caret selection at the beginning of a cell, we have nothing to do.
        Node* enclosingTableCell = enclosingNodeOfType(visibleStart.deepEquivalent(), &isTableCell);
        if (enclosingTableCell && visibleStart == firstPositionInNode(enclosingTableCell))
            return;

        // If the caret is at the start of a paragraph after a table, move content into the last table cell.
        if (isStartOfParagraph(visibleStart) && isFirstPositionAfterTable(visibleStart.previous(CannotCrossEditingBoundary))) {
            // Unless the caret is just before a table.  We don't want to move a table into the last table cell.
            if (isLastPositionBeforeTable(visibleStart))
                return;
            // Extend the selection backward into the last cell, then deletion will handle the move.
            selection.modify(FrameSelection::AlterationExtend, DirectionBackward, granularity);
        // If the caret is just after a table, select the table and don't delete anything.
        } else if (Node* table = isFirstPositionAfterTable(visibleStart)) {
            setEndingSelection(VisibleSelection(positionBeforeNode(table), endingSelection().start(), DOWNSTREAM, endingSelection().isDirectional()));
            typingAddedToOpenCommand(DeleteKey);
            return;
        }

        selectionToDelete = selection.selection();

        if (granularity == CharacterGranularity && selectionToDelete.end().containerNode() == selectionToDelete.start().containerNode()
            && selectionToDelete.end().computeOffsetInContainerNode() - selectionToDelete.start().computeOffsetInContainerNode() > 1) {
            // If there are multiple Unicode code points to be deleted, adjust the range to match platform conventions.
            selectionToDelete.setWithoutValidation(selectionToDelete.end(), selectionToDelete.end().previous(BackwardDeletion));
        }

        if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start())
            selectionAfterUndo = selectionToDelete;
        else
            // It's a little tricky to compute what the starting selection would have been in the original document.
            // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
            // the current state of the document and we'll get the wrong result.
            selectionAfterUndo.setWithoutValidation(startingSelection().end(), selectionToDelete.extent());
        break;
    }
    case VisibleSelection::NoSelection:
        ASSERT_NOT_REACHED();
        break;
    }
    
    ASSERT(!selectionToDelete.isNone());
    if (selectionToDelete.isNone())
        return;
    
    if (selectionToDelete.isCaret() || !frame->selection()->shouldDeleteSelection(selectionToDelete))
        return;
    
    if (killRing)
        frame->editor()->addToKillRing(selectionToDelete.toNormalizedRange().get(), false);
    // Make undo select everything that has been deleted, unless an undo will undo more than just this deletion.
    // FIXME: This behaves like TextEdit except for the case where you open with text insertion and then delete
    // more text than you insert.  In that case all of the text that was around originally should be selected.
    if (m_openedByBackwardDelete)
        setStartingSelection(selectionAfterUndo);
    CompositeEditCommand::deleteSelection(selectionToDelete, m_smartDelete);
//.........这里部分代码省略.........

static void getSelectionOffsetsForObject(AccessibilityObject* coreObject, VisibleSelection& selection, gint& startOffset, gint& endOffset)
{
    // Default values, unless the contrary is proved.
    startOffset = 0;
    endOffset = 0;

    Node* node = getNodeForAccessibilityObject(coreObject);
    if (!node)
        return;

    if (selection.isNone())
        return;

    // We need to limit our search to positions that fall inside the domain of the current object.
    Position firstValidPosition = firstPositionInOrBeforeNode(node->firstDescendant());
    Position lastValidPosition = lastPositionInOrAfterNode(node->lastDescendant());

    // Early return with proper values if the selection falls entirely out of the object.
    if (!selectionBelongsToObject(coreObject, selection)) {
        startOffset = comparePositions(selection.start(), firstValidPosition) < 0 ? 0 : accessibilityObjectLength(coreObject);
        endOffset = startOffset;
        return;
    }

    // Find the proper range for the selection that falls inside the object.
    Position nodeRangeStart = selection.start();
    if (comparePositions(nodeRangeStart, firstValidPosition) < 0)
        nodeRangeStart = firstValidPosition;

    Position nodeRangeEnd = selection.end();
    if (comparePositions(nodeRangeEnd, lastValidPosition) > 0)
        nodeRangeEnd = lastValidPosition;

    // Calculate position of the selected range inside the object.
    Position parentFirstPosition = firstPositionInOrBeforeNode(node);
    RefPtr<Range> rangeInParent = Range::create(&node->document(), parentFirstPosition, nodeRangeStart);

