[plasma/plasma-login-manager] src/daemon: Move seat related tasks out of Display

Git commit 26fae2b354361d986e3bdad70e318530bd7a69fc by David Edmundson.
Committed on 20/07/2026 at 12:16.
Pushed by davidedmundson into branch 'master'.

Move seat related tasks out of Display

Looking up if existing sessions exist or switching to a new session is a
operation on the seat.

This commit has no behavioural changes.

M  +3    -59   src/daemon/Display.cpp
M  +86   -7    src/daemon/Seat.cpp
M  +6    -0    src/daemon/Seat.h

https://invent.kde.org/plasma/plasma-login-manager/-/commit/26fae2b354361d986e3bdad70e318530bd7a69fc

diff --git a/src/daemon/Display.cpp b/src/daemon/Display.cpp
index 4a63f69d..e5065ae3 100644
--- a/src/daemon/Display.cpp
+++ b/src/daemon/Display.cpp
@@ -24,7 +24,6 @@
 #include "MainConfigLoader.h"
 #include "Seat.h"
 #include "SocketServer.h"
-#include "Utils.h"
 
 #include <QDebug>
 #include <QFile>
@@ -38,16 +37,10 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 
-#include <QDBusConnection>
-#include <QDBusMessage>
-#include <QDBusReply>
-
 #include <KConfig>
 #include <KConfigGroup>
 #include <KDesktopFile>
 
-#include "Login1Manager.h"
-#include "Login1Session.h"
 #include "VirtualTerminal.h"
 #include "config.h"
 
@@ -55,38 +48,6 @@ static int s_ttyFailures = 0;
 
 namespace PLASMALOGIN
 {
-bool isTtyInUse(const QString &desiredTty)
-{
-    if (Logind::isAvailable()) {
-        OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
-        auto reply = manager.ListSessions();
-        reply.waitForFinished();
-
-        const auto info = reply.value();
-        for (const SessionInfo &s : info) {
-            OrgFreedesktopLogin1SessionInterface session(Logind::serviceName(), s.sessionPath.path(), QDBusConnection::systemBus());
-            if (desiredTty == session.tTY() && session.state() != QLatin1String("closing")) {
-                qDebug() << "tty" << desiredTty << "already in use by" << session.user().path.path() << session.state() << session.display()
-                         << session.desktop() << session.vTNr();
-                return true;
-            }
-        }
-    }
-    return false;
-}
-
-int fetchAvailableVt()
-{
-    if (!isTtyInUse(QStringLiteral("tty%1").arg(PLASMALOGIN_INITIAL_VT))) {
-        return PLASMALOGIN_INITIAL_VT;
-    }
-    const auto vt = VirtualTerminal::currentVt();
-    if (vt > 0 && !isTtyInUse(QStringLiteral("tty%1").arg(vt))) {
-        return vt;
-    }
-    return VirtualTerminal::setUpNewVt();
-}
-
 Display::Display(Seat *parent)
     : QObject(parent)
     , m_auth(new Auth(this))
@@ -95,7 +56,7 @@ Display::Display(Seat *parent)
     , m_greeter(new Greeter(this))
 {
     if (seat()->canTTY()) {
-        m_terminalId = fetchAvailableVt();
+        m_terminalId = seat()->availableVt();
     }
     qDebug("Using VT %d", m_terminalId);
 
@@ -317,22 +278,7 @@ bool Display::startAuth(const QString &user, const QString &password, const Sess
 
     m_reuseSessionId = QString();
 
-    if (Logind::isAvailable()) {
-        OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
-        auto reply = manager.ListSessions();
-        reply.waitForFinished();
-
-        const auto info = reply.value();
-        for (const SessionInfo &s : reply.value()) {
-            if (s.userName == user) {
-                OrgFreedesktopLogin1SessionInterface session(Logind::serviceName(), s.sessionPath.path(), QDBusConnection::systemBus());
-                if (session.service() == QLatin1String("plasmalogin") && session.state() == QLatin1String("online")) {
-                    m_reuseSessionId = s.sessionId;
-                    break;
-                }
-            }
-        }
-    }
+    m_reuseSessionId = seat()->reusableSessionId(user);
 
     // save session desktop file name, we'll use it to set the
     // last session later, in slotAuthenticationFinished()
@@ -387,9 +333,7 @@ void Display::slotAuthenticationFinished(const QString &user, bool success)
         qDebug() << "Authentication for user " << user << " successful";
 
         if (!m_reuseSessionId.isNull()) {
-            OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
-            manager.UnlockSession(m_reuseSessionId);
-            manager.ActivateSession(m_reuseSessionId);
+            seat()->activateSession(m_reuseSessionId);
         }
 
         if (m_socket) {
diff --git a/src/daemon/Seat.cpp b/src/daemon/Seat.cpp
index 95387dd5..8f5a59be 100644
--- a/src/daemon/Seat.cpp
+++ b/src/daemon/Seat.cpp
@@ -26,6 +26,7 @@
 #include <QTimer>
 
