third_party/WebKit/Source/core/events/TouchEvent.cpp - chromium/src - Git at Google

 /*
  * Copyright 2008, The Android Open Source Project
  * Copyright (C) 2012 Research In Motion Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * 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 THE COPYRIGHT HOLDERS ``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 "core/events/TouchEvent.h"

 #include "bindings/core/v8/DOMWrapperWorld.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/events/EventDispatcher.h"
 #include "core/frame/FrameConsole.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "platform/Histogram.h"

 namespace blink {

 namespace {

 // These offsets change indicies into the ListenerHistogram
 // enumeration. The addition of a series of offsets then
 // produces the resulting ListenerHistogram value.
 // TODO(dtapuska): Remove all of these histogram counts once
 // https://crbug.com/599609 is fixed.
 const size_t kTouchTargetHistogramRootScrollerOffset = 6;
 const size_t kTouchTargetHistogramScrollableDocumentOffset = 3;
 const size_t kTouchTargetHistogramAlreadyHandledOffset = 0;
 const size_t kTouchTargetHistogramNotHandledOffset = 1;
 const size_t kTouchTargetHistogramHandledOffset = 2;
 const size_t kCapturingOffset = 0;
 const size_t kAtTargetOffset = 12;
 const size_t kBubblingOffset = 24;

 enum TouchTargetAndDispatchResultType {
     // The following enums represent state captured during the CAPTURING_PHASE.
     CapturingNonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
     CapturingNonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
     CapturingNonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
     CapturingNonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
     CapturingNonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
     CapturingNonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
     CapturingRootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
     CapturingRootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
     CapturingRootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
     CapturingRootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
     CapturingRootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
     CapturingRootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.

     // The following enums represent state captured during the AT_TARGET phase.
     NonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
     NonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
     NonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
     NonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
     NonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
     NonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
     RootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
     RootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
     RootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
     RootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
     RootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
     RootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.

     // The following enums represent state captured during the BUBBLING_PHASE.
     BubblingNonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
     BubblingNonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
     BubblingNonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
     BubblingNonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
     BubblingNonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
     BubblingNonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
     BubblingRootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
     BubblingRootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
     BubblingRootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
     BubblingRootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
     BubblingRootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
     BubblingRootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.
     TouchTargetAndDispatchResultTypeMax,
 };

 void logTouchTargetHistogram(EventTarget* eventTarget, unsigned short phase, bool defaultPreventedBeforeCurrentTarget, bool defaultPrevented)
 {
     int result = 0;
     Document* document = nullptr;

     switch (phase) {
     default:
     case Event::NONE:
         return;
     case Event::CAPTURING_PHASE:
         result += kCapturingOffset;
         break;
     case Event::AT_TARGET:
         result += kAtTargetOffset;
         break;
     case Event::BUBBLING_PHASE:
         result += kBubblingOffset;
         break;
     }

     if (const LocalDOMWindow* domWindow = eventTarget->toLocalDOMWindow()) {
         // Treat the window as a root scroller as well.
         document = domWindow->document();
         result += kTouchTargetHistogramRootScrollerOffset;
     } else if (Node* node = eventTarget->toNode()) {
         // Report if the target node is the document or body.
         if (node->isDocumentNode() || node->document().documentElement() == node || node->document().body() == node) {
             result += kTouchTargetHistogramRootScrollerOffset;
         }
         document = &node->document();
     }

     if (document) {
         FrameView* view = document->view();
         if (view && view->isScrollable())
             result += kTouchTargetHistogramScrollableDocumentOffset;
     }

     if (defaultPreventedBeforeCurrentTarget)
         result += kTouchTargetHistogramAlreadyHandledOffset;
     else if (defaultPrevented)
         result += kTouchTargetHistogramHandledOffset;
     else
         result += kTouchTargetHistogramNotHandledOffset;

