Source/WebCore/dom/EventDispatcher.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004-2017 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010, 2011, 2012, 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 #include "config.h"
 #include "EventDispatcher.h"

 #include "CompositionEvent.h"
 #include "EventContext.h"
 #include "EventNames.h"
 #include "EventPath.h"
 #include "Frame.h"
 #include "FrameLoader.h"
 #include "FrameView.h"
 #include "HTMLInputElement.h"
 #include "InputEvent.h"
 #include "KeyboardEvent.h"
 #include "Logging.h"
 #include "MouseEvent.h"
 #include "ScopedEventQueue.h"
 #include "ScriptDisallowedScope.h"
 #include "ShadowRoot.h"
 #include "TextEvent.h"
 #include "TouchEvent.h"
 #include <wtf/text/TextStream.h>

 namespace WebCore {

 void EventDispatcher::dispatchScopedEvent(Node& node, Event& event)
 {
     // Need to set the target here so the scoped event queue knows which node to dispatch to.
     event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
     ScopedEventQueue::singleton().enqueueEvent(event);
 }

 static void callDefaultEventHandlersInBubblingOrder(Event& event, const EventPath& path)
 {
     if (path.isEmpty())
         return;

     // Non-bubbling events call only one default event handler, the one for the target.
     path.contextAt(0).node()->defaultEventHandler(event);
     ASSERT(!event.defaultPrevented());

     if (event.defaultHandled() || !event.bubbles())
         return;

     size_t size = path.size();
     for (size_t i = 1; i < size; ++i) {
         path.contextAt(i).node()->defaultEventHandler(event);
         ASSERT(!event.defaultPrevented());
         if (event.defaultHandled())
             return;
     }
 }

 static bool isInShadowTree(EventTarget* target)
 {
     return is<Node>(target) && downcast<Node>(*target).isInShadowTree();
 }

 static void dispatchEventInDOM(Event& event, const EventPath& path)
 {
     // Invoke capturing event listeners in the reverse order.
     for (size_t i = path.size(); i > 0; --i) {
         const EventContext& eventContext = path.contextAt(i - 1);
         if (eventContext.currentTarget() == eventContext.target())
             event.setEventPhase(Event::AT_TARGET);
         else
             event.setEventPhase(Event::CAPTURING_PHASE);
         eventContext.handleLocalEvents(event, EventTarget::EventInvokePhase::Capturing);
         if (event.propagationStopped())
             return;
     }

     // Invoke bubbling event listeners.
     size_t size = path.size();
     for (size_t i = 0; i < size; ++i) {
         const EventContext& eventContext = path.contextAt(i);
         if (eventContext.currentTarget() == eventContext.target())
             event.setEventPhase(Event::AT_TARGET);
         else if (event.bubbles())
             event.setEventPhase(Event::BUBBLING_PHASE);
         else
             continue;
         eventContext.handleLocalEvents(event, EventTarget::EventInvokePhase::Bubbling);
         if (event.propagationStopped())
             return;
     }
 }

 static bool shouldSuppressEventDispatchInDOM(Node& node, Event& event)
 {
     if (!event.isTrusted())
         return false;

     auto frame = node.document().frame();
     if (!frame)
         return false;

     if (!frame->mainFrame().loader().shouldSuppressTextInputFromEditing())
         return false;

     if (is<TextEvent>(event)) {
         auto& textEvent = downcast<TextEvent>(event);
         return textEvent.isKeyboard() || textEvent.isComposition();
     }

     return is<CompositionEvent>(event) || is<InputEvent>(event) || is<KeyboardEvent>(event);
 }

 static HTMLInputElement* findInputElementInEventPath(const EventPath& path)
 {
     size_t size = path.size();
     for (size_t i = 0; i < size; ++i) {
         const EventContext& eventContext = path.contextAt(i);
         if (is<HTMLInputElement>(eventContext.currentTarget()))
             return downcast<HTMLInputElement>(eventContext.currentTarget());
     }
     return nullptr;
 }

 void EventDispatcher::dispatchEvent(Node& node, Event& event)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(ScriptDisallowedScope::InMainThread::isEventDispatchAllowedInSubtree(node));

     LOG_WITH_STREAM(Events, stream << "EventDispatcher::dispatchEvent " << event << " on node " << node);

     Ref protectedNode { node };
     RefPtr protectedView { node.document().view() };

     EventPath eventPath { node, event };

     std::optional<bool> shouldClearTargetsAfterDispatch;
     for (size_t i = eventPath.size(); i > 0; --i) {
         const EventContext& eventContext = eventPath.contextAt(i - 1);
         // FIXME: We should also set shouldClearTargetsAfterDispatch to true if an EventTarget object in eventContext's touch target list
         // is a node and its root is a shadow root.
         if (eventContext.target()) {
             shouldClearTargetsAfterDispatch = isInShadowTree(eventContext.target()) || isInShadowTree(eventContext.relatedTarget());
             break;
         }
     }

     ChildNodesLazySnapshot::takeChildNodesLazySnapshot();

     event.resetBeforeDispatch();

     event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
     if (!event.target())
         return;

