Source/WebCore/editing/Editor.cpp

/*
 * Copyright (C) 2006, 2007, 2008, 2011, 2013 Apple Inc. All rights reserved.
 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "Editor.h"

#include "AXObjectCache.h"
#include "AlternativeTextController.h"
#include "ApplyStyleCommand.h"
#include "CSSComputedStyleDeclaration.h"
#include "CSSPropertyNames.h"
#include "CachedResourceLoader.h"
#include "Clipboard.h"
#include "ClipboardEvent.h"
#include "CompositionEvent.h"
#include "CreateLinkCommand.h"
#include "DeleteSelectionCommand.h"
#include "DictationAlternative.h"
#include "DictationCommand.h"
#include "DocumentFragment.h"
#include "DocumentMarkerController.h"
#include "EditorClient.h"
#include "EventHandler.h"
#include "EventNames.h"
#include "ExceptionCodePlaceholder.h"
#include "FocusController.h"
#include "Frame.h"
#include "FrameTree.h"
#include "FrameView.h"
#include "GraphicsContext.h"
#include "HTMLFormControlElement.h"
#include "HTMLFrameOwnerElement.h"
#include "HTMLImageElement.h"
#include "HTMLNames.h"
#include "HTMLTextAreaElement.h"
#include "HitTestResult.h"
#include "IndentOutdentCommand.h"
#include "InsertListCommand.h"
#include "KeyboardEvent.h"
#include "KillRing.h"
#include "ModifySelectionListLevel.h"
#include "NodeList.h"
#include "NodeTraversal.h"
#include "Page.h"
#include "Pasteboard.h"
#include "RemoveFormatCommand.h"
#include "RenderBlock.h"
#include "RenderTextControl.h"
#include "RenderedPosition.h"
#include "ReplaceSelectionCommand.h"
#include "Settings.h"
#include "ShadowRoot.h"
#include "SimplifyMarkupCommand.h"
#include "Sound.h"
#include "SpellChecker.h"
#include "SpellingCorrectionCommand.h"
#include "StylePropertySet.h"
#include "Text.h"
#include "TextCheckerClient.h"
#include "TextCheckingHelper.h"
#include "TextEvent.h"
#include "TextIterator.h"
#include "TypingCommand.h"
#include "UserTypingGestureIndicator.h"
#include "VisibleUnits.h"
#include "htmlediting.h"
#include "markup.h"
#include <wtf/unicode/CharacterNames.h>
#include <wtf/unicode/Unicode.h>

#if ENABLE(DELETION_UI)
#include "DeleteButtonController.h"
#endif

namespace WebCore {

using namespace HTMLNames;
using namespace WTF;
using namespace Unicode;

#if ENABLE(DELETION_UI)

PassRefPtr<Range> Editor::avoidIntersectionWithDeleteButtonController(const Range* range) const
{
    if (!range)
        return 0;

    Node* startContainer = range->startContainer();
    int startOffset = range->startOffset();
    Node* endContainer = range->endContainer();
    int endOffset = range->endOffset();

    if (!startContainer)
        return 0;

    ASSERT(endContainer);

    Element* element = m_deleteButtonController->containerElement();
    if (startContainer == element || startContainer->isDescendantOf(element)) {
        ASSERT(element->parentNode());
        startContainer = element->parentNode();
        startOffset = element->nodeIndex();
    }
    if (endContainer == element || endContainer->isDescendantOf(element)) {
        ASSERT(element->parentNode());
        endContainer = element->parentNode();
        endOffset = element->nodeIndex();
    }

    return Range::create(range->ownerDocument(), startContainer, startOffset, endContainer, endOffset);
}

VisibleSelection Editor::avoidIntersectionWithDeleteButtonController(const VisibleSelection& selection) const
{
    if (selection.isNone())
        return selection;

    Element* element = m_deleteButtonController->containerElement();
    if (!element)
        return selection;
    VisibleSelection updatedSelection = selection;

    Position updatedBase = selection.base();
    updatePositionForNodeRemoval(updatedBase, element);
    if (updatedBase != selection.base())
        updatedSelection.setBase(updatedBase);

    Position updatedExtent = selection.extent();
    updatePositionForNodeRemoval(updatedExtent, element);
    if (updatedExtent != selection.extent())
        updatedSelection.setExtent(updatedExtent);

    return updatedSelection;
}

#endif

// When an event handler has moved the selection outside of a text control
// we should use the target control's selection for this editing operation.
VisibleSelection Editor::selectionForCommand(Event* event)
{
    VisibleSelection selection = m_frame.selection().selection();
    if (!event)
        return selection;
    // If the target is a text control, and the current selection is outside of its shadow tree,
    // then use the saved selection for that text control.
    HTMLTextFormControlElement* textFormControlOfSelectionStart = enclosingTextFormControl(selection.start());
    HTMLTextFormControlElement* textFromControlOfTarget = isHTMLTextFormControlElement(*event->target()->toNode()) ? toHTMLTextFormControlElement(event->target()->toNode()) : nullptr;
    if (textFromControlOfTarget && (selection.start().isNull() || textFromControlOfTarget != textFormControlOfSelectionStart)) {
        if (RefPtr<Range> range = textFromControlOfTarget->selection())
            return VisibleSelection(range.get(), DOWNSTREAM, selection.isDirectional());
    }
    return selection;
}

// Function considers Mac editing behavior a fallback when Page or Settings is not available.
EditingBehavior Editor::behavior() const
{
    return EditingBehavior(m_frame.settings().editingBehaviorType());
}

EditorClient* Editor::client() const
{
    if (Page* page = m_frame.page())
        return page->editorClient();
    return 0;
}


TextCheckerClient* Editor::textChecker() const
{
    if (EditorClient* owner = client())
        return owner->textChecker();
    return 0;
}

void Editor::handleKeyboardEvent(KeyboardEvent* event)
{
    if (EditorClient* c = client())
        c->handleKeyboardEvent(event);
}

void Editor::handleInputMethodKeydown(KeyboardEvent* event)
{
    if (EditorClient* c = client())
        c->handleInputMethodKeydown(event);
}

bool Editor::handleTextEvent(TextEvent* event)
{
    // Default event handling for Drag and Drop will be handled by DragController
    // so we leave the event for it.
    if (event->isDrop())
        return false;

    if (event->isPaste()) {
        if (event->pastingFragment())
            replaceSelectionWithFragment(event->pastingFragment(), false, event->shouldSmartReplace(), event->shouldMatchStyle());
        else 
            replaceSelectionWithText(event->data(), false, event->shouldSmartReplace());
        return true;
    }

    String data = event->data();
    if (data == "\n") {
        if (event->isLineBreak())
            return insertLineBreak();
        return insertParagraphSeparator();
    }

    return insertTextWithoutSendingTextEvent(data, false, event);
}

bool Editor::canEdit() const
{
    return m_frame.selection().rootEditableElement();
}

bool Editor::canEditRichly() const
{
    return m_frame.selection().isContentRichlyEditable();
}

// WinIE uses onbeforecut and onbeforepaste to enables the cut and paste menu items.  They
// also send onbeforecopy, apparently for symmetry, but it doesn't affect the menu items.
// We need to use onbeforecopy as a real menu enabler because we allow elements that are not
// normally selectable to implement copy/paste (like divs, or a document body).

bool Editor::canDHTMLCut()
{
    return !m_frame.selection().isInPasswordField() && !dispatchCPPEvent(eventNames().beforecutEvent, ClipboardNumb);
}

bool Editor::canDHTMLCopy()
{
    return !m_frame.selection().isInPasswordField() && !dispatchCPPEvent(eventNames().beforecopyEvent, ClipboardNumb);
}

bool Editor::canDHTMLPaste()
{
    return !dispatchCPPEvent(eventNames().beforepasteEvent, ClipboardNumb);
}

bool Editor::canCut() const
{
    return canCopy() && canDelete();
}

static HTMLImageElement* imageElementFromImageDocument(Document& document)
{
    if (!document.isImageDocument())
        return 0;
    
    HTMLElement* body = document.body();
    if (!body)
        return 0;
    
    Node* node = body->firstChild();
    if (!node)
        return 0;
    if (!isHTMLImageElement(node))
        return 0;
    return toHTMLImageElement(node);
}

bool Editor::canCopy() const
{
    if (imageElementFromImageDocument(document()))
        return true;
    FrameSelection& selection = m_frame.selection();
    return selection.isRange() && !selection.isInPasswordField();
}

bool Editor::canPaste() const
{
    return canEdit();
}

bool Editor::canDelete() const
{
    FrameSelection& selection = m_frame.selection();
    return selection.isRange() && selection.rootEditableElement();
}

bool Editor::canDeleteRange(Range* range) const
{
    Node* startContainer = range->startContainer();
    Node* endContainer = range->endContainer();
    if (!startContainer || !endContainer)
        return false;
    
    if (!startContainer->rendererIsEditable() || !endContainer->rendererIsEditable())
        return false;

    if (range->collapsed(IGNORE_EXCEPTION)) {
        VisiblePosition start(range->startPosition(), DOWNSTREAM);
        VisiblePosition previous = start.previous();
        // FIXME: We sometimes allow deletions at the start of editable roots, like when the caret is in an empty list item.
        if (previous.isNull() || previous.deepEquivalent().deprecatedNode()->rootEditableElement() != startContainer->rootEditableElement())
            return false;
    }
    return true;
}

bool Editor::smartInsertDeleteEnabled()
{   
    return client() && client()->smartInsertDeleteEnabled();
}
    
bool Editor::canSmartCopyOrDelete()
{
    return client() && client()->smartInsertDeleteEnabled() && m_frame.selection().granularity() == WordGranularity;
}

bool Editor::isSelectTrailingWhitespaceEnabled()
{
    return client() && client()->isSelectTrailingWhitespaceEnabled();
}

bool Editor::deleteWithDirection(SelectionDirection direction, TextGranularity granularity, bool killRing, bool isTypingAction)
{
    if (!canEdit())
        return false;

    if (m_frame.selection().isRange()) {
        if (isTypingAction) {
            TypingCommand::deleteKeyPressed(document(), canSmartCopyOrDelete() ? TypingCommand::SmartDelete : 0, granularity);
            revealSelectionAfterEditingOperation();
        } else {
            if (killRing)
                addToKillRing(selectedRange().get(), false);
            deleteSelectionWithSmartDelete(canSmartCopyOrDelete());
            // Implicitly calls revealSelectionAfterEditingOperation().
        }
    } else {
        TypingCommand::Options options = 0;
        if (canSmartCopyOrDelete())
            options |= TypingCommand::SmartDelete;
        if (killRing)
            options |= TypingCommand::KillRing;
        switch (direction) {
        case DirectionForward:
        case DirectionRight:
            TypingCommand::forwardDeleteKeyPressed(document(), options, granularity);
            break;
        case DirectionBackward:
        case DirectionLeft:
            TypingCommand::deleteKeyPressed(document(), options, granularity);
            break;
        }
        revealSelectionAfterEditingOperation();
    }

    // FIXME: We should to move this down into deleteKeyPressed.
    // clear the "start new kill ring sequence" setting, because it was set to true
    // when the selection was updated by deleting the range
    if (killRing)
        setStartNewKillRingSequence(false);

    return true;
}

void Editor::deleteSelectionWithSmartDelete(bool smartDelete)
{
    if (m_frame.selection().isNone())
        return;

    applyCommand(DeleteSelectionCommand::create(document(), smartDelete));
}

void Editor::pasteAsPlainText(const String& pastingText, bool smartReplace)
{
    Node* target = findEventTargetFromSelection();
    if (!target)
        return;
    target->dispatchEvent(TextEvent::createForPlainTextPaste(document().domWindow(), pastingText, smartReplace), IGNORE_EXCEPTION);
}

void Editor::pasteAsFragment(PassRefPtr<DocumentFragment> pastingFragment, bool smartReplace, bool matchStyle)
{
    Node* target = findEventTargetFromSelection();
    if (!target)
        return;
    target->dispatchEvent(TextEvent::createForFragmentPaste(document().domWindow(), pastingFragment, smartReplace, matchStyle), IGNORE_EXCEPTION);
}

void Editor::pasteAsPlainTextBypassingDHTML()
{
    pasteAsPlainTextWithPasteboard(*Pasteboard::createForCopyAndPaste());
}

void Editor::pasteAsPlainTextWithPasteboard(Pasteboard& pasteboard)
{
    String text = readPlainTextFromPasteboard(pasteboard);
    if (client() && client()->shouldInsertText(text, selectedRange().get(), EditorInsertActionPasted))
        pasteAsPlainText(text, canSmartReplaceWithPasteboard(pasteboard));
}

String Editor::readPlainTextFromPasteboard(Pasteboard& pasteboard)
{
    PasteboardPlainText text;
    pasteboard.read(text);
    return plainTextFromPasteboard(text);
}

#if !(PLATFORM(MAC) && !PLATFORM(IOS))

String Editor::plainTextFromPasteboard(const PasteboardPlainText& text)
{
    return text.text;
}

#endif

#if !PLATFORM(MAC) && !PLATFORM(EFL)
void Editor::pasteWithPasteboard(Pasteboard* pasteboard, bool allowPlainText)
{
    RefPtr<Range> range = selectedRange();
    if (!range)
        return;

    bool chosePlainText;
    RefPtr<DocumentFragment> fragment = pasteboard->documentFragment(m_frame, *range, allowPlainText, chosePlainText);
    if (fragment && shouldInsertFragment(fragment, range, EditorInsertActionPasted))
        pasteAsFragment(fragment, canSmartReplaceWithPasteboard(*pasteboard), chosePlainText);
}
#endif

bool Editor::canSmartReplaceWithPasteboard(Pasteboard& pasteboard)
{
    return client() && client()->smartInsertDeleteEnabled() && pasteboard.canSmartReplace();
}

bool Editor::shouldInsertFragment(PassRefPtr<DocumentFragment> fragment, PassRefPtr<Range> replacingDOMRange, EditorInsertAction givenAction)
{
    if (!client())
        return false;
    
    if (fragment) {
        Node* child = fragment->firstChild();
        if (child && fragment->lastChild() == child && child->isCharacterDataNode())
            return client()->shouldInsertText(toCharacterData(child)->data(), replacingDOMRange.get(), givenAction);
    }

    return client()->shouldInsertNode(fragment.get(), replacingDOMRange.get(), givenAction);
}

void Editor::replaceSelectionWithFragment(PassRefPtr<DocumentFragment> fragment, bool selectReplacement, bool smartReplace, bool matchStyle)
{
    if (m_frame.selection().isNone() || !m_frame.selection().isContentEditable() || !fragment)
        return;