    // Set values for start offsets and calculate initial range length.
    // These values might be adjusted later to cover special cases.
    startOffset = webCoreOffsetToAtkOffset(coreObject, TextIterator::rangeLength(rangeInParent.get(), true));
    RefPtr<Range> nodeRange = Range::create(&node->document(), nodeRangeStart, nodeRangeEnd);
    int rangeLength = TextIterator::rangeLength(nodeRange.get(), true);

    // Special cases that are only relevant when working with *_END boundaries.
    if (selection.affinity() == UPSTREAM) {
        VisiblePosition visibleStart(nodeRangeStart, UPSTREAM);
        VisiblePosition visibleEnd(nodeRangeEnd, UPSTREAM);

        // We need to adjust offsets when finding wrapped lines so the position at the end
        // of the line is properly taking into account when calculating the offsets.
        if (isEndOfLine(visibleStart) && !lineBreakExistsAtVisiblePosition(visibleStart)) {
            if (isStartOfLine(visibleStart.next()))
                rangeLength++;

            if (!isEndOfBlock(visibleStart))
                startOffset = std::max(startOffset - 1, 0);
        }

        if (isEndOfLine(visibleEnd) && !lineBreakExistsAtVisiblePosition(visibleEnd) && !isEndOfBlock(visibleEnd))
            rangeLength--;
    }

    endOffset = std::min(startOffset + rangeLength, static_cast<int>(accessibilityObjectLength(coreObject)));
}

bool InPageSearchManager::findNextString(const String& text, FindOptions findOptions, bool wrap, bool highlightAllMatches, bool selectActiveMatchOnClear)
{
    bool highlightAllMatchesStateChanged = m_highlightAllMatches != highlightAllMatches;
    m_highlightAllMatches = highlightAllMatches;

    if (!text.length()) {
        clearTextMatches(selectActiveMatchOnClear);
        cancelPendingScopingEffort();
        m_activeSearchString = String();
        m_webPage->m_client->updateFindStringResult(m_activeMatchCount, m_activeMatchIndex);
        return false;
    }

    if (!shouldSearchForText(text)) {
        m_activeSearchString = text;
        m_webPage->m_client->updateFindStringResult(m_activeMatchCount, m_activeMatchIndex);
        return false;
    }

    // Validate the range in case any node has been removed since last search.
    if (m_activeMatch && !m_activeMatch->boundaryPointsValid())
        m_activeMatch = 0;

    ExceptionCode ec = 0;
    RefPtr<Range> searchStartingPoint = m_activeMatch ? m_activeMatch->cloneRange(ec) : 0;
    bool newSearch = highlightAllMatchesStateChanged || (m_activeSearchString != text);
    bool forward = !(findOptions & WebCore::Backwards);
    if (newSearch) { // Start a new search.
        m_activeSearchString = text;
        cancelPendingScopingEffort();
        m_scopingCaseInsensitive = findOptions & CaseInsensitive;
        m_webPage->m_page->unmarkAllTextMatches();
    } else {
        // Searching for same string should start from the end of last match.
        if (m_activeMatch) {
            if (forward)
                searchStartingPoint->setStart(searchStartingPoint->endPosition());
            else
                searchStartingPoint->setEnd(searchStartingPoint->startPosition());
        }
    }

    // If there is any active selection, new search should start from the beginning of it.
    bool startFromSelection = false;
    VisibleSelection selection = m_webPage->focusedOrMainFrame()->selection().selection();
    if (!selection.isNone()) {
        searchStartingPoint = selection.firstRange().get();
        m_webPage->focusedOrMainFrame()->selection().clear();
        startFromSelection = true;
    }

    Frame* currentActiveMatchFrame = selection.isNone() && m_activeMatch ? m_activeMatch->ownerDocument().frame() : m_webPage->focusedOrMainFrame();

    if (findAndMarkText(text, searchStartingPoint.get(), currentActiveMatchFrame, findOptions, newSearch, startFromSelection))
        return true;

