[Reland] Refactor the selection code in EventHandler

Source/core/page/EventHandler.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. 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.
@@ skipping 16 matching lines @@
 
 #include "config.h"
 #include "core/page/EventHandler.h"
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/HTMLNames.h"
 #include "core/InputTypeNames.h"
 #include "core/clipboard/DataObject.h"
 #include "core/clipboard/DataTransfer.h"
 #include "core/dom/Document.h"
-#include "core/dom/DocumentMarkerController.h"
 #include "core/dom/TouchList.h"
 #include "core/dom/shadow/ComposedTreeTraversal.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/editing/Editor.h"
 #include "core/editing/FrameSelection.h"
-#include "core/editing/htmlediting.h"
-#include "core/editing/iterators/TextIterator.h"
+#include "core/editing/SelectionController.h"
 #include "core/events/EventPath.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
 #include "core/events/TextEvent.h"
 #include "core/events/TouchEvent.h"
 #include "core/events/WheelEvent.h"
 #include "core/fetch/ImageResource.h"
 #include "core/frame/EventHandlerRegistry.h"
 #include "core/frame/FrameHost.h"
 #include "core/frame/FrameView.h"
@@ skipping 158 matching lines @@
 
     // FIXME: we should exclude the document in some cases, as part
     // of crbug.com/410974.
     scrollChain.prepend(frame.document()->documentElement());
 }
 
 EventHandler::EventHandler(LocalFrame* frame)
     : m_frame(frame)
     , m_mousePressed(false)
     , m_capturesDragging(false)
-    , m_mouseDownMayStartSelect(false)
     , m_mouseDownMayStartDrag(false)
-    , m_mouseDownWasSingleClickInSelection(false)
-    , m_selectionInitiationState(HaveNotStartedSelection)
+    , m_selectionController(SelectionController::create(frame, &frame->selection()))

[yosin_UTC9, 2015/05/19 09:41:19]

nit: We don't need to pass |FrameSelection| in second parameter.

[Miyoung Shin(g), 2015/05/19 16:12:51]

Done.

     , m_hoverTimer(this, &EventHandler::hoverTimerFired)
     , m_cursorUpdateTimer(this, &EventHandler::cursorUpdateTimerFired)
     , m_mouseDownMayStartAutoscroll(false)
     , m_fakeMouseMoveEventTimer(this, &EventHandler::fakeMouseMoveEventTimerFired)
     , m_svgPan(false)
     , m_resizeScrollableArea(nullptr)
     , m_eventHandlerWillResetCapturingMouseEventsNode(0)
     , m_clickCount(0)
     , m_shouldOnlyFireDragOverEvent(false)
     , m_mousePositionIsUnknown(true)
@@ skipping 73 matching lines @@
     m_previousWheelScrolledNode = nullptr;
     m_targetForTouchID.clear();
     m_touchSequenceDocument.clear();
     m_touchSequenceUserGestureToken.clear();
     m_scrollGestureHandlingNode = nullptr;
     m_lastGestureScrollOverWidget = false;
     m_previousGestureScrolledNode = nullptr;
     m_scrollbarHandlingScrollGesture = nullptr;
     m_maxMouseMovedDuration = 0;
     m_touchPressed = false;
-    m_mouseDownMayStartSelect = false;
     m_mouseDownMayStartDrag = false;
     m_lastShowPressTimestamp = 0;
     m_lastDeferredTapElement = nullptr;
     m_eventHandlerWillResetCapturingMouseEventsNode = false;
-    m_mouseDownWasSingleClickInSelection = false;
-    m_selectionInitiationState = HaveNotStartedSelection;
     m_mouseDownMayStartAutoscroll = false;
     m_svgPan = false;
     m_mouseDownPos = IntPoint();
     m_mouseDownTimestamp = 0;
     m_longTapShouldInvokeContextMenu = false;
     m_dragStartPos = LayoutPoint();
     m_offsetFromResizeCorner = LayoutSize();
     m_mouseDown = PlatformMouseEvent();
+
+    selectionController().clear();

[yosin_UTC9, 2015/05/19 09:41:19]

nit: We don't need to call |clear()| here. |SelectionController| does what
|clear()| does. Basically, after ctor, object should be clear state.

[Miyoung Shin(g), 2015/05/19 16:12:51]

Done.