    ReplaceSelectionCommand::CommandOptions options = ReplaceSelectionCommand::PreventNesting | ReplaceSelectionCommand::SanitizeFragment;
    if (selectReplacement)
        options |= ReplaceSelectionCommand::SelectReplacement;
    if (smartReplace)
        options |= ReplaceSelectionCommand::SmartReplace;
    if (matchStyle)
        options |= ReplaceSelectionCommand::MatchStyle;
    applyCommand(ReplaceSelectionCommand::create(document(), fragment, options, EditActionPaste));
    revealSelectionAfterEditingOperation();

    if (m_frame.selection().isInPasswordField() || !isContinuousSpellCheckingEnabled())
        return;
    Node* nodeToCheck = m_frame.selection().rootEditableElement();
    if (!nodeToCheck)
        return;

    RefPtr<Range> rangeToCheck = Range::create(document(), firstPositionInNode(nodeToCheck), lastPositionInNode(nodeToCheck));
    m_spellChecker->requestCheckingFor(SpellCheckRequest::create(resolveTextCheckingTypeMask(TextCheckingTypeSpelling | TextCheckingTypeGrammar), TextCheckingProcessBatch, rangeToCheck, rangeToCheck));
}

void Editor::replaceSelectionWithText(const String& text, bool selectReplacement, bool smartReplace)
{
    RefPtr<Range> range = selectedRange();
    if (!range)
        return;

    replaceSelectionWithFragment(createFragmentFromText(*range, text), selectReplacement, smartReplace, true);
}

PassRefPtr<Range> Editor::selectedRange()
{
    return m_frame.selection().toNormalizedRange();
}

bool Editor::shouldDeleteRange(Range* range) const
{
    if (!range || range->collapsed(IGNORE_EXCEPTION))
        return false;
    
    if (!canDeleteRange(range))
        return false;

    return client() && client()->shouldDeleteRange(range);
}

bool Editor::tryDHTMLCopy()
{   
    if (m_frame.selection().isInPasswordField())
        return false;

    return !dispatchCPPEvent(eventNames().copyEvent, ClipboardWritable);
}

bool Editor::tryDHTMLCut()
{
    if (m_frame.selection().isInPasswordField())
        return false;
    
    return !dispatchCPPEvent(eventNames().cutEvent, ClipboardWritable);
}

bool Editor::tryDHTMLPaste()
{
    return !dispatchCPPEvent(eventNames().pasteEvent, ClipboardReadable);
}

bool Editor::shouldInsertText(const String& text, Range* range, EditorInsertAction action) const
{
    return client() && client()->shouldInsertText(text, range, action);
}

void Editor::notifyComponentsOnChangedSelection(const VisibleSelection& oldSelection, FrameSelection::SetSelectionOptions options)
{
    if (client())
        client()->respondToChangedSelection(&m_frame);
    setStartNewKillRingSequence(true);
#if ENABLE(DELETION_UI)
    m_deleteButtonController->respondToChangedSelection(oldSelection);
#endif
    m_alternativeTextController->respondToChangedSelection(oldSelection, options);
}

void Editor::respondToChangedContents(const VisibleSelection& endingSelection)
{
    if (AXObjectCache::accessibilityEnabled()) {
        Node* node = endingSelection.start().deprecatedNode();
        if (AXObjectCache* cache = document().existingAXObjectCache())
            cache->postNotification(node, AXObjectCache::AXValueChanged, TargetObservableParent);
    }

    updateMarkersForWordsAffectedByEditing(true);

    if (client())
        client()->respondToChangedContents();
}

bool Editor::hasBidiSelection() const
{
    if (m_frame.selection().isNone())
        return false;

    Node* startNode;
    if (m_frame.selection().isRange()) {
        startNode = m_frame.selection().selection().start().downstream().deprecatedNode();
        Node* endNode = m_frame.selection().selection().end().upstream().deprecatedNode();
        if (enclosingBlock(startNode) != enclosingBlock(endNode))
            return false;
    } else
        startNode = m_frame.selection().selection().visibleStart().deepEquivalent().deprecatedNode();

    auto renderer = startNode->renderer();
    while (renderer && !renderer->isRenderBlockFlow())
        renderer = renderer->parent();

    if (!renderer)
        return false;

    if (!renderer->style().isLeftToRightDirection())
        return true;

    return toRenderBlockFlow(renderer)->containsNonZeroBidiLevel();
}

TriState Editor::selectionUnorderedListState() const
{
    if (m_frame.selection().isCaret()) {
        if (enclosingNodeWithTag(m_frame.selection().selection().start(), ulTag))
            return TrueTriState;
    } else if (m_frame.selection().isRange()) {
        Node* startNode = enclosingNodeWithTag(m_frame.selection().selection().start(), ulTag);
        Node* endNode = enclosingNodeWithTag(m_frame.selection().selection().end(), ulTag);
        if (startNode && endNode && startNode == endNode)
            return TrueTriState;
    }

    return FalseTriState;
}

TriState Editor::selectionOrderedListState() const
{
    if (m_frame.selection().isCaret()) {
        if (enclosingNodeWithTag(m_frame.selection().selection().start(), olTag))
            return TrueTriState;
    } else if (m_frame.selection().isRange()) {
        Node* startNode = enclosingNodeWithTag(m_frame.selection().selection().start(), olTag);
        Node* endNode = enclosingNodeWithTag(m_frame.selection().selection().end(), olTag);
        if (startNode && endNode && startNode == endNode)
            return TrueTriState;
    }

    return FalseTriState;
}

PassRefPtr<Node> Editor::insertOrderedList()
{
    if (!canEditRichly())
        return 0;
        
    RefPtr<Node> newList = InsertListCommand::insertList(document(), InsertListCommand::OrderedList);
    revealSelectionAfterEditingOperation();
    return newList;
}

PassRefPtr<Node> Editor::insertUnorderedList()
{
    if (!canEditRichly())
        return 0;
        
    RefPtr<Node> newList = InsertListCommand::insertList(document(), InsertListCommand::UnorderedList);
    revealSelectionAfterEditingOperation();
    return newList;
}

bool Editor::canIncreaseSelectionListLevel()
{
    return canEditRichly() && IncreaseSelectionListLevelCommand::canIncreaseSelectionListLevel(&document());
}

bool Editor::canDecreaseSelectionListLevel()
{
    return canEditRichly() && DecreaseSelectionListLevelCommand::canDecreaseSelectionListLevel(&document());
}

PassRefPtr<Node> Editor::increaseSelectionListLevel()
{
    if (!canEditRichly() || m_frame.selection().isNone())
        return 0;
    
    RefPtr<Node> newList = IncreaseSelectionListLevelCommand::increaseSelectionListLevel(&document());
    revealSelectionAfterEditingOperation();
    return newList;
}

PassRefPtr<Node> Editor::increaseSelectionListLevelOrdered()
{
    if (!canEditRichly() || m_frame.selection().isNone())
        return 0;
    
    RefPtr<Node> newList = IncreaseSelectionListLevelCommand::increaseSelectionListLevelOrdered(&document());
    revealSelectionAfterEditingOperation();
    return newList.release();
}

PassRefPtr<Node> Editor::increaseSelectionListLevelUnordered()
{
    if (!canEditRichly() || m_frame.selection().isNone())
        return 0;
    
    RefPtr<Node> newList = IncreaseSelectionListLevelCommand::increaseSelectionListLevelUnordered(&document());
    revealSelectionAfterEditingOperation();
    return newList.release();
}

void Editor::decreaseSelectionListLevel()
{
    if (!canEditRichly() || m_frame.selection().isNone())
        return;
    
    DecreaseSelectionListLevelCommand::decreaseSelectionListLevel(&document());
    revealSelectionAfterEditingOperation();
}

void Editor::removeFormattingAndStyle()
{
    applyCommand(RemoveFormatCommand::create(document()));
}

void Editor::clearLastEditCommand() 
{
    m_lastEditCommand.clear();
}

// Returns whether caller should continue with "the default processing", which is the same as 
// the event handler NOT setting the return value to false
bool Editor::dispatchCPPEvent(const AtomicString& eventType, ClipboardAccessPolicy policy)
{
    Node* target = findEventTargetFromSelection();
    if (!target)
        return true;

    RefPtr<Clipboard> clipboard = Clipboard::createForCopyAndPaste(policy);

    RefPtr<Event> event = ClipboardEvent::create(eventType, true, true, clipboard);
    target->dispatchEvent(event, IGNORE_EXCEPTION);
    bool noDefaultProcessing = event->defaultPrevented();
    if (noDefaultProcessing && policy == ClipboardWritable) {
        OwnPtr<Pasteboard> pasteboard = Pasteboard::createForCopyAndPaste();
        pasteboard->clear();
        pasteboard->writePasteboard(clipboard->pasteboard());
    }

    // invalidate clipboard here for security
    clipboard->setAccessPolicy(ClipboardNumb);
    
    return !noDefaultProcessing;
}

Node* Editor::findEventTargetFrom(const VisibleSelection& selection) const
{
    Node* target = selection.start().element();
    if (!target)
        target = document().body();
    if (!target)
        return 0;

    return target;
}

Node* Editor::findEventTargetFromSelection() const
{
    return findEventTargetFrom(m_frame.selection().selection());
}

void Editor::applyStyle(StylePropertySet* style, EditAction editingAction)
{
    switch (m_frame.selection().selectionType()) {
    case VisibleSelection::NoSelection:
        // do nothing
        break;
    case VisibleSelection::CaretSelection:
        computeAndSetTypingStyle(style, editingAction);
        break;
    case VisibleSelection::RangeSelection:
        if (style)
            applyCommand(ApplyStyleCommand::create(document(), EditingStyle::create(style).get(), editingAction));
        break;
    }
}
    
bool Editor::shouldApplyStyle(StylePropertySet* style, Range* range)
{   
    return client()->shouldApplyStyle(style, range);
}
    
void Editor::applyParagraphStyle(StylePropertySet* style, EditAction editingAction)
{
    switch (m_frame.selection().selectionType()) {
    case VisibleSelection::NoSelection:
        // do nothing
        break;
    case VisibleSelection::CaretSelection:
    case VisibleSelection::RangeSelection:
        if (style)
            applyCommand(ApplyStyleCommand::create(document(), EditingStyle::create(style).get(), editingAction, ApplyStyleCommand::ForceBlockProperties));
        break;
    }
}

void Editor::applyStyleToSelection(StylePropertySet* style, EditAction editingAction)
{
    if (!style || style->isEmpty() || !canEditRichly())
        return;

    if (client() && client()->shouldApplyStyle(style, m_frame.selection().toNormalizedRange().get()))
        applyStyle(style, editingAction);
}

void Editor::applyParagraphStyleToSelection(StylePropertySet* style, EditAction editingAction)
{
    if (!style || style->isEmpty() || !canEditRichly())
        return;
    
    if (client() && client()->shouldApplyStyle(style, m_frame.selection().toNormalizedRange().get()))
        applyParagraphStyle(style, editingAction);
}

bool Editor::selectionStartHasStyle(CSSPropertyID propertyID, const String& value) const
{
    return EditingStyle::create(propertyID, value)->triStateOfStyle(
        EditingStyle::styleAtSelectionStart(m_frame.selection().selection(), propertyID == CSSPropertyBackgroundColor).get());
}

TriState Editor::selectionHasStyle(CSSPropertyID propertyID, const String& value) const
{
    return EditingStyle::create(propertyID, value)->triStateOfStyle(m_frame.selection().selection());
}

String Editor::selectionStartCSSPropertyValue(CSSPropertyID propertyID)
{
    RefPtr<EditingStyle> selectionStyle = EditingStyle::styleAtSelectionStart(m_frame.selection().selection(),
        propertyID == CSSPropertyBackgroundColor);
    if (!selectionStyle || !selectionStyle->style())
        return String();

    if (propertyID == CSSPropertyFontSize)
        return String::number(selectionStyle->legacyFontSize(&document()));
    return selectionStyle->style()->getPropertyValue(propertyID);
}

void Editor::indent()
{
    applyCommand(IndentOutdentCommand::create(document(), IndentOutdentCommand::Indent));
}

void Editor::outdent()
{
    applyCommand(IndentOutdentCommand::create(document(), IndentOutdentCommand::Outdent));
}

static void dispatchEditableContentChangedEvents(PassRefPtr<Element> prpStartRoot, PassRefPtr<Element> prpEndRoot)
{
    RefPtr<Element> startRoot = prpStartRoot;
    RefPtr<Element> endRoot = prpEndRoot;
    if (startRoot)
        startRoot->dispatchEvent(Event::create(eventNames().webkitEditableContentChangedEvent, false, false), IGNORE_EXCEPTION);
    if (endRoot && endRoot != startRoot)
        endRoot->dispatchEvent(Event::create(eventNames().webkitEditableContentChangedEvent, false, false), IGNORE_EXCEPTION);
}

void Editor::appliedEditing(PassRefPtr<CompositeEditCommand> cmd)
{
    document().updateLayout();

    EditCommandComposition* composition = cmd->composition();
    ASSERT(composition);
    VisibleSelection newSelection(cmd->endingSelection());

    m_alternativeTextController->respondToAppliedEditing(cmd.get());

    // Don't clear the typing style with this selection change.  We do those things elsewhere if necessary.
    FrameSelection::SetSelectionOptions options = cmd->isDictationCommand() ? FrameSelection::DictationTriggered : 0;
    changeSelectionAfterCommand(newSelection, options);
    dispatchEditableContentChangedEvents(composition->startingRootEditableElement(), composition->endingRootEditableElement());

    if (!cmd->preservesTypingStyle())
        m_frame.selection().clearTypingStyle();

    // Command will be equal to last edit command only in the case of typing
    if (m_lastEditCommand.get() == cmd)
        ASSERT(cmd->isTypingCommand());
    else {
        // Only register a new undo command if the command passed in is
        // different from the last command
        m_lastEditCommand = cmd;
        if (client())
            client()->registerUndoStep(m_lastEditCommand->ensureComposition());
    }

    respondToChangedContents(newSelection);
}

void Editor::unappliedEditing(PassRefPtr<EditCommandComposition> cmd)
{
    document().updateLayout();

    VisibleSelection newSelection(cmd->startingSelection());
    changeSelectionAfterCommand(newSelection, FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle);
    dispatchEditableContentChangedEvents(cmd->startingRootEditableElement(), cmd->endingRootEditableElement());

    m_alternativeTextController->respondToUnappliedEditing(cmd.get());

    m_lastEditCommand = 0;
    if (client())
        client()->registerRedoStep(cmd);
    respondToChangedContents(newSelection);
}

void Editor::reappliedEditing(PassRefPtr<EditCommandComposition> cmd)
{
    document().updateLayout();

    VisibleSelection newSelection(cmd->endingSelection());
    changeSelectionAfterCommand(newSelection, FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle);
    dispatchEditableContentChangedEvents(cmd->startingRootEditableElement(), cmd->endingRootEditableElement());

    m_lastEditCommand = 0;
    if (client())
        client()->registerUndoStep(cmd);
    respondToChangedContents(newSelection);
}