     DEFINE_STATIC_LOCAL(EnumerationHistogram, rootDocumentListenerHistogram, ("Event.Touch.TargetAndDispatchResult2", TouchTargetAndDispatchResultTypeMax));
     rootDocumentListenerHistogram.count(static_cast<TouchTargetAndDispatchResultType>(result));
 }

 } // namespace

 TouchEvent::TouchEvent()
     : m_causesScrollingIfUncanceled(false)
     , m_firstTouchMoveOrStart(false)
     , m_defaultPreventedBeforeCurrentTarget(false)
 {
 }

 TouchEvent::TouchEvent(TouchList* touches, TouchList* targetTouches,
     TouchList* changedTouches, const AtomicString& type,
     AbstractView* view,
     PlatformEvent::Modifiers modifiers, bool cancelable, bool causesScrollingIfUncanceled, bool firstTouchMoveOrStart,
     double platformTimeStamp)
     // Pass a sourceCapabilities including the ability to fire touchevents when creating this touchevent, which is always created from input device capabilities from EventHandler.
     : UIEventWithKeyState(type, true, cancelable, view, 0, modifiers, platformTimeStamp, InputDeviceCapabilities::firesTouchEventsSourceCapabilities()),
     m_touches(touches),
     m_targetTouches(targetTouches),
     m_changedTouches(changedTouches),
     m_causesScrollingIfUncanceled(causesScrollingIfUncanceled),
     m_firstTouchMoveOrStart(firstTouchMoveOrStart),
     m_defaultPreventedBeforeCurrentTarget(false)
 {
 }

 TouchEvent::TouchEvent(const AtomicString& type, const TouchEventInit& initializer)
     : UIEventWithKeyState(type, initializer)
     , m_touches(TouchList::create(initializer.touches()))
     , m_targetTouches(TouchList::create(initializer.targetTouches()))
     , m_changedTouches(TouchList::create(initializer.changedTouches()))
     , m_causesScrollingIfUncanceled(false)
     , m_firstTouchMoveOrStart(false)
     , m_defaultPreventedBeforeCurrentTarget(false)
 {
 }

 TouchEvent::~TouchEvent()
 {
 }

 void TouchEvent::initTouchEvent(ScriptState* scriptState, TouchList* touches, TouchList* targetTouches,
     TouchList* changedTouches, const AtomicString& type,
     AbstractView* view,
     int, int, int, int,
     bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
 {
     if (isBeingDispatched())
         return;

     if (scriptState->world().isIsolatedWorld())
         UIEventWithKeyState::didCreateEventInIsolatedWorld(ctrlKey, altKey, shiftKey, metaKey);

     bool cancelable = true;
     if (type == EventTypeNames::touchcancel)
         cancelable = false;

     initUIEvent(type, true, cancelable, view, 0);

     m_touches = touches;
     m_targetTouches = targetTouches;
     m_changedTouches = changedTouches;
     initModifiers(ctrlKey, altKey, shiftKey, metaKey);
 }

 const AtomicString& TouchEvent::interfaceName() const
 {
     return EventNames::TouchEvent;
 }

 bool TouchEvent::isTouchEvent() const
 {
     return true;
 }

 void TouchEvent::preventDefault()
 {
     UIEventWithKeyState::preventDefault();

     // A common developer error is to wait too long before attempting to stop
     // scrolling by consuming a touchmove event. Generate a warning if this
     // event is uncancelable.
     if (!cancelable() && view() && view()->isLocalDOMWindow() && view()->frame()) {
         toLocalDOMWindow(view())->frame()->console().addMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel,
             "Ignored attempt to cancel a " + type() + " event with cancelable=false, for example because scrolling is in progress and cannot be interrupted."));
     }
 }

 void TouchEvent::doneDispatchingEventAtCurrentTarget()
 {
     // Do not log for non-cancelable events, events that don't block
     // scrolling, have more than one touch point or aren't on the main frame.
     if (!cancelable() || !m_firstTouchMoveOrStart || !(m_touches && m_touches->length() == 1) || !(view() && view()->frame() && view()->frame()->isMainFrame()))
         return;

     bool canceled = defaultPrevented();
     logTouchTargetHistogram(currentTarget(), eventPhase(), m_defaultPreventedBeforeCurrentTarget, canceled);
     m_defaultPreventedBeforeCurrentTarget = canceled;
 }