 }
 
 void EventHandler::nodeWillBeRemoved(Node& nodeToBeRemoved)
 {
     if (nodeToBeRemoved.containsIncludingShadowDOM(m_clickNode.get())) {
         // We don't dispatch click events if the mousedown node is removed
         // before a mouseup event. It is compatible with IE and Firefox.
         m_clickNode = nullptr;
     }
 }
 
-static void setSelectionIfNeeded(FrameSelection& selection, const VisibleSelection& newSelection)
-{
-    if (selection.selection() != newSelection)
-        selection.setSelection(newSelection);
-}
-
-static inline bool dispatchSelectStart(Node* node)
-{
-    if (!node || !node->layoutObject())
-        return true;
-
-    return node->dispatchEvent(Event::createCancelableBubble(EventTypeNames::selectstart));
-}
-
-static VisibleSelection expandSelectionToRespectUserSelectAll(Node* targetNode, const VisibleSelection& selection)
-{
-    Node* rootUserSelectAll = Position::rootUserSelectAllForNode(targetNode);
-    if (!rootUserSelectAll)
-        return selection;
-
-    VisibleSelection newSelection(selection);
-    newSelection.setBase(positionBeforeNode(rootUserSelectAll).upstream(CanCrossEditingBoundary));
-    newSelection.setExtent(positionAfterNode(rootUserSelectAll).downstream(CanCrossEditingBoundary));
-
-    return newSelection;
-}
-
-bool EventHandler::updateSelectionForMouseDownDispatchingSelectStart(Node* targetNode, const VisibleSelection& selection, TextGranularity granularity)
-{
-    if (Position::nodeIsUserSelectNone(targetNode))
-        return false;
-
-    if (!dispatchSelectStart(targetNode))
-        return false;
-
-    if (selection.isRange()) {
-        m_selectionInitiationState = ExtendedSelection;
-    } else {
-        granularity = CharacterGranularity;
-        m_selectionInitiationState = PlacedCaret;
-    }
-
-    m_frame->selection().setNonDirectionalSelectionIfNeeded(selection, granularity);
-
-    return true;
-}
-
-void EventHandler::selectClosestWordFromHitTestResult(const HitTestResult& result, AppendTrailingWhitespace appendTrailingWhitespace)
-{
-    Node* innerNode = result.innerNode();
-    VisibleSelection newSelection;
-
-    if (innerNode && innerNode->layoutObject()) {
-        VisiblePosition pos(innerNode->layoutObject()->positionForPoint(result.localPoint()));
-        if (pos.isNotNull()) {
-            newSelection = VisibleSelection(pos);
-            newSelection.expandUsingGranularity(WordGranularity);
-        }
-
-        if (appendTrailingWhitespace == ShouldAppendTrailingWhitespace && newSelection.isRange())
-            newSelection.appendTrailingWhitespace();
-
-        updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), WordGranularity);
-    }
-}
-
-void EventHandler::selectClosestMisspellingFromHitTestResult(const HitTestResult& result, AppendTrailingWhitespace appendTrailingWhitespace)
-{
-    Node* innerNode = result.innerNode();
-    VisibleSelection newSelection;
-
-    if (innerNode && innerNode->layoutObject()) {
-        VisiblePosition pos(innerNode->layoutObject()->positionForPoint(result.localPoint()));
-        Position start = pos.deepEquivalent();
-        Position end = pos.deepEquivalent();
-        if (pos.isNotNull()) {
-            DocumentMarkerVector markers = innerNode->document().markers().markersInRange(makeRange(pos, pos).get(), DocumentMarker::MisspellingMarkers());
-            if (markers.size() == 1) {
-                start.moveToOffset(markers[0]->startOffset());
-                end.moveToOffset(markers[0]->endOffset());
-                newSelection = VisibleSelection(start, end);
-            }
-        }
-
-        if (appendTrailingWhitespace == ShouldAppendTrailingWhitespace && newSelection.isRange())
-            newSelection.appendTrailingWhitespace();
-
-        updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), WordGranularity);
-    }
-}
-
-void EventHandler::selectClosestWordFromMouseEvent(const MouseEventWithHitTestResults& result)
-{
-    if (m_mouseDownMayStartSelect) {
-        selectClosestWordFromHitTestResult(result.hitTestResult(),
-            (result.event().clickCount() == 2 && m_frame->editor().isSelectTrailingWhitespaceEnabled()) ? ShouldAppendTrailingWhitespace : DontAppendTrailingWhitespace);
-    }
-}
-
-void EventHandler::selectClosestMisspellingFromMouseEvent(const MouseEventWithHitTestResults& result)
-{
-    if (m_mouseDownMayStartSelect) {
-        selectClosestMisspellingFromHitTestResult(result.hitTestResult(),
-            (result.event().clickCount() == 2 && m_frame->editor().isSelectTrailingWhitespaceEnabled()) ? ShouldAppendTrailingWhitespace : DontAppendTrailingWhitespace);
-    }
-}
-
-void EventHandler::selectClosestWordOrLinkFromMouseEvent(const MouseEventWithHitTestResults& result)
-{
-    if (!result.hitTestResult().isLiveLink())
-        return selectClosestWordFromMouseEvent(result);
-
-    Node* innerNode = result.innerNode();
-
-    if (innerNode && innerNode->layoutObject() && m_mouseDownMayStartSelect) {
-        VisibleSelection newSelection;
-        Element* URLElement = result.hitTestResult().URLElement();
-        VisiblePosition pos(innerNode->layoutObject()->positionForPoint(result.localPoint()));
-        if (pos.isNotNull() && pos.deepEquivalent().deprecatedNode()->isDescendantOf(URLElement))
-            newSelection = VisibleSelection::selectionFromContentsOfNode(URLElement);
-
-        updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), WordGranularity);
-    }
-}
-
