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

/*
 * 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(); }
    int clientY() const { return m_clientLocation.y(); }
    int movementX() const { return m_movementDelta.x(); }
    int movementY() const { return m_movementDelta.y(); }
    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