4 files changed, 27 insertions, 12 deletions

diff --git a/src/ivicore/qiviabstractzonedfeature.cpp b/src/ivicore/qiviabstractzonedfeature.cpp
index 5d7c0c4..911893e 100644
--- a/src/ivicore/qiviabstractzonedfeature.cpp
+++ b/src/ivicore/qiviabstractzonedfeature.cpp
@@ -111,8 +111,12 @@ void QIviAbstractZonedFeature::connectToServiceObject(QIviServiceObject *service
     else if (serviceObject)
         backend = qobject_cast<QIviZonedFeatureInterface*>(serviceObject->interfaceInstance(interfaceName()));
 
-    if (backend)
-        initializeZones();
+    connect(backend, &QIviZonedFeatureInterface::availableZonesChanged, this, &QIviAbstractZonedFeature::initializeZones);
+
+    if (backend) {
+        QStringList zones = backend->availableZones();
+        initializeZones(zones);
+    }
 
     QIviAbstractFeature::connectToServiceObject(serviceObject);
 }
@@ -213,13 +217,12 @@ void QIviAbstractZonedFeature::setZone(const QString &zone)
     emit zoneChanged();
 }
 
-void QIviAbstractZonedFeature::initializeZones()
+void QIviAbstractZonedFeature::initializeZones(const QStringList &zones)
 {
     if (!backend() || !zone().isEmpty())
         return;
 
     Q_D(QIviAbstractZonedFeature);
-    const auto zones = backend()->availableZones();
     for (const QString &zone : zones) {
         QIviAbstractZonedFeature *f = zoneAt(zone);
         if (!f) {
@@ -251,10 +254,8 @@ void QIviAbstractZonedFeature::initializeZones()
 */
 QStringList QIviAbstractZonedFeature::availableZones() const
 {
-    if (backend()) {
-        return backend()->availableZones();
-    }
-    return QStringList();
+    Q_D(const QIviAbstractZonedFeature);
+    return d->m_zoneFeatureMap.keys();
 }
 
 
diff --git a/src/ivicore/qiviabstractzonedfeature.h b/src/ivicore/qiviabstractzonedfeature.h
index 7e24d44..3c7b168 100644
--- a/src/ivicore/qiviabstractzonedfeature.h
+++ b/src/ivicore/qiviabstractzonedfeature.h
@@ -74,7 +74,7 @@ public:
     QList<QIviAbstractZonedFeature*> zones() const;
 
 Q_SIGNALS:
-    void availableZonesChanged(QStringList zones);
+    void availableZonesChanged(const QStringList &zones);
     void zoneChanged();
     void zonesChanged();
 
@@ -90,10 +90,9 @@ protected:
 
 private Q_SLOTS:
     void setZone(const QString &zone);
+    void initializeZones(const QStringList &zones);
 
 private:
-    void initializeZones();
-
     QVariantList attributeList() const;
     QVariantMap attributeMap() const;
     QVariantMap zoneFeatureMap() const;
diff --git a/src/ivicore/qivizonedfeatureinterface.cpp b/src/ivicore/qivizonedfeatureinterface.cpp
index 944f3a3..435e9d2 100644
--- a/src/ivicore/qivizonedfeatureinterface.cpp
+++ b/src/ivicore/qivizonedfeatureinterface.cpp
@@ -178,7 +178,19 @@ QIviZonedFeatureInterface::QIviZonedFeatureInterface(QObject *parent)
 
     The returned names must be valid QML property names, i.e. \c {[a-z_][A-Za-z0-9_]*}.
 
-    \sa {Providing Available Zones}
+    \sa availableZonesChanged() {Providing Available Zones}
+*/
+
+/*!
+    \fn void QIviZonedFeatureInterface::availableZonesChanged(const QStringList &zones)
+    \since 5.13
+
+    Emitted when the available zones changed.
+
+    Use this signal when the list of available zones first need to be retrieved and are not available
+    when the backend instance is created.
+
+    \sa availableZones() {Providing Available Zones}
 */
 
 QT_END_NAMESPACE
diff --git a/src/ivicore/qivizonedfeatureinterface.h b/src/ivicore/qivizonedfeatureinterface.h
index 0fbca0a..244dc9e 100644
--- a/src/ivicore/qivizonedfeatureinterface.h
+++ b/src/ivicore/qivizonedfeatureinterface.h
@@ -56,6 +56,9 @@ public:
     explicit QIviZonedFeatureInterface(QObject *parent = nullptr);
 
     virtual QStringList availableZones() const = 0;
+
+Q_SIGNALS:
+    void availableZonesChanged(const QStringList &zones);
 };
 
 QT_END_NAMESPACE