citra_qt: Prevent OS sleep on Linux when a game is running (#6249)

src/citra_qt/CMakeLists.txt

@@ -269,6 +269,10 @@ target_link_libraries(citra-qt PRIVATE audio_core common core input_common netwo
 target_link_libraries(citra-qt PRIVATE Boost::boost glad nihstro-headers Qt5::Widgets Qt5::Multimedia Qt5::Concurrent)
 target_link_libraries(citra-qt PRIVATE ${PLATFORM_LIBRARIES} Threads::Threads)
 
+if (UNIX AND NOT APPLE)
+    target_link_libraries(citra-qt PRIVATE Qt5::DBus)
+endif()
+
 target_compile_definitions(citra-qt PRIVATE
     # Use QStringBuilder for string concatenation to reduce
     # the overall number of temporary strings created.

src/citra_qt/main.cpp

@@ -24,6 +24,11 @@
 #ifdef _WIN32
 #include <windows.h>
 #endif
+#ifdef __unix__
+#include <QVariant>
+#include <QtDBus/QDBusInterface>
+#include <QtDBus/QtDBus>
+#endif
 #include "citra_qt/aboutdialog.h"
 #include "citra_qt/applets/mii_selector.h"
 #include "citra_qt/applets/swkbd.h"
@@ -945,16 +950,72 @@ void GMainWindow::OnOpenUpdater() {
     updater->LaunchUI();
 }
 
+#if defined(__unix__) && !defined(__APPLE__)
+static std::optional<QDBusObjectPath> HoldWakeLockLinux(u32 window_id = 0) {
+    if (!QDBusConnection::sessionBus().isConnected()) {
+        return {};
+    }
+    // reference: https://flatpak.github.io/xdg-desktop-portal/#gdbus-org.freedesktop.portal.Inhibit
+    QDBusInterface xdp(QStringLiteral("org.freedesktop.portal.Desktop"),
+                       QStringLiteral("/org/freedesktop/portal/desktop"),
+                       QStringLiteral("org.freedesktop.portal.Inhibit"));
+    if (!xdp.isValid()) {
+        LOG_WARNING(Frontend, "Couldn't connect to XDP D-Bus endpoint");
+        return {};
+    }
+    QVariantMap options = {};
+    //: TRANSLATORS: This string is shown to the user to explain why Citra needs to prevent the
+    //: computer from sleeping
+    options.insert(QString::fromLatin1("reason"),
+                   QCoreApplication::translate("GMainWindow", "Citra is running a game"));
+    // 0x4: Suspend lock; 0x8: Idle lock
+    QDBusReply<QDBusObjectPath> reply =
+        xdp.call(QString::fromLatin1("Inhibit"),
+                 QString::fromLatin1("x11:") + QString::number(window_id, 16), 12U, options);
+
+    if (reply.isValid()) {
+        return reply.value();
+    }
+    LOG_WARNING(Frontend, "Couldn't read Inhibit reply from XDP: {}",
+                reply.error().message().toStdString());
+    return {};
+}
+
+static void ReleaseWakeLockLinux(const QDBusObjectPath& lock) {
+    if (!QDBusConnection::sessionBus().isConnected()) {
+        return;
+    }
+    QDBusInterface unlocker(QString::fromLatin1("org.freedesktop.portal.Desktop"), lock.path(),
+                            QString::fromLatin1("org.freedesktop.portal.Request"));
+    unlocker.call(QString::fromLatin1("Close"));
+}
+#endif // __unix__
+
 void GMainWindow::PreventOSSleep() {
 #ifdef _WIN32
     SetThreadExecutionState(ES_CONTINUOUS | ES_SYSTEM_REQUIRED | ES_DISPLAY_REQUIRED);
-#endif
+#elif defined(HAVE_SDL2)
+    SDL_DisableScreenSaver();
+#ifdef __unix__
+    auto reply = HoldWakeLockLinux(winId());
+    if (reply) {
+        wake_lock = std::move(reply.value());
+    }
+#endif // __unix__
+#endif // _WIN32
 }
 
 void GMainWindow::AllowOSSleep() {
 #ifdef _WIN32
     SetThreadExecutionState(ES_CONTINUOUS);
-#endif
+#elif defined(HAVE_SDL2)
+    SDL_EnableScreenSaver();
+#ifdef __unix__
+    if (!wake_lock.path().isEmpty()) {
+        ReleaseWakeLockLinux(wake_lock);
+    }
+#endif // __unix__
+#endif // _WIN32
 }
 
 bool GMainWindow::LoadROM(const QString& filename) {

src/citra_qt/main.h

@@ -16,6 +16,10 @@
 #include "core/hle/service/am/am.h"
 #include "core/savestate.h"
 
+#ifdef __unix__
+#include <QDBusObjectPath>
+#endif
+
 class AboutDialog;
 class Config;
 class ClickableLabel;
@@ -329,6 +333,10 @@ private:
 
     HotkeyRegistry hotkey_registry;
 
+#ifdef __unix__
+    QDBusObjectPath wake_lock{};
+#endif
+
 protected:
     void dropEvent(QDropEvent* event) override;
     void dragEnterEvent(QDragEnterEvent* event) override;