File indexing completed on 2024-04-21 15:05:29

 /*
     SPDX-FileCopyrightText: 2013 Martin Gräßlin <mgraesslin@kde.org>
 
     SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
 */
 #ifndef NETTESTHELPER_H
 #define NETTESTHELPER_H
 
 #include <QByteArray>
 #include <memory>
 #include <xcb/xcb.h>
 
 #include "cptr_p.h"
 
 namespace KXUtils
 {
 
 /**
  * @brief Small helper class to fetch an intern atom through XCB.
  *
  * This class allows to request an intern atom and delay the retrieval of the reply
  * till it is needed. In case the reply is never retrieved the reply gets discarded
  * in the dtor. So there is no need to keep track manually about which atoms have been
  * retrieved.
  *
  * This class can be used as a drop-in replacement for everywhere where a xcb_atom_t is
  * needed as it implements the cast operator. The first time this operator is invoked it
  * will retrieve the reply. If the xcb request failed the value is @c XCB_ATOM_NONE, which
  * can be used to check whether the returned value is valid.
  *
  * This class has two modes of operations: a direct one which performs the request directly
  * during construction, and an indirect one which needs an explicit call to {@link fetch}.
  *
  * @code
  * Atom direct(QX11Info::connection(), QByteArrayLiteral("myAtomName"));
  * Atom indirect(QByteArrayLiteral("myAtomName"));
  * indirect.setConnection(QX11Info::connection());
  * indirect.fetch();
  *
  * if (direct == XCB_ATOM_NONE) {
  *     qWarning() << "Request failed";
  * }
  * if (indirect == XCB_ATOM_NONE) {
  *     qWarning() << "Request failed";
  * }
  * @endcode
  */
 class Atom
 {
 public:
     explicit Atom(const QByteArray &name)
         : m_connection(nullptr)
         , m_retrieved(false)
         , m_atom(XCB_ATOM_NONE)
         , m_name(name)
     {
         m_cookie.sequence = 0;
     }
     explicit Atom(xcb_connection_t *c, const QByteArray &name, bool onlyIfExists = false)
         : m_connection(c)
         , m_retrieved(false)
         , m_cookie(xcb_intern_atom_unchecked(m_connection, onlyIfExists, name.length(), name.constData()))
         , m_atom(XCB_ATOM_NONE)
         , m_name(name)
     {
     }
     Atom() Q_DECL_EQ_DELETE;
     Atom(const Atom &) Q_DECL_EQ_DELETE;
 
     ~Atom()
     {
         if (!m_retrieved && m_cookie.sequence) {
             xcb_discard_reply(m_connection, m_cookie.sequence);
         }
     }
 
     void setConnection(xcb_connection_t *c)
     {
         m_connection = c;
     }
 
     void fetch(bool onlyIfExists = false)
     {
         if (!m_connection) {
             // set connection first!
             return;
         }
         if (m_retrieved || m_cookie.sequence) {
             // already fetched, don't fetch again
             return;
         }
         m_cookie = xcb_intern_atom_unchecked(m_connection, onlyIfExists, m_name.length(), m_name.constData());
     }
 
     operator xcb_atom_t() const
     {
         (const_cast<Atom *>(this))->getReply();
         return m_atom;
     }
 
     const QByteArray &name() const
     {
         return m_name;
     }
 
 private:
     void getReply()
     {
         if (m_retrieved || !m_cookie.sequence) {
             return;
         }
         UniqueCPointer<xcb_intern_atom_reply_t> reply(xcb_intern_atom_reply(m_connection, m_cookie, nullptr));
         if (reply) {
             m_atom = reply->atom;
         }
         m_retrieved = true;
     }
     xcb_connection_t *m_connection;
     bool m_retrieved;
     xcb_intern_atom_cookie_t m_cookie;
     xcb_atom_t m_atom;
     QByteArray m_name;
 };
 
 inline xcb_window_t rootWindow(xcb_connection_t *c, int screen)
 {
     xcb_screen_iterator_t iter = xcb_setup_roots_iterator(xcb_get_setup(c));
     for (xcb_screen_iterator_t it = xcb_setup_roots_iterator(xcb_get_setup(c)); it.rem; --screen, xcb_screen_next(&it)) {
         if (screen == 0) {
             return iter.data->root;
         }
     }
     return XCB_WINDOW_NONE;
 }
 
 }
 
 #endif