kwin/src/wayland/xdgforeign_v2_interface.h

/*
    SPDX-FileCopyrightText: 2017 Marco Martin <notmart@gmail.com>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/
#pragma once

#include <QObject>

#include <KWaylandServer/kwaylandserver_export.h>

namespace KWaylandServer
{

class Display;
class SurfaceInterface;
class XdgForeignV2InterfacePrivate;

/**
 * This class encapsulates the server side logic of the XdgForeign protocol.
 * a process can export a surface to be identifiable by a server-wide unique
 * string handle, and another process can in turn import that surface, and set it
 * as transient parent for one of its own surfaces.
 * This parent relationship is traced by the transientChanged signal and the
 * transientFor method.
 */
class KWAYLANDSERVER_EXPORT XdgForeignV2Interface : public QObject
{
    Q_OBJECT
public:
    XdgForeignV2Interface(Display *display, QObject *parent = nullptr);
    ~XdgForeignV2Interface() override;

    /**
     * If a client did import a surface and set one of its own as child of the
     * imported one, this returns the mapping.
     * @param surface the child surface we want to search an imported transientParent for.
     * @returns the transient parent of the surface, if found, nullptr otherwise.
     */
    SurfaceInterface *transientFor(SurfaceInterface *surface);

Q_SIGNALS:
    /**
     * A surface got a new imported transient parent
     * @param parent is the surface exported by one client and imported into another, which will act as parent.
     * @param child is the surface that the importer client did set as child of the surface
     * that it imported.
     * If one of the two paramenters is nullptr, it means that a previously relation is not
     * valid anymore and either one of the surfaces has been unmapped, or the parent surface
     * is not exported anymore.
     */
    void transientChanged(KWaylandServer::SurfaceInterface *child, KWaylandServer::SurfaceInterface *parent);

private:
    friend class XdgExporterV2Interface;
    friend class XdgImporterV2Interface;
    QScopedPointer<XdgForeignV2InterfacePrivate> d;
};

}