Editor::Editor(Frame& frame)
    : m_frame(frame)
#if ENABLE(DELETION_UI)
    , m_deleteButtonController(adoptPtr(new DeleteButtonController(frame)))
#endif
    , m_ignoreCompositionSelectionChange(false)
    , m_shouldStartNewKillRingSequence(false)
    // This is off by default, since most editors want this behavior (this matches IE but not FF).
    , m_shouldStyleWithCSS(false)
    , m_killRing(adoptPtr(new KillRing))
    , m_spellChecker(adoptPtr(new SpellChecker(frame)))
    , m_alternativeTextController(adoptPtr(new AlternativeTextController(frame)))
    , m_areMarkedTextMatchesHighlighted(false)
    , m_defaultParagraphSeparator(EditorParagraphSeparatorIsDiv)
    , m_overwriteModeEnabled(false)
{
}

Editor::~Editor()
{
}

void Editor::clear()
{
    m_compositionNode = 0;
    m_customCompositionUnderlines.clear();
    m_shouldStyleWithCSS = false;
    m_defaultParagraphSeparator = EditorParagraphSeparatorIsDiv;

#if ENABLE(DELETION_UI)
    m_deleteButtonController = adoptPtr(new DeleteButtonController(m_frame));
#endif
}

bool Editor::insertText(const String& text, Event* triggeringEvent)
{
    return m_frame.eventHandler().handleTextInputEvent(text, triggeringEvent);
}

bool Editor::insertTextForConfirmedComposition(const String& text)
{
    return m_frame.eventHandler().handleTextInputEvent(text, 0, TextEventInputComposition);
}

bool Editor::insertDictatedText(const String& text, const Vector<DictationAlternative>& dictationAlternatives, Event* triggeringEvent)
{
    return m_alternativeTextController->insertDictatedText(text, dictationAlternatives, triggeringEvent);
}

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

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

    if (!shouldInsertText(text, range.get(), EditorInsertActionTyped))
        return true;

    if (!text.isEmpty())
        updateMarkersForWordsAffectedByEditing(isSpaceOrNewline(text[0]));

    bool shouldConsiderApplyingAutocorrection = false;
    if (text == " " || text == "\t")
        shouldConsiderApplyingAutocorrection = true;

    if (text.length() == 1 && u_ispunct(text[0]) && !isAmbiguousBoundaryCharacter(text[0]))
        shouldConsiderApplyingAutocorrection = true;

    bool autocorrectionWasApplied = shouldConsiderApplyingAutocorrection && m_alternativeTextController->applyAutocorrectionBeforeTypingIfAppropriate();

    // 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()) {
            Ref<Document> document(selectionStart->document());

            // Insert the text
            if (triggeringEvent && triggeringEvent->isDictation())
                DictationCommand::insertText(&document.get(), text, triggeringEvent->dictationAlternatives(), selection);
            else {
                TypingCommand::Options options = 0;
                if (selectInsertedText)
                    options |= TypingCommand::SelectInsertedText;
                if (autocorrectionWasApplied)
                    options |= TypingCommand::RetainAutocorrectionIndicator;
                TypingCommand::insertText(document.get(), text, selection, options, triggeringEvent && triggeringEvent->isComposition() ? TypingCommand::TextCompositionConfirm : TypingCommand::TextCompositionNone);
            }

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

    return true;
}

bool Editor::insertLineBreak()
{
    if (!canEdit())
        return false;

    if (!shouldInsertText("\n", m_frame.selection().toNormalizedRange().get(), EditorInsertActionTyped))
        return true;

    VisiblePosition caret = m_frame.selection().selection().visibleStart();
    bool alignToEdge = isEndOfEditableOrNonEditableContent(caret);
    bool autocorrectionIsApplied = m_alternativeTextController->applyAutocorrectionBeforeTypingIfAppropriate();
    TypingCommand::insertLineBreak(document(), autocorrectionIsApplied ? TypingCommand::RetainAutocorrectionIndicator : 0);
    revealSelectionAfterEditingOperation(alignToEdge ? ScrollAlignment::alignToEdgeIfNeeded : ScrollAlignment::alignCenterIfNeeded);

    return true;
}

bool Editor::insertParagraphSeparator()
{
    if (!canEdit())
        return false;

    if (!canEditRichly())
        return insertLineBreak();

    if (!shouldInsertText("\n", m_frame.selection().toNormalizedRange().get(), EditorInsertActionTyped))
        return true;

    VisiblePosition caret = m_frame.selection().selection().visibleStart();
    bool alignToEdge = isEndOfEditableOrNonEditableContent(caret);
    bool autocorrectionIsApplied = m_alternativeTextController->applyAutocorrectionBeforeTypingIfAppropriate();
    TypingCommand::insertParagraphSeparator(document(), autocorrectionIsApplied ? TypingCommand::RetainAutocorrectionIndicator : 0);
    revealSelectionAfterEditingOperation(alignToEdge ? ScrollAlignment::alignToEdgeIfNeeded : ScrollAlignment::alignCenterIfNeeded);

    return true;
}

void Editor::cut()
{
    if (tryDHTMLCut())
        return; // DHTML did the whole operation
    if (!canCut()) {
        systemBeep();
        return;
    }

    // FIXME: This should share more code with the copy function; there is a lot of overlap.
    RefPtr<Range> selection = selectedRange();
    willWriteSelectionToPasteboard(selection);
    if (shouldDeleteRange(selection.get())) {
        updateMarkersForWordsAffectedByEditing(true);
        if (enclosingTextFormControl(m_frame.selection().start()))
            Pasteboard::createForCopyAndPaste()->writePlainText(selectedTextForClipboard(), canSmartCopyOrDelete() ? Pasteboard::CanSmartReplace : Pasteboard::CannotSmartReplace);
        else {
#if PLATFORM(MAC) || PLATFORM(EFL)
            writeSelectionToPasteboard(*Pasteboard::createForCopyAndPaste());
#else
            // FIXME: Convert all other platforms to match Mac and delete this.
            Pasteboard::createForCopyAndPaste()->writeSelection(*selection, canSmartCopyOrDelete(), m_frame, IncludeImageAltTextForClipboard);
#endif
        }
        didWriteSelectionToPasteboard();
        deleteSelectionWithSmartDelete(canSmartCopyOrDelete());
    }
}

void Editor::copy()
{
    if (tryDHTMLCopy())
        return; // DHTML did the whole operation
    if (!canCopy()) {
        systemBeep();
        return;
    }

    willWriteSelectionToPasteboard(selectedRange());
    if (enclosingTextFormControl(m_frame.selection().start())) {
        Pasteboard::createForCopyAndPaste()->writePlainText(selectedTextForClipboard(),
            canSmartCopyOrDelete() ? Pasteboard::CanSmartReplace : Pasteboard::CannotSmartReplace);
    } else {
        if (HTMLImageElement* imageElement = imageElementFromImageDocument(document())) {
#if (PLATFORM(MAC) && !PLATFORM(IOS)) || PLATFORM(EFL)
            writeImageToPasteboard(*Pasteboard::createForCopyAndPaste(), *imageElement, document().url(), document().title());
#else
            Pasteboard::createForCopyAndPaste()->writeImage(*imageElement, document().url(), document().title());
#endif
        } else {
#if (PLATFORM(MAC) && !PLATFORM(IOS)) || PLATFORM(EFL)
            writeSelectionToPasteboard(*Pasteboard::createForCopyAndPaste());
#else
            // FIXME: Convert all other platforms to match Mac and delete this.
            Pasteboard::createForCopyAndPaste()->writeSelection(*selectedRange(), canSmartCopyOrDelete(), m_frame, IncludeImageAltTextForClipboard);
#endif
        }
    }

    didWriteSelectionToPasteboard();
}

void Editor::paste()
{
    paste(*Pasteboard::createForCopyAndPaste());
}

void Editor::paste(Pasteboard& pasteboard)
{
    if (tryDHTMLPaste())
        return; // DHTML did the whole operation
    if (!canPaste())
        return;
    updateMarkersForWordsAffectedByEditing(false);
    CachedResourceLoader* loader = document().cachedResourceLoader();
    ResourceCacheValidationSuppressor validationSuppressor(loader);
    if (m_frame.selection().isContentRichlyEditable())
        pasteWithPasteboard(&pasteboard, true);
    else
        pasteAsPlainTextWithPasteboard(pasteboard);
}

void Editor::pasteAsPlainText()
{
    if (tryDHTMLPaste())
        return;
    if (!canPaste())
        return;
    updateMarkersForWordsAffectedByEditing(false);
    pasteAsPlainTextWithPasteboard(*Pasteboard::createForCopyAndPaste());
}

void Editor::performDelete()
{
    if (!canDelete()) {
        systemBeep();
        return;
    }

    addToKillRing(selectedRange().get(), false);
    deleteSelectionWithSmartDelete(canSmartCopyOrDelete());

    // clear the "start new kill ring sequence" setting, because it was set to true
    // when the selection was updated by deleting the range
    setStartNewKillRingSequence(false);
}

void Editor::simplifyMarkup(Node* startNode, Node* endNode)
{
    if (!startNode)
        return;
    if (endNode) {
        if (&startNode->document() != &endNode->document())
            return;
        // check if start node is before endNode
        Node* node = startNode;
        while (node && node != endNode)
            node = NodeTraversal::next(node);
        if (!node)
            return;
    }
    
    applyCommand(SimplifyMarkupCommand::create(document(), startNode, (endNode) ? NodeTraversal::next(endNode) : 0));
}

void Editor::copyURL(const URL& url, const String& title)
{
    copyURL(url, title, *Pasteboard::createForCopyAndPaste());
}

void Editor::copyURL(const URL& url, const String& title, Pasteboard& pasteboard)
{
    PasteboardURL pasteboardURL;
    pasteboardURL.url = url;
    pasteboardURL.title = title;

#if PLATFORM(MAC) && !PLATFORM(IOS)
    fillInUserVisibleForm(pasteboardURL);
#endif

    pasteboard.write(pasteboardURL);
}

void Editor::copyImage(const HitTestResult& result)
{
    Element* element = result.innerNonSharedElement();
    if (!element)
        return;

    URL url = result.absoluteLinkURL();
    if (url.isEmpty())
        url = result.absoluteImageURL();

#if PLATFORM(MAC) || PLATFORM(EFL)
    writeImageToPasteboard(*Pasteboard::createForCopyAndPaste(), *element, url, result.altDisplayString());
#else
    Pasteboard::createForCopyAndPaste()->writeImage(*element, url, result.altDisplayString());
#endif
}

bool Editor::isContinuousSpellCheckingEnabled() const
{
    return client() && client()->isContinuousSpellCheckingEnabled();
}

void Editor::toggleContinuousSpellChecking()
{
    if (client())
        client()->toggleContinuousSpellChecking();
}

bool Editor::isGrammarCheckingEnabled()
{
    return client() && client()->isGrammarCheckingEnabled();
}

void Editor::toggleGrammarChecking()
{
    if (client())
        client()->toggleGrammarChecking();
}

int Editor::spellCheckerDocumentTag()
{
    return client() ? client()->spellCheckerDocumentTag() : 0;
}

#if USE(APPKIT)

void Editor::uppercaseWord()
{
    if (client())
        client()->uppercaseWord();
}

void Editor::lowercaseWord()
{
    if (client())
        client()->lowercaseWord();
}

void Editor::capitalizeWord()
{
    if (client())
        client()->capitalizeWord();
}
    
#endif

#if USE(AUTOMATIC_TEXT_REPLACEMENT)

void Editor::showSubstitutionsPanel()
{
    if (!client()) {
        LOG_ERROR("No NSSpellChecker");
        return;
    }

    if (client()->substitutionsPanelIsShowing()) {
        client()->showSubstitutionsPanel(false);
        return;
    }
    client()->showSubstitutionsPanel(true);
}

bool Editor::substitutionsPanelIsShowing()
{
    if (!client())
        return false;
    return client()->substitutionsPanelIsShowing();
}

void Editor::toggleSmartInsertDelete()
{
    if (client())
        client()->toggleSmartInsertDelete();
}

bool Editor::isAutomaticQuoteSubstitutionEnabled()
{
    return client() && client()->isAutomaticQuoteSubstitutionEnabled();
}

void Editor::toggleAutomaticQuoteSubstitution()
{
    if (client())
        client()->toggleAutomaticQuoteSubstitution();
}

bool Editor::isAutomaticLinkDetectionEnabled()
{
    return client() && client()->isAutomaticLinkDetectionEnabled();
}

void Editor::toggleAutomaticLinkDetection()
{
    if (client())
        client()->toggleAutomaticLinkDetection();
}

bool Editor::isAutomaticDashSubstitutionEnabled()
{
    return client() && client()->isAutomaticDashSubstitutionEnabled();
}

void Editor::toggleAutomaticDashSubstitution()
{
    if (client())
        client()->toggleAutomaticDashSubstitution();
}

bool Editor::isAutomaticTextReplacementEnabled()
{
    return client() && client()->isAutomaticTextReplacementEnabled();
}

void Editor::toggleAutomaticTextReplacement()
{
    if (client())
        client()->toggleAutomaticTextReplacement();
}

bool Editor::isAutomaticSpellingCorrectionEnabled()
{
    return m_alternativeTextController->isAutomaticSpellingCorrectionEnabled();
}

void Editor::toggleAutomaticSpellingCorrection()
{
    if (client())
        client()->toggleAutomaticSpellingCorrection();
}

#endif

bool Editor::shouldEndEditing(Range* range)
{
    return client() && client()->shouldEndEditing(range);
}

bool Editor::shouldBeginEditing(Range* range)
{
    return client() && client()->shouldBeginEditing(range);
}

void Editor::clearUndoRedoOperations()
{
    if (client())
        client()->clearUndoRedoOperations();
}

bool Editor::canUndo()
{
    return client() && client()->canUndo();
}

void Editor::undo()
{
    if (client())
        client()->undo();
}

bool Editor::canRedo()
{
    return client() && client()->canRedo();
}

void Editor::redo()
{
    if (client())
        client()->redo();
}

void Editor::didBeginEditing()
{
    if (client())
        client()->didBeginEditing();
}

void Editor::didEndEditing()
{
    if (client())
        client()->didEndEditing();
}

void Editor::willWriteSelectionToPasteboard(PassRefPtr<Range> range)
{
    if (client())
        client()->willWriteSelectionToPasteboard(range.get());
}

void Editor::didWriteSelectionToPasteboard()
{
    if (client())
        client()->didWriteSelectionToPasteboard();
}

void Editor::toggleBold()
{
    command("ToggleBold").execute();
}

void Editor::toggleUnderline()
{
    command("ToggleUnderline").execute();
}

void Editor::setBaseWritingDirection(WritingDirection direction)
{
    Element* focusedElement = document().focusedElement();
    if (focusedElement && isHTMLTextFormControlElement(*focusedElement)) {
        if (direction == NaturalWritingDirection)
            return;
        toHTMLElement(focusedElement)->setAttribute(dirAttr, direction == LeftToRightWritingDirection ? "ltr" : "rtl");
        focusedElement->dispatchInputEvent();
        document().updateStyleIfNeeded();
        return;
    }