-bool EventHandler::handleMousePressEventDoubleClick(const MouseEventWithHitTestResults& event)
-{
-    TRACE_EVENT0("blink", "EventHandler::handleMousePressEventDoubleClick");
-
-    if (event.event().button() != LeftButton)
-        return false;
-
-    if (m_frame->selection().isRange()) {
-        // A double-click when range is already selected
-        // should not change the selection.  So, do not call
-        // selectClosestWordFromMouseEvent, but do set
-        // m_beganSelectingText to prevent handleMouseReleaseEvent
-        // from setting caret selection.
-        m_selectionInitiationState = ExtendedSelection;
-    } else {
-        selectClosestWordFromMouseEvent(event);
-    }
-    return true;
-}
-
-bool EventHandler::handleMousePressEventTripleClick(const MouseEventWithHitTestResults& event)
-{
-    TRACE_EVENT0("blink", "EventHandler::handleMousePressEventTripleClick");
-
-    if (event.event().button() != LeftButton)
-        return false;
-
-    Node* innerNode = event.innerNode();
-    if (!(innerNode && innerNode->layoutObject() && m_mouseDownMayStartSelect))
-        return false;
-
-    VisibleSelection newSelection;
-    VisiblePosition pos(innerNode->layoutObject()->positionForPoint(event.localPoint()));
-    if (pos.isNotNull()) {
-        newSelection = VisibleSelection(pos);
-        newSelection.expandUsingGranularity(ParagraphGranularity);
-    }
-
-    return updateSelectionForMouseDownDispatchingSelectStart(innerNode, expandSelectionToRespectUserSelectAll(innerNode, newSelection), ParagraphGranularity);
-}
-
-static int textDistance(const Position& start, const Position& end)
-{
-    RefPtrWillBeRawPtr<Range> range = Range::create(*start.document(), start, end);
-    return TextIterator::rangeLength(range->startPosition(), range->endPosition(), true);
-}
-
-bool EventHandler::handleMousePressEventSingleClick(const MouseEventWithHitTestResults& event)
-{
-    TRACE_EVENT0("blink", "EventHandler::handleMousePressEventSingleClick");
-
-    m_frame->document()->updateLayoutIgnorePendingStylesheets();
-    Node* innerNode = event.innerNode();
-    if (!(innerNode && innerNode->layoutObject() && m_mouseDownMayStartSelect))
-        return false;
-
-    // Extend the selection if the Shift key is down, unless the click is in a link.
-    bool extendSelection = event.event().shiftKey() && !event.isOverLink();
-
-    // Don't restart the selection when the mouse is pressed on an
-    // existing selection so we can allow for text dragging.
-    if (FrameView* view = m_frame->view()) {
-        LayoutPoint vPoint = view->rootFrameToContents(event.event().position());
-        if (!extendSelection && m_frame->selection().contains(vPoint)) {
-            m_mouseDownWasSingleClickInSelection = true;
-            return false;
-        }
-    }
-
-    VisiblePosition visiblePos(innerNode->layoutObject()->positionForPoint(event.localPoint()));
-    if (visiblePos.isNull())
-        visiblePos = VisiblePosition(firstPositionInOrBeforeNode(innerNode), DOWNSTREAM);
-    Position pos = visiblePos.deepEquivalent();
-
-    VisibleSelection newSelection = m_frame->selection().selection();
-    TextGranularity granularity = CharacterGranularity;
-
-    if (extendSelection && newSelection.isCaretOrRange()) {
-        VisibleSelection selectionInUserSelectAll(expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(VisiblePosition(pos))));
-        if (selectionInUserSelectAll.isRange()) {
-            if (comparePositions(selectionInUserSelectAll.start(), newSelection.start()) < 0)
-                pos = selectionInUserSelectAll.start();
-            else if (comparePositions(newSelection.end(), selectionInUserSelectAll.end()) < 0)
-                pos = selectionInUserSelectAll.end();
-        }
-
-        if (!m_frame->editor().behavior().shouldConsiderSelectionAsDirectional()) {
-            if (pos.isNotNull()) {
-                // See <rdar://problem/3668157> REGRESSION (Mail): shift-click deselects when selection
-                // was created right-to-left
-                Position start = newSelection.start();
-                Position end = newSelection.end();
-                int distanceToStart = textDistance(start, pos);
-                int distanceToEnd = textDistance(pos, end);
-                if (distanceToStart <= distanceToEnd)
-                    newSelection = VisibleSelection(end, pos);
-                else
-                    newSelection = VisibleSelection(start, pos);
-            }
-        } else {
-            newSelection.setExtent(pos);
-        }
-
-        if (m_frame->selection().granularity() != CharacterGranularity) {
-            granularity = m_frame->selection().granularity();
-            newSelection.expandUsingGranularity(m_frame->selection().granularity());
-        }
-    } else {
-        newSelection = expandSelectionToRespectUserSelectAll(innerNode, VisibleSelection(visiblePos));
-    }
-
-    // Updating the selection is considered side-effect of the event and so it doesn't impact the handled state.
-    updateSelectionForMouseDownDispatchingSelectStart(innerNode, newSelection, granularity);
-    return false;
-}
-
-static inline bool canMouseDownStartSelect(Node* node)
-{
-    if (!node || !node->layoutObject())
-        return true;
-
-    if (!node->canStartSelection())
-        return false;
-
-    return true;
-}
-
 bool EventHandler::handleMousePressEvent(const MouseEventWithHitTestResults& event)
 {
     TRACE_EVENT0("blink", "EventHandler::handleMousePressEvent");
 
