/*
    SPDX-FileCopyrightText: 2014 Martin Gräßlin <mgraesslin@kde.org>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/
#ifndef WAYLAND_POINTER_H
#define WAYLAND_POINTER_H

#include <QObject>
#include <QPoint>

#include "KWayland/Client/kwaylandclient_export.h"

struct wl_pointer;

namespace KWayland
{
namespace Client
{
class Surface;

/**
 * @short Wrapper for the wl_pointer interface.
 *
 * This class is a convenient wrapper for the wl_pointer interface.
 *
 * To create an instance use Seat::createPointer.
 *
 * @see Seat
 **/
class KWAYLANDCLIENT_EXPORT Pointer : public QObject
{
    Q_OBJECT
public:
    enum class ButtonState {
        Released,
        Pressed,
    };
    enum class Axis {
        Vertical,
        Horizontal,
    };
    enum class AxisSource {
        Wheel,
        Finger,
        Continuous,
        WheelTilt,
    };
    explicit Pointer(QObject *parent = nullptr);
    ~Pointer() override;

    /**
     * @returns @c true if managing a wl_pointer.
     **/
    bool isValid() const;
    /**
     * Setup this Pointer to manage the @p pointer.
     * When using Seat::createPointer there is no need to call this
     * method.
     **/
    void setup(wl_pointer *pointer);
    /**
     * Releases the wl_pointer interface.
     * After the interface has been released the Pointer instance is no
     * longer valid and can be setup with another wl_pointer interface.
     *
     * This method is automatically invoked when the Seat which created this
     * Pointer gets released.
     **/
    void release();
    /**
     * Destroys the data held by this Pointer.
     * This method is supposed to be used when the connection to the Wayland
     * server goes away. If the connection is not valid anymore, it's not
     * possible to call release anymore as that calls into the Wayland
     * connection and the call would fail. This method cleans up the data, so
     * that the instance can be deleted or set up to a new wl_pointer interface
     * once there is a new connection available.
     *
     * This method is automatically invoked when the Seat which created this
     * Pointer gets destroyed.
     *
     * @see release
     **/
    void destroy();

    /**
     * Sets the cursor image for this Pointer.
     *
     * This has only an effect if a Surface of the same client is focused.
     *
     * @param surface The Surface pointing to the image data, if @c null the cursor will be hidden
     * @param hotspot The hotspot of the cursor image
     * @see hideCursor
     * @since 5.3
     **/
    void setCursor(Surface *surface, const QPoint &hotspot = QPoint());
    /**
     * Hides the cursor. Same as calling setCursor with @c null for surface.
     * @see setCursor
     * @since 5.3
     **/
    void hideCursor();

    /**
     * @returns The Surface the Pointer is on, may be @c null.
     **/
    Surface *enteredSurface() const;
    /**
     * @overload
     **/
    Surface *enteredSurface();

    operator wl_pointer *();
    operator wl_pointer *() const;

Q_SIGNALS:
    /**
     * Notification that this seat's pointer is focused on a certain surface.
     *
     * When an seat's focus enters a surface, the pointer image is undefined
     * and a client should respond to this event by setting an appropriate pointer
     * image with the set_cursor request.
     *
     * @param serial The serial for this enter
     * @param relativeToSurface Coordinates relative to the upper-left corner of the Surface.
     **/
    void entered(quint32 serial, const QPointF &relativeToSurface);
    /**
     * Notification that this seat's pointer is no longer focused on a certain surface.
     *
     * The leave notification is sent before the enter notification for the new focus.
     *
     * @param serial The serial of this leave event
     **/
    void left(quint32 serial);
    /**
     * Notification of pointer location change.
     *
     * @param relativeToSurface  Coordinates relative to the upper-left corner of the entered Surface.
     * @param time timestamp with millisecond granularity
     **/
    void motion(const QPointF &relativeToSurface, quint32 time);
    /**
     * Mouse button click and release notifications.
     *
     * The location of the click is given by the last motion or enter event.
     *
     * @param serial The serial of this button state change
     * @param time timestamp with millisecond granularity, with an undefined base.
     * @param button The button which got changed
     * @param state @c Released or @c Pressed
     **/
    void buttonStateChanged(quint32 serial, quint32 time, quint32 button, KWayland::Client::Pointer::ButtonState state);
    /**
     * Scroll and other axis notifications.
     *
     * @param time timestamp with millisecond granularity
     * @param axis @c Vertical or @c Horizontal
     * @param delta
     **/
    void axisChanged(quint32 time, KWayland::Client::Pointer::Axis axis, qreal delta);
    /**
     * Indicates the source of scroll and other axes.
     *
     * @since 5.59
     **/
    void axisSourceChanged(KWayland::Client::Pointer::AxisSource source);
    /**
     * Discrete step information for scroll and other axes.
     *
     * @since 5.59
     **/
    void axisDiscreteChanged(KWayland::Client::Pointer::Axis axis, qint32 discreteDelta);
    /**
     * Stop notification for scroll and other axes.
     *
     * @since 5.59
     **/
    void axisStopped(quint32 time, KWayland::Client::Pointer::Axis axis);

    /**
     * Indicates the end of a set of events that logically belong together.
     * A client is expected to accumulate the data in all events within the
     * frame before proceeding.
     * @since 5.45
     **/
    void frame();

private:
    class Private;
    QScopedPointer<Private> d;
};

}
}

Q_DECLARE_METATYPE(KWayland::Client::Pointer::ButtonState)
Q_DECLARE_METATYPE(KWayland::Client::Pointer::Axis)
Q_DECLARE_METATYPE(KWayland::Client::Pointer::AxisSource)

#endif