gui: add QInputDevice::seatNames()

Change-Id: Ie6cedd62dcd684a8fd9adbc2409e5aa1f3490ede
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/gui/kernel/qinputdevice.cpp

@@ -280,6 +280,25 @@ QList<const QInputDevice *> QInputDevice::devices()
     return *deviceList();
 }
 
+/*!
+    \since 6.3
+
+    Returns a list of seat names for all registered input devices (keyboards and pointing devices).
+*/
+QStringList QInputDevice::seatNames()
+{
+    QMutexLocker locker(&devicesMutex);
+    const InputDevicesList devices = *deviceList();
+    locker.unlock();
+    QStringList result;
+    for (const QInputDevice *d : devices) {
+        if (!result.contains(d->seatName()))
+            result.append(d->seatName());
+    }
+
+    return result;
+}
+
 /*!
     Returns the core or master keyboard on the given seat \a seatName.
 */

src/gui/kernel/qinputdevice.h

@@ -110,6 +110,7 @@ public:
     QString seatName() const;
     QRect availableVirtualGeometry() const;
 
+    static QStringList seatNames();
     static QList<const QInputDevice *> devices();
     static const QInputDevice *primaryKeyboard(const QString& seatName = QString());