 EventDispatchMediator* TouchEvent::createMediator()
 {
     return TouchEventDispatchMediator::create(this);
 }

 DEFINE_TRACE(TouchEvent)
 {
     visitor->trace(m_touches);
     visitor->trace(m_targetTouches);
     visitor->trace(m_changedTouches);
     UIEventWithKeyState::trace(visitor);
 }

 TouchEventDispatchMediator* TouchEventDispatchMediator::create(TouchEvent* touchEvent)
 {
     return new TouchEventDispatchMediator(touchEvent);
 }

 TouchEventDispatchMediator::TouchEventDispatchMediator(TouchEvent* touchEvent)
     : EventDispatchMediator(touchEvent)
 {
 }

 TouchEvent& TouchEventDispatchMediator::event() const
 {
     return toTouchEvent(EventDispatchMediator::event());
 }

 DispatchEventResult TouchEventDispatchMediator::dispatchEvent(EventDispatcher& dispatcher) const
 {
     event().eventPath().adjustForTouchEvent(event());
     return dispatcher.dispatch();
 }

 } // namespace blink
	/*
	* Copyright 2008, The Android Open Source Project
	* Copyright (C) 2012 Research In Motion Limited. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * 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 THE COPYRIGHT HOLDERS ``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 "core/events/TouchEvent.h"

	#include "bindings/core/v8/DOMWrapperWorld.h"
	#include "bindings/core/v8/ScriptState.h"
	#include "core/events/EventDispatcher.h"
	#include "core/frame/FrameConsole.h"
	#include "core/frame/FrameView.h"
	#include "core/frame/LocalDOMWindow.h"
	#include "core/inspector/ConsoleMessage.h"
	#include "platform/Histogram.h"

	namespace blink {

	namespace {

	// These offsets change indicies into the ListenerHistogram
	// enumeration. The addition of a series of offsets then
	// produces the resulting ListenerHistogram value.
	// TODO(dtapuska): Remove all of these histogram counts once
	// https://crbug.com/599609 is fixed.
	const size_t kTouchTargetHistogramRootScrollerOffset = 6;
	const size_t kTouchTargetHistogramScrollableDocumentOffset = 3;
	const size_t kTouchTargetHistogramAlreadyHandledOffset = 0;
	const size_t kTouchTargetHistogramNotHandledOffset = 1;
	const size_t kTouchTargetHistogramHandledOffset = 2;
	const size_t kCapturingOffset = 0;
	const size_t kAtTargetOffset = 12;
	const size_t kBubblingOffset = 24;

	enum TouchTargetAndDispatchResultType {
	// The following enums represent state captured during the CAPTURING_PHASE.
	CapturingNonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
	CapturingNonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
	CapturingNonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
	CapturingNonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
	CapturingNonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
	CapturingNonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
	CapturingRootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
	CapturingRootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
	CapturingRootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
	CapturingRootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
	CapturingRootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
	CapturingRootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.

	// The following enums represent state captured during the AT_TARGET phase.
	NonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
	NonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
	NonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
	NonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
	NonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
	NonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
	RootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
	RootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
	RootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
	RootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
	RootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
	RootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.

