File indexing completed on 2025-01-12 11:03:14

 /*
     SPDX-FileCopyrightText: 2013 Marco Martin <mart@kde.org>
     SPDX-FileCopyrightText: 2021 Aleix Pol Gonzalez <aleixpol@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "primaryoutputwatcher.h"
 
 #include <KWindowSystem>
 #include <QDebug>
 #include <QGuiApplication>
 #include <QScreen>
 
 #include "qwayland-kde-primary-output-v1.h"
 #include <KWayland/Client/connection_thread.h>
 #include <KWayland/Client/registry.h>
 
 #include <config-latte.h>
 #if HAVE_X11
 #include <QTimer> //Used only in x11 case
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 #include <private/qtx11extras_p.h>
 #else
 #include <QX11Info>
 #endif
 #include <xcb/randr.h>
 #include <xcb/xcb.h>
 #include <xcb/xcb_event.h>
 #endif
 
 class WaylandPrimaryOutput : public QObject, public QtWayland::kde_primary_output_v1
 {
     Q_OBJECT
 public:
     WaylandPrimaryOutput(struct ::wl_registry *registry, int id, int version, QObject *parent)
         : QObject(parent)
         , QtWayland::kde_primary_output_v1(registry, id, version)
     {
     }
 
     void kde_primary_output_v1_primary_output(const QString &outputName) override
     {
         Q_EMIT primaryOutputChanged(outputName);
     }
 
 Q_SIGNALS:
     void primaryOutputChanged(const QString &outputName);
 };
 
 PrimaryOutputWatcher::PrimaryOutputWatcher(QObject *parent)
     : QObject(parent)
 {
 #if HAVE_X11
     if (KWindowSystem::isPlatformX11()) {
         m_primaryOutputName = qGuiApp->primaryScreen()->name();
         qGuiApp->installNativeEventFilter(this);
         const xcb_query_extension_reply_t *reply = xcb_get_extension_data(QX11Info::connection(), &xcb_randr_id);
         m_xrandrExtensionOffset = reply->first_event;
         setPrimaryOutputName(qGuiApp->primaryScreen()->name());
         connect(qGuiApp, &QGuiApplication::primaryScreenChanged, this, [this](QScreen *newPrimary) {
             setPrimaryOutputName(newPrimary->name());
         });
     }
 #endif
     if (KWindowSystem::isPlatformWayland()) {
         setupRegistry();
     }
 }
 
 void PrimaryOutputWatcher::setPrimaryOutputName(const QString &newOutputName)
 {
     if (newOutputName != m_primaryOutputName) {
         const QString oldOutputName = m_primaryOutputName;
         m_primaryOutputName = newOutputName;
         Q_EMIT primaryOutputNameChanged(oldOutputName, newOutputName);
     }
 }
 
 void PrimaryOutputWatcher::setupRegistry()
 {
     auto m_connection = KWayland::Client::ConnectionThread::fromApplication(this);
     if (!m_connection) {
         return;
     }
 
     // Asking for primaryOutputName() before this happened, will return qGuiApp->primaryScreen()->name() anyways, so set it so the primaryOutputNameChange will
     // have parameters that are coherent
     m_primaryOutputName = qGuiApp->primaryScreen()->name();
     m_registry = new KWayland::Client::Registry(this);
     connect(m_registry, &KWayland::Client::Registry::interfaceAnnounced, this, [this](const QByteArray &interface, quint32 name, quint32 version) {
         if (interface == WaylandPrimaryOutput::interface()->name) {
             auto m_outputManagement = new WaylandPrimaryOutput(m_registry->registry(), name, version, this);
             connect(m_outputManagement, &WaylandPrimaryOutput::primaryOutputChanged, this, [this](const QString &outputName) {
                 m_primaryOutputWayland = outputName;
                 // Only set the outputName when there's a QScreen attached to it
                 if (screenForName(outputName)) {
                     setPrimaryOutputName(outputName);
                 }
             });
         }
     });
 
     // In case the outputName was received before Qt reported the screen
     connect(qGuiApp, &QGuiApplication::screenAdded, this, [this](QScreen *screen) {
         if (screen->name() == m_primaryOutputWayland) {
             setPrimaryOutputName(m_primaryOutputWayland);
         }
     });
 
     m_registry->create(m_connection);
     m_registry->setup();
 }
 
 #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
 bool PrimaryOutputWatcher::nativeEventFilter(const QByteArray &eventType, void *message, long int *result)
 #else
 bool PrimaryOutputWatcher::nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result)
 #endif
 {
     Q_UNUSED(result);
 #if HAVE_X11
     // a particular edge case: when we switch the only enabled screen
     // we don't have any signal about it, the primary screen changes but we have the same old QScreen* getting recycled
     // see https://bugs.kde.org/show_bug.cgi?id=373880
     // if this slot will be invoked many times, their//second time on will do nothing as name and primaryOutputName will be the same by then
     if (eventType[0] != 'x') {
         return false;
     }
 
     xcb_generic_event_t *ev = static_cast<xcb_generic_event_t *>(message);
 
     const auto responseType = XCB_EVENT_RESPONSE_TYPE(ev);
 
     if (responseType == m_xrandrExtensionOffset + XCB_RANDR_SCREEN_CHANGE_NOTIFY) {
         QTimer::singleShot(0, this, [this]() {
             setPrimaryOutputName(qGuiApp->primaryScreen()->name());
         });
     }
 #endif
     return false;
 }
 
 QScreen *PrimaryOutputWatcher::screenForName(const QString &outputName) const
 {
     const auto screens = qGuiApp->screens();
     for (auto screen : screens) {
         if (screen->name() == outputName) {
             return screen;
         }
     }
     return nullptr;
 }
 
 QScreen *PrimaryOutputWatcher::primaryScreen() const
 {
     auto screen = screenForName(m_primaryOutputName);
     if (!screen) {
         qDebug() << "PrimaryOutputWatcher: Could not find primary screen:" << m_primaryOutputName;
         return qGuiApp->primaryScreen();
     }
     return screen;
 }
 
 #include "primaryoutputwatcher.moc"