     // Reset drag state.
     dragState().m_dragSrc = nullptr;
 
     cancelFakeMouseMoveEvent();
 
     m_frame->document()->updateLayoutIgnorePendingStylesheets();
 
     if (FrameView* frameView = m_frame->view()) {
         if (frameView->isPointInScrollbarCorner(event.event().position()))
             return false;
     }
 
     bool singleClick = event.event().clickCount() <= 1;
 
-    // If we got the event back, that must mean it wasn't prevented,
-    // so it's allowed to start a drag or selection if it wasn't in a scrollbar.
-    m_mouseDownMayStartSelect = canMouseDownStartSelect(event.innerNode()) && !event.scrollbar();
-
     m_mouseDownMayStartDrag = singleClick;
 
-    m_mouseDownWasSingleClickInSelection = false;
+    selectionController().handleMousePressEvent(event);
 
     m_mouseDown = event.event();
 
     if (m_frame->document()->isSVGDocument() && m_frame->document()->accessSVGExtensions().zoomAndPanEnabled()) {
         if (event.event().shiftKey() && singleClick) {
             m_svgPan = true;
             m_frame->document()->accessSVGExtensions().startPan(m_frame->view()->rootFrameToContents(event.event().position()));
             return true;
         }
     }
 
     // We don't do this at the start of mouse down handling,
     // because we don't want to do it until we know we didn't hit a widget.
     if (singleClick)
         focusDocumentView();
 
     Node* innerNode = event.innerNode();
 
     m_mousePressNode = innerNode;
     m_dragStartPos = event.event().position();
 
     bool swallowEvent = false;
     m_mousePressed = true;
-    m_selectionInitiationState = HaveNotStartedSelection;
+    selectionController().initializeSelectionState();
 
     if (event.event().clickCount() == 2)
-        swallowEvent = handleMousePressEventDoubleClick(event);
+        swallowEvent = selectionController().handleMousePressEventDoubleClick(event);
     else if (event.event().clickCount() >= 3)
-        swallowEvent = handleMousePressEventTripleClick(event);
+        swallowEvent = selectionController().handleMousePressEventTripleClick(event);
     else
-        swallowEvent = handleMousePressEventSingleClick(event);
+        swallowEvent = selectionController().handleMousePressEventSingleClick(event);
 