    RefPtr<MutableStylePropertySet> style = MutableStylePropertySet::create();
    style->setProperty(CSSPropertyDirection, direction == LeftToRightWritingDirection ? "ltr" : direction == RightToLeftWritingDirection ? "rtl" : "inherit", false);
    applyParagraphStyleToSelection(style.get(), EditActionSetWritingDirection);
}

WritingDirection Editor::baseWritingDirectionForSelectionStart() const
{
    WritingDirection result = LeftToRightWritingDirection;

    Position pos = m_frame.selection().selection().visibleStart().deepEquivalent();
    Node* node = pos.deprecatedNode();
    if (!node)
        return result;

    auto renderer = node->renderer();
    if (!renderer)
        return result;

    if (!renderer->isRenderBlockFlow()) {
        renderer = renderer->containingBlock();
        if (!renderer)
            return result;
    }

    switch (renderer->style().direction()) {
    case LTR:
        return LeftToRightWritingDirection;
    case RTL:
        return RightToLeftWritingDirection;
    }
    
    return result;
}

void Editor::selectComposition()
{
    RefPtr<Range> range = compositionRange();
    if (!range)
        return;
    
    // The composition can start inside a composed character sequence, so we have to override checks.
    // See <http://bugs.webkit.org/show_bug.cgi?id=15781>
    VisibleSelection selection;
    selection.setWithoutValidation(range->startPosition(), range->endPosition());
    m_frame.selection().setSelection(selection, 0);
}

void Editor::confirmComposition()
{
    if (!m_compositionNode)
        return;
    setComposition(m_compositionNode->data().substring(m_compositionStart, m_compositionEnd - m_compositionStart), ConfirmComposition);
}

void Editor::cancelComposition()
{
    if (!m_compositionNode)
        return;
    setComposition(emptyString(), CancelComposition);
}

bool Editor::cancelCompositionIfSelectionIsInvalid()
{
    unsigned start;
    unsigned end;
    if (!hasComposition() || ignoreCompositionSelectionChange() || getCompositionSelection(start, end))
        return false;

    cancelComposition();
    return true;
}

void Editor::confirmComposition(const String& text)
{
    setComposition(text, ConfirmComposition);
}

void Editor::setComposition(const String& text, SetCompositionMode mode)
{
    ASSERT(mode == ConfirmComposition || mode == CancelComposition);
    UserTypingGestureIndicator typingGestureIndicator(m_frame);

    setIgnoreCompositionSelectionChange(true);

    if (mode == CancelComposition)
        ASSERT(text == emptyString());
    else
        selectComposition();

    if (m_frame.selection().isNone()) {
        setIgnoreCompositionSelectionChange(false);
        return;
    }
    
    // Dispatch a compositionend event to the focused node.
    // We should send this event before sending a TextEvent as written in Section 6.2.2 and 6.2.3 of
    // the DOM Event specification.
    if (Element* target = document().focusedElement()) {
        RefPtr<CompositionEvent> event = CompositionEvent::create(eventNames().compositionendEvent, document().domWindow(), text);
        target->dispatchEvent(event.release(), IGNORE_EXCEPTION);
    }

    // If text is empty, then delete the old composition here.  If text is non-empty, InsertTextCommand::input
    // will delete the old composition with an optimized replace operation.
    if (text.isEmpty() && mode != CancelComposition)
        TypingCommand::deleteSelection(document(), 0);

    m_compositionNode = 0;
    m_customCompositionUnderlines.clear();

    insertTextForConfirmedComposition(text);

    if (mode == CancelComposition) {
        // An open typing command that disagrees about current selection would cause issues with typing later on.
        TypingCommand::closeTyping(&m_frame);
    }

    setIgnoreCompositionSelectionChange(false);
}

void Editor::setComposition(const String& text, const Vector<CompositionUnderline>& underlines, unsigned selectionStart, unsigned selectionEnd)
{
    UserTypingGestureIndicator typingGestureIndicator(m_frame);

    setIgnoreCompositionSelectionChange(true);

    // Updates styles before setting selection for composition to prevent
    // inserting the previous composition text into text nodes oddly.
    // See https://bugs.webkit.org/show_bug.cgi?id=46868
    document().updateStyleIfNeeded();

    selectComposition();

    if (m_frame.selection().isNone()) {
        setIgnoreCompositionSelectionChange(false);
        return;
    }

    Element* target = document().focusedElement();
    if (target) {
        // Dispatch an appropriate composition event to the focused node.
        // We check the composition status and choose an appropriate composition event since this
        // function is used for three purposes:
        // 1. Starting a new composition.
        //    Send a compositionstart and a compositionupdate event when this function creates
        //    a new composition node, i.e.
        //    m_compositionNode == 0 && !text.isEmpty().
        //    Sending a compositionupdate event at this time ensures that at least one
        //    compositionupdate event is dispatched.
        // 2. Updating the existing composition node.
        //    Send a compositionupdate event when this function updates the existing composition
        //    node, i.e. m_compositionNode != 0 && !text.isEmpty().
        // 3. Canceling the ongoing composition.
        //    Send a compositionend event when function deletes the existing composition node, i.e.
        //    m_compositionNode != 0 && test.isEmpty().
        RefPtr<CompositionEvent> event;
        if (!m_compositionNode) {
            // We should send a compositionstart event only when the given text is not empty because this
            // function doesn't create a composition node when the text is empty.
            if (!text.isEmpty()) {
                target->dispatchEvent(CompositionEvent::create(eventNames().compositionstartEvent, document().domWindow(), selectedText()));
                event = CompositionEvent::create(eventNames().compositionupdateEvent, document().domWindow(), text);
            }
        } else {
            if (!text.isEmpty())
                event = CompositionEvent::create(eventNames().compositionupdateEvent, document().domWindow(), text);
            else
                event = CompositionEvent::create(eventNames().compositionendEvent, document().domWindow(), text);
        }
        if (event.get())
            target->dispatchEvent(event, IGNORE_EXCEPTION);
    }

    // If text is empty, then delete the old composition here.  If text is non-empty, InsertTextCommand::input
    // will delete the old composition with an optimized replace operation.
    if (text.isEmpty())
        TypingCommand::deleteSelection(document(), TypingCommand::PreventSpellChecking);

    m_compositionNode = 0;
    m_customCompositionUnderlines.clear();

    if (!text.isEmpty()) {
        TypingCommand::insertText(document(), text, TypingCommand::SelectInsertedText | TypingCommand::PreventSpellChecking, TypingCommand::TextCompositionUpdate);

        // Find out what node has the composition now.
        Position base = m_frame.selection().base().downstream();
        Position extent = m_frame.selection().extent();
        Node* baseNode = base.deprecatedNode();
        unsigned baseOffset = base.deprecatedEditingOffset();
        Node* extentNode = extent.deprecatedNode();
        unsigned extentOffset = extent.deprecatedEditingOffset();

        if (baseNode && baseNode == extentNode && baseNode->isTextNode() && baseOffset + text.length() == extentOffset) {
            m_compositionNode = toText(baseNode);
            m_compositionStart = baseOffset;
            m_compositionEnd = extentOffset;
            m_customCompositionUnderlines = underlines;
            size_t numUnderlines = m_customCompositionUnderlines.size();
            for (size_t i = 0; i < numUnderlines; ++i) {
                m_customCompositionUnderlines[i].startOffset += baseOffset;
                m_customCompositionUnderlines[i].endOffset += baseOffset;
            }
            if (baseNode->renderer())
                baseNode->renderer()->repaint();

            unsigned start = std::min(baseOffset + selectionStart, extentOffset);
            unsigned end = std::min(std::max(start, baseOffset + selectionEnd), extentOffset);
            RefPtr<Range> selectedRange = Range::create(baseNode->document(), baseNode, start, baseNode, end);
            m_frame.selection().setSelectedRange(selectedRange.get(), DOWNSTREAM, false);
        }
    }

    setIgnoreCompositionSelectionChange(false);
}

void Editor::ignoreSpelling()
{
    if (!client())
        return;
        
    RefPtr<Range> selectedRange = m_frame.selection().toNormalizedRange();
    if (selectedRange)
        document().markers().removeMarkers(selectedRange.get(), DocumentMarker::Spelling);

    String text = selectedText();
    ASSERT(text.length());
    textChecker()->ignoreWordInSpellDocument(text);
}

void Editor::learnSpelling()
{
    if (!client())
        return;
        
    // FIXME: On Mac OS X, when use "learn" button on "Spelling and Grammar" panel, we don't call this function. It should remove misspelling markers around the learned word, see <rdar://problem/5396072>.

    RefPtr<Range> selectedRange = m_frame.selection().toNormalizedRange();
    if (selectedRange)
        document().markers().removeMarkers(selectedRange.get(), DocumentMarker::Spelling);

    String text = selectedText();
    ASSERT(text.length());
    textChecker()->learnWord(text);
}

void Editor::advanceToNextMisspelling(bool startBeforeSelection)
{
    // The basic approach is to search in two phases - from the selection end to the end of the doc, and
    // then we wrap and search from the doc start to (approximately) where we started.
    
    // Start at the end of the selection, search to edge of document.  Starting at the selection end makes
    // repeated "check spelling" commands work.
    VisibleSelection selection(m_frame.selection().selection());
    RefPtr<Range> spellingSearchRange(rangeOfContents(document()));

    bool startedWithSelection = false;
    if (selection.start().deprecatedNode()) {
        startedWithSelection = true;
        if (startBeforeSelection) {
            VisiblePosition start(selection.visibleStart());
            // We match AppKit's rule: Start 1 character before the selection.
            VisiblePosition oneBeforeStart = start.previous();
            setStart(spellingSearchRange.get(), oneBeforeStart.isNotNull() ? oneBeforeStart : start);
        } else
            setStart(spellingSearchRange.get(), selection.visibleEnd());
    }

    Position position = spellingSearchRange->startPosition();
    if (!isEditablePosition(position)) {
        // This shouldn't happen in very often because the Spelling menu items aren't enabled unless the
        // selection is editable.
        // This can happen in Mail for a mix of non-editable and editable content (like Stationary), 
        // when spell checking the whole document before sending the message.
        // In that case the document might not be editable, but there are editable pockets that need to be spell checked.

        position = firstEditablePositionAfterPositionInRoot(position, document().documentElement()).deepEquivalent();
        if (position.isNull())
            return;
        
        Position rangeCompliantPosition = position.parentAnchoredEquivalent();
        spellingSearchRange->setStart(rangeCompliantPosition.deprecatedNode(), rangeCompliantPosition.deprecatedEditingOffset(), IGNORE_EXCEPTION);
        startedWithSelection = false; // won't need to wrap
    }
    
    // topNode defines the whole range we want to operate on 
    Node* topNode = highestEditableRoot(position);
    // FIXME: lastOffsetForEditing() is wrong here if editingIgnoresContent(highestEditableRoot()) returns true (e.g. a <table>)
    spellingSearchRange->setEnd(topNode, lastOffsetForEditing(topNode), IGNORE_EXCEPTION);

    // If spellingSearchRange starts in the middle of a word, advance to the next word so we start checking
    // at a word boundary. Going back by one char and then forward by a word does the trick.
    if (startedWithSelection) {
        VisiblePosition oneBeforeStart = startVisiblePosition(spellingSearchRange.get(), DOWNSTREAM).previous();
        if (oneBeforeStart.isNotNull())
            setStart(spellingSearchRange.get(), endOfWord(oneBeforeStart));
        // else we were already at the start of the editable node
    }

    if (spellingSearchRange->collapsed(IGNORE_EXCEPTION))
        return; // nothing to search in
    
    // Get the spell checker if it is available
    if (!client())
        return;
        
    // We go to the end of our first range instead of the start of it, just to be sure
    // we don't get foiled by any word boundary problems at the start.  It means we might
    // do a tiny bit more searching.
    Node* searchEndNodeAfterWrap = spellingSearchRange->endContainer();
    int searchEndOffsetAfterWrap = spellingSearchRange->endOffset();
    
    int misspellingOffset = 0;
    GrammarDetail grammarDetail;
    int grammarPhraseOffset = 0;
    RefPtr<Range> grammarSearchRange;
    String badGrammarPhrase;
    String misspelledWord;

    bool isSpelling = true;
    int foundOffset = 0;
    String foundItem;
    RefPtr<Range> firstMisspellingRange;
    if (unifiedTextCheckerEnabled()) {
        grammarSearchRange = spellingSearchRange->cloneRange(IGNORE_EXCEPTION);
        foundItem = TextCheckingHelper(client(), spellingSearchRange).findFirstMisspellingOrBadGrammar(isGrammarCheckingEnabled(), isSpelling, foundOffset, grammarDetail);
        if (isSpelling) {
            misspelledWord = foundItem;
            misspellingOffset = foundOffset;
        } else {
            badGrammarPhrase = foundItem;
            grammarPhraseOffset = foundOffset;
        }
    } else {
        misspelledWord = TextCheckingHelper(client(), spellingSearchRange).findFirstMisspelling(misspellingOffset, false, firstMisspellingRange);

#if USE(GRAMMAR_CHECKING)
        grammarSearchRange = spellingSearchRange->cloneRange(IGNORE_EXCEPTION);
        if (!misspelledWord.isEmpty()) {
            // Stop looking at start of next misspelled word
            CharacterIterator chars(grammarSearchRange.get());
            chars.advance(misspellingOffset);
            grammarSearchRange->setEnd(chars.range()->startContainer(), chars.range()->startOffset(), IGNORE_EXCEPTION);
        }
    
        if (isGrammarCheckingEnabled())
            badGrammarPhrase = TextCheckingHelper(client(), grammarSearchRange).findFirstBadGrammar(grammarDetail, grammarPhraseOffset, false);
#endif
    }
    
    // If we found neither bad grammar nor a misspelled word, wrap and try again (but don't bother if we started at the beginning of the
    // block rather than at a selection).
    if (startedWithSelection && !misspelledWord && !badGrammarPhrase) {
        spellingSearchRange->setStart(topNode, 0, IGNORE_EXCEPTION);
        // going until the end of the very first chunk we tested is far enough
        spellingSearchRange->setEnd(searchEndNodeAfterWrap, searchEndOffsetAfterWrap, IGNORE_EXCEPTION);
        
        if (unifiedTextCheckerEnabled()) {
            grammarSearchRange = spellingSearchRange->cloneRange(IGNORE_EXCEPTION);
            foundItem = TextCheckingHelper(client(), spellingSearchRange).findFirstMisspellingOrBadGrammar(isGrammarCheckingEnabled(), isSpelling, foundOffset, grammarDetail);
            if (isSpelling) {
                misspelledWord = foundItem;
                misspellingOffset = foundOffset;
            } else {
                badGrammarPhrase = foundItem;
                grammarPhraseOffset = foundOffset;
            }
        } else {
            misspelledWord = TextCheckingHelper(client(), spellingSearchRange).findFirstMisspelling(misspellingOffset, false, firstMisspellingRange);

#if USE(GRAMMAR_CHECKING)
            grammarSearchRange = spellingSearchRange->cloneRange(IGNORE_EXCEPTION);
            if (!misspelledWord.isEmpty()) {
                // Stop looking at start of next misspelled word
                CharacterIterator chars(grammarSearchRange.get());
                chars.advance(misspellingOffset);
                grammarSearchRange->setEnd(chars.range()->startContainer(), chars.range()->startOffset(), IGNORE_EXCEPTION);
            }

            if (isGrammarCheckingEnabled())
                badGrammarPhrase = TextCheckingHelper(client(), grammarSearchRange).findFirstBadGrammar(grammarDetail, grammarPhraseOffset, false);
#endif
        }
    }
    
#if !USE(GRAMMAR_CHECKING)
    ASSERT(badGrammarPhrase.isEmpty());
    UNUSED_PARAM(grammarPhraseOffset);
#else
    if (!badGrammarPhrase.isEmpty()) {
        // We found bad grammar. Since we only searched for bad grammar up to the first misspelled word, the bad grammar
        // takes precedence and we ignore any potential misspelled word. Select the grammar detail, update the spelling
        // panel, and store a marker so we draw the green squiggle later.
        