     InputElementClickState clickHandlingState;

     bool isActivationEvent = event.type() == eventNames().clickEvent;
     RefPtr inputForLegacyPreActivationBehavior = dynamicDowncast<HTMLInputElement>(node);
     if (!inputForLegacyPreActivationBehavior && isActivationEvent && event.bubbles())
         inputForLegacyPreActivationBehavior = findInputElementInEventPath(eventPath);
     if (inputForLegacyPreActivationBehavior)
         inputForLegacyPreActivationBehavior->willDispatchEvent(event, clickHandlingState);

     if (shouldSuppressEventDispatchInDOM(node, event))
         event.stopPropagation();

     if (!event.propagationStopped() && !eventPath.isEmpty()) {
         event.setEventPath(eventPath);
         dispatchEventInDOM(event, eventPath);
     }

     event.resetAfterDispatch();

     if (clickHandlingState.stateful)
         inputForLegacyPreActivationBehavior->didDispatchClickEvent(event, clickHandlingState);

     // Call default event handlers. While the DOM does have a concept of preventing
     // default handling, the detail of which handlers are called is an internal
     // implementation detail and not part of the DOM.
     if (!event.defaultPrevented() && !event.defaultHandled() && !event.isDefaultEventHandlerIgnored()) {
         // FIXME: Not clear why we need to reset the target for the default event handlers.
         // We should research this, and remove this code if possible.
         auto* finalTarget = event.target();
         event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
         callDefaultEventHandlersInBubblingOrder(event, eventPath);
         event.setTarget(finalTarget);
     }

     if (shouldClearTargetsAfterDispatch.value_or(false)) {
         event.setTarget(nullptr);
         event.setRelatedTarget(nullptr);
         // FIXME: We should also clear the event's touch target list.
     }
 }

 template<typename T>
 static void dispatchEventWithType(const Vector<T*>& targets, Event& event)
 {
     ASSERT(targets.size() >= 1);
     ASSERT(*targets.begin());

     EventPath eventPath { targets };
     event.setTarget(*targets.begin());
     event.setEventPath(eventPath);
     event.resetBeforeDispatch();
     dispatchEventInDOM(event, eventPath);
     event.resetAfterDispatch();
 }

 void EventDispatcher::dispatchEvent(const Vector<EventTarget*>& targets, Event& event)
 {
     dispatchEventWithType<EventTarget>(targets, event);
 }

 }
	/*
	* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
	* (C) 1999 Antti Koivisto (koivisto@kde.org)
	* (C) 2001 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2004-2017 Apple Inc. All rights reserved.
	* Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
	* Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
	* Copyright (C) 2010, 2011, 2012, 2013 Google Inc. All rights reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	#include "config.h"
	#include "EventDispatcher.h"

	#include "CompositionEvent.h"
	#include "EventContext.h"
	#include "EventNames.h"
	#include "EventPath.h"
	#include "Frame.h"
	#include "FrameLoader.h"
	#include "FrameView.h"
	#include "HTMLInputElement.h"
	#include "InputEvent.h"
	#include "KeyboardEvent.h"
	#include "Logging.h"
	#include "MouseEvent.h"
	#include "ScopedEventQueue.h"
	#include "ScriptDisallowedScope.h"
	#include "ShadowRoot.h"
	#include "TextEvent.h"
	#include "TouchEvent.h"
	#include <wtf/text/TextStream.h>

	namespace WebCore {

	void EventDispatcher::dispatchScopedEvent(Node& node, Event& event)
	{
	// Need to set the target here so the scoped event queue knows which node to dispatch to.
	event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
	ScopedEventQueue::singleton().enqueueEvent(event);
	}

	static void callDefaultEventHandlersInBubblingOrder(Event& event, const EventPath& path)
	{
	if (path.isEmpty())
	return;

	// Non-bubbling events call only one default event handler, the one for the target.
	path.contextAt(0).node()->defaultEventHandler(event);
	ASSERT(!event.defaultPrevented());

	if (event.defaultHandled() \|\| !event.bubbles())
	return;

	size_t size = path.size();
	for (size_t i = 1; i < size; ++i) {
	path.contextAt(i).node()->defaultEventHandler(event);
	ASSERT(!event.defaultPrevented());
	if (event.defaultHandled())
	return;
	}
	}

	static bool isInShadowTree(EventTarget* target)
	{
	return is<Node>(target) && downcast<Node>(*target).isInShadowTree();
	}

	static void dispatchEventInDOM(Event& event, const EventPath& path)
	{
	// Invoke capturing event listeners in the reverse order.
	for (size_t i = path.size(); i > 0; --i) {
	const EventContext& eventContext = path.contextAt(i - 1);
	if (eventContext.currentTarget() == eventContext.target())
	event.setEventPhase(Event::AT_TARGET);
	else
	event.setEventPhase(Event::CAPTURING_PHASE);
	eventContext.handleLocalEvents(event, EventTarget::EventInvokePhase::Capturing);
	if (event.propagationStopped())
	return;
	}

