/*
 * 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 Apple Computer, Inc.
 *
 * 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 MouseRelatedEvent_h
#define MouseRelatedEvent_h

#include "core/CoreExport.h"
#include "core/events/MouseEventInit.h"
#include "core/events/UIEventWithKeyState.h"
#include "platform/geometry/LayoutPoint.h"

namespace blink {

// Internal only: Helper class for what's common between mouse and wheel events.
class CORE_EXPORT MouseRelatedEvent : public UIEventWithKeyState {
 public:
  enum class PositionType {
    Position,
    // Positionless mouse events are used, for example, for 'click' events from
    // keyboard input.  It's kind of surprising for a mouse event not to have a
    // position.
    Positionless
  };
  // Note that these values are adjusted to counter the effects of zoom, so that
  // values exposed via DOM APIs are invariant under zooming.
  int screenX() const { return m_screenLocation.x(); }
  int screenY() const { return m_screenLocation.y(); }
  const IntPoint& screenLocation() const { return m_screenLocation; }
  int clientX() const { return m_clientLocation.x().toInt(); }
  int clientY() const { return m_clientLocation.y().toInt(); }
  int movementX() const { return m_movementDelta.x().toInt(); }
  int movementY() const { return m_movementDelta.y().toInt(); }
  const LayoutPoint& clientLocation() const { return m_clientLocation; }
  int layerX();
  int layerY();
  int offsetX();
  int offsetY();
  int pageX() const;
  int pageY() const;
  int x() const;
  int y() const;
  bool hasPosition() const { return m_positionType == PositionType::Position; }

  // Page point in "absolute" coordinates (i.e. post-zoomed, page-relative
  // coords, usable with LayoutObject::absoluteToLocal) relative to view(), i.e.
  // the local frame.
  const LayoutPoint& absoluteLocation() const { return m_absoluteLocation; }
  void setAbsoluteLocation(const LayoutPoint& p) { m_absoluteLocation = p; }

  DECLARE_VIRTUAL_TRACE();

 protected:
  MouseRelatedEvent();
  // TODO(lanwei): Will make this argument non-optional and all the callers need
  // to provide sourceCapabilities even when it is null, see
  // https://crbug.com/476530.
  MouseRelatedEvent(const AtomicString& type,
                    bool canBubble,
                    bool cancelable,
                    AbstractView*,
                    int detail,
                    const IntPoint& screenLocation,
                    const IntPoint& rootFrameLocation,
                    const IntPoint& movementDelta,
                    PlatformEvent::Modifiers,
                    double platformTimeStamp,
                    PositionType,
                    InputDeviceCapabilities* sourceCapabilities = nullptr);

  MouseRelatedEvent(const AtomicString& type,
                    const MouseEventInit& initializer);

  void initCoordinates(const LayoutPoint& clientLocation);
  void receivedTarget() final;

  void computePageLocation();
  void computeRelativePosition();

  // Expose these so MouseEvent::initMouseEvent can set them.
  IntPoint m_screenLocation;
  LayoutPoint m_clientLocation;
  LayoutPoint m_movementDelta;

 private:
  LayoutPoint m_pageLocation;
  LayoutPoint m_layerLocation;
  LayoutPoint m_offsetLocation;
  LayoutPoint m_absoluteLocation;
  PositionType m_positionType;
  bool m_hasCachedRelativePosition;
};

}  // namespace blink

#endif  // MouseRelatedEvent_h