/*
 * Copyright (C) 2001 Peter Kelly (pmk@post.com)
 * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
 * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
 * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple 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.
 *
 */

#ifndef Event_h
#define Event_h

#include "bindings/core/v8/ScriptWrappable.h"
#include "core/CoreExport.h"
#include "core/dom/DOMHighResTimeStamp.h"
#include "core/dom/DOMTimeStamp.h"
#include "core/events/EventInit.h"
#include "core/events/EventPath.h"
#include "platform/heap/Handle.h"
#include "wtf/Time.h"
#include "wtf/text/AtomicString.h"

namespace blink {

class DOMWrapperWorld;
class EventDispatchMediator;
class EventTarget;
class ExecutionContext;

class CORE_EXPORT Event : public GarbageCollectedFinalized<Event>,
                          public ScriptWrappable {
  DEFINE_WRAPPERTYPEINFO();

 public:
  enum PhaseType {
    kNone = 0,
    kCapturingPhase = 1,
    kAtTarget = 2,
    kBubblingPhase = 3
  };

  enum RailsMode {
    RailsModeFree = 0,
    RailsModeHorizontal = 1,
    RailsModeVertical = 2
  };

  enum class ComposedMode {
    Composed,
    Scoped,
  };

  enum class PassiveMode {
    // Not passive, default initialized.
    NotPassiveDefault,
    // Not passive, explicitly specified.
    NotPassive,
    // Passive, explicitly specified.
    Passive,
    // Passive, not explicitly specified and forced due to document level
    // listener.
    PassiveForcedDocumentLevel,
    // Passive, default initialized.
    PassiveDefault,
  };

  static Event* create() { return new Event; }

  // A factory for a simple event. The event doesn't bubble, and isn't
  // cancelable.
  // http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#fire-a-simple-event
  static Event* create(const AtomicString& type) {
    return new Event(type, false, false);
  }
  static Event* createCancelable(const AtomicString& type) {
    return new Event(type, false, true);
  }
  static Event* createBubble(const AtomicString& type) {
    return new Event(type, true, false);
  }
  static Event* createCancelableBubble(const AtomicString& type) {
    return new Event(type, true, true);
  }

  static Event* create(const AtomicString& type, const EventInit& initializer) {
    return new Event(type, initializer);
  }

  virtual ~Event();

  void initEvent(const AtomicString& type, bool canBubble, bool cancelable);
  void initEvent(const AtomicString& eventTypeArg,
                 bool canBubbleArg,
                 bool cancelableArg,
                 EventTarget* relatedTarget);

  const AtomicString& type() const { return m_type; }
  void setType(const AtomicString& type) { m_type = type; }

  EventTarget* target() const { return m_target.get(); }
  void setTarget(EventTarget*);

  EventTarget* currentTarget() const { return m_currentTarget; }
  void setCurrentTarget(EventTarget* currentTarget) {
    m_currentTarget = currentTarget;
  }

  // This callback is invoked when an event listener has been dispatched
  // at the current target. It should only be used to influence UMA metrics
  // and not change functionality since observing the presence of listeners
  // is dangerous.
  virtual void doneDispatchingEventAtCurrentTarget() {}

  unsigned short eventPhase() const { return m_eventPhase; }
  void setEventPhase(unsigned short eventPhase) { m_eventPhase = eventPhase; }

  bool bubbles() const { return m_canBubble; }
  bool cancelable() const { return m_cancelable; }
  bool composed() const { return m_composed; }
  bool isScopedInV0() const;

  // Event creation timestamp in milliseconds. It returns a DOMHighResTimeStamp
  // using the platform timestamp (see |m_platformTimeStamp|).
  // For more info see http://crbug.com/160524
  double timeStamp(ScriptState*) const;
  TimeTicks platformTimeStamp() const { return m_platformTimeStamp; }

  void stopPropagation() { m_propagationStopped = true; }
  void setStopPropagation(bool stopPropagation) {
    m_propagationStopped = stopPropagation;
  }
  void stopImmediatePropagation() { m_immediatePropagationStopped = true; }
  void setStopImmediatePropagation(bool stopImmediatePropagation) {
    m_immediatePropagationStopped = stopImmediatePropagation;
  }

  // IE Extensions
  EventTarget* srcElement() const {
    return target();
  }  // MSIE extension - "the object that fired the event"

  bool legacyReturnValue(ExecutionContext*) const;
  void setLegacyReturnValue(ExecutionContext*, bool returnValue);

  virtual const AtomicString& interfaceName() const;
  bool hasInterface(const AtomicString&) const;

  // These events are general classes of events.
  virtual bool isUIEvent() const;
  virtual bool isMouseEvent() const;
  virtual bool isFocusEvent() const;
  virtual bool isKeyboardEvent() const;
  virtual bool isTouchEvent() const;
  virtual bool isGestureEvent() const;
  virtual bool isWheelEvent() const;
  virtual bool isRelatedEvent() const;
  virtual bool isPointerEvent() const;
  virtual bool isInputEvent() const;