        ASSERT(badGrammarPhrase.length() > 0);
        ASSERT(grammarDetail.location != -1 && grammarDetail.length > 0);
        
        // FIXME 4859190: This gets confused with doubled punctuation at the end of a paragraph
        RefPtr<Range> badGrammarRange = TextIterator::subrange(grammarSearchRange.get(), grammarPhraseOffset + grammarDetail.location, grammarDetail.length);
        m_frame.selection().setSelection(VisibleSelection(badGrammarRange.get(), SEL_DEFAULT_AFFINITY));
        m_frame.selection().revealSelection();
        
        client()->updateSpellingUIWithGrammarString(badGrammarPhrase, grammarDetail);
        document().markers().addMarker(badGrammarRange.get(), DocumentMarker::Grammar, grammarDetail.userDescription);
    } else
#endif
    if (!misspelledWord.isEmpty()) {
        // We found a misspelling, but not any earlier bad grammar. Select the misspelling, update the spelling panel, and store
        // a marker so we draw the red squiggle later.
        
        RefPtr<Range> misspellingRange = TextIterator::subrange(spellingSearchRange.get(), misspellingOffset, misspelledWord.length());
        m_frame.selection().setSelection(VisibleSelection(misspellingRange.get(), DOWNSTREAM));
        m_frame.selection().revealSelection();
        
        client()->updateSpellingUIWithMisspelledWord(misspelledWord);
        document().markers().addMarker(misspellingRange.get(), DocumentMarker::Spelling);
    }
}

String Editor::misspelledWordAtCaretOrRange(Node* clickedNode) const
{
    if (!isContinuousSpellCheckingEnabled() || !clickedNode || !isSpellCheckingEnabledFor(clickedNode))
        return String();

    VisibleSelection selection = m_frame.selection().selection();
    if (!selection.isContentEditable() || selection.isNone())
        return String();

    VisibleSelection wordSelection(selection.base());
    wordSelection.expandUsingGranularity(WordGranularity);
    RefPtr<Range> wordRange = wordSelection.toNormalizedRange();

    // In compliance with GTK+ applications, additionally allow to provide suggestions when the current
    // selection exactly match the word selection.
    if (selection.isRange() && !areRangesEqual(wordRange.get(), selection.toNormalizedRange().get()))
        return String();

    String word = wordRange->text();
    if (word.isEmpty() || !client())
        return String();

    int wordLength = word.length();
    int misspellingLocation = -1;
    int misspellingLength = 0;
    textChecker()->checkSpellingOfString(word.characters(), wordLength, &misspellingLocation, &misspellingLength);

    return misspellingLength == wordLength ? word : String();
}

String Editor::misspelledSelectionString() const
{
    String selectedString = selectedText();
    int length = selectedString.length();
    if (!length || !client())
        return String();

    int misspellingLocation = -1;
    int misspellingLength = 0;
    textChecker()->checkSpellingOfString(selectedString.characters(), length, &misspellingLocation, &misspellingLength);
    
    // The selection only counts as misspelled if the selected text is exactly one misspelled word
    if (misspellingLength != length)
        return String();
    
    // Update the spelling panel to be displaying this error (whether or not the spelling panel is on screen).
    // This is necessary to make a subsequent call to [NSSpellChecker ignoreWord:inSpellDocumentWithTag:] work
    // correctly; that call behaves differently based on whether the spelling panel is displaying a misspelling
    // or a grammar error.
    client()->updateSpellingUIWithMisspelledWord(selectedString);
    
    return selectedString;
}

bool Editor::isSelectionUngrammatical()
{
#if USE(GRAMMAR_CHECKING)
    RefPtr<Range> range = m_frame.selection().toNormalizedRange();
    if (!range)
        return false;
    return TextCheckingHelper(client(), range).isUngrammatical();
#else
    return false;
#endif
}

Vector<String> Editor::guessesForMisspelledWord(const String& word) const
{
    ASSERT(word.length());

    Vector<String> guesses;
    if (client())
        textChecker()->getGuessesForWord(word, String(), guesses);
    return guesses;
}

Vector<String> Editor::guessesForMisspelledOrUngrammatical(bool& misspelled, bool& ungrammatical)
{
    if (unifiedTextCheckerEnabled()) {
        RefPtr<Range> range;
        FrameSelection& frameSelection = m_frame.selection();
        if (frameSelection.isCaret() && behavior().shouldAllowSpellingSuggestionsWithoutSelection()) {
            VisibleSelection wordSelection = VisibleSelection(frameSelection.base());
            wordSelection.expandUsingGranularity(WordGranularity);
            range = wordSelection.toNormalizedRange();
        } else
            range = frameSelection.toNormalizedRange();
        if (!range)
            return Vector<String>();
        return TextCheckingHelper(client(), range).guessesForMisspelledOrUngrammaticalRange(isGrammarCheckingEnabled(), misspelled, ungrammatical);
    }

    String misspelledWord = behavior().shouldAllowSpellingSuggestionsWithoutSelection() ? misspelledWordAtCaretOrRange(document().focusedElement()) : misspelledSelectionString();
    misspelled = !misspelledWord.isEmpty();
    // Only unified text checker supports guesses for ungrammatical phrases.
    ungrammatical = false;

    if (misspelled)
        return guessesForMisspelledWord(misspelledWord);
    return Vector<String>();
}

void Editor::showSpellingGuessPanel()
{
    if (!client()) {
        LOG_ERROR("No NSSpellChecker");
        return;
    }

    if (client()->spellingUIIsShowing()) {
        client()->showSpellingUI(false);
        return;
    }
    
    advanceToNextMisspelling(true);
    client()->showSpellingUI(true);
}

bool Editor::spellingPanelIsShowing()
{
    if (!client())
        return false;
    return client()->spellingUIIsShowing();
}

void Editor::clearMisspellingsAndBadGrammar(const VisibleSelection &movingSelection)
{
    RefPtr<Range> selectedRange = movingSelection.toNormalizedRange();
    if (selectedRange) {
        document().markers().removeMarkers(selectedRange.get(), DocumentMarker::Spelling);
        document().markers().removeMarkers(selectedRange.get(), DocumentMarker::Grammar);
    }
}

void Editor::markMisspellingsAndBadGrammar(const VisibleSelection &movingSelection)
{
    markMisspellingsAndBadGrammar(movingSelection, isContinuousSpellCheckingEnabled() && isGrammarCheckingEnabled(), movingSelection);
}

void Editor::markMisspellingsAfterTypingToWord(const VisiblePosition &wordStart, const VisibleSelection& selectionAfterTyping, bool doReplacement)
{
#if !USE(AUTOMATIC_TEXT_REPLACEMENT)
    UNUSED_PARAM(doReplacement);
#endif

    if (unifiedTextCheckerEnabled()) {
        m_alternativeTextController->applyPendingCorrection(selectionAfterTyping);

        TextCheckingTypeMask textCheckingOptions = 0;

        if (isContinuousSpellCheckingEnabled())
            textCheckingOptions |= TextCheckingTypeSpelling;

#if USE(AUTOMATIC_TEXT_REPLACEMENT)
        if (doReplacement
            && (isAutomaticQuoteSubstitutionEnabled()
                || isAutomaticLinkDetectionEnabled()
                || isAutomaticDashSubstitutionEnabled()
                || isAutomaticTextReplacementEnabled()
                || ((textCheckingOptions & TextCheckingTypeSpelling) && isAutomaticSpellingCorrectionEnabled())))
            textCheckingOptions |= TextCheckingTypeReplacement;
#endif
        if (!(textCheckingOptions & (TextCheckingTypeSpelling | TextCheckingTypeReplacement)))
            return;

        if (isGrammarCheckingEnabled())
            textCheckingOptions |= TextCheckingTypeGrammar;

        VisibleSelection adjacentWords = VisibleSelection(startOfWord(wordStart, LeftWordIfOnBoundary), endOfWord(wordStart, RightWordIfOnBoundary));
        if (textCheckingOptions & TextCheckingTypeGrammar) {
            VisibleSelection selectedSentence = VisibleSelection(startOfSentence(wordStart), endOfSentence(wordStart));
            markAllMisspellingsAndBadGrammarInRanges(textCheckingOptions, adjacentWords.toNormalizedRange().get(), selectedSentence.toNormalizedRange().get());
        } else
            markAllMisspellingsAndBadGrammarInRanges(textCheckingOptions, adjacentWords.toNormalizedRange().get(), adjacentWords.toNormalizedRange().get());
        return;
    }

    if (!isContinuousSpellCheckingEnabled())
        return;

    // Check spelling of one word
    RefPtr<Range> misspellingRange;
    markMisspellings(VisibleSelection(startOfWord(wordStart, LeftWordIfOnBoundary), endOfWord(wordStart, RightWordIfOnBoundary)), misspellingRange);

    // Autocorrect the misspelled word.
    if (!misspellingRange)
        return;
    
    // Get the misspelled word.
    const String misspelledWord = plainText(misspellingRange.get());
    String autocorrectedString = textChecker()->getAutoCorrectSuggestionForMisspelledWord(misspelledWord);

    // If autocorrected word is non empty, replace the misspelled word by this word.
    if (!autocorrectedString.isEmpty()) {
        VisibleSelection newSelection(misspellingRange.get(), DOWNSTREAM);
        if (newSelection != m_frame.selection().selection()) {
            if (!m_frame.selection().shouldChangeSelection(newSelection))
                return;
            m_frame.selection().setSelection(newSelection);
        }

        if (!m_frame.editor().shouldInsertText(autocorrectedString, misspellingRange.get(), EditorInsertActionTyped))
            return;
        m_frame.editor().replaceSelectionWithText(autocorrectedString, false, false);

        // Reset the charet one character further.
        m_frame.selection().moveTo(m_frame.selection().end());
        m_frame.selection().modify(FrameSelection::AlterationMove, DirectionForward, CharacterGranularity);
    }

    if (!isGrammarCheckingEnabled())
        return;
    
    // Check grammar of entire sentence
    markBadGrammar(VisibleSelection(startOfSentence(wordStart), endOfSentence(wordStart)));
}
    
void Editor::markMisspellingsOrBadGrammar(const VisibleSelection& selection, bool checkSpelling, RefPtr<Range>& firstMisspellingRange)
{
    // This function is called with a selection already expanded to word boundaries.
    // Might be nice to assert that here.
    
    // This function is used only for as-you-type checking, so if that's off we do nothing. Note that
    // grammar checking can only be on if spell checking is also on.
    if (!isContinuousSpellCheckingEnabled())
        return;
    
    RefPtr<Range> searchRange(selection.toNormalizedRange());
    if (!searchRange)
        return;
    
    // If we're not in an editable node, bail.
    Node* editableNode = searchRange->startContainer();
    if (!editableNode || !editableNode->rendererIsEditable())
        return;

    if (!isSpellCheckingEnabledFor(editableNode))
        return;

    // Get the spell checker if it is available
    if (!client())
        return;
    
    TextCheckingHelper checker(client(), searchRange);
    if (checkSpelling)
        checker.markAllMisspellings(firstMisspellingRange);
    else {
#if USE(GRAMMAR_CHECKING)
        if (isGrammarCheckingEnabled())
            checker.markAllBadGrammar();
#else
        ASSERT_NOT_REACHED();
#endif
    }    
}

bool Editor::isSpellCheckingEnabledFor(Node* node) const
{
    if (!node)
        return false;
    const Element* focusedElement = node->isElementNode() ? toElement(node) : node->parentElement();
    if (!focusedElement)
        return false;
    return focusedElement->isSpellCheckingEnabled();
}

bool Editor::isSpellCheckingEnabledInFocusedNode() const
{
    return isSpellCheckingEnabledFor(m_frame.selection().start().deprecatedNode());
}

void Editor::markMisspellings(const VisibleSelection& selection, RefPtr<Range>& firstMisspellingRange)
{
    markMisspellingsOrBadGrammar(selection, true, firstMisspellingRange);
}
    
void Editor::markBadGrammar(const VisibleSelection& selection)
{
#if USE(GRAMMAR_CHECKING)
    RefPtr<Range> firstMisspellingRange;
    markMisspellingsOrBadGrammar(selection, false, firstMisspellingRange);
#else
    ASSERT_NOT_REACHED();
#endif
}

void Editor::markAllMisspellingsAndBadGrammarInRanges(TextCheckingTypeMask textCheckingOptions, Range* spellingRange, Range* grammarRange)
{
    ASSERT(unifiedTextCheckerEnabled());

    // There shouldn't be pending autocorrection at this moment.
    ASSERT(!m_alternativeTextController->hasPendingCorrection());

    bool shouldMarkGrammar = textCheckingOptions & TextCheckingTypeGrammar;
    bool shouldShowCorrectionPanel = textCheckingOptions & TextCheckingTypeShowCorrectionPanel;

    // This function is called with selections already expanded to word boundaries.
    if (!client() || !spellingRange || (shouldMarkGrammar && !grammarRange))
        return;