	// The following enums represent state captured during the BUBBLING_PHASE.
	BubblingNonRootScrollerNonScrollableAlreadyHandled, // Non-root-scroller, non-scrollable document, already handled.
	BubblingNonRootScrollerNonScrollableNotHandled, // Non-root-scroller, non-scrollable document, not handled.
	BubblingNonRootScrollerNonScrollableHandled, // Non-root-scroller, non-scrollable document, handled application.
	BubblingNonRootScrollerScrollableDocumentAlreadyHandled, // Non-root-scroller, scrollable document, already handled.
	BubblingNonRootScrollerScrollableDocumentNotHandled, // Non-root-scroller, scrollable document, not handled.
	BubblingNonRootScrollerScrollableDocumentHandled, // Non-root-scroller, scrollable document, handled application.
	BubblingRootScrollerNonScrollableAlreadyHandled, // Root-scroller, non-scrollable document, already handled.
	BubblingRootScrollerNonScrollableNotHandled, // Root-scroller, non-scrollable document, not handled.
	BubblingRootScrollerNonScrollableHandled, // Root-scroller, non-scrollable document, handled.
	BubblingRootScrollerScrollableDocumentAlreadyHandled, // Root-scroller, scrollable document, already handled.
	BubblingRootScrollerScrollableDocumentNotHandled, // Root-scroller, scrollable document, not handled.
	BubblingRootScrollerScrollableDocumentHandled, // Root-scroller, scrollable document, handled.
	TouchTargetAndDispatchResultTypeMax,
	};

	void logTouchTargetHistogram(EventTarget* eventTarget, unsigned short phase, bool defaultPreventedBeforeCurrentTarget, bool defaultPrevented)
	{
	int result = 0;
	Document* document = nullptr;

	switch (phase) {
	default:
	case Event::NONE:
	return;
	case Event::CAPTURING_PHASE:
	result += kCapturingOffset;
	break;
	case Event::AT_TARGET:
	result += kAtTargetOffset;
	break;
	case Event::BUBBLING_PHASE:
	result += kBubblingOffset;
	break;
	}

	if (const LocalDOMWindow* domWindow = eventTarget->toLocalDOMWindow()) {
	// Treat the window as a root scroller as well.
	document = domWindow->document();
	result += kTouchTargetHistogramRootScrollerOffset;
	} else if (Node* node = eventTarget->toNode()) {
	// Report if the target node is the document or body.
	if (node->isDocumentNode() \|\| node->document().documentElement() == node \|\| node->document().body() == node) {
	result += kTouchTargetHistogramRootScrollerOffset;
	}
	document = &node->document();
	}

	if (document) {
	FrameView* view = document->view();
	if (view && view->isScrollable())
	result += kTouchTargetHistogramScrollableDocumentOffset;
	}

	if (defaultPreventedBeforeCurrentTarget)
	result += kTouchTargetHistogramAlreadyHandledOffset;
	else if (defaultPrevented)
	result += kTouchTargetHistogramHandledOffset;
	else
	result += kTouchTargetHistogramNotHandledOffset;

	DEFINE_STATIC_LOCAL(EnumerationHistogram, rootDocumentListenerHistogram, ("Event.Touch.TargetAndDispatchResult2", TouchTargetAndDispatchResultTypeMax));
	rootDocumentListenerHistogram.count(static_cast<TouchTargetAndDispatchResultType>(result));
	}

	} // namespace

	TouchEvent::TouchEvent()
	: m_causesScrollingIfUncanceled(false)
	, m_firstTouchMoveOrStart(false)
	, m_defaultPreventedBeforeCurrentTarget(false)
	{
	}

	TouchEvent::TouchEvent(TouchList* touches, TouchList* targetTouches,
	TouchList* changedTouches, const AtomicString& type,
	AbstractView* view,
	PlatformEvent::Modifiers modifiers, bool cancelable, bool causesScrollingIfUncanceled, bool firstTouchMoveOrStart,
	double platformTimeStamp)
	// Pass a sourceCapabilities including the ability to fire touchevents when creating this touchevent, which is always created from input device capabilities from EventHandler.
	: UIEventWithKeyState(type, true, cancelable, view, 0, modifiers, platformTimeStamp, InputDeviceCapabilities::firesTouchEventsSourceCapabilities()),
	m_touches(touches),
	m_targetTouches(targetTouches),
	m_changedTouches(changedTouches),
	m_causesScrollingIfUncanceled(causesScrollingIfUncanceled),
	m_firstTouchMoveOrStart(firstTouchMoveOrStart),
	m_defaultPreventedBeforeCurrentTarget(false)
	{
	}

