C++ VisibleSelection::start方法代码示例

static void expandSelectionToGranularity(Frame* frame, int x, int y, TextGranularity granularity, bool isInputMode)
{
    ASSERT(frame);
    ASSERT(frame->selection());

    VisibleSelection selection;
    if (x < 0 || y < 0) {
        if (!isInputMode)
            return; // Invalid request

        // Input mode based selection, use the current selection as the selection point.
        ASSERT(frame->selection()->selectionType() != VisibleSelection::NoSelection);
        selection = frame->selection()->selection();
    } else {
        VisiblePosition pointLocation(frame->visiblePositionForPoint(WebCore::IntPoint(x, y)));
        selection = VisibleSelection(pointLocation, pointLocation);
    }

    if (!(selection.start().anchorNode() && selection.start().anchorNode()->isTextNode()))
        return;

    selection.expandUsingGranularity(granularity);
    RefPtr<Range> newRange = selection.toNormalizedRange();
    if (!newRange)
        return;
    ExceptionCode ec = 0;
    if (newRange->collapsed(ec))
        return;
    RefPtr<Range> oldRange = frame->selection()->selection().toNormalizedRange();
    EAffinity affinity = frame->selection()->affinity();
    if (isInputMode && !frame->editor()->client()->shouldChangeSelectedRange(oldRange.get(), newRange.get(), affinity, false))
        return;
    frame->selection()->setSelectedRange(newRange.get(), affinity, true);
}

TEST_F(SurroundingTextTest, TreeCaretSelection)
{
    setHTML(String("<div>This is outside of <p id='selection'>foo bar</p> the selected node</div>"));

    {
        VisibleSelection selection = select(0);
        SurroundingText surroundingText(selection.start(), 1);

        EXPECT_EQ("f", surroundingText.content());
        EXPECT_EQ(0u, surroundingText.startOffsetInContent());
        EXPECT_EQ(0u, surroundingText.endOffsetInContent());
    }

    {
        VisibleSelection selection = select(0);
        SurroundingText surroundingText(selection.start(), 5);

        EXPECT_EQ("foo", surroundingText.content().simplifyWhiteSpace());
        EXPECT_EQ(1u, surroundingText.startOffsetInContent());
        EXPECT_EQ(1u, surroundingText.endOffsetInContent());
    }

    {
        VisibleSelection selection = select(0);
        SurroundingText surroundingText(selection.start(), 1337);

        EXPECT_EQ("This is outside of foo bar the selected node", surroundingText.content().simplifyWhiteSpace());
        EXPECT_EQ(20u, surroundingText.startOffsetInContent());
        EXPECT_EQ(20u, surroundingText.endOffsetInContent());
    }

    {
        VisibleSelection selection = select(6);
        SurroundingText surroundingText(selection.start(), 2);

        EXPECT_EQ("ar", surroundingText.content());
        EXPECT_EQ(1u, surroundingText.startOffsetInContent());
        EXPECT_EQ(1u, surroundingText.endOffsetInContent());
    }

    {
        VisibleSelection selection = select(6);
        SurroundingText surroundingText(selection.start(), 1337);

        EXPECT_EQ("This is outside of foo bar the selected node", surroundingText.content().simplifyWhiteSpace());
        EXPECT_EQ(26u, surroundingText.startOffsetInContent());
        EXPECT_EQ(26u, surroundingText.endOffsetInContent());
    }
}

static char* webkitAccessibleTextGetWordForBoundary(AtkText* text, int offset, AtkTextBoundary boundaryType, GetTextRelativePosition textPosition, int* startOffset, int* endOffset)
{
    AccessibilityObject* coreObject = core(text);
    Document* document = coreObject->document();
    if (!document)
        return emptyTextSelectionAtOffset(0, startOffset, endOffset);

    Node* node = getNodeForAccessibilityObject(coreObject);
    if (!node)
        return emptyTextSelectionAtOffset(0, startOffset, endOffset);

    int actualOffset = atkOffsetToWebCoreOffset(text, offset);

    // Besides of the usual conversion from ATK offsets to WebCore offsets,
    // we need to consider the potential embedded objects that might have been
    // inserted in the text exposed through AtkText when calculating the offset.
    actualOffset -= numberOfReplacedElementsBeforeOffset(text, actualOffset);

