Implement XDG Desktop Portal support

src/CMakeLists.txt

@@ -41,6 +41,14 @@ find_package(Qt${QT_VERSION_MAJOR}Core5Compat ${REQUIRED_QT_VERSION} CONFIG QUIE
      TYPE REQUIRED
  )
 
+if(UNIX AND NOT APPLE)
+  find_package(Qt${QT_VERSION_MAJOR}DBus ${REQUIRED_QT_VERSION} CONFIG QUIET)
+  set_package_properties(Qt${QT_VERSION_MAJOR}DBus PROPERTIES
+      DESCRIPTION "Qt${QT_VERSION_MAJOR} DBus component."
+      TYPE REQUIRED
+  )
+endif()
+
 get_target_property (QT_QMAKE_EXECUTABLE Qt::qmake IMPORTED_LOCATION)
 message(STATUS "Using Qt ${Qt${QT_MAJOR_VERSION}Core_VERSION} (${QT_QMAKE_EXECUTABLE})")
 

src/common/common.cmake

@@ -41,6 +41,8 @@ elseif(APPLE)
 elseif(UNIX AND NOT APPLE)
     list(APPEND common_SOURCES
         ${CMAKE_CURRENT_LIST_DIR}/utility_unix.cpp
+        ${CMAKE_CURRENT_LIST_DIR}/xdg_portal.h
+        ${CMAKE_CURRENT_LIST_DIR}/xdg_portal.cpp
     )
 endif()
 

src/common/utility.h

@@ -153,6 +153,10 @@ namespace Utility {
     OCSYNC_EXPORT uint convertSizeToUint(size_t &convertVar);
     OCSYNC_EXPORT int convertSizeToInt(size_t &convertVar);
 
+#ifdef Q_OS_UNIX
+    OCSYNC_EXPORT QString getAppExecutablePath();
+#endif
+
 #ifdef Q_OS_WIN
     OCSYNC_EXPORT DWORD convertSizeToDWORD(size_t &convertVar);
 #endif

src/common/utility_unix.cpp

@@ -6,6 +6,7 @@
 
 #include "utility.h"
 #include "config.h"
+#include "xdg_portal.h"
 
 #include <QCoreApplication>
 #include <QDir>
@@ -72,6 +73,10 @@ bool Utility::hasSystemLaunchOnStartup(const QString &appName)
 
 bool Utility::hasLaunchOnStartup(const QString &appName)
 {
+    //! if we are using portals this check will not work, that's why its usage in generalsettings.cpp is currently disabled.
+    //! as far as i can tell the portal does not let us do this check. how badly do we want it? the only two times its used is
+    //! that time in generalsettings.cpp and in tests, for settings as far as i can tell that check isn't really *needed* and
+    //! we might want to adapt tests to portals anyway...
     const QString desktopFileLocation = getUserAutostartDir() + appName + QLatin1String(".desktop");
     return QFile::exists(desktopFileLocation);
 }
@@ -96,43 +101,58 @@ QString Utility::syncFolderDisplayName(const QString &folder, const QString &dis
 