  // Drag events are a subset of mouse events.
  virtual bool isDragEvent() const;

  // These events lack a DOM interface.
  virtual bool isClipboardEvent() const;
  virtual bool isBeforeTextInsertedEvent() const;

  virtual bool isBeforeUnloadEvent() const;

  bool propagationStopped() const {
    return m_propagationStopped || m_immediatePropagationStopped;
  }
  bool immediatePropagationStopped() const {
    return m_immediatePropagationStopped;
  }
  bool wasInitialized() { return m_wasInitialized; }

  bool defaultPrevented() const { return m_defaultPrevented; }
  virtual void preventDefault();
  void setDefaultPrevented(bool defaultPrevented) {
    m_defaultPrevented = defaultPrevented;
  }

  bool defaultHandled() const { return m_defaultHandled; }
  void setDefaultHandled() { m_defaultHandled = true; }

  bool cancelBubble(ExecutionContext* = nullptr) const {
    return m_cancelBubble;
  }
  void setCancelBubble(ExecutionContext*, bool);

  Event* underlyingEvent() const { return m_underlyingEvent.get(); }
  void setUnderlyingEvent(Event*);

  bool hasEventPath() { return m_eventPath; }
  EventPath& eventPath() {
    DCHECK(m_eventPath);
    return *m_eventPath;
  }
  void initEventPath(Node&);

  HeapVector<Member<EventTarget>> path(ScriptState*) const;
  HeapVector<Member<EventTarget>> composedPath(ScriptState*) const;

  bool isBeingDispatched() const { return eventPhase(); }

  // Events that must not leak across isolated world, similar to how
  // ErrorEvent behaves, can override this method.
  virtual bool canBeDispatchedInWorld(const DOMWrapperWorld&) const {
    return true;
  }

  virtual EventDispatchMediator* createMediator();

  bool isTrusted() const { return m_isTrusted; }
  void setTrusted(bool value) { m_isTrusted = value; }

  void setComposed(bool composed) {
    DCHECK(!isBeingDispatched());
    m_composed = composed;
  }

  void setHandlingPassive(PassiveMode);

  bool preventDefaultCalledDuringPassive() const {
    return m_preventDefaultCalledDuringPassive;
  }

  bool preventDefaultCalledOnUncancelableEvent() const {
    return m_preventDefaultCalledOnUncancelableEvent;
  }

  DECLARE_VIRTUAL_TRACE();

 protected:
  Event();
  Event(const AtomicString& type,
        bool canBubble,
        bool cancelable,
        ComposedMode,
        TimeTicks platformTimeStamp);
  Event(const AtomicString& type,
        bool canBubble,
        bool cancelable,
        TimeTicks platformTimeStamp);
  Event(const AtomicString& type,
        bool canBubble,
        bool cancelable,
        ComposedMode = ComposedMode::Scoped);
  Event(const AtomicString& type, const EventInit&);

  virtual void receivedTarget();

  void setCanBubble(bool bubble) { m_canBubble = bubble; }

  PassiveMode handlingPassive() const { return m_handlingPassive; }

 private:
  enum EventPathMode { EmptyAfterDispatch, NonEmptyAfterDispatch };

  HeapVector<Member<EventTarget>> pathInternal(ScriptState*,
                                               EventPathMode) const;

  AtomicString m_type;
  unsigned m_canBubble : 1;
  unsigned m_cancelable : 1;
  unsigned m_composed : 1;
  unsigned m_isEventTypeScopedInV0 : 1;

  unsigned m_propagationStopped : 1;
  unsigned m_immediatePropagationStopped : 1;
  unsigned m_defaultPrevented : 1;
  unsigned m_defaultHandled : 1;
  unsigned m_cancelBubble : 1;
  unsigned m_wasInitialized : 1;
  unsigned m_isTrusted : 1;

  // Whether preventDefault was called when |m_handlingPassive| is
  // true. This field is reset on each call to setHandlingPassive.
  unsigned m_preventDefaultCalledDuringPassive : 1;
  // Whether preventDefault was called on uncancelable event.
  unsigned m_preventDefaultCalledOnUncancelableEvent : 1;

  PassiveMode m_handlingPassive;
  unsigned short m_eventPhase;
  Member<EventTarget> m_currentTarget;
  Member<EventTarget> m_target;
  Member<Event> m_underlyingEvent;
  Member<EventPath> m_eventPath;
  // The monotonic platform time in seconds, for input events it is the
  // event timestamp provided by the host OS and reported in the original
  // WebInputEvent instance.
  TimeTicks m_platformTimeStamp;
};

#define DEFINE_EVENT_TYPE_CASTS(typeName)                          \
  DEFINE_TYPE_CASTS(typeName, Event, event, event->is##typeName(), \
                    event.is##typeName())

}  // namespace blink

#endif  // Event_h