    VisiblePosition caretPosition = coreObject->visiblePositionForIndex(actualOffset);
    VisibleSelection currentWord = wordAtPositionForAtkBoundary(coreObject, caretPosition, boundaryType);

    // Take into account other relative positions, if needed, by
    // calculating the new position that we would need to consider.
    VisiblePosition newPosition = caretPosition;
    switch (textPosition) {
    case GetTextPositionAt:
        break;

    case GetTextPositionBefore:
        // Early return if asking for the previous word while already at the beginning.
        if (isFirstVisiblePositionInNode(currentWord.visibleStart(), node))
            return emptyTextSelectionAtOffset(0, startOffset, endOffset);

        if (isStartOfLine(currentWord.end()))
            newPosition = currentWord.visibleStart().previous();
        else
            newPosition = startOfWord(currentWord.start(), LeftWordIfOnBoundary);
        break;

    case GetTextPositionAfter:
        // Early return if asking for the following word while already at the end.
        if (isLastVisiblePositionInNode(currentWord.visibleEnd(), node))
            return emptyTextSelectionAtOffset(accessibilityObjectLength(coreObject), startOffset, endOffset);

        if (isEndOfLine(currentWord.end()))
            newPosition = currentWord.visibleEnd().next();
        else
            newPosition = endOfWord(currentWord.end(), RightWordIfOnBoundary);
        break;

    default:
        ASSERT_NOT_REACHED();
    }

    // Determine the relevant word we are actually interested in
    // and calculate the ATK offsets for it, then return everything.
    VisibleSelection selectedWord = newPosition != caretPosition ? wordAtPositionForAtkBoundary(coreObject, newPosition, boundaryType) : currentWord;
    getSelectionOffsetsForObject(coreObject, selectedWord, *startOffset, *endOffset);
    return webkitAccessibleTextGetText(text, *startOffset, *endOffset);
}

// 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();
}

bool Editor::insertTextWithoutSendingTextEvent(const String& text, bool selectInsertedText, TextEvent* triggeringEvent)
{
    if (text.isEmpty())
        return false;

    VisibleSelection selection = selectionForCommand(triggeringEvent);
    if (!selection.isContentEditable())
        return false;

    spellChecker().updateMarkersForWordsAffectedByEditing(isSpaceOrNewline(text[0]));

    // Get the selection to use for the event that triggered this insertText.
    // If the event handler changed the selection, we may want to use a different selection
    // that is contained in the event target.
    selection = selectionForCommand(triggeringEvent);
    if (selection.isContentEditable()) {
        if (Node* selectionStart = selection.start().deprecatedNode()) {
            RefPtr<Document> document(selectionStart->document());

            // Insert the text
            TypingCommand::Options options = 0;
            if (selectInsertedText)
                options |= TypingCommand::SelectInsertedText;
            TypingCommand::insertText(*document.get(), text, selection, options, triggeringEvent && triggeringEvent->isComposition() ? TypingCommand::TextCompositionConfirm : TypingCommand::TextCompositionNone);

            // Reveal the current selection
            if (LocalFrame* editedFrame = document->frame()) {
                if (Page* page = editedFrame->page())
                    page->focusController().focusedOrMainFrame()->selection().revealSelection(ScrollAlignment::alignCenterIfNeeded);
            }
        }
    }

    return true;
}

bool static selectionIsContainedByAnchorNode(const VisibleSelection& selection)
{
    // Check whether the start or end of the selection is outside of the selections
    // anchor node.
    return (selection.start().anchorType() == WebCore::Position::PositionIsOffsetInAnchor
            && selection.end().anchorType() == WebCore::Position::PositionIsOffsetInAnchor);
}

void TypingCommand::postTextStateChangeNotificationForDeletion(const VisibleSelection& selection)
{
    if (!AXObjectCache::accessibilityEnabled())
        return;
    postTextStateChangeNotification(AXTextEditTypeDelete, AccessibilityObject::stringForVisiblePositionRange(selection), selection.start());
    VisiblePositionIndexRange range;
    range.startIndex.value = indexForVisiblePosition(selection.start(), range.startIndex.scope);
    range.endIndex.value = indexForVisiblePosition(selection.end(), range.endIndex.scope);
    composition()->setTextInsertedByUnapplyRange(range);
}

