/****************************************************************************
Copyright 2015  Martin Gräßlin <mgraesslin@kde.org>

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) version 3, or any
later version accepted by the membership of KDE e.V. (or its
successor approved by the membership of KDE e.V.), which shall
act as a proxy defined in Section 6 of version 3 of the license.

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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library.  If not, see <http://www.gnu.org/licenses/>.
****************************************************************************/
#ifndef KWAYLAND_CLIENT_SERVER_DECORATION_H
#define KWAYLAND_CLIENT_SERVER_DECORATION_H

#include <QObject>

#include <KWayland/Client/kwaylandclient_export.h>

struct org_kde_kwin_server_decoration_manager;
struct org_kde_kwin_server_decoration;
struct wl_surface;

namespace KWayland
{
namespace Client
{

class EventQueue;
class Surface;
class ServerSideDecoration;

/**
 * @short Wrapper for the org_kde_kwin_server_decoration_manager interface.
 *
 * This class provides a convenient wrapper for the org_kde_kwin_server_decoration_manager interface.
 *
 * To use this class one needs to interact with the Registry. There are two
 * possible ways to create the ServerSideDecorationManager interface:
 * @code
 * ServerSideDecorationManager *c = registry->createServerSideDecorationManager(name, version);
 * @endcode
 *
 * This creates the ServerSideDecorationManager and sets it up directly. As an alternative this
 * can also be done in a more low level way:
 * @code
 * ServerSideDecorationManager *c = new ServerSideDecorationManager;
 * c->setup(registry->bindServerSideDecorationManager(name, version));
 * @endcode
 *
 * The ServerSideDecorationManager can be used as a drop-in replacement for any org_kde_kwin_server_decoration_manager
 * pointer as it provides matching cast operators.
 *
 * @see Registry
 * @since 5.6
 **/
class KWAYLANDCLIENT_EXPORT ServerSideDecorationManager : public QObject
{
    Q_OBJECT
public:
    /**
     * Creates a new ServerSideDecorationManager.
     * Note: after constructing the ServerSideDecorationManager it is not yet valid and one needs
     * to call setup. In order to get a ready-to-use ServerSideDecorationManager prefer using
     * Registry::createServerSideDecorationManager.
     **/
    explicit ServerSideDecorationManager(QObject *parent = nullptr);
    virtual ~ServerSideDecorationManager();

    /**
     * Setup this ServerSideDecorationManager to manage the @p serversidedecorationmanager.
     * When using Registry::createServerSideDecorationManager there is no need to call this
     * method.
     **/
    void setup(org_kde_kwin_server_decoration_manager *serversidedecorationmanager);
    /**
     * @returns @c true if managing a org_kde_kwin_server_decoration_manager.
     **/
    bool isValid() const;
    /**
     * Releases the org_kde_kwin_server_decoration_manager interface.
     * After the interface has been released the ServerSideDecorationManager instance is no
     * longer valid and can be setup with another org_kde_kwin_server_decoration_manager interface.
     **/
    void release();
    /**
     * Destroys the data held by this ServerSideDecorationManager.
     * 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 org_kde_kwin_server_decoration_manager interface
     * once there is a new connection available.
     *
     * It is suggested to connect this method to ConnectionThread::connectionDied:
     * @code
     * connect(connection, &ConnectionThread::connectionDied, serversidedecorationmanager, &ServerSideDecorationManager::destroy);
     * @endcode
     *
     * @see release
     **/
    void destroy();

    /**
     * Sets the @p queue to use for creating objects with this ServerSideDecorationManager.
     **/
    void setEventQueue(EventQueue *queue);
    /**
     * @returns The event queue to use for creating objects with this ServerSideDecorationManager.
     **/
    EventQueue *eventQueue();

    ServerSideDecoration *create(Surface *surface, QObject *parent = nullptr);
    ServerSideDecoration *create(wl_surface *surface, QObject *parent = nullptr);

    operator org_kde_kwin_server_decoration_manager*();
    operator org_kde_kwin_server_decoration_manager*() const;

Q_SIGNALS:
    /**
     * The corresponding global for this interface on the Registry got removed.
     *
     * This signal gets only emitted if the ServerSideDecorationManager got created by
     * Registry::createServerSideDecorationManager
     **/
    void removed();

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

/**
 * @brief Describing how a Surface should be decorated.
 *
 * Use ServerSideDecorationManager::create to create a ServerSideDecoration.
 *
 * @see ServerSideDecorationManager
 * @since 5.6
 **/
class KWAYLANDCLIENT_EXPORT ServerSideDecoration : public QObject
{
    Q_OBJECT
public:
    virtual ~ServerSideDecoration();

    /**
     * Setup this ServerSideDecoration to manage the @p serversidedecoration.
     * When using ServerSideDecorationManager::createServerSideDecoration there is no need to call this
     * method.
     **/
    void setup(org_kde_kwin_server_decoration *serversidedecoration);
    /**
     * @returns @c true if managing a org_kde_kwin_server_decoration.
     **/
    bool isValid() const;
    /**
     * Releases the org_kde_kwin_server_decoration interface.
     * After the interface has been released the ServerSideDecoration instance is no
     * longer valid and can be setup with another org_kde_kwin_server_decoration interface.
     **/
    void release();
    /**
     * Destroys the data held by this ServerSideDecoration.
     * 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 org_kde_kwin_server_decoration interface
     * once there is a new connection available.
     *
     * It is suggested to connect this method to ConnectionThread::connectionDied:
     * @code
     * connect(connection, &ConnectionThread::connectionDied, serversidedecoration, &ServerSideDecoration::destroy);
     * @endcode
     *
     * @see release
     **/
    void destroy();

    /**
     * Decoration mode used for the Surface.
     **/
    enum class Mode {
        /**
         * Undecorated: neither client, nor server provide decoration. Example: popups.
         **/
        None,
        /**
         * The decoration is part of the surface.
         **/
        Client,
        /**
         * The surface gets embedded into a decoration frame provided by the Server.
         **/
        Server,
    };

    /**
     * Request the decoration @p mode for the Surface.
     *
     * The server will acknowledge the change which will trigger the modeChanged signal.
     *
     * @see mode
     * @see modeChanged
     **/
    void requestMode(Mode mode);

    /**
     * @returns The current decoration mode for the Surface.
     *
     * The mode represents the mode pushed from the Server.
     * @see requestMode
     * @see modeChanged
     **/
    Mode mode() const;

    operator org_kde_kwin_server_decoration*();
    operator org_kde_kwin_server_decoration*() const;

Q_SIGNALS:
    /**
     * Emitted whenever the Server changes the decoration mode for the Surface.
     * @see requestMode
     * @see mode
     **/
    void modeChanged();

private:
    friend class ServerSideDecorationManager;
    explicit ServerSideDecoration(QObject *parent = nullptr);
    class Private;
    QScopedPointer<Private> d;
};


}
}

Q_DECLARE_METATYPE(KWayland::Client::ServerSideDecoration::Mode)

#endif