    // If we're not in an editable node, bail.
    Node* editableNode = spellingRange->startContainer();
    if (!editableNode || !editableNode->rendererIsEditable())
        return;

    if (!isSpellCheckingEnabledFor(editableNode))
        return;

    Range* rangeToCheck = shouldMarkGrammar ? grammarRange : spellingRange;
    TextCheckingParagraph paragraphToCheck(rangeToCheck);
    if (paragraphToCheck.isRangeEmpty() || paragraphToCheck.isEmpty())
        return;
    RefPtr<Range> paragraphRange = paragraphToCheck.paragraphRange();

    bool asynchronous = m_frame.settings().asynchronousSpellCheckingEnabled() && !shouldShowCorrectionPanel;

    // In asynchronous mode, we intentionally check paragraph-wide sentence.
    RefPtr<SpellCheckRequest> request = SpellCheckRequest::create(resolveTextCheckingTypeMask(textCheckingOptions), TextCheckingProcessIncremental, asynchronous ? paragraphRange : rangeToCheck, paragraphRange);

    if (asynchronous) {
        m_spellChecker->requestCheckingFor(request);
        return;
    }

    Vector<TextCheckingResult> results;
    checkTextOfParagraph(textChecker(), paragraphToCheck.textCharacters(), paragraphToCheck.textLength(),
        resolveTextCheckingTypeMask(textCheckingOptions), results);
    markAndReplaceFor(request, results);
}

static bool isAutomaticTextReplacementType(TextCheckingType type)
{
    switch (type) {
    case TextCheckingTypeNone:
    case TextCheckingTypeSpelling:
    case TextCheckingTypeGrammar:
        return false;
    case TextCheckingTypeLink:
    case TextCheckingTypeQuote:
    case TextCheckingTypeDash:
    case TextCheckingTypeReplacement:
    case TextCheckingTypeCorrection:
    case TextCheckingTypeShowCorrectionPanel:
        return true;
    }
    ASSERT_NOT_REACHED();
    return false;
}

static void correctSpellcheckingPreservingTextCheckingParagraph(TextCheckingParagraph& paragraph, PassRefPtr<Range> rangeToReplace, const String& replacement, int resultLocation, int resultLength)
{
    ContainerNode* scope = toContainerNode(highestAncestor(paragraph.paragraphRange()->startContainer()));

    size_t paragraphLocation;
    size_t paragraphLength;
    TextIterator::getLocationAndLengthFromRange(scope, paragraph.paragraphRange().get(), paragraphLocation, paragraphLength);

    applyCommand(SpellingCorrectionCommand::create(rangeToReplace, replacement));

    // TextCheckingParagraph may be orphaned after SpellingCorrectionCommand mutated DOM.
    // See <rdar://10305315>, http://webkit.org/b/89526.

    RefPtr<Range> newParagraphRange = TextIterator::rangeFromLocationAndLength(scope, paragraphLocation, paragraphLength + replacement.length() - resultLength);

    paragraph = TextCheckingParagraph(TextIterator::subrange(newParagraphRange.get(), resultLocation, replacement.length()), newParagraphRange);
}

void Editor::markAndReplaceFor(PassRefPtr<SpellCheckRequest> request, const Vector<TextCheckingResult>& results)
{
    ASSERT(request);

    TextCheckingTypeMask textCheckingOptions = request->data().mask();
    TextCheckingParagraph paragraph(request->checkingRange(), request->paragraphRange());

    const bool shouldMarkSpelling = textCheckingOptions & TextCheckingTypeSpelling;
    const bool shouldMarkGrammar = textCheckingOptions & TextCheckingTypeGrammar;
    const bool shouldMarkLink = textCheckingOptions & TextCheckingTypeLink;
    const bool shouldPerformReplacement = textCheckingOptions & TextCheckingTypeReplacement;
    const bool shouldShowCorrectionPanel = textCheckingOptions & TextCheckingTypeShowCorrectionPanel;
    const bool shouldCheckForCorrection = shouldShowCorrectionPanel || (textCheckingOptions & TextCheckingTypeCorrection);
#if !USE(AUTOCORRECTION_PANEL)
    ASSERT(!shouldShowCorrectionPanel);
#endif

    // Expand the range to encompass entire paragraphs, since text checking needs that much context.
    int selectionOffset = 0;
    bool useAmbiguousBoundaryOffset = false;
    bool selectionChanged = false;
    bool restoreSelectionAfterChange = false;
    bool adjustSelectionForParagraphBoundaries = false;

    if (shouldPerformReplacement || shouldMarkSpelling || shouldCheckForCorrection) {
        if (m_frame.selection().selectionType() == VisibleSelection::CaretSelection) {
            // Attempt to save the caret position so we can restore it later if needed
            Position caretPosition = m_frame.selection().end();
            selectionOffset = paragraph.offsetTo(caretPosition, ASSERT_NO_EXCEPTION);
            restoreSelectionAfterChange = true;
            if (selectionOffset > 0 && (selectionOffset > paragraph.textLength() || paragraph.textCharAt(selectionOffset - 1) == newlineCharacter))
                adjustSelectionForParagraphBoundaries = true;
            if (selectionOffset > 0 && selectionOffset <= paragraph.textLength() && isAmbiguousBoundaryCharacter(paragraph.textCharAt(selectionOffset - 1)))
                useAmbiguousBoundaryOffset = true;
        }
    }

    int offsetDueToReplacement = 0;

    for (unsigned i = 0; i < results.size(); i++) {
        const int spellingRangeEndOffset = paragraph.checkingEnd() + offsetDueToReplacement;
        const TextCheckingType resultType = results[i].type;
        const int resultLocation = results[i].location + offsetDueToReplacement;
        const int resultLength = results[i].length;
        const int resultEndLocation = resultLocation + resultLength;
        const String& replacement = results[i].replacement;
        const bool resultEndsAtAmbiguousBoundary = useAmbiguousBoundaryOffset && resultEndLocation == selectionOffset - 1;

        // Only mark misspelling if:
        // 1. Current text checking isn't done for autocorrection, in which case shouldMarkSpelling is false.
        // 2. Result falls within spellingRange.
        // 3. The word in question doesn't end at an ambiguous boundary. For instance, we would not mark
        //    "wouldn'" as misspelled right after apostrophe is typed.
        if (shouldMarkSpelling && !shouldShowCorrectionPanel && resultType == TextCheckingTypeSpelling
            && resultLocation >= paragraph.checkingStart() && resultEndLocation <= spellingRangeEndOffset && !resultEndsAtAmbiguousBoundary) {
            ASSERT(resultLength > 0 && resultLocation >= 0);
            RefPtr<Range> misspellingRange = paragraph.subrange(resultLocation, resultLength);
            if (!m_alternativeTextController->isSpellingMarkerAllowed(misspellingRange))
                continue;
            misspellingRange->startContainer()->document().markers().addMarker(misspellingRange.get(), DocumentMarker::Spelling, replacement);
        } else if (shouldMarkGrammar && resultType == TextCheckingTypeGrammar && paragraph.checkingRangeCovers(resultLocation, resultLength)) {
            ASSERT(resultLength > 0 && resultLocation >= 0);
            const Vector<GrammarDetail>& details = results[i].details;
            for (unsigned j = 0; j < details.size(); j++) {
                const GrammarDetail& detail = details[j];
                ASSERT(detail.length > 0 && detail.location >= 0);
                if (paragraph.checkingRangeCovers(resultLocation + detail.location, detail.length)) {
                    RefPtr<Range> badGrammarRange = paragraph.subrange(resultLocation + detail.location, detail.length);
                    badGrammarRange->startContainer()->document().markers().addMarker(badGrammarRange.get(), DocumentMarker::Grammar, detail.userDescription);
                }
            }
        } else if (resultEndLocation <= spellingRangeEndOffset && resultEndLocation >= paragraph.checkingStart()
            && isAutomaticTextReplacementType(resultType)) {
            // In this case the result range just has to touch the spelling range, so we can handle replacing non-word text such as punctuation.
            ASSERT(resultLength > 0 && resultLocation >= 0);

            if (shouldShowCorrectionPanel && (resultEndLocation < spellingRangeEndOffset
                || !(resultType & (TextCheckingTypeReplacement | TextCheckingTypeCorrection))))
                continue;

            // Apply replacement if:
            // 1. The replacement length is non-zero.
            // 2. The result doesn't end at an ambiguous boundary.
            //    (FIXME: this is required until 6853027 is fixed and text checking can do this for us
            bool doReplacement = replacement.length() > 0 && !resultEndsAtAmbiguousBoundary;
            RefPtr<Range> rangeToReplace = paragraph.subrange(resultLocation, resultLength);

            // adding links should be done only immediately after they are typed
            if (resultType == TextCheckingTypeLink && selectionOffset != resultEndLocation + 1)
                continue;

            if (!(shouldPerformReplacement || shouldCheckForCorrection || shouldMarkLink) || !doReplacement)
                continue;

            String replacedString = plainText(rangeToReplace.get());
            const bool existingMarkersPermitReplacement = m_alternativeTextController->processMarkersOnTextToBeReplacedByResult(&results[i], rangeToReplace.get(), replacedString);
            if (!existingMarkersPermitReplacement)
                continue;

            if (shouldShowCorrectionPanel) {
                if (resultEndLocation == spellingRangeEndOffset) {
                    // We only show the correction panel on the last word.
                    m_alternativeTextController->show(rangeToReplace, replacement);
                    break;
                }
                // If this function is called for showing correction panel, we ignore other correction or replacement.
                continue;
            }

            VisibleSelection selectionToReplace(rangeToReplace.get(), DOWNSTREAM);
            if (selectionToReplace != m_frame.selection().selection()) {
                if (!m_frame.selection().shouldChangeSelection(selectionToReplace))
                    continue;
            }

            if (resultType == TextCheckingTypeLink) {
                m_frame.selection().setSelection(selectionToReplace);
                selectionChanged = true;
                restoreSelectionAfterChange = false;
                if (canEditRichly())
                    applyCommand(CreateLinkCommand::create(document(), replacement));
            } else if (canEdit() && shouldInsertText(replacement, rangeToReplace.get(), EditorInsertActionTyped)) {
                correctSpellcheckingPreservingTextCheckingParagraph(paragraph, rangeToReplace, replacement, resultLocation, resultLength);

                if (AXObjectCache* cache = document().existingAXObjectCache()) {
                    if (Element* root = m_frame.selection().selection().rootEditableElement())
                        cache->postNotification(root, AXObjectCache::AXAutocorrectionOccured);
                }

                // Skip all other results for the replaced text.
                while (i + 1 < results.size() && results[i + 1].location + offsetDueToReplacement <= resultLocation)
                    i++;

                selectionChanged = true;
                offsetDueToReplacement += replacement.length() - resultLength;
                if (resultLocation < selectionOffset)
                    selectionOffset += replacement.length() - resultLength;

                // Add a marker so that corrections can easily be undone and won't be re-corrected.
                if (resultType == TextCheckingTypeCorrection)
                    m_alternativeTextController->markCorrection(paragraph.subrange(resultLocation, replacement.length()), replacedString);
            }
        }
    }

    if (selectionChanged) {
        TextCheckingParagraph extendedParagraph(paragraph);
        // Restore the caret position if we have made any replacements
        extendedParagraph.expandRangeToNextEnd();
        if (restoreSelectionAfterChange && selectionOffset >= 0 && selectionOffset <= extendedParagraph.rangeLength()) {
            RefPtr<Range> selectionRange = extendedParagraph.subrange(0, selectionOffset);
            m_frame.selection().moveTo(selectionRange->endPosition(), DOWNSTREAM);
            if (adjustSelectionForParagraphBoundaries)
                m_frame.selection().modify(FrameSelection::AlterationMove, DirectionForward, CharacterGranularity);
        } else {
            // If this fails for any reason, the fallback is to go one position beyond the last replacement
            m_frame.selection().moveTo(m_frame.selection().end());
            m_frame.selection().modify(FrameSelection::AlterationMove, DirectionForward, CharacterGranularity);
        }
    }
}

void Editor::changeBackToReplacedString(const String& replacedString)
{
    ASSERT(unifiedTextCheckerEnabled());

    if (replacedString.isEmpty())
        return;

    RefPtr<Range> selection = selectedRange();
    if (!shouldInsertText(replacedString, selection.get(), EditorInsertActionPasted))
        return;
    
    m_alternativeTextController->recordAutocorrectionResponseReversed(replacedString, selection);
    TextCheckingParagraph paragraph(selection);
    replaceSelectionWithText(replacedString, false, false);
    RefPtr<Range> changedRange = paragraph.subrange(paragraph.checkingStart(), replacedString.length());
    changedRange->startContainer()->document().markers().addMarker(changedRange.get(), DocumentMarker::Replacement, String());
    m_alternativeTextController->markReversed(changedRange.get());
}


void Editor::markMisspellingsAndBadGrammar(const VisibleSelection& spellingSelection, bool markGrammar, const VisibleSelection& grammarSelection)
{
    if (unifiedTextCheckerEnabled()) {
        if (!isContinuousSpellCheckingEnabled())
            return;

        // markMisspellingsAndBadGrammar() is triggered by selection change, in which case we check spelling and grammar, but don't autocorrect misspellings.
        TextCheckingTypeMask textCheckingOptions = TextCheckingTypeSpelling;
        if (markGrammar && isGrammarCheckingEnabled())
            textCheckingOptions |= TextCheckingTypeGrammar;
        markAllMisspellingsAndBadGrammarInRanges(textCheckingOptions, spellingSelection.toNormalizedRange().get(), grammarSelection.toNormalizedRange().get());
        return;
    }

    RefPtr<Range> firstMisspellingRange;
    markMisspellings(spellingSelection, firstMisspellingRange);
    if (markGrammar)
        markBadGrammar(grammarSelection);
}

void Editor::unappliedSpellCorrection(const VisibleSelection& selectionOfCorrected, const String& corrected, const String& correction)
{
    m_alternativeTextController->respondToUnappliedSpellCorrection(selectionOfCorrected, corrected, correction);
}

void Editor::updateMarkersForWordsAffectedByEditing(bool doNotRemoveIfSelectionAtWordBoundary)
{
    if (!document().markers().hasMarkers())
        return;

    if (!m_alternativeTextController->shouldRemoveMarkersUponEditing() && (!textChecker() || textChecker()->shouldEraseMarkersAfterChangeSelection(TextCheckingTypeSpelling)))
        return;