// FIXME: We shouldn't need to take selectionForInsertion. It should be identical to SelectionController's current selection.
void TypingCommand::insertText(Document* document, const String& text, const VisibleSelection& selectionForInsertion, bool selectInsertedText, TextCompositionType compositionType)
{
#if REMOVE_MARKERS_UPON_EDITING
    if (!text.isEmpty())
        document->frame()->editor()->removeSpellAndCorrectionMarkersFromWordsToBeEdited(isSpaceOrNewline(text.characters()[0]));
#endif

    ASSERT(document);

    RefPtr<Frame> frame = document->frame();
    ASSERT(frame);

    VisibleSelection currentSelection = frame->selection()->selection();
    bool changeSelection = currentSelection != selectionForInsertion;
    String newText = text;
    Node* startNode = selectionForInsertion.start().node();
    
    if (startNode && startNode->rootEditableElement() && compositionType != TextCompositionUpdate) {
        // Send BeforeTextInsertedEvent. The event handler will update text if necessary.
        ExceptionCode ec = 0;
        RefPtr<BeforeTextInsertedEvent> evt = BeforeTextInsertedEvent::create(text);
        startNode->rootEditableElement()->dispatchEvent(evt, ec);
        newText = evt->text();
    }
    
    if (newText.isEmpty())
        return;
    
    // Set the starting and ending selection appropriately if we are using a selection
    // that is different from the current selection.  In the future, we should change EditCommand
    // to deal with custom selections in a general way that can be used by all of the commands.
    RefPtr<EditCommand> lastEditCommand = frame->editor()->lastEditCommand();
    if (isOpenForMoreTypingCommand(lastEditCommand.get())) {
        TypingCommand* lastTypingCommand = static_cast<TypingCommand*>(lastEditCommand.get());
        if (lastTypingCommand->endingSelection() != selectionForInsertion) {
            lastTypingCommand->setStartingSelection(selectionForInsertion);
            lastTypingCommand->setEndingSelection(selectionForInsertion);
        }
        
        lastTypingCommand->setCompositionType(compositionType);
        lastTypingCommand->insertText(newText, selectInsertedText);
        return;
    }

    RefPtr<TypingCommand> cmd = TypingCommand::create(document, InsertText, newText, selectInsertedText, compositionType);
    if (changeSelection)  {
        cmd->setStartingSelection(selectionForInsertion);
        cmd->setEndingSelection(selectionForInsertion);
    }
    applyCommand(cmd);
    if (changeSelection) {
        cmd->setEndingSelection(currentSelection);
        frame->selection()->setSelection(currentSelection);
    }
}

VisibleSelection visibleSelectionForClosestActualWordStart(const VisibleSelection& selection)
{
    // VisibleSelection validation has a special case when the caret is at the end of a paragraph where
    // it selects the paragraph marker. As well, if the position is at the end of a word, it will select
    // only the space between words. We want to select an actual word so we move the selection to
    // the start of the leftmost word if the character after the selection point is whitespace.

    if (selection.selectionType() != VisibleSelection::RangeSelection) {
        int leftDistance = 0;
        int rightDistance = 0;

        VisibleSelection leftSelection(previousWordPosition(selection.start()));
        bool leftSelectionIsOnWord = !isWhitespace(leftSelection.visibleStart().characterAfter()) && leftSelection.start().containerNode() == selection.start().containerNode();
        if (leftSelectionIsOnWord) {
            VisibleSelection rangeSelection(endOfWord(leftSelection.start()), selection.visibleStart());
            leftDistance = TextIterator::rangeLength(rangeSelection.toNormalizedRange().get());
        }

        VisibleSelection rightSelection = previousWordPosition(nextWordPosition(selection.start()));
        bool rightSelectionIsOnWord = !isWhitespace(rightSelection.visibleStart().characterAfter()) && rightSelection.start().containerNode() == selection.start().containerNode();
        if (rightSelectionIsOnWord) {
            VisibleSelection rangeSelection = VisibleSelection(rightSelection.visibleStart(), selection.visibleStart());
            rightDistance = TextIterator::rangeLength(rangeSelection.toNormalizedRange().get());
        }

        // Make sure we found an actual word. If not, return the original selection.
        if (!leftSelectionIsOnWord && !rightSelectionIsOnWord)
            return selection;

        if (!rightSelectionIsOnWord || (leftSelectionIsOnWord && leftDistance <= rightDistance)) {
            // Left is closer or right is invalid.
            return leftSelection;
        }