-    m_mouseDownMayStartAutoscroll = m_mouseDownMayStartSelect
+    m_mouseDownMayStartAutoscroll = selectionController().mouseDownMayStartSelect()
         || (m_mousePressNode && m_mousePressNode->layoutBox() && m_mousePressNode->layoutBox()->canBeProgramaticallyScrolled());
 
     return swallowEvent;
 }
 
 bool EventHandler::handleMouseDraggedEvent(const MouseEventWithHitTestResults& event)
 {
     TRACE_EVENT0("blink", "EventHandler::handleMouseDraggedEvent");
 
     // While resetting m_mousePressed here may seem out of place, it turns out
@@ skipping 36 matching lines @@
 
     m_mouseDownMayStartDrag = false;
 
     if (m_mouseDownMayStartAutoscroll && !panScrollInProgress()) {
         if (AutoscrollController* controller = autoscrollController()) {
             controller->startAutoscrollForSelection(layoutObject);
             m_mouseDownMayStartAutoscroll = false;
         }
     }
 
-    if (m_selectionInitiationState != ExtendedSelection) {
-        HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active);
-        HitTestResult result(request, m_mouseDownPos);
-        m_frame->document()->layoutView()->hitTest(result);
-
-        updateSelectionForMouseDrag(result);
-    }
-    updateSelectionForMouseDrag(event.hitTestResult());
+    selectionController().handleMouseDraggedEvent(event, m_mouseDownPos, m_dragStartPos, m_mousePressNode, m_lastKnownMousePosition);
     return true;
 }
 
 void EventHandler::updateSelectionForMouseDrag()
 {
-    FrameView* view = m_frame->view();
-    if (!view)
-        return;
-    LayoutView* layoutObject = m_frame->contentLayoutObject();
-    if (!layoutObject)
-        return;
-
-    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::Move);
-    HitTestResult result(request, view->rootFrameToContents(m_lastKnownMousePosition));
-    layoutObject->hitTest(result);
-    updateSelectionForMouseDrag(result);
-}
-
-void EventHandler::updateSelectionForMouseDrag(const HitTestResult& hitTestResult)
-{
-    if (!m_mouseDownMayStartSelect)
-        return;
-
-    Node* target = hitTestResult.innerNode();
-    if (!target)
-        return;
-
-    VisiblePosition targetPosition = m_frame->selection().selection().visiblePositionRespectingEditingBoundary(hitTestResult.localPoint(), target);
-    // Don't modify the selection if we're not on a node.
-    if (targetPosition.isNull())
-        return;
-
-    // Restart the selection if this is the first mouse move. This work is usually
-    // done in handleMousePressEvent, but not if the mouse press was on an existing selection.
-    VisibleSelection newSelection = m_frame->selection().selection();
-
-    // Special case to limit selection to the containing block for SVG text.
-    // FIXME: Isn't there a better non-SVG-specific way to do this?
-    if (Node* selectionBaseNode = newSelection.base().deprecatedNode()) {
-        if (LayoutObject* selectionBaseLayoutObject = selectionBaseNode->layoutObject()) {
-            if (selectionBaseLayoutObject->isSVGText()) {
-                if (target->layoutObject()->containingBlock() != selectionBaseLayoutObject->containingBlock())
-                    return;
-            }
-        }
-    }
-
-    if (m_selectionInitiationState == HaveNotStartedSelection && !dispatchSelectStart(target))
-        return;
-
-    if (m_selectionInitiationState != ExtendedSelection) {
-        // Always extend selection here because it's caused by a mouse drag
-        m_selectionInitiationState = ExtendedSelection;
-        newSelection = VisibleSelection(targetPosition);
-    }
-
-    if (RuntimeEnabledFeatures::userSelectAllEnabled()) {
-        Node* rootUserSelectAllForMousePressNode = Position::rootUserSelectAllForNode(m_mousePressNode.get());
-        if (rootUserSelectAllForMousePressNode && rootUserSelectAllForMousePressNode == Position::rootUserSelectAllForNode(target)) {
-            newSelection.setBase(positionBeforeNode(rootUserSelectAllForMousePressNode).upstream(CanCrossEditingBoundary));
-            newSelection.setExtent(positionAfterNode(rootUserSelectAllForMousePressNode).downstream(CanCrossEditingBoundary));
-        } else {
-            // Reset base for user select all when base is inside user-select-all area and extent < base.
-            if (rootUserSelectAllForMousePressNode && comparePositions(target->layoutObject()->positionForPoint(hitTestResult.localPoint()), m_mousePressNode->layoutObject()->positionForPoint(m_dragStartPos)) < 0)
-                newSelection.setBase(positionAfterNode(rootUserSelectAllForMousePressNode).downstream(CanCrossEditingBoundary));
-
-            Node* rootUserSelectAllForTarget = Position::rootUserSelectAllForNode(target);
-            if (rootUserSelectAllForTarget && m_mousePressNode->layoutObject() && comparePositions(target->layoutObject()->positionForPoint(hitTestResult.localPoint()), m_mousePressNode->layoutObject()->positionForPoint(m_dragStartPos)) < 0)
-                newSelection.setExtent(positionBeforeNode(rootUserSelectAllForTarget).upstream(CanCrossEditingBoundary));
-            else if (rootUserSelectAllForTarget && m_mousePressNode->layoutObject())
-                newSelection.setExtent(positionAfterNode(rootUserSelectAllForTarget).downstream(CanCrossEditingBoundary));
-            else
-                newSelection.setExtent(targetPosition);
-        }
-    } else {
-        newSelection.setExtent(targetPosition);
-    }
-
-    if (m_frame->selection().granularity() != CharacterGranularity)
-        newSelection.expandUsingGranularity(m_frame->selection().granularity());
-
-    m_frame->selection().setNonDirectionalSelectionIfNeeded(newSelection, m_frame->selection().granularity(),
-        FrameSelection::AdjustEndpointsAtBidiBoundary);
+    selectionController().updateSelectionForMouseDrag(m_mousePressNode, m_dragStartPos, m_lastKnownMouseGlobalPosition);
 }
 