    Frame* startFrame = currentActiveMatchFrame;
    do {
        currentActiveMatchFrame = DOMSupport::incrementFrame(currentActiveMatchFrame, forward, wrap);

        if (!currentActiveMatchFrame) {
            // We should only ever have a null frame if we haven't found any
            // matches and we're not wrapping. We have searched every frame.
            ASSERT(!wrap);
            m_webPage->m_client->updateFindStringResult(m_activeMatchCount, m_activeMatchIndex);
            return false;
        }

        if (findAndMarkText(text, 0, currentActiveMatchFrame, findOptions, newSearch, startFromSelection))
            return true;
    } while (startFrame != currentActiveMatchFrame);

    clearTextMatches();

    m_webPage->m_client->updateFindStringResult(m_activeMatchCount, m_activeMatchIndex);
    return false;
}

void TypingCommand::forwardDeleteKeyPressed(TextGranularity granularity, bool killRing)
{
    VisibleSelection selectionToDelete;
    VisibleSelection selectionAfterUndo;

    switch (endingSelection().selectionType()) {
        case VisibleSelection::RangeSelection:
            selectionToDelete = endingSelection();
            selectionAfterUndo = selectionToDelete;
            break;
        case VisibleSelection::CaretSelection: {
            m_smartDelete = false;

            // Handle delete at beginning-of-block case.
            // Do nothing in the case that the caret is at the start of a
            // root editable element or at the start of a document.
            SelectionController selection;
            selection.setSelection(endingSelection());
            selection.modify(SelectionController::EXTEND, SelectionController::FORWARD, granularity);
            if (killRing && selection.isCaret() && granularity != CharacterGranularity) 
                selection.modify(SelectionController::EXTEND, SelectionController::FORWARD, CharacterGranularity); 
            
            Position downstreamEnd = endingSelection().end().downstream();
            VisiblePosition visibleEnd = endingSelection().visibleEnd();
            if (visibleEnd == endOfParagraph(visibleEnd))
                downstreamEnd = visibleEnd.next(true).deepEquivalent().downstream();
            // When deleting tables: Select the table first, then perform the deletion
            if (downstreamEnd.node() && downstreamEnd.node()->renderer() && downstreamEnd.node()->renderer()->isTable() && downstreamEnd.deprecatedEditingOffset() == 0) {
                setEndingSelection(VisibleSelection(endingSelection().end(), lastDeepEditingPositionForNode(downstreamEnd.node()), DOWNSTREAM));
                typingAddedToOpenCommand(ForwardDeleteKey);
                return;
            }

            // deleting to end of paragraph when at end of paragraph needs to merge the next paragraph (if any)
            if (granularity == ParagraphBoundary && selection.selection().isCaret() && isEndOfParagraph(selection.selection().visibleEnd()))
                selection.modify(SelectionController::EXTEND, SelectionController::FORWARD, CharacterGranularity);

            selectionToDelete = selection.selection();
            if (!startingSelection().isRange() || selectionToDelete.base() != startingSelection().start())
                selectionAfterUndo = selectionToDelete;
            else {
                // It's a little tricky to compute what the starting selection would have been in the original document.
                // We can't let the VisibleSelection class's validation kick in or it'll adjust for us based on
                // the current state of the document and we'll get the wrong result.
                Position extent = startingSelection().end();
                if (extent.node() != selectionToDelete.end().node())
                    extent = selectionToDelete.extent();
                else {
                    int extraCharacters;
                    if (selectionToDelete.start().node() == selectionToDelete.end().node())
                        extraCharacters = selectionToDelete.end().deprecatedEditingOffset() - selectionToDelete.start().deprecatedEditingOffset();
                    else
                        extraCharacters = selectionToDelete.end().deprecatedEditingOffset();
                    extent = Position(extent.node(), extent.deprecatedEditingOffset() + extraCharacters);
                }
                selectionAfterUndo.setWithoutValidation(startingSelection().start(), extent);
            }
            break;
        }
        case VisibleSelection::NoSelection:
            ASSERT_NOT_REACHED();
            break;
    }
    
    ASSERT(!selectionToDelete.isNone());
    if (selectionToDelete.isNone())
        return;
    
    if (selectionToDelete.isCaret() || !document()->frame()->shouldDeleteSelection(selectionToDelete))
        return;
        
    if (killRing)
        document()->frame()->editor()->addToKillRing(selectionToDelete.toNormalizedRange().get(), false);
    // make undo select what was deleted
    setStartingSelection(selectionAfterUndo);
    CompositeEditCommand::deleteSelection(selectionToDelete, m_smartDelete);
    setSmartDelete(false);
    typingAddedToOpenCommand(ForwardDeleteKey);
}

static bool isSpellCheckingEnabledFor(const VisibleSelection& selection) {
  if (selection.isNone())
    return false;
  return isSpellCheckingEnabledFor(selection.start());
}