    // We want to remove the markers from a word if an editing command will change the word. This can happen in one of
    // several scenarios:
    // 1. Insert in the middle of a word.
    // 2. Appending non whitespace at the beginning of word.
    // 3. Appending non whitespace at the end of word.
    // Note that, appending only whitespaces at the beginning or end of word won't change the word, so we don't need to
    // remove the markers on that word.
    // Of course, if current selection is a range, we potentially will edit two words that fall on the boundaries of
    // selection, and remove words between the selection boundaries.
    //
    VisiblePosition startOfSelection = m_frame.selection().selection().start();
    VisiblePosition endOfSelection = m_frame.selection().selection().end();
    if (startOfSelection.isNull())
        return;
    // First word is the word that ends after or on the start of selection.
    VisiblePosition startOfFirstWord = startOfWord(startOfSelection, LeftWordIfOnBoundary);
    VisiblePosition endOfFirstWord = endOfWord(startOfSelection, LeftWordIfOnBoundary);
    // Last word is the word that begins before or on the end of selection
    VisiblePosition startOfLastWord = startOfWord(endOfSelection, RightWordIfOnBoundary);
    VisiblePosition endOfLastWord = endOfWord(endOfSelection, RightWordIfOnBoundary);

    if (startOfFirstWord.isNull()) {
        startOfFirstWord = startOfWord(startOfSelection, RightWordIfOnBoundary);
        endOfFirstWord = endOfWord(startOfSelection, RightWordIfOnBoundary);
    }
    
    if (endOfLastWord.isNull()) {
        startOfLastWord = startOfWord(endOfSelection, LeftWordIfOnBoundary);
        endOfLastWord = endOfWord(endOfSelection, LeftWordIfOnBoundary);
    }

    // If doNotRemoveIfSelectionAtWordBoundary is true, and first word ends at the start of selection,
    // we choose next word as the first word.
    if (doNotRemoveIfSelectionAtWordBoundary && endOfFirstWord == startOfSelection) {
        startOfFirstWord = nextWordPosition(startOfFirstWord);
        endOfFirstWord = endOfWord(startOfFirstWord, RightWordIfOnBoundary);
        if (startOfFirstWord == endOfSelection)
            return;
    }

    // If doNotRemoveIfSelectionAtWordBoundary is true, and last word begins at the end of selection,
    // we choose previous word as the last word.
    if (doNotRemoveIfSelectionAtWordBoundary && startOfLastWord == endOfSelection) {
        startOfLastWord = previousWordPosition(startOfLastWord);
        endOfLastWord = endOfWord(startOfLastWord, RightWordIfOnBoundary);
        if (endOfLastWord == startOfSelection)
            return;
    }

    if (startOfFirstWord.isNull() || endOfFirstWord.isNull() || startOfLastWord.isNull() || endOfLastWord.isNull())
        return;

    // Now we remove markers on everything between startOfFirstWord and endOfLastWord.
    // However, if an autocorrection change a single word to multiple words, we want to remove correction mark from all the
    // resulted words even we only edit one of them. For example, assuming autocorrection changes "avantgarde" to "avant
    // garde", we will have CorrectionIndicator marker on both words and on the whitespace between them. If we then edit garde,
    // we would like to remove the marker from word "avant" and whitespace as well. So we need to get the continous range of
    // of marker that contains the word in question, and remove marker on that whole range.
    RefPtr<Range> wordRange = Range::create(document(), startOfFirstWord.deepEquivalent(), endOfLastWord.deepEquivalent());

    Vector<DocumentMarker*> markers = document().markers().markersInRange(wordRange.get(), DocumentMarker::DictationAlternatives);
    for (size_t i = 0; i < markers.size(); ++i)
        m_alternativeTextController->removeDictationAlternativesForMarker(markers[i]);

    document().markers().removeMarkers(wordRange.get(), DocumentMarker::Spelling | DocumentMarker::Grammar | DocumentMarker::CorrectionIndicator | DocumentMarker::SpellCheckingExemption | DocumentMarker::DictationAlternatives, DocumentMarkerController::RemovePartiallyOverlappingMarker);
    document().markers().clearDescriptionOnMarkersIntersectingRange(wordRange.get(), DocumentMarker::Replacement);
}

void Editor::deletedAutocorrectionAtPosition(const Position& position, const String& originalString)
{
    m_alternativeTextController->deletedAutocorrectionAtPosition(position, originalString);
}

PassRefPtr<Range> Editor::rangeForPoint(const IntPoint& windowPoint)
{
    Document* document = m_frame.documentAtPoint(windowPoint);
    if (!document)
        return 0;
    
    Frame* frame = document->frame();
    ASSERT(frame);
    FrameView* frameView = frame->view();
    if (!frameView)
        return 0;
    IntPoint framePoint = frameView->windowToContents(windowPoint);
    VisibleSelection selection(frame->visiblePositionForPoint(framePoint));

    return avoidIntersectionWithDeleteButtonController(selection.toNormalizedRange().get());
}

void Editor::revealSelectionAfterEditingOperation(const ScrollAlignment& alignment, RevealExtentOption revealExtentOption)
{
    if (m_ignoreCompositionSelectionChange)
        return;

    m_frame.selection().revealSelection(alignment, revealExtentOption);
}

void Editor::setIgnoreCompositionSelectionChange(bool ignore)
{
    if (m_ignoreCompositionSelectionChange == ignore)
        return;

    m_ignoreCompositionSelectionChange = ignore;
    if (!ignore)
        revealSelectionAfterEditingOperation(ScrollAlignment::alignToEdgeIfNeeded, RevealExtent);
}

PassRefPtr<Range> Editor::compositionRange() const
{
    if (!m_compositionNode)
        return 0;
    unsigned length = m_compositionNode->length();
    unsigned start = std::min(m_compositionStart, length);
    unsigned end = std::min(std::max(start, m_compositionEnd), length);
    if (start >= end)
        return 0;
    return Range::create(m_compositionNode->document(), m_compositionNode.get(), start, m_compositionNode.get(), end);
}

bool Editor::getCompositionSelection(unsigned& selectionStart, unsigned& selectionEnd) const
{
    if (!m_compositionNode)
        return false;
    Position start = m_frame.selection().start();
    if (start.deprecatedNode() != m_compositionNode)
        return false;
    Position end = m_frame.selection().end();
    if (end.deprecatedNode() != m_compositionNode)
        return false;

    if (static_cast<unsigned>(start.deprecatedEditingOffset()) < m_compositionStart)
        return false;
    if (static_cast<unsigned>(end.deprecatedEditingOffset()) > m_compositionEnd)
        return false;

    selectionStart = start.deprecatedEditingOffset() - m_compositionStart;
    selectionEnd = start.deprecatedEditingOffset() - m_compositionEnd;
    return true;
}

void Editor::transpose()
{
    if (!canEdit())
        return;

    VisibleSelection selection = m_frame.selection().selection();
    if (!selection.isCaret())
        return;

    // Make a selection that goes back one character and forward two characters.
    VisiblePosition caret = selection.visibleStart();
    VisiblePosition next = isEndOfParagraph(caret) ? caret : caret.next();
    VisiblePosition previous = next.previous();
    if (next == previous)
        return;
    previous = previous.previous();
    if (!inSameParagraph(next, previous))
        return;
    RefPtr<Range> range = makeRange(previous, next);
    if (!range)
        return;
    VisibleSelection newSelection(range.get(), DOWNSTREAM);

    // Transpose the two characters.
    String text = plainText(range.get());
    if (text.length() != 2)
        return;
    String transposed = text.right(1) + text.left(1);

    // Select the two characters.
    if (newSelection != m_frame.selection().selection()) {
        if (!m_frame.selection().shouldChangeSelection(newSelection))
            return;
        m_frame.selection().setSelection(newSelection);
    }

    // Insert the transposed characters.
    if (!shouldInsertText(transposed, range.get(), EditorInsertActionTyped))
        return;
    replaceSelectionWithText(transposed, false, false);
}

void Editor::addToKillRing(Range* range, bool prepend)
{
    if (m_shouldStartNewKillRingSequence)
        killRing().startNewSequence();

    String text = plainText(range);
    if (prepend)
        killRing().prepend(text);
    else
        killRing().append(text);
    m_shouldStartNewKillRingSequence = false;
}

void Editor::startAlternativeTextUITimer()
{
    m_alternativeTextController->startAlternativeTextUITimer(AlternativeTextTypeCorrection);
}

void Editor::handleAlternativeTextUIResult(const String& correction)
{
    m_alternativeTextController->handleAlternativeTextUIResult(correction);
}


void Editor::dismissCorrectionPanelAsIgnored()
{
    m_alternativeTextController->dismiss(ReasonForDismissingAlternativeTextIgnored);
}

void Editor::changeSelectionAfterCommand(const VisibleSelection& newSelection,  FrameSelection::SetSelectionOptions options)
{
    // If the new selection is orphaned, then don't update the selection.
    if (newSelection.start().isOrphan() || newSelection.end().isOrphan())
        return;

    // If there is no selection change, don't bother sending shouldChangeSelection, but still call setSelection,
    // because there is work that it must do in this situation.
    // The old selection can be invalid here and calling shouldChangeSelection can produce some strange calls.
    // See <rdar://problem/5729315> Some shouldChangeSelectedDOMRange contain Ranges for selections that are no longer valid
    bool selectionDidNotChangeDOMPosition = newSelection == m_frame.selection().selection();
    if (selectionDidNotChangeDOMPosition || m_frame.selection().shouldChangeSelection(newSelection))
        m_frame.selection().setSelection(newSelection, options);

    // Some editing operations change the selection visually without affecting its position within the DOM.
    // For example when you press return in the following (the caret is marked by ^):
    // <div contentEditable="true"><div>^Hello</div></div>
    // WebCore inserts <div><br></div> *before* the current block, which correctly moves the paragraph down but which doesn't
    // change the caret's DOM position (["hello", 0]). In these situations the above FrameSelection::setSelection call
    // does not call EditorClient::respondToChangedSelection(), which, on the Mac, sends selection change notifications and
    // starts a new kill ring sequence, but we want to do these things (matches AppKit).
    if (selectionDidNotChangeDOMPosition && client())
        client()->respondToChangedSelection(&m_frame);
}

String Editor::selectedText() const
{
    return selectedText(TextIteratorDefaultBehavior);
}

String Editor::selectedTextForClipboard() const
{
    if (m_frame.settings().selectionIncludesAltImageText())
        return selectedText(TextIteratorEmitsImageAltText);
    return selectedText();
}

String Editor::selectedText(TextIteratorBehavior behavior) const
{
    // We remove '\0' characters because they are not visibly rendered to the user.
    return plainText(m_frame.selection().toNormalizedRange().get(), behavior).replaceWithLiteral('\0', "");
}

static inline void collapseCaretWidth(IntRect& rect)
{
    // FIXME: Width adjustment doesn't work for rotated text.
    if (rect.width() == caretWidth)
        rect.setWidth(0);
    else if (rect.height() == caretWidth)
        rect.setHeight(0);
}

IntRect Editor::firstRectForRange(Range* range) const
{
    ASSERT(range->startContainer());
    ASSERT(range->endContainer());

    VisiblePosition startVisiblePosition(range->startPosition(), DOWNSTREAM);

    if (range->collapsed(ASSERT_NO_EXCEPTION)) {
        // FIXME: Getting caret rect and removing caret width is a very roundabout way to get collapsed range location.
        // In particular, width adjustment doesn't work for rotated text.
        IntRect startCaretRect = RenderedPosition(startVisiblePosition).absoluteRect();
        collapseCaretWidth(startCaretRect);
        return startCaretRect;
    }

    VisiblePosition endVisiblePosition(range->endPosition(), UPSTREAM);

    if (inSameLine(startVisiblePosition, endVisiblePosition))
        return enclosingIntRect(RenderObject::absoluteBoundingBoxRectForRange(range));

    LayoutUnit extraWidthToEndOfLine = 0;
    IntRect startCaretRect = RenderedPosition(startVisiblePosition).absoluteRect(&extraWidthToEndOfLine);
    if (startCaretRect == IntRect())
        return IntRect();

    // When start and end aren't on the same line, we want to go from start to the end of its line.
    bool textIsHorizontal = startCaretRect.width() == caretWidth;
    return textIsHorizontal ?
        IntRect(startCaretRect.x(),
            startCaretRect.y(),
            startCaretRect.width() + extraWidthToEndOfLine,
            startCaretRect.height()) :
        IntRect(startCaretRect.x(),
            startCaretRect.y(),
            startCaretRect.width(),
            startCaretRect.height() + extraWidthToEndOfLine);
}

bool Editor::shouldChangeSelection(const VisibleSelection& oldSelection, const VisibleSelection& newSelection, EAffinity affinity, bool stillSelecting) const
{
    return client() && client()->shouldChangeSelectedRange(oldSelection.toNormalizedRange().get(), newSelection.toNormalizedRange().get(), affinity, stillSelecting);
}

void Editor::computeAndSetTypingStyle(StylePropertySet* style, EditAction editingAction)
{
    if (!style || style->isEmpty()) {
        m_frame.selection().clearTypingStyle();
        return;
    }

    // Calculate the current typing style.
    RefPtr<EditingStyle> typingStyle;
    if (m_frame.selection().typingStyle()) {
        typingStyle = m_frame.selection().typingStyle()->copy();
        typingStyle->overrideWithStyle(style);
    } else
        typingStyle = EditingStyle::create(style);

    typingStyle->prepareToApplyAt(m_frame.selection().selection().visibleStart().deepEquivalent(), EditingStyle::PreserveWritingDirection);

    // Handle block styles, substracting these from the typing style.
    RefPtr<EditingStyle> blockStyle = typingStyle->extractAndRemoveBlockProperties();
    if (!blockStyle->isEmpty())
        applyCommand(ApplyStyleCommand::create(document(), blockStyle.get(), editingAction));

    // Set the remaining style as the typing style.
    m_frame.selection().setTypingStyle(typingStyle);
}

void Editor::textFieldDidBeginEditing(Element* e)
{
    if (client())
        client()->textFieldDidBeginEditing(e);
}

void Editor::textFieldDidEndEditing(Element* e)
{
    dismissCorrectionPanelAsIgnored();
    if (client())
        client()->textFieldDidEndEditing(e);
}

void Editor::textDidChangeInTextField(Element* e)
{
    if (client())
        client()->textDidChangeInTextField(e);
}

bool Editor::doTextFieldCommandFromEvent(Element* e, KeyboardEvent* ke)
{
    if (client())
        return client()->doTextFieldCommandFromEvent(e, ke);

    return false;
}

void Editor::textWillBeDeletedInTextField(Element* input)
{
    if (client())
        client()->textWillBeDeletedInTextField(input);
}

void Editor::textDidChangeInTextArea(Element* e)
{
    if (client())
        client()->textDidChangeInTextArea(e);
}

void Editor::applyEditingStyleToBodyElement() const
{
    RefPtr<NodeList> list = document().getElementsByTagName("body");
    unsigned len = list->length();
    for (unsigned i = 0; i < len; i++)
        applyEditingStyleToElement(toElement(list->item(i)));
}

void Editor::applyEditingStyleToElement(Element* element) const
{
    if (!element)
        return;
    ASSERT(element->isStyledElement());
    if (!element->isStyledElement())
        return;