 void Utility::setLaunchOnStartup(const QString &appName, const QString &guiName, bool enable)
 {
-    const auto userAutoStartPath = getUserAutostartDir();
-    const QString desktopFileLocation = userAutoStartPath + appName + QLatin1String(".desktop");
-    if (enable) {
-        if (!QDir().exists(userAutoStartPath) && !QDir().mkpath(userAutoStartPath)) {
-            qCWarning(lcUtility) << "Could not create autostart folder" << userAutoStartPath;
-            return;
-        }
-        QFile iniFile(desktopFileLocation);
-        if (!iniFile.open(QIODevice::WriteOnly)) {
-            qCWarning(lcUtility) << "Could not write auto start entry" << desktopFileLocation;
-            return;
-        }
-        // When running inside an AppImage, we need to set the path to the
-        // AppImage instead of the path to the executable
-        const QString appImagePath = qEnvironmentVariable("APPIMAGE");
-        const bool runningInsideAppImage = !appImagePath.isNull() && QFile::exists(appImagePath);
-        const QString executablePath = runningInsideAppImage ? appImagePath : QCoreApplication::applicationFilePath();
-
-        QTextStream ts(&iniFile);
-        ts << QLatin1String("[Desktop Entry]\n")
-           << QLatin1String("Name=") << guiName << QLatin1Char('\n')
-           << QLatin1String("GenericName=") << QLatin1String("File Synchronizer\n")
-           << QLatin1String("Exec=\"") << executablePath << "\" --background\n"
-           << QLatin1String("Terminal=") << "false\n"
-           << QLatin1String("Icon=") << APPLICATION_ICON_NAME << QLatin1Char('\n')
-           << QLatin1String("Categories=") << QLatin1String("Network\n")
-           << QLatin1String("Type=") << QLatin1String("Application\n")
-           << QLatin1String("StartupNotify=") << "false\n"
-           << QLatin1String("X-GNOME-Autostart-enabled=") << "true\n"
-           << QLatin1String("X-GNOME-Autostart-Delay=10") << Qt::endl;
+    const bool usePortals = true; // TODO: how should this be configured? probably a build flag? or should we just default always use portals and if the call fails *then* fallback? XdgPortal::background does return a bool for if it was successful so that wouldn't be a difficulty.
+    if (usePortals) {
+        XdgPortal portal;
+        portal.background(appName, enable);
     } else {
-        if (!QFile::remove(desktopFileLocation)) {
-            qCWarning(lcUtility) << "Could not remove autostart desktop file";
+        const auto userAutoStartPath = getUserAutostartDir();
+        const QString desktopFileLocation = userAutoStartPath + appName + QLatin1String(".desktop");
+        if (enable) {
+            if (!QDir().exists(userAutoStartPath) && !QDir().mkpath(userAutoStartPath)) {
+                qCWarning(lcUtility) << "Could not create autostart folder" << userAutoStartPath;
+                return;
+            }
+            QFile iniFile(desktopFileLocation);
+            if (!iniFile.open(QIODevice::WriteOnly)) {
+                qCWarning(lcUtility) << "Could not write auto start entry" << desktopFileLocation;
+                return;
+            }
+
+            const auto executablePath = Utility::getAppExecutablePath();
+
+            QTextStream ts(&iniFile);
+            ts << QLatin1String("[Desktop Entry]\n")
+            << QLatin1String("Name=") << guiName << QLatin1Char('\n')
+            << QLatin1String("GenericName=") << QLatin1String("File Synchronizer\n")
+            << QLatin1String("Exec=\"") << executablePath << "\" --background\n"
+            << QLatin1String("Terminal=") << "false\n"
+            << QLatin1String("Icon=") << APPLICATION_ICON_NAME << QLatin1Char('\n')
+            << QLatin1String("Categories=") << QLatin1String("Network\n")
+            << QLatin1String("Type=") << QLatin1String("Application\n")
+            << QLatin1String("StartupNotify=") << "false\n"
+            << QLatin1String("X-GNOME-Autostart-enabled=") << "true\n"
+            << QLatin1String("X-GNOME-Autostart-Delay=10") << Qt::endl;
+        } else {
+            if (!QFile::remove(desktopFileLocation)) {
+                qCWarning(lcUtility) << "Could not remove autostart desktop file";
+            }
         }
     }
 }
 
+QString Utility::getAppExecutablePath()
+{
+    // When running inside an AppImage, we need to set the path to the
+    // AppImage instead of the path to the executable
+    const QString appImagePath = qEnvironmentVariable("APPIMAGE");
+    const QString flatpakId = qEnvironmentVariable("FLATPAK_ID");
+    const bool runningInsideAppImage = !appImagePath.isNull() && QFile::exists(appImagePath);
+    const bool runningInsideFlatpak = !flatpakId.isNull();
+    const QString executablePath = runningInsideAppImage ? QLatin1String("\"%1\"").arg(appImagePath) : runningInsideFlatpak ? QLatin1String("flatpak run %1").arg(flatpakId) : QLatin1String("\"%1\"").arg(QCoreApplication::applicationFilePath());
+    return executablePath;
+}
+
 bool Utility::hasDarkSystray()
 {
     return true;

src/common/xdg_portal.cpp

@@ -0,0 +1,84 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "xdg_portal.h"
+#include "utility.h"
+#include <QtDBus/QDBusConnection>
+#include <QtDBus/QDBusConnectionInterface>
+#include <QtDBus/QDBusInterface>
+#include <QtDBus/QDBusMessage>
+#include <QDebug>
+#include <QFileInfo>
+#include <QCoreApplication>
+
+namespace OCC {
+
+constexpr auto portalDesktopService = "org.freedesktop.portal.Desktop";
+constexpr auto portalDesktopPath = "/org/freedesktop/portal/desktop";
+
+XdgPortal::XdgPortal(QObject *parent)
+    : QObject(parent)
+    , m_available(false)
+{
+    initPortalInterface();
+}
+
+void XdgPortal::initPortalInterface()
+{
+    auto *busInterface = QDBusConnection::sessionBus().interface();
+    if (!busInterface) {
+        qWarning() << "XDG Desktop Portal not available";
+        return;
+    }
+
+    const auto registered = busInterface->isServiceRegistered(QLatin1String(portalDesktopService));
+    m_available = registered.isValid() && registered.value();
+    if (!m_available) {
+        qWarning() << "XDG Desktop Portal not available";
+    }
+}
+
+bool XdgPortal::background(const QString &handle_token, const bool &autostart)
+{
+    if (!m_available) {
+        return false;
+    }
+
+    QDBusInterface backgroundInterface(
+        QLatin1String(portalDesktopService),
+        QLatin1String(portalDesktopPath),
+        QLatin1String("org.freedesktop.portal.Background"),
+        QDBusConnection::sessionBus());
+    if (!backgroundInterface.isValid()) { // just in case
+        qWarning() << "org.freedesktop.portal.Background not available";
+        return false;
+    }
+
+    QVariantMap options;
+    options[QLatin1String("autostart")] = autostart;
+    const QString flatpakId = qEnvironmentVariable("FLATPAK_ID");
+    if (flatpakId.isNull()) {
+        QStringList list = {Utility::getAppExecutablePath(), QLatin1String("--background")};
+        options[QLatin1String("commandline")] = list;
+    } else { // when an app is running as a flatpak its "commandline" parameter is handled differently
+        QStringList list = {QFileInfo(QCoreApplication::applicationFilePath()).fileName(), QLatin1String("--background")};
+        options[QLatin1String("commandline")] = list;
+    }
+
+    QDBusMessage reply = backgroundInterface.call(
+        QLatin1String("RequestBackground"),
+        handle_token,
+        options
+    );
+
+    if (reply.type() == QDBusMessage::ErrorMessage) {
+        qWarning() << "Background request failed: " << reply.errorMessage();
+        return false;
+    }
+
+    return true;
+}
+
+} // namespace OCC

src/common/xdg_portal.h

@@ -0,0 +1,43 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef XDG_PORTAL_H
+#define XDG_PORTAL_H
+
+#include <QObject>
+#include <QString>
+#include <QVariantMap>
+
+namespace OCC {
+
+/**
+ * @brief XDG Desktop Portal interface for Qt D-Bus
+ *
+ * Adstracts D-Bus calls behind simpler methods.
+ */
+class XdgPortal : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit XdgPortal(QObject *parent = nullptr);
+
+    /**
+     * @brief Requests that the application is allowed to run in the background; see https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Background.html
+     * @param handle_token A string that will be used as the last element of the handle. Must be a valid object path element. See the [Request](https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Request.html#org-freedesktop-portal-request) documentation for more information about the handle.
+     * @param autostart true if the app also wants to be started automatically at login.
+     * @return True if successful
+     */
+    bool background(const QString &handle_token, const bool &autostart);
+
+private:
+    bool m_available;
+
+    void initPortalInterface();
+};
+
+} // namespace OCC
+
+#endif // XDG_PORTAL_H

src/gui/generalsettings.cpp

@@ -651,9 +651,10 @@ void GeneralSettings::saveMiscSettings()
 void GeneralSettings::slotToggleLaunchOnStartup(bool enable)
 {
     const auto theme = Theme::instance();
-    if (enable == Utility::hasLaunchOnStartup(theme->appName())) {
-        return;
-    }
+    //! please see Utility::hasLaunchOnStartup for why this is disabled
+    // if (enable == Utility::hasLaunchOnStartup(theme->appName())) {
+    //     return;
+    // }
 
     ConfigFile configFile;
     configFile.setLaunchOnSystemStartup(enable);