        // Right is closer or equal, or left was invalid.
        return rightSelection;
    }

    // No adjustment required.
    return selection;
}

static void writeSelection(TextStream& ts, const RenderObject* o)
{
    Node* n = o->node();
    if (!n || !n->isDocumentNode())
        return;

    Document* doc = static_cast<Document*>(n);
    Frame* frame = doc->frame();
    if (!frame)
        return;

    VisibleSelection selection = frame->selection()->selection();
    if (selection.isCaret()) {
        ts << "caret: position " << selection.start().deprecatedEditingOffset() << " of " << nodePosition(selection.start().node());
        if (selection.affinity() == UPSTREAM)
            ts << " (upstream affinity)";
        ts << "\n";
    } else if (selection.isRange())
        ts << "selection start: position " << selection.start().deprecatedEditingOffset() << " of " << nodePosition(selection.start().node()) << "\n"
           << "selection end:   position " << selection.end().deprecatedEditingOffset() << " of " << nodePosition(selection.end().node()) << "\n";
}

void visibleTextQuads(const VisibleSelection& selection, Vector<FloatQuad>& quads)
{
    if (!selection.isRange())
        return;

    // Make sure that both start and end have valid nodes associated otherwise
    // this can crash. See PR 220628.
    if (!selection.start().anchorNode() || !selection.end().anchorNode())
        return;

    visibleTextQuads(*(selection.firstRange()), quads, true /* useSelectionHeight */);
}

// FIXME: We shouldn't need to take selectionForInsertion. It should be identical to SelectionController's current selection.
void TypingCommand::insertText(Document* document, const String& text, const VisibleSelection& selectionForInsertion, Options options, TextCompositionType compositionType)
{
    ASSERT(document);

    RefPtr<Frame> frame = document->frame();
    ASSERT(frame);

    VisibleSelection currentSelection = frame->selection()->selection();
    bool changeSelection = currentSelection != selectionForInsertion;
    String newText = text;
    Node* startNode = selectionForInsertion.start().deprecatedNode();
    
    if (startNode && startNode->rootEditableElement() && compositionType != TextCompositionUpdate) {
        // Send BeforeTextInsertedEvent. The event handler will update text if necessary.
        ExceptionCode ec = 0;
        RefPtr<BeforeTextInsertedEvent> evt = BeforeTextInsertedEvent::create(text);
        startNode->rootEditableElement()->dispatchEvent(evt, ec);
        newText = evt->text();
    }
    
    if (newText.isEmpty())
        return;
    
    // Set the starting and ending selection appropriately if we are using a selection
    // that is different from the current selection.  In the future, we should change EditCommand
    // to deal with custom selections in a general way that can be used by all of the commands.
    RefPtr<EditCommand> lastEditCommand = frame->editor()->lastEditCommand();
    if (isOpenForMoreTypingCommand(lastEditCommand.get())) {
        TypingCommand* lastTypingCommand = static_cast<TypingCommand*>(lastEditCommand.get());
        if (lastTypingCommand->endingSelection() != selectionForInsertion) {
            lastTypingCommand->setStartingSelection(selectionForInsertion);
            lastTypingCommand->setEndingSelection(selectionForInsertion);
        }

        lastTypingCommand->setCompositionType(compositionType);
        lastTypingCommand->setShouldRetainAutocorrectionIndicator(options & RetainAutocorrectionIndicator);
        lastTypingCommand->setShouldPreventSpellChecking(options & PreventSpellChecking);
        lastTypingCommand->insertText(newText, options & SelectInsertedText);
        return;
    }

    RefPtr<TypingCommand> cmd = TypingCommand::create(document, InsertText, newText, options, compositionType);
    if (changeSelection)  {
        cmd->setStartingSelection(selectionForInsertion);
        cmd->setEndingSelection(selectionForInsertion);
    }
    applyCommand(cmd);
    if (changeSelection) {
        cmd->setEndingSelection(currentSelection);
        frame->selection()->setSelection(currentSelection);
    }
}