    // Mutate using the CSSOM wrapper so we get the same event behavior as a script.
    CSSStyleDeclaration* style = static_cast<StyledElement*>(element)->style();
    style->setPropertyInternal(CSSPropertyWordWrap, "break-word", false, IGNORE_EXCEPTION);
    style->setPropertyInternal(CSSPropertyWebkitNbspMode, "space", false, IGNORE_EXCEPTION);
    style->setPropertyInternal(CSSPropertyWebkitLineBreak, "after-white-space", false, IGNORE_EXCEPTION);
}

bool Editor::findString(const String& target, FindOptions options)
{
    VisibleSelection selection = m_frame.selection().selection();

    RefPtr<Range> resultRange = rangeOfString(target, selection.firstRange().get(), options);

    if (!resultRange)
        return false;

    m_frame.selection().setSelection(VisibleSelection(resultRange.get(), DOWNSTREAM));
    m_frame.selection().revealSelection();
    return true;
}

PassRefPtr<Range> Editor::findStringAndScrollToVisible(const String& target, Range* previousMatch, FindOptions options)
{
    RefPtr<Range> nextMatch = rangeOfString(target, previousMatch, options);
    if (!nextMatch)
        return 0;

    nextMatch->firstNode()->renderer()->scrollRectToVisible(nextMatch->boundingBox(),
        ScrollAlignment::alignCenterIfNeeded, ScrollAlignment::alignCenterIfNeeded);

    return nextMatch.release();
}

PassRefPtr<Range> Editor::rangeOfString(const String& target, Range* referenceRange, FindOptions options)
{
    if (target.isEmpty())
        return 0;

    // Start from an edge of the reference range, if there's a reference range that's not in shadow content. Which edge
    // is used depends on whether we're searching forward or backward, and whether startInSelection is set.
    RefPtr<Range> searchRange(rangeOfContents(document()));

    bool forward = !(options & Backwards);
    bool startInReferenceRange = referenceRange && (options & StartInSelection);
    if (referenceRange) {
        if (forward)
            searchRange->setStart(startInReferenceRange ? referenceRange->startPosition() : referenceRange->endPosition());
        else
            searchRange->setEnd(startInReferenceRange ? referenceRange->endPosition() : referenceRange->startPosition());
    }

    RefPtr<Node> shadowTreeRoot = referenceRange && referenceRange->startContainer() ? referenceRange->startContainer()->nonBoundaryShadowTreeRootNode() : 0;
    if (shadowTreeRoot) {
        if (forward)
            searchRange->setEnd(shadowTreeRoot.get(), shadowTreeRoot->childNodeCount());
        else
            searchRange->setStart(shadowTreeRoot.get(), 0);
    }

    RefPtr<Range> resultRange(findPlainText(searchRange.get(), target, options));
    // If we started in the reference range and the found range exactly matches the reference range, find again.
    // Build a selection with the found range to remove collapsed whitespace.
    // Compare ranges instead of selection objects to ignore the way that the current selection was made.
    if (startInReferenceRange && areRangesEqual(VisibleSelection(resultRange.get()).toNormalizedRange().get(), referenceRange)) {
        searchRange = rangeOfContents(document());
        if (forward)
            searchRange->setStart(referenceRange->endPosition());
        else
            searchRange->setEnd(referenceRange->startPosition());

        if (shadowTreeRoot) {
            if (forward)
                searchRange->setEnd(shadowTreeRoot.get(), shadowTreeRoot->childNodeCount());
            else
                searchRange->setStart(shadowTreeRoot.get(), 0);
        }

        resultRange = findPlainText(searchRange.get(), target, options);
    }

    // If nothing was found in the shadow tree, search in main content following the shadow tree.
    if (resultRange->collapsed(ASSERT_NO_EXCEPTION) && shadowTreeRoot) {
        searchRange = rangeOfContents(document());
        if (forward)
            searchRange->setStartAfter(shadowTreeRoot->shadowHost());
        else
            searchRange->setEndBefore(shadowTreeRoot->shadowHost());

        resultRange = findPlainText(searchRange.get(), target, options);
    }

    // If we didn't find anything and we're wrapping, search again in the entire document (this will
    // redundantly re-search the area already searched in some cases).
    if (resultRange->collapsed(ASSERT_NO_EXCEPTION) && options & WrapAround) {
        searchRange = rangeOfContents(document());
        resultRange = findPlainText(searchRange.get(), target, options);
        // We used to return false here if we ended up with the same range that we started with
        // (e.g., the reference range was already the only instance of this text). But we decided that
        // this should be a success case instead, so we'll just fall through in that case.
    }

    return resultRange->collapsed(ASSERT_NO_EXCEPTION) ? 0 : resultRange.release();
}

static bool isFrameInRange(Frame* frame, Range* range)
{
    bool inRange = false;
    for (HTMLFrameOwnerElement* ownerElement = frame->ownerElement(); ownerElement; ownerElement = ownerElement->document().ownerElement()) {
        if (&ownerElement->document() == &range->ownerDocument()) {
            inRange = range->intersectsNode(ownerElement, IGNORE_EXCEPTION);
            break;
        }
    }
    return inRange;
}

unsigned Editor::countMatchesForText(const String& target, Range* range, FindOptions options, unsigned limit, bool markMatches, Vector<RefPtr<Range>>* matches)
{
    if (target.isEmpty())
        return 0;

    RefPtr<Range> searchRange;
    if (range) {
        if (&range->ownerDocument() == &document())
            searchRange = range;
        else if (!isFrameInRange(&m_frame, range))
            return 0;
    }
    if (!searchRange)
        searchRange = rangeOfContents(document());

    Node* originalEndContainer = searchRange->endContainer();
    int originalEndOffset = searchRange->endOffset();

    unsigned matchCount = 0;
    do {
        RefPtr<Range> resultRange(findPlainText(searchRange.get(), target, options & ~Backwards));
        if (resultRange->collapsed(IGNORE_EXCEPTION)) {
            if (!resultRange->startContainer()->isInShadowTree())
                break;

            searchRange->setStartAfter(resultRange->startContainer()->shadowHost(), IGNORE_EXCEPTION);
            searchRange->setEnd(originalEndContainer, originalEndOffset, IGNORE_EXCEPTION);
            continue;
        }

        ++matchCount;
        if (matches)
            matches->append(resultRange);
        
        if (markMatches)
            document().markers().addMarker(resultRange.get(), DocumentMarker::TextMatch);

        // Stop looking if we hit the specified limit. A limit of 0 means no limit.
        if (limit > 0 && matchCount >= limit)
            break;

        // Set the new start for the search range to be the end of the previous
        // result range. There is no need to use a VisiblePosition here,
        // since findPlainText will use a TextIterator to go over the visible
        // text nodes. 
        searchRange->setStart(resultRange->endContainer(IGNORE_EXCEPTION), resultRange->endOffset(IGNORE_EXCEPTION), IGNORE_EXCEPTION);

        Node* shadowTreeRoot = searchRange->shadowRoot();
        if (searchRange->collapsed(IGNORE_EXCEPTION) && shadowTreeRoot)
            searchRange->setEnd(shadowTreeRoot, shadowTreeRoot->childNodeCount(), IGNORE_EXCEPTION);
    } while (true);

    if (markMatches || matches) {
        // Do a "fake" paint in order to execute the code that computes the rendered rect for each text match.
        if (m_frame.view() && m_frame.contentRenderer()) {
            document().updateLayout(); // Ensure layout is up to date.
            LayoutRect visibleRect = m_frame.view()->visibleContentRect();
            if (!visibleRect.isEmpty()) {
                GraphicsContext context((PlatformGraphicsContext*)0);
                context.setPaintingDisabled(true);

                PaintBehavior oldBehavior = m_frame.view()->paintBehavior();
                m_frame.view()->setPaintBehavior(oldBehavior | PaintBehaviorFlattenCompositingLayers);
                m_frame.view()->paintContents(&context, enclosingIntRect(visibleRect));
                m_frame.view()->setPaintBehavior(oldBehavior);
            }
        }
    }

    return matchCount;
}

void Editor::setMarkedTextMatchesAreHighlighted(bool flag)
{
    if (flag == m_areMarkedTextMatchesHighlighted)
        return;

    m_areMarkedTextMatchesHighlighted = flag;
    document().markers().repaintMarkers(DocumentMarker::TextMatch);
}

void Editor::respondToChangedSelection(const VisibleSelection& oldSelection, FrameSelection::SetSelectionOptions options)
{
    m_alternativeTextController->stopPendingCorrection(oldSelection);

    bool closeTyping = options & FrameSelection::CloseTyping;
    bool isContinuousSpellCheckingEnabled = this->isContinuousSpellCheckingEnabled();
    bool isContinuousGrammarCheckingEnabled = isContinuousSpellCheckingEnabled && isGrammarCheckingEnabled();
    if (isContinuousSpellCheckingEnabled) {
        VisibleSelection newAdjacentWords;
        VisibleSelection newSelectedSentence;
        bool caretBrowsing = m_frame.settings().caretBrowsingEnabled();
        if (m_frame.selection().selection().isContentEditable() || caretBrowsing) {
            VisiblePosition newStart(m_frame.selection().selection().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.
        if (shouldCheckSpellingAndGrammar && closeTyping && oldSelection.isContentEditable() && oldSelection.start().deprecatedNode() && oldSelection.start().anchorNode()->inDocument()) {
            VisiblePosition oldStart(oldSelection.visibleStart());
            VisibleSelection oldAdjacentWords = VisibleSelection(startOfWord(oldStart, LeftWordIfOnBoundary), endOfWord(oldStart, RightWordIfOnBoundary));
            if (oldAdjacentWords != newAdjacentWords) {
                if (isContinuousGrammarCheckingEnabled) {
                    VisibleSelection oldSelectedSentence = VisibleSelection(startOfSentence(oldStart), endOfSentence(oldStart));
                    markMisspellingsAndBadGrammar(oldAdjacentWords, oldSelectedSentence != newSelectedSentence, oldSelectedSentence);
                } else
                    markMisspellingsAndBadGrammar(oldAdjacentWords, false, oldAdjacentWords);
            }
        }

        if (!textChecker() || textChecker()->shouldEraseMarkersAfterChangeSelection(TextCheckingTypeSpelling)) {
            if (RefPtr<Range> wordRange = newAdjacentWords.toNormalizedRange())
                document().markers().removeMarkers(wordRange.get(), DocumentMarker::Spelling);
        }
        if (!textChecker() || textChecker()->shouldEraseMarkersAfterChangeSelection(TextCheckingTypeGrammar)) {
            if (RefPtr<Range> sentenceRange = newSelectedSentence.toNormalizedRange())
                document().markers().removeMarkers(sentenceRange.get(), DocumentMarker::Grammar);
        }
    }

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

    notifyComponentsOnChangedSelection(oldSelection, options);
}

static Node* findFirstMarkable(Node* node)
{
    while (node) {
        if (!node->renderer())
            return 0;
        if (node->renderer()->isTextOrLineBreak())
            return node;
        if (isHTMLTextFormControlElement(*node))
            node = toHTMLTextFormControlElement(node)->visiblePositionForIndex(1).deepEquivalent().deprecatedNode();
        else if (node->firstChild())
            node = node->firstChild();
        else
            node = node->nextSibling();
    }

    return 0;
}

bool Editor::selectionStartHasMarkerFor(DocumentMarker::MarkerType markerType, int from, int length) const
{
    Node* node = findFirstMarkable(m_frame.selection().start().deprecatedNode());
    if (!node)
        return false;

    unsigned int startOffset = static_cast<unsigned int>(from);
    unsigned int endOffset = static_cast<unsigned int>(from + length);
    Vector<DocumentMarker*> markers = document().markers().markersFor(node);
    for (size_t i = 0; i < markers.size(); ++i) {
        DocumentMarker* marker = markers[i];
        if (marker->startOffset() <= startOffset && endOffset <= marker->endOffset() && marker->type() == markerType)
            return true;
    }

    return false;
}       

TextCheckingTypeMask Editor::resolveTextCheckingTypeMask(TextCheckingTypeMask textCheckingOptions)
{
    bool shouldMarkSpelling = textCheckingOptions & TextCheckingTypeSpelling;
    bool shouldMarkGrammar = textCheckingOptions & TextCheckingTypeGrammar;
    bool shouldShowCorrectionPanel = textCheckingOptions & TextCheckingTypeShowCorrectionPanel;
    bool shouldCheckForCorrection = shouldShowCorrectionPanel || (textCheckingOptions & TextCheckingTypeCorrection);

    TextCheckingTypeMask checkingTypes = 0;
    if (shouldMarkSpelling)
        checkingTypes |= TextCheckingTypeSpelling;
    if (shouldMarkGrammar)
        checkingTypes |= TextCheckingTypeGrammar;
    if (shouldCheckForCorrection)
        checkingTypes |= TextCheckingTypeCorrection;
    if (shouldShowCorrectionPanel)
        checkingTypes |= TextCheckingTypeShowCorrectionPanel;

#if USE(AUTOMATIC_TEXT_REPLACEMENT)
    bool shouldPerformReplacement = textCheckingOptions & TextCheckingTypeReplacement;
    if (shouldPerformReplacement) {
        if (isAutomaticLinkDetectionEnabled())
            checkingTypes |= TextCheckingTypeLink;
        if (isAutomaticQuoteSubstitutionEnabled())
            checkingTypes |= TextCheckingTypeQuote;
        if (isAutomaticDashSubstitutionEnabled())
            checkingTypes |= TextCheckingTypeDash;
        if (isAutomaticTextReplacementEnabled())
            checkingTypes |= TextCheckingTypeReplacement;
        if (shouldMarkSpelling && isAutomaticSpellingCorrectionEnabled())
            checkingTypes |= TextCheckingTypeCorrection;
    }
#endif

    return checkingTypes;
}

void Editor::deviceScaleFactorChanged()
{
#if ENABLE(DELETION_UI)
    m_deleteButtonController->deviceScaleFactorChanged();
#endif
}

bool Editor::unifiedTextCheckerEnabled() const
{
    return WebCore::unifiedTextCheckerEnabled(&m_frame);
}

Vector<String> Editor::dictationAlternativesForMarker(const DocumentMarker* marker)
{
    return m_alternativeTextController->dictationAlternativesForMarker(marker);
}

void Editor::applyDictationAlternativelternative(const String& alternativeString)
{
    m_alternativeTextController->applyDictationAlternative(alternativeString);
}

void Editor::toggleOverwriteModeEnabled()
{
    m_overwriteModeEnabled = !m_overwriteModeEnabled;
    m_frame.selection().setShouldShowBlockCursor(m_overwriteModeEnabled);
}

Document& Editor::document() const
{
    ASSERT(m_frame.document());
    return *m_frame.document();
}

} // namespace WebCore