File indexing completed on 2024-04-21 03:59:22

 /*
     SPDX-FileCopyrightText: 2001-2003 Lubos Lunak <l.lunak@kde.org>
     SPDX-FileCopyrightText: 2012 David Faure <faure@kde.org>
 
     SPDX-License-Identifier: MIT
 */
 
 #include "kxmessages.h"
 #include "cptr_p.h"
 #include "kxutils_p.h"
 
 #if KWINDOWSYSTEM_HAVE_X11
 
 #include <QAbstractNativeEventFilter>
 #include <QCoreApplication>
 #include <QDebug>
 #include <QWindow> // WId
 
 #include <X11/Xlib.h>
 
 #include <private/qtx11extras_p.h>
 
 class XcbAtom
 {
 public:
     explicit XcbAtom(const QByteArray &name, bool onlyIfExists = false)
         : m_name(name)
         , m_atom(XCB_ATOM_NONE)
         , m_connection(nullptr)
         , m_retrieved(false)
         , m_onlyIfExists(onlyIfExists)
     {
         m_cookie.sequence = 0;
     }
     explicit XcbAtom(xcb_connection_t *c, const QByteArray &name, bool onlyIfExists = false)
         : m_name(name)
         , m_atom(XCB_ATOM_NONE)
         , m_cookie(xcb_intern_atom_unchecked(c, onlyIfExists, name.length(), name.constData()))
         , m_connection(c)
         , m_retrieved(false)
         , m_onlyIfExists(onlyIfExists)
     {
     }
 
     ~XcbAtom()
     {
         if (!m_retrieved && m_cookie.sequence && m_connection) {
             xcb_discard_reply(m_connection, m_cookie.sequence);
         }
     }
 
     operator xcb_atom_t()
     {
         getReply();
         return m_atom;
     }
 
     inline const QByteArray &name() const
     {
         return m_name;
     }
 
     inline void setConnection(xcb_connection_t *c)
     {
         m_connection = c;
     }
 
     inline void fetch()
     {
         if (!m_connection || m_name.isEmpty()) {
             return;
         }
         m_cookie = xcb_intern_atom_unchecked(m_connection, m_onlyIfExists, m_name.length(), m_name.constData());
     }
 
 private:
     void getReply()
     {
         if (m_retrieved || !m_cookie.sequence || !m_connection) {
             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;
     }
     QByteArray m_name;
     xcb_atom_t m_atom;
     xcb_intern_atom_cookie_t m_cookie;
     xcb_connection_t *m_connection;
     bool m_retrieved;
     bool m_onlyIfExists;
 };
 
 class KXMessagesPrivate : public QAbstractNativeEventFilter
 {
 public:
     KXMessagesPrivate(KXMessages *parent, const char *acceptBroadcast, xcb_connection_t *c, xcb_window_t root)
         : accept_atom1(acceptBroadcast ? QByteArray(acceptBroadcast) + QByteArrayLiteral("_BEGIN") : QByteArray())
         , accept_atom2(acceptBroadcast ? QByteArray(acceptBroadcast) : QByteArray())
         , handle(new QWindow)
         , q(parent)
         , valid(c)
         , connection(c)
         , rootWindow(root)
     {
         if (acceptBroadcast) {
             accept_atom1.setConnection(c);
             accept_atom1.fetch();
             accept_atom2.setConnection(c);
             accept_atom2.fetch();
             QCoreApplication::instance()->installNativeEventFilter(this);
         }
     }
     XcbAtom accept_atom1;
     XcbAtom accept_atom2;
     QMap<WId, QByteArray> incoming_messages;
     std::unique_ptr<QWindow> handle;
     KXMessages *q;
     bool valid;
     xcb_connection_t *connection;
     xcb_window_t rootWindow;
 
     bool nativeEventFilter(const QByteArray &eventType, void *message, qintptr *) override
     {
         // A faster comparison than eventType != "xcb_generic_event_t"
         if (eventType[0] != 'x') {
             return false;
         }
         xcb_generic_event_t *event = reinterpret_cast<xcb_generic_event_t *>(message);
         uint response_type = event->response_type & ~0x80;
         if (response_type != XCB_CLIENT_MESSAGE) {
             return false;
         }
         xcb_client_message_event_t *cm_event = reinterpret_cast<xcb_client_message_event_t *>(event);
         if (cm_event->format != 8) {
             return false;
         }
         if (cm_event->type != accept_atom1 && cm_event->type != accept_atom2) {
             return false;
         }
         char buf[21]; // can't be longer
         // Copy the data in order to null-terminate it
         qstrncpy(buf, reinterpret_cast<char *>(cm_event->data.data8), 21);
         // qDebug() << cm_event->window << "buf=\"" << buf << "\" atom=" << (cm_event->type == accept_atom1 ? "atom1" : "atom2");
         if (incoming_messages.contains(cm_event->window)) {
             if (cm_event->type == accept_atom1)
             // two different messages on the same window at the same time shouldn't happen anyway
             {
                 incoming_messages[cm_event->window] = QByteArray();
             }
             incoming_messages[cm_event->window] += buf;
         } else {
             if (cm_event->type == accept_atom2) {
                 return false; // middle of message, but we don't have the beginning
             }
             incoming_messages[cm_event->window] = buf;
         }
         if (strlen(buf) < 20) { // last message fragment
             Q_EMIT q->gotMessage(QString::fromUtf8(incoming_messages[cm_event->window].constData()));
             incoming_messages.remove(cm_event->window);
         }
         return false; // lets other KXMessages instances get the event too
     }
 };
 