void SpellChecker::respondToChangedSelection(const VisibleSelection& oldSelection, FrameSelection::SetSelectionOptions options)
{
    bool closeTyping = options & FrameSelection::CloseTyping;
    bool isContinuousSpellCheckingEnabled = this->isContinuousSpellCheckingEnabled();
    bool isContinuousGrammarCheckingEnabled = isContinuousSpellCheckingEnabled && isGrammarCheckingEnabled();
    if (isContinuousSpellCheckingEnabled) {
        VisibleSelection newAdjacentWords;
        VisibleSelection newSelectedSentence;
        const VisibleSelection newSelection = m_frame.selection().selection();
        VisiblePosition newStart(newSelection.visibleStart());
        newAdjacentWords = VisibleSelection(startOfWord(newStart, LeftWordIfOnBoundary), endOfWord(newStart, RightWordIfOnBoundary));
        if (isContinuousGrammarCheckingEnabled)
            newSelectedSentence = VisibleSelection(startOfSentence(newStart), endOfSentence(newStart));

        // Don't check spelling and grammar if the change of selection is triggered by spelling correction itself.
        bool shouldCheckSpellingAndGrammar = !(options & FrameSelection::SpellCorrectionTriggered);

        // When typing we check spelling elsewhere, so don't redo it here.
        // If this is a change in selection resulting from a delete operation,
        // oldSelection may no longer be in the document.
        // FIXME(http://crbug.com/382809): if oldSelection is on a textarea
        // element, we cause synchronous layout.
        if (shouldCheckSpellingAndGrammar
            && closeTyping
            && !isSelectionInTextField(oldSelection)
            && (isSelectionInTextArea(oldSelection) || oldSelection.isContentEditable())
            && oldSelection.start().inDocument()) {
            spellCheckOldSelection(oldSelection, newAdjacentWords);
        }

        // FIXME(http://crbug.com/382809):
        // shouldEraseMarkersAfterChangeSelection is true, we cause synchronous
        // layout.
        if (textChecker().shouldEraseMarkersAfterChangeSelection(TextCheckingTypeSpelling)) {
            if (RefPtr<Range> wordRange = newAdjacentWords.toNormalizedRange())
                m_frame.document()->markers().removeMarkers(wordRange.get(), DocumentMarker::Spelling);
        }
        if (textChecker().shouldEraseMarkersAfterChangeSelection(TextCheckingTypeGrammar)) {
            if (RefPtr<Range> sentenceRange = newSelectedSentence.toNormalizedRange())
                m_frame.document()->markers().removeMarkers(sentenceRange.get(), DocumentMarker::Grammar);
        }
    }

    // When continuous spell checking is off, existing markers disappear after the selection changes.
    if (!isContinuousSpellCheckingEnabled)
        m_frame.document()->markers().removeMarkers(DocumentMarker::Spelling);
    if (!isContinuousGrammarCheckingEnabled)
        m_frame.document()->markers().removeMarkers(DocumentMarker::Grammar);
}

String dispatchBeforeTextInsertedEvent(const String& text, const VisibleSelection& selectionForInsertion, bool insertionIsForUpdatingComposition)
{
    if (insertionIsForUpdatingComposition)
        return text;

    String newText = text;
    if (Node* startNode = selectionForInsertion.start().containerNode()) {
        if (startNode->rootEditableElement()) {
            // Send BeforeTextInsertedEvent. The event handler will update text if necessary.
            RefPtr<BeforeTextInsertedEvent> evt = BeforeTextInsertedEvent::create(text);
            startNode->rootEditableElement()->dispatchEvent(evt, IGNORE_EXCEPTION);
            newText = evt->text();
        }
    }
    return newText;
}

DeleteSelectionCommand::DeleteSelectionCommand(const VisibleSelection& selection, bool smartDelete, bool mergeBlocksAfterDelete, bool replace, bool expandForSpecialElements)
    : CompositeEditCommand(selection.start().anchorNode()->document())
    , m_hasSelectionToDelete(true)
    , m_smartDelete(smartDelete)
    , m_mergeBlocksAfterDelete(mergeBlocksAfterDelete)
    , m_needPlaceholder(false)
    , m_replace(replace)
    , m_expandForSpecialElements(expandForSpecialElements)
    , m_pruneStartBlockIfNecessary(false)
    , m_startsAtEmptyLine(false)
    , m_selectionToDelete(selection)
    , m_startBlock(0)
    , m_endBlock(0)
    , m_typingStyle(0)
    , m_deleteIntoBlockquoteStyle(0)
{
}