	TouchEvent::TouchEvent(const AtomicString& type, const TouchEventInit& initializer)
	: UIEventWithKeyState(type, initializer)
	, m_touches(TouchList::create(initializer.touches()))
	, m_targetTouches(TouchList::create(initializer.targetTouches()))
	, m_changedTouches(TouchList::create(initializer.changedTouches()))
	, m_causesScrollingIfUncanceled(false)
	, m_firstTouchMoveOrStart(false)
	, m_defaultPreventedBeforeCurrentTarget(false)
	{
	}

	TouchEvent::~TouchEvent()
	{
	}

	void TouchEvent::initTouchEvent(ScriptState* scriptState, TouchList* touches, TouchList* targetTouches,
	TouchList* changedTouches, const AtomicString& type,
	AbstractView* view,
	int, int, int, int,
	bool ctrlKey, bool altKey, bool shiftKey, bool metaKey)
	{
	if (isBeingDispatched())
	return;

	if (scriptState->world().isIsolatedWorld())
	UIEventWithKeyState::didCreateEventInIsolatedWorld(ctrlKey, altKey, shiftKey, metaKey);

	bool cancelable = true;
	if (type == EventTypeNames::touchcancel)
	cancelable = false;

	initUIEvent(type, true, cancelable, view, 0);

	m_touches = touches;
	m_targetTouches = targetTouches;
	m_changedTouches = changedTouches;
	initModifiers(ctrlKey, altKey, shiftKey, metaKey);
	}

	const AtomicString& TouchEvent::interfaceName() const
	{
	return EventNames::TouchEvent;
	}

	bool TouchEvent::isTouchEvent() const
	{
	return true;
	}

	void TouchEvent::preventDefault()
	{
	UIEventWithKeyState::preventDefault();

	// A common developer error is to wait too long before attempting to stop
	// scrolling by consuming a touchmove event. Generate a warning if this
	// event is uncancelable.
	if (!cancelable() && view() && view()->isLocalDOMWindow() && view()->frame()) {
	toLocalDOMWindow(view())->frame()->console().addMessage(ConsoleMessage::create(JSMessageSource, WarningMessageLevel,
	"Ignored attempt to cancel a " + type() + " event with cancelable=false, for example because scrolling is in progress and cannot be interrupted."));
	}
	}

	void TouchEvent::doneDispatchingEventAtCurrentTarget()
	{
	// Do not log for non-cancelable events, events that don't block
	// scrolling, have more than one touch point or aren't on the main frame.
	if (!cancelable() \|\| !m_firstTouchMoveOrStart \|\| !(m_touches && m_touches->length() == 1) \|\| !(view() && view()->frame() && view()->frame()->isMainFrame()))
	return;

	bool canceled = defaultPrevented();
	logTouchTargetHistogram(currentTarget(), eventPhase(), m_defaultPreventedBeforeCurrentTarget, canceled);
	m_defaultPreventedBeforeCurrentTarget = canceled;
	}

	EventDispatchMediator* TouchEvent::createMediator()
	{
	return TouchEventDispatchMediator::create(this);
	}

	DEFINE_TRACE(TouchEvent)
	{
	visitor->trace(m_touches);
	visitor->trace(m_targetTouches);
	visitor->trace(m_changedTouches);
	UIEventWithKeyState::trace(visitor);
	}

	TouchEventDispatchMediator* TouchEventDispatchMediator::create(TouchEvent* touchEvent)
	{
	return new TouchEventDispatchMediator(touchEvent);
	}

	TouchEventDispatchMediator::TouchEventDispatchMediator(TouchEvent* touchEvent)
	: EventDispatchMediator(touchEvent)
	{
	}

	TouchEvent& TouchEventDispatchMediator::event() const
	{
	return toTouchEvent(EventDispatchMediator::event());
	}

	DispatchEventResult TouchEventDispatchMediator::dispatchEvent(EventDispatcher& dispatcher) const
	{
	event().eventPath().adjustForTouchEvent(event());
	return dispatcher.dispatch();
	}

	} // namespace blink