third_party/WebKit/Source/core/events/EventTarget.h

/*
 * 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, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
 *
 * 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.
 *
 */

#ifndef EventTarget_h
#define EventTarget_h

#include "bindings/core/v8/AddEventListenerOptionsOrBoolean.h"
#include "bindings/core/v8/EventListenerOptionsOrBoolean.h"
#include "bindings/core/v8/ScriptWrappable.h"
#include "core/CoreExport.h"
#include "core/EventNames.h"
#include "core/EventTargetNames.h"
#include "core/EventTypeNames.h"
#include "core/events/AddEventListenerOptionsResolved.h"
#include "core/events/EventDispatchResult.h"
#include "core/events/EventListenerMap.h"
#include "core/frame/UseCounter.h"
#include "platform/heap/Handle.h"
#include "wtf/Allocator.h"
#include "wtf/text/AtomicString.h"
#include <memory>

namespace blink {

class DOMWindow;
class Event;
class LocalDOMWindow;
class ExceptionState;
class MessagePort;
class Node;

struct FiringEventIterator {
  DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
  FiringEventIterator(const AtomicString& eventType,
                      size_t& iterator,
                      size_t& end)
      : eventType(eventType), iterator(iterator), end(end) {}

  const AtomicString& eventType;
  size_t& iterator;
  size_t& end;
};
using FiringEventIteratorVector = Vector<FiringEventIterator, 1>;

class CORE_EXPORT EventTargetData final
    : public GarbageCollectedFinalized<EventTargetData> {
  WTF_MAKE_NONCOPYABLE(EventTargetData);

 public:
  EventTargetData();
  ~EventTargetData();

  DECLARE_TRACE();

  EventListenerMap eventListenerMap;
  std::unique_ptr<FiringEventIteratorVector> firingEventIterators;
};

// This is the base class for all DOM event targets. To make your class an
// EventTarget, follow these steps:
// - Make your IDL interface inherit from EventTarget.
// - Inherit from EventTargetWithInlineData (only in rare cases should you
//   use EventTarget directly).
// - In your class declaration, EventTargetWithInlineData must come first in
//   the base class list. If your class is non-final, classes inheriting from
//   your class need to come first, too.
// - If you added an onfoo attribute, use DEFINE_ATTRIBUTE_EVENT_LISTENER(foo)
//   in your class declaration. Add "attribute EventHandler onfoo;" to the IDL
//   file.
// - Override EventTarget::interfaceName() and getExecutionContext(). The former
//   will typically return EventTargetNames::YourClassName. The latter will
//   return ActiveDOMObject::executionContext (if you are an ActiveDOMObject)
//   or the document you're in.
// - Your trace() method will need to call EventTargetWithInlineData::trace
//   depending on the base class of your class.
// - EventTargets do not support EAGERLY_FINALIZE. You need to use
//   a pre-finalizer instead.
class CORE_EXPORT EventTarget : public GarbageCollectedFinalized<EventTarget>,
                                public ScriptWrappable {
  DEFINE_WRAPPERTYPEINFO();

 public:
  virtual ~EventTarget();

  virtual const AtomicString& interfaceName() const = 0;
  virtual ExecutionContext* getExecutionContext() const = 0;

  virtual Node* toNode();
  virtual const DOMWindow* toDOMWindow() const;
  virtual const LocalDOMWindow* toLocalDOMWindow() const;
  virtual LocalDOMWindow* toLocalDOMWindow();
  virtual MessagePort* toMessagePort();

  bool addEventListener(const AtomicString& eventType,
                        EventListener*,
                        bool useCapture = false);
  bool addEventListener(const AtomicString& eventType,
                        EventListener*,
                        const AddEventListenerOptionsOrBoolean&);
  bool addEventListener(const AtomicString& eventType,
                        EventListener*,
                        AddEventListenerOptionsResolved&);

  bool removeEventListener(const AtomicString& eventType,
                           const EventListener*,
                           bool useCapture = false);
  bool removeEventListener(const AtomicString& eventType,
                           const EventListener*,
                           const EventListenerOptionsOrBoolean&);
  bool removeEventListener(const AtomicString& eventType,
                           const EventListener*,
                           EventListenerOptions&);
  virtual void removeAllEventListeners();

  DispatchEventResult dispatchEvent(Event*);

  // dispatchEventForBindings is intended to only be called from
  // javascript originated calls. This method will validate and may adjust
  // the Event object before dispatching.
  bool dispatchEventForBindings(Event*, ExceptionState&);
  virtual void uncaughtExceptionInEventHandler();

  // Used for legacy "onEvent" attribute APIs.
  bool setAttributeEventListener(const AtomicString& eventType, EventListener*);
  EventListener* getAttributeEventListener(const AtomicString& eventType);

  bool hasEventListeners() const;
  bool hasEventListeners(const AtomicString& eventType) const;
  bool hasCapturingEventListeners(const AtomicString& eventType);
  EventListenerVector* getEventListeners(const AtomicString& eventType);
  Vector<AtomicString> eventTypes();

  DispatchEventResult fireEventListeners(Event*);

  static DispatchEventResult dispatchEventResult(const Event&);

  DEFINE_INLINE_VIRTUAL_TRACE() {}

  DECLARE_VIRTUAL_TRACE_WRAPPERS();

  virtual bool keepEventInNode(Event*) { return false; }

 protected:
  EventTarget();

  virtual bool addEventListenerInternal(const AtomicString& eventType,
                                        EventListener*,
                                        const AddEventListenerOptionsResolved&);
  virtual bool removeEventListenerInternal(const AtomicString& eventType,
                                           const EventListener*,
                                           const EventListenerOptions&);

  // Called when an event listener has been successfully added.
  virtual void addedEventListener(const AtomicString& eventType,
                                  RegisteredEventListener&);

