2 files changed, 44 insertions, 3 deletions
diff --git a/src/corelib/statemachine/qabstracttransition.cpp b/src/corelib/statemachine/qabstracttransition.cpp
index 49091de8a8..e446c69519 100644
--- a/src/corelib/statemachine/qabstracttransition.cpp
+++ b/src/corelib/statemachine/qabstracttransition.cpp
@@ -201,10 +201,15 @@ QAbstractState *QAbstractTransition::targetState() const
 void QAbstractTransition::setTargetState(QAbstractState* target)
 {
     Q_D(QAbstractTransition);
+    if ((d->targetStates.size() == 1 && target == d->targetStates.at(0).data()) ||
+         (d->targetStates.isEmpty() && target == 0)) {
+        return;
+    }
     if (!target)
         d->targetStates.clear();
     else
         setTargetStates(QList<QAbstractState*>() << target);
+    emit targetStateChanged(QPrivateSignal());
 }
 
 /*!
@@ -229,18 +234,26 @@ QList<QAbstractState*> QAbstractTransition::targetStates() const
 void QAbstractTransition::setTargetStates(const QList<QAbstractState*> &targets)
 {
     Q_D(QAbstractTransition);
-
+    QList<QPointer<QAbstractState> > copy(d->targetStates);
+    bool sameList = true;
     for (int i = 0; i < targets.size(); ++i) {
         QAbstractState *target = targets.at(i);
         if (!target) {
             qWarning("QAbstractTransition::setTargetStates: target state(s) cannot be null");
             return;
+        } else {
+            sameList &= copy.removeOne(target);
         }
     }
 
+    sameList &= copy.isEmpty();
+
     d->targetStates.clear();
     for (int i = 0; i < targets.size(); ++i)
         d->targetStates.append(targets.at(i));
+
+    if (!sameList)
+        emit targetStatesChanged(QPrivateSignal());
 }
 
 /*!
@@ -324,6 +337,24 @@ QList<QAbstractAnimation*> QAbstractTransition::animations() const
 */
 
 /*!
+  \fn QAbstractTransition::targetStateChanged()
+  \since 5.4
+
+  This signal is emitted when the targetState property is changed.
+
+  \sa QAbstractTransition::targetState
+*/
+
+/*!
+  \fn QAbstractTransition::targetStatesChanged()
+  \since 5.4
+
+  This signal is emitted when the targetStates property is changed.
+
+  \sa QAbstractTransition::targetStates
+*/
+
+/*!
   \reimp
 */
 bool QAbstractTransition::event(QEvent *e)
diff --git a/src/corelib/statemachine/qabstracttransition.h b/src/corelib/statemachine/qabstracttransition.h
index a35ad4ca96..ac3b40e55e 100644
--- a/src/corelib/statemachine/qabstracttransition.h
+++ b/src/corelib/statemachine/qabstracttransition.h
@@ -65,8 +65,8 @@ class Q_CORE_EXPORT QAbstractTransition : public QObject
 {
     Q_OBJECT
     Q_PROPERTY(QState* sourceState READ sourceState)
-    Q_PROPERTY(QAbstractState* targetState READ targetState WRITE setTargetState)
-    Q_PROPERTY(QList<QAbstractState*> targetStates READ targetStates WRITE setTargetStates)
+    Q_PROPERTY(QAbstractState* targetState READ targetState WRITE setTargetState NOTIFY targetStateChanged)
+    Q_PROPERTY(QList<QAbstractState*> targetStates READ targetStates WRITE setTargetStates NOTIFY targetStatesChanged)
 public:
     QAbstractTransition(QState *sourceState = 0);
     virtual ~QAbstractTransition();
@@ -91,6 +91,16 @@ Q_SIGNALS:
       QPrivateSignal
 #endif
     );
+    void targetStateChanged(
+#if !defined(Q_QDOC)
+      QPrivateSignal
+#endif
+    );
+    void targetStatesChanged(
+#if !defined(Q_QDOC)
+      QPrivateSignal
+#endif
+    );
 
 protected:
     virtual bool eventTest(QEvent *event) = 0;