 bool EventHandler::handleMouseReleaseEvent(const MouseEventWithHitTestResults& event)
 {
     AutoscrollController* controller = autoscrollController();
     if (controller && controller->autoscrollInProgress())
         stopAutoscroll();
 
     // Used to prevent mouseMoveEvent from initiating a drag before
     // the mouse is pressed again.
     m_mousePressed = false;
     m_capturesDragging = false;
     m_mouseDownMayStartDrag = false;
-    m_mouseDownMayStartSelect = false;
     m_mouseDownMayStartAutoscroll = false;
 
-    bool handled = false;
-
-    // Clear the selection if the mouse didn't move after the last mouse
-    // press and it's not a context menu click.  We do this so when clicking
-    // on the selection, the selection goes away.  However, if we are
-    // editing, place the caret.
-    if (m_mouseDownWasSingleClickInSelection && m_selectionInitiationState != ExtendedSelection
-        && m_dragStartPos == event.event().position()
-        && m_frame->selection().isRange()
-        && event.event().button() != RightButton) {
-        VisibleSelection newSelection;
-        Node* node = event.innerNode();
-        bool caretBrowsing = m_frame->settings() && m_frame->settings()->caretBrowsingEnabled();
-        if (node && node->layoutObject() && (caretBrowsing || node->hasEditableStyle())) {
-            VisiblePosition pos = VisiblePosition(node->layoutObject()->positionForPoint(event.localPoint()));
-            newSelection = VisibleSelection(pos);
-        }
-
-        setSelectionIfNeeded(m_frame->selection(), newSelection);
-
-        handled = true;
-    }
-
-    m_frame->selection().notifyLayoutObjectOfSelectionChange(UserTriggered);
-
-    m_frame->selection().selectFrameElementInParentIfFullySelected();
-
-    if (event.event().button() == MiddleButton && !event.isOverLink()) {
-        // Ignore handled, since we want to paste to where the caret was placed anyway.
-        handled = handlePasteGlobalSelection(event.event()) || handled;
-    }
-
-    return handled;
+    return selectionController().handleMouseReleaseEvent(event, m_dragStartPos);
 }
 
 #if OS(WIN)
 
 void EventHandler::startPanScrolling(LayoutObject* layoutObject)
 {
     if (!layoutObject->isBox())
         return;
     AutoscrollController* controller = autoscrollController();
     if (!controller)
@@ skipping 365 matching lines @@
 
     bool inResizer = false;
     LayoutObject* layoutObject = node ? node->layoutObject() : nullptr;
     if (layoutObject && m_frame->view()) {
         DeprecatedPaintLayer* layer = layoutObject->enclosingLayer();
         inResizer = layer->scrollableArea() && layer->scrollableArea()->isPointInResizeControl(result.roundedPointInMainFrame(), ResizerForPointer);
     }
 