  // Called when an event listener is removed. The original registration
  // parameters of this event listener are available to be queried.
  virtual void removedEventListener(const AtomicString& eventType,
                                    const RegisteredEventListener&);

  virtual DispatchEventResult dispatchEventInternal(Event*);

  // Subclasses should likely not override these themselves; instead, they
  // should subclass EventTargetWithInlineData.
  virtual EventTargetData* eventTargetData() = 0;
  virtual EventTargetData& ensureEventTargetData() = 0;

 private:
  LocalDOMWindow* executingWindow();
  void setDefaultAddEventListenerOptions(const AtomicString& eventType,
                                         AddEventListenerOptionsResolved&);

  // UseCounts the event if it has the specified type. Returns true iff the
  // event type matches.
  bool checkTypeThenUseCount(const Event*,
                             const AtomicString&,
                             const UseCounter::Feature);

  bool fireEventListeners(Event*, EventTargetData*, EventListenerVector&);
  void countLegacyEvents(const AtomicString& legacyTypeName,
                         EventListenerVector*,
                         EventListenerVector*);

  bool clearAttributeEventListener(const AtomicString& eventType);

  friend class EventListenerIterator;
};

// EventTargetData is a GCed object, so it should not be used as a part of
// object. However, we intentionally use it as a part of object for performance,
// assuming that no one extracts a pointer of
// EventTargetWithInlineData::m_eventTargetData and store it to a Member etc.
class GC_PLUGIN_IGNORE("513199") CORE_EXPORT EventTargetWithInlineData
    : public EventTarget {
 public:
  ~EventTargetWithInlineData() override {}

  DEFINE_INLINE_VIRTUAL_TRACE() {
    visitor->trace(m_eventTargetData);
    EventTarget::trace(visitor);
  }

 protected:
  EventTargetData* eventTargetData() final { return &m_eventTargetData; }
  EventTargetData& ensureEventTargetData() final { return m_eventTargetData; }

 private:
  EventTargetData m_eventTargetData;
};

// FIXME: These macros should be split into separate DEFINE and DECLARE
// macros to avoid causing so many header includes.
#define DEFINE_ATTRIBUTE_EVENT_LISTENER(attribute)                        \
  EventListener* on##attribute() {                                        \
    return this->getAttributeEventListener(EventTypeNames::attribute);    \
  }                                                                       \
  void setOn##attribute(EventListener* listener) {                        \
    this->setAttributeEventListener(EventTypeNames::attribute, listener); \
  }

#define DEFINE_STATIC_ATTRIBUTE_EVENT_LISTENER(attribute)                    \
  static EventListener* on##attribute(EventTarget& eventTarget) {            \
    return eventTarget.getAttributeEventListener(EventTypeNames::attribute); \
  }                                                                          \
  static void setOn##attribute(EventTarget& eventTarget,                     \
                               EventListener* listener) {                    \
    eventTarget.setAttributeEventListener(EventTypeNames::attribute,         \
                                          listener);                         \
  }

#define DEFINE_WINDOW_ATTRIBUTE_EVENT_LISTENER(attribute)                 \
  EventListener* on##attribute() {                                        \
    return document().getWindowAttributeEventListener(                    \
        EventTypeNames::attribute);                                       \
  }                                                                       \
  void setOn##attribute(EventListener* listener) {                        \
    document().setWindowAttributeEventListener(EventTypeNames::attribute, \
                                               listener);                 \
  }

#define DEFINE_STATIC_WINDOW_ATTRIBUTE_EVENT_LISTENER(attribute)             \
  static EventListener* on##attribute(EventTarget& eventTarget) {            \
    if (Node* node = eventTarget.toNode())                                   \
      return node->document().getWindowAttributeEventListener(               \
          EventTypeNames::attribute);                                        \
    DCHECK(eventTarget.toLocalDOMWindow());                                  \
    return eventTarget.getAttributeEventListener(EventTypeNames::attribute); \
  }                                                                          \
  static void setOn##attribute(EventTarget& eventTarget,                     \
                               EventListener* listener) {                    \
    if (Node* node = eventTarget.toNode())                                   \
      node->document().setWindowAttributeEventListener(                      \
          EventTypeNames::attribute, listener);                              \
    else {                                                                   \
      DCHECK(eventTarget.toLocalDOMWindow());                                \
      eventTarget.setAttributeEventListener(EventTypeNames::attribute,       \
                                            listener);                       \
    }                                                                        \
  }

#define DEFINE_MAPPED_ATTRIBUTE_EVENT_LISTENER(attribute, eventName) \
  EventListener* on##attribute() {                                   \
    return getAttributeEventListener(EventTypeNames::eventName);     \
  }                                                                  \
  void setOn##attribute(EventListener* listener) {                   \
    setAttributeEventListener(EventTypeNames::eventName, listener);  \
  }

DISABLE_CFI_PERF
inline bool EventTarget::hasEventListeners() const {
  // FIXME: We should have a const version of eventTargetData.
  if (const EventTargetData* d =
          const_cast<EventTarget*>(this)->eventTargetData())
    return !d->eventListenerMap.isEmpty();
  return false;
}

DISABLE_CFI_PERF
inline bool EventTarget::hasEventListeners(
    const AtomicString& eventType) const {
  // FIXME: We should have const version of eventTargetData.
  if (const EventTargetData* d =
          const_cast<EventTarget*>(this)->eventTargetData())
    return d->eventListenerMap.contains(eventType);
  return false;
}

inline bool EventTarget::hasCapturingEventListeners(
    const AtomicString& eventType) {
  EventTargetData* d = eventTargetData();
  if (!d)
    return false;
  return d->eventListenerMap.containsCapturing(eventType);
}

}  // namespace blink

#endif  // EventTarget_h