 static void
 send_message_internal(xcb_window_t w, const QString &msg, xcb_connection_t *c, xcb_atom_t leadingMessage, xcb_atom_t followingMessage, xcb_window_t handle);
 
 KXMessages::KXMessages(const char *accept_broadcast_P, QObject *parent_P)
     : QObject(parent_P)
     , d(new KXMessagesPrivate(this,
                               accept_broadcast_P,
                               QX11Info::isPlatformX11() ? QX11Info::connection() : nullptr,
                               QX11Info::isPlatformX11() ? QX11Info::appRootWindow() : 0))
 {
 }
 
 KXMessages::KXMessages(xcb_connection_t *connection, xcb_window_t rootWindow, const char *accept_broadcast, QObject *parent)
     : QObject(parent)
     , d(new KXMessagesPrivate(this, accept_broadcast, connection, rootWindow))
 {
 }
 
 KXMessages::~KXMessages()
 {
     delete d;
 }
 
 static xcb_screen_t *defaultScreen(xcb_connection_t *c, int screen)
 {
     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 it.data;
         }
     }
     return nullptr;
 }
 
 void KXMessages::broadcastMessage(const char *msg_type_P, const QString &message_P, int screen_P)
 {
     if (!d->valid) {
         qWarning() << "KXMessages used on non-X11 platform! This is an application bug.";
         return;
     }
     const QByteArray msg(msg_type_P);
     XcbAtom a2(d->connection, msg);
     XcbAtom a1(d->connection, msg + QByteArrayLiteral("_BEGIN"));
     xcb_window_t root = screen_P == -1 ? d->rootWindow : defaultScreen(d->connection, screen_P)->root;
     send_message_internal(root, message_P, d->connection, a1, a2, d->handle->winId());
 }
 
 bool KXMessages::broadcastMessageX(xcb_connection_t *c, const char *msg_type_P, const QString &message, int screenNumber)
 {
     if (!c) {
         return false;
     }
     const QByteArray msg(msg_type_P);
     XcbAtom a2(c, msg);
     XcbAtom a1(c, msg + QByteArrayLiteral("_BEGIN"));
     const xcb_screen_t *screen = defaultScreen(c, screenNumber);
     if (!screen) {
         return false;
     }
     const xcb_window_t root = screen->root;
     const xcb_window_t win = xcb_generate_id(c);
     xcb_create_window(c, XCB_COPY_FROM_PARENT, win, root, 0, 0, 1, 1, 0, XCB_COPY_FROM_PARENT, XCB_COPY_FROM_PARENT, 0, nullptr);
     send_message_internal(root, message, c, a1, a2, win);
     xcb_destroy_window(c, win);
     return true;
 }
 
 static void
 send_message_internal(xcb_window_t w, const QString &msg_P, xcb_connection_t *c, xcb_atom_t leadingMessage, xcb_atom_t followingMessage, xcb_window_t handle)
 {
     unsigned int pos = 0;
     QByteArray msg = msg_P.toUtf8();
     const size_t len = msg.size();
 
     xcb_client_message_event_t event;
     event.response_type = XCB_CLIENT_MESSAGE;
     event.format = 8;
     event.sequence = 0;
     event.window = handle;
     event.type = leadingMessage;
 
     do {
         unsigned int i;
         for (i = 0; i < 20 && i + pos < len; ++i) {
             event.data.data8[i] = msg[i + pos];
         }
         for (; i < 20; ++i) {
             event.data.data8[i] = 0;
         }
         xcb_send_event(c, false, w, XCB_EVENT_MASK_PROPERTY_CHANGE, (const char *)&event);
         event.type = followingMessage;
         pos += i;
     } while (pos <= len);
 
     xcb_flush(c);
 }
 
 #endif
 
 #include "moc_kxmessages.cpp"