     // During selection, use an I-beam no matter what we're over.
     // If a drag may be starting or we're capturing mouse events for a particular node, don't treat this as a selection.
-    if (m_mousePressed && m_mouseDownMayStartSelect
+    if (m_mousePressed && selectionController().mouseDownMayStartSelect()
         && !m_mouseDownMayStartDrag
         && m_frame->selection().isCaretOrRange()
         && !m_capturingMouseEventsNode) {
         return iBeam;
     }
 
     if ((editable || (layoutObject && layoutObject->isText() && node->canStartSelection())) && !inResizer && !result.scrollbar())
         return iBeam;
     return pointerCursor();
 }
@@ skipping 16 matching lines @@
     m_frame->localFrameRoot()->eventHandler().m_lastMouseDownUserGestureToken = gestureIndicator.currentToken();
 
     cancelFakeMouseMoveEvent();
     if (m_eventHandlerWillResetCapturingMouseEventsNode)
         m_capturingMouseEventsNode = nullptr;
     m_mousePressed = true;
     m_capturesDragging = true;
     setLastKnownMousePosition(mouseEvent);
     m_mouseDownTimestamp = mouseEvent.timestamp();
     m_mouseDownMayStartDrag = false;
-    m_mouseDownMayStartSelect = false;
+    selectionController().setMouseDownMayStartSelect(false);
     m_mouseDownMayStartAutoscroll = false;
     if (FrameView* view = m_frame->view()) {
         m_mouseDownPos = view->rootFrameToContents(mouseEvent.position());
     } else {
         invalidateClick();
         return false;
     }
 
     HitTestRequest request(HitTestRequest::Active);
     // Save the document point we generate in case the window coordinate is invalidated by what happens
@@ skipping 351 matching lines @@
 
     bool swallowMouseReleaseEvent = false;
     if (!swallowMouseUpEvent)
         swallowMouseReleaseEvent = handleMouseReleaseEvent(mev);
 
     invalidateClick();
 
     return swallowMouseUpEvent || swallowClickEvent || swallowMouseReleaseEvent;
 }
 
-bool EventHandler::handlePasteGlobalSelection(const PlatformMouseEvent& mouseEvent)
-{
-    // If the event was a middle click, attempt to copy global selection in after
-    // the newly set caret position.
-    //
-    // This code is called from either the mouse up or mouse down handling. There
-    // is some debate about when the global selection is pasted:
-    //   xterm: pastes on up.
-    //   GTK: pastes on down.
-    //   Qt: pastes on up.
-    //   Firefox: pastes on up.
-    //   Chromium: pastes on up.
-    //
-    // There is something of a webcompat angle to this well, as highlighted by
-    // crbug.com/14608. Pages can clear text boxes 'onclick' and, if we paste on
-    // down then the text is pasted just before the onclick handler runs and
-    // clears the text box. So it's important this happens after the event
-    // handlers have been fired.
-    if (mouseEvent.type() != PlatformEvent::MouseReleased)
-        return false;
-
-    if (!m_frame->page())
-        return false;
-    Frame* focusFrame = m_frame->page()->focusController().focusedOrMainFrame();
-    // Do not paste here if the focus was moved somewhere else.
-    if (m_frame == focusFrame && m_frame->editor().behavior().supportsGlobalSelection())
-        return m_frame->editor().command("PasteGlobalSelection").execute();
-
-    return false;
-}
-
-
 bool EventHandler::dispatchDragEvent(const AtomicString& eventType, Node* dragTarget, const PlatformMouseEvent& event, DataTransfer* dataTransfer)
 {
     FrameView* view = m_frame->view();
 
     // FIXME: We might want to dispatch a dragleave even if the view is gone.
     if (!view)
         return false;
 
     RefPtrWillBeRawPtr<MouseEvent> me = MouseEvent::create(eventType,
         true, true, m_frame->document()->domWindow(),
@@ skipping 829 matching lines @@
 #endif
     if (shouldLongPressSelectWord) {
         IntPoint hitTestPoint = m_frame->view()->rootFrameToContents(gestureEvent.position());
         HitTestResult result = hitTestResultAtPoint(hitTestPoint);
         Node* innerNode = result.innerNode();
         if (!result.isLiveLink() && innerNode && (innerNode->isContentEditable() || innerNode->isTextNode()
 #if OS(ANDROID)
             || innerNode->canStartSelection()
 #endif
             )) {
-            selectClosestWordFromHitTestResult(result, DontAppendTrailingWhitespace);
+            selectionController().selectClosestWordFromHitTestResult(result, DontAppendTrailingWhitespace);
             if (m_frame->selection().isRange()) {
                 focusDocumentView();
                 return true;
             }
         }
     }
     return sendContextMenuEventForGesture(targetedEvent);
 }
 
 bool EventHandler::handleGestureLongTap(const GestureEventWithHitTestResults& targetedEvent)
@@ skipping 462 matching lines @@
     FrameView* v = m_frame->view();
     if (!v)
         return false;
 