	// Invoke bubbling event listeners.
	size_t size = path.size();
	for (size_t i = 0; i < size; ++i) {
	const EventContext& eventContext = path.contextAt(i);
	if (eventContext.currentTarget() == eventContext.target())
	event.setEventPhase(Event::AT_TARGET);
	else if (event.bubbles())
	event.setEventPhase(Event::BUBBLING_PHASE);
	else
	continue;
	eventContext.handleLocalEvents(event, EventTarget::EventInvokePhase::Bubbling);
	if (event.propagationStopped())
	return;
	}
	}

	static bool shouldSuppressEventDispatchInDOM(Node& node, Event& event)
	{
	if (!event.isTrusted())
	return false;

	auto frame = node.document().frame();
	if (!frame)
	return false;

	if (!frame->mainFrame().loader().shouldSuppressTextInputFromEditing())
	return false;

	if (is<TextEvent>(event)) {
	auto& textEvent = downcast<TextEvent>(event);
	return textEvent.isKeyboard() \|\| textEvent.isComposition();
	}

	return is<CompositionEvent>(event) \|\| is<InputEvent>(event) \|\| is<KeyboardEvent>(event);
	}

	static HTMLInputElement* findInputElementInEventPath(const EventPath& path)
	{
	size_t size = path.size();
	for (size_t i = 0; i < size; ++i) {
	const EventContext& eventContext = path.contextAt(i);
	if (is<HTMLInputElement>(eventContext.currentTarget()))
	return downcast<HTMLInputElement>(eventContext.currentTarget());
	}
	return nullptr;
	}

	void EventDispatcher::dispatchEvent(Node& node, Event& event)
	{
	ASSERT_WITH_SECURITY_IMPLICATION(ScriptDisallowedScope::InMainThread::isEventDispatchAllowedInSubtree(node));

	LOG_WITH_STREAM(Events, stream << "EventDispatcher::dispatchEvent " << event << " on node " << node);

	Ref protectedNode { node };
	RefPtr protectedView { node.document().view() };

	EventPath eventPath { node, event };

	std::optional<bool> shouldClearTargetsAfterDispatch;
	for (size_t i = eventPath.size(); i > 0; --i) {
	const EventContext& eventContext = eventPath.contextAt(i - 1);
	// FIXME: We should also set shouldClearTargetsAfterDispatch to true if an EventTarget object in eventContext's touch target list
	// is a node and its root is a shadow root.
	if (eventContext.target()) {
	shouldClearTargetsAfterDispatch = isInShadowTree(eventContext.target()) \|\| isInShadowTree(eventContext.relatedTarget());
	break;
	}
	}

	ChildNodesLazySnapshot::takeChildNodesLazySnapshot();

	event.resetBeforeDispatch();

	event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
	if (!event.target())
	return;

	InputElementClickState clickHandlingState;

	bool isActivationEvent = event.type() == eventNames().clickEvent;
	RefPtr inputForLegacyPreActivationBehavior = dynamicDowncast<HTMLInputElement>(node);
	if (!inputForLegacyPreActivationBehavior && isActivationEvent && event.bubbles())
	inputForLegacyPreActivationBehavior = findInputElementInEventPath(eventPath);
	if (inputForLegacyPreActivationBehavior)
	inputForLegacyPreActivationBehavior->willDispatchEvent(event, clickHandlingState);

	if (shouldSuppressEventDispatchInDOM(node, event))
	event.stopPropagation();

	if (!event.propagationStopped() && !eventPath.isEmpty()) {
	event.setEventPath(eventPath);
	dispatchEventInDOM(event, eventPath);
	}

	event.resetAfterDispatch();

	if (clickHandlingState.stateful)
	inputForLegacyPreActivationBehavior->didDispatchClickEvent(event, clickHandlingState);

	// Call default event handlers. While the DOM does have a concept of preventing
	// default handling, the detail of which handlers are called is an internal
	// implementation detail and not part of the DOM.
	if (!event.defaultPrevented() && !event.defaultHandled() && !event.isDefaultEventHandlerIgnored()) {
	// FIXME: Not clear why we need to reset the target for the default event handlers.
	// We should research this, and remove this code if possible.
	auto* finalTarget = event.target();
	event.setTarget(EventPath::eventTargetRespectingTargetRules(node));
	callDefaultEventHandlersInBubblingOrder(event, eventPath);
	event.setTarget(finalTarget);
	}

	if (shouldClearTargetsAfterDispatch.value_or(false)) {
	event.setTarget(nullptr);
	event.setRelatedTarget(nullptr);
	// FIXME: We should also clear the event's touch target list.
	}
	}

	template<typename T>
	static void dispatchEventWithType(const Vector<T*>& targets, Event& event)
	{
	ASSERT(targets.size() >= 1);
	ASSERT(*targets.begin());

	EventPath eventPath { targets };
	event.setTarget(*targets.begin());
	event.setEventPath(eventPath);
	event.resetBeforeDispatch();
	dispatchEventInDOM(event, eventPath);
	event.resetAfterDispatch();
	}

	void EventDispatcher::dispatchEvent(const Vector<EventTarget*>& targets, Event& event)
	{
	dispatchEventWithType<EventTarget>(targets, event);
	}

	}