 #include "Constants.h"
+#include "config.h"
 #include <KConfig>
 #include <KSharedConfig>
 #include <QDir>
@@ -52,6 +53,90 @@ const QString &Seat::name() const
     return m_name;
 }
 
+bool Seat::isTtyInUse(const QString &tty) const
+{
+    if (!Logind::isAvailable()) {
+        return false;
+    }
+
+    OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
+    auto reply = manager.ListSessions();
+    reply.waitForFinished();
+
+    const auto info = reply.value();
+    for (const SessionInfo &sessionInfo : info) {
+        OrgFreedesktopLogin1SessionInterface session(Logind::serviceName(), sessionInfo.sessionPath.path(), QDBusConnection::systemBus());
+        if (tty == session.tTY() && session.state() != QLatin1String("closing")) {
+            qDebug() << "tty" << tty << "already in use by" << session.user().path.path() << session.state() << session.display() << session.desktop()
+                     << session.vTNr();
+            return true;
+        }
+    }
+
+    return false;
+}
+
+int Seat::availableVt() const
+{
+    if (!isTtyInUse(QStringLiteral("tty%1").arg(PLASMALOGIN_INITIAL_VT))) {
+        return PLASMALOGIN_INITIAL_VT;
+    }
+
+    const auto vt = VirtualTerminal::currentVt();
+    if (vt > 0 && !isTtyInUse(QStringLiteral("tty%1").arg(vt))) {
+        return vt;
+    }
+
+    return VirtualTerminal::setUpNewVt();
+}
+
+QString Seat::reusableSessionId(const QString &user) const
+{
+    OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
+    auto reply = manager.ListSessions();
+    reply.waitForFinished();
+
+    for (const SessionInfo &sessionInfo : reply.value()) {
+        if (sessionInfo.userName != user) {
+            continue;
+        }
+
+        OrgFreedesktopLogin1SessionInterface session(Logind::serviceName(), sessionInfo.sessionPath.path(), QDBusConnection::systemBus());
+        if (session.service() == QLatin1String("plasmalogin") && session.state() == QLatin1String("online")) {
+            return sessionInfo.sessionId;
+        }
+    }
+
+    return {};
+}
+
+void Seat::activateSession(const QString &sessionId) const
+{
+    if (sessionId.isEmpty()) {
+        return;
+    }
+
+    OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
+    manager.UnlockSession(sessionId);
+    manager.ActivateSession(sessionId);
+}
+
+std::optional<int> Seat::vtForSession(const QString &sessionId) const
+{
+    if (sessionId.isEmpty()) {
+        return std::nullopt;
+    }
+
+    OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
+    if (!manager.isValid()) {
+        return std::nullopt;
+    }
+
+    auto sessionPath = manager.GetSession(sessionId);
+    OrgFreedesktopLogin1SessionInterface session(Logind::serviceName(), sessionPath.value().path(), QDBusConnection::systemBus());
+    return QStringView(session.tTY()).mid(3).toInt(); // we need to convert ttyN to N
+}
+
 void Seat::createDisplay()
 {
     PlasmaLogin::config()->load();
@@ -115,14 +200,8 @@ void Seat::removeDisplay(Display *display)
 void Seat::displayStopped()
 {
     Display *display = qobject_cast<Display *>(sender());
-    OrgFreedesktopLogin1ManagerInterface manager(Logind::serviceName(), Logind::managerPath(), QDBusConnection::systemBus());
     std::optional<int> nextVt;
-    auto reusing = display->reuseSessionId();
-    if (manager.isValid() && !reusing.isEmpty()) {
-        auto sessionPath = manager.GetSession(reusing);
-        OrgFreedesktopLogin1SessionInterface sessionIface(Logind::serviceName(), sessionPath.value().path(), QDBusConnection::systemBus());
-        nextVt = QStringView(sessionIface.tTY()).mid(3).toInt(); // we need to convert ttyN to N
-    }
+    nextVt = vtForSession(display->reuseSessionId());
 
     // remove display
     removeDisplay(display);
diff --git a/src/daemon/Seat.h b/src/daemon/Seat.h
index 1cc84a5a..34b52c14 100644
--- a/src/daemon/Seat.h
+++ b/src/daemon/Seat.h
@@ -20,6 +20,7 @@
 #include "Display.h"
 #include <QObject>
 #include <QVector>
+#include <optional>
 
 namespace PLASMALOGIN
 {
@@ -36,6 +37,10 @@ public:
     void createDisplay();
     bool canTTY();
     bool tryLockFirstLogin();
+    int availableVt() const;
+    QString reusableSessionId(const QString &user) const;
+    void activateSession(const QString &sessionId) const;
+    std::optional<int> vtForSession(const QString &sessionId) const;
 
 public slots:
     void removeDisplay(PLASMALOGIN::Display *display);
@@ -45,6 +50,7 @@ private slots:
 
 private:
     void startDisplay(PLASMALOGIN::Display *display, int tryNr = 1);
+    bool isTtyInUse(const QString &tty) const;
 
     QString m_name;