     // Clear mouse press state to avoid initiating a drag while context menu is up.
     m_mousePressed = false;
     LayoutPoint positionInContents = v->rootFrameToContents(event.position());
     HitTestRequest request(HitTestRequest::Active);
     MouseEventWithHitTestResults mev = m_frame->document()->prepareMouseEvent(request, positionInContents, event);
 
-    if (!m_frame->selection().contains(positionInContents)
-        && !mev.scrollbar()
-        // FIXME: In the editable case, word selection sometimes selects content that isn't underneath the mouse.
-        // If the selection is non-editable, we do word selection to make it easier to use the contextual menu items
-        // available for text selections.  But only if we're above text.
-        && (m_frame->selection().isContentEditable() || (mev.innerNode() && mev.innerNode()->isTextNode()))) {
-        m_mouseDownMayStartSelect = true; // context menu events are always allowed to perform a selection
-
-        if (mev.hitTestResult().isMisspelled())
-            selectClosestMisspellingFromMouseEvent(mev);
-        else if (m_frame->editor().behavior().shouldSelectOnContextualMenuClick())
-            selectClosestWordOrLinkFromMouseEvent(mev);
-    }
+    selectionController().prepareForContextMenu(mev, positionInContents);
 
     Node* targetNode = overrideTargetNode ? overrideTargetNode : mev.innerNode();
     return !dispatchMouseEvent(EventTypeNames::contextmenu, targetNode, 0, event, false);
 }
 
 bool EventHandler::sendContextMenuEventForKey(Element* overrideTargetElement)
 {
     FrameView* view = m_frame->view();
     if (!view)
         return false;
@@ skipping 488 matching lines @@
             dragState().m_dragSrc = m_frame->page()->dragController().draggableNode(m_frame, node, m_mouseDownPos, selectionDragPolicy, dragState().m_dragType);
         } else {
             dragState().m_dragSrc = nullptr;
         }
 
         if (!dragState().m_dragSrc)
             m_mouseDownMayStartDrag = false; // no element is draggable
     }
 
     if (!m_mouseDownMayStartDrag)
-        return initiator == DragInitiator::Mouse && !mouseDownMayStartSelect() && !m_mouseDownMayStartAutoscroll;
+        return initiator == DragInitiator::Mouse && !selectionController().mouseDownMayStartSelect() && !m_mouseDownMayStartAutoscroll;
 
     // We are starting a text/image/url drag, so the cursor should be an arrow
     // FIXME <rdar://7577595>: Custom cursors aren't supported during drag and drop (default to pointer).
     m_frame->view()->setCursor(pointerCursor());
 
     if (initiator == DragInitiator::Mouse && !dragHysteresisExceeded(event.event().position()))
         return true;
 
     // Once we're past the hysteresis point, we don't want to treat this gesture as a click
     invalidateClick();
@@ skipping 564 matching lines @@
 
 void EventHandler::setLastKnownMousePosition(const PlatformMouseEvent& event)
 {
     m_mousePositionIsUnknown = false;
     m_lastKnownMousePosition = event.position();
     m_lastKnownMouseGlobalPosition = event.globalPosition();
 }
 
 bool EventHandler::passMousePressEventToSubframe(MouseEventWithHitTestResults& mev, LocalFrame* subframe)
 {
-    // If we're clicking into a frame that is selected, the frame will appear
-    // greyed out even though we're clicking on the selection.  This looks
-    // really strange (having the whole frame be greyed out), so we deselect the
-    // selection.
-    IntPoint p = m_frame->view()->rootFrameToContents(mev.event().position());
-    if (m_frame->selection().contains(p)) {
-        VisiblePosition visiblePos(
-            mev.innerNode()->layoutObject()->positionForPoint(mev.localPoint()));
-        VisibleSelection newSelection(visiblePos);
-        m_frame->selection().setSelection(newSelection);
-    }
-
+    selectionController().preparePassMousePressEventToSubframe(mev);
     subframe->eventHandler().handleMousePressEvent(mev.event());
     return true;
 }
 
 bool EventHandler::passMouseMoveEventToSubframe(MouseEventWithHitTestResults& mev, LocalFrame* subframe, HitTestResult* hoveredNode)
 {
     if (m_mouseDownMayStartDrag)
         return false;
     subframe->eventHandler().handleMouseMoveOrLeaveEvent(mev.event(), hoveredNode);
     return true;
@@ skipping 31 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink