2 files changed, 53 insertions, 2 deletions

diff --git a/src/corelib/statemachine/qstatemachine.cpp b/src/corelib/statemachine/qstatemachine.cpp
index 760ac59bf4..a681688d46 100644
--- a/src/corelib/statemachine/qstatemachine.cpp
+++ b/src/corelib/statemachine/qstatemachine.cpp
@@ -1430,9 +1430,11 @@ void QStateMachinePrivate::_q_process()
     Q_ASSERT(!processing);
     processing = true;
     processingScheduled = false;
+    beginMacrostep();
 #ifdef QSTATEMACHINE_DEBUG
     qDebug() << q << ": starting the event processing loop";
 #endif
+    bool didChange = false;
     while (processing) {
         if (stop) {
             processing = false;
@@ -1473,15 +1475,17 @@ void QStateMachinePrivate::_q_process()
             }
         }
         if (!enabledTransitions.isEmpty()) {
+            didChange = true;
             q->beginMicrostep(e);
             microstep(e, enabledTransitions.toList());
             q->endMicrostep(e);
         }
-#ifdef QSTATEMACHINE_DEBUG
         else {
+            noMicrostep();
+#ifdef QSTATEMACHINE_DEBUG
             qDebug() << q << ": no transitions enabled";
-        }
 #endif
+        }
         delete e;
     }
 #ifdef QSTATEMACHINE_DEBUG
@@ -1494,6 +1498,7 @@ void QStateMachinePrivate::_q_process()
 
     switch (stopProcessingReason) {
     case EventQueueEmpty:
+        processedPendingEvents(didChange);
         break;
     case Finished:
         state = NotRunning;
@@ -1510,6 +1515,7 @@ void QStateMachinePrivate::_q_process()
         emit q->runningChanged(false);
         break;
     }
+    endMacrostep(didChange);
 }
 
 void QStateMachinePrivate::_q_startDelayedEventTimer(int id, int delay)
@@ -1619,6 +1625,47 @@ void QStateMachinePrivate::cancelAllDelayedEvents()
     delayedEvents.clear();
 }
 
+/*
+  This function is called when the state machine is performing no
+  microstep because no transition is enabled (i.e. an event is ignored).
+
+  The default implementation does nothing.
+*/
+void QStateMachinePrivate::noMicrostep()
+{ }
+
+/*
+  This function is called when the state machine has reached a stable
+  state (no pending events), and has not finished yet.
+  For each event the state machine receives it is guaranteed that
+  1) beginMacrostep is called
+  2) selectTransition is called at least once
+  3) begin/endMicrostep is called at least once or noMicrostep is called
+     at least once (possibly both, but at least one)
+  4) the state machine either enters an infinite loop, or stops (runningChanged(false),
+     and either finished or stopped are emitted), or processedPendingEvents() is called.
+  5) if the machine is not in an infinite loop endMacrostep is called
+
+  didChange is set to true if at least one microstep was performed, it is possible
+  that the machine returned to exactly the same state as before, but some transitions
+  were triggered.
+
+  The default implementation does nothing.
+*/
+void QStateMachinePrivate::processedPendingEvents(bool didChange)
+{
+    Q_UNUSED(didChange);
+}
+
+void QStateMachinePrivate::beginMacrostep()
+{ }
+
+void QStateMachinePrivate::endMacrostep(bool didChange)
+{
+    Q_UNUSED(didChange);
+}
+
+
 namespace _QStateMachine_Internal{
 
 class GoToStateTransition : public QAbstractTransition
diff --git a/src/corelib/statemachine/qstatemachine_p.h b/src/corelib/statemachine/qstatemachine_p.h
index 3a93c47c5b..b7f2644255 100644
--- a/src/corelib/statemachine/qstatemachine_p.h
+++ b/src/corelib/statemachine/qstatemachine_p.h
@@ -123,6 +123,10 @@ public:
     QAbstractTransition *createInitialTransition() const;
 
     void microstep(QEvent *event, const QList<QAbstractTransition*> &transitionList);
+    virtual void noMicrostep();
+    virtual void processedPendingEvents(bool didChange);
+    virtual void beginMacrostep();
+    virtual void endMacrostep(bool didChange);
     bool isPreempted(const QAbstractState *s, const QSet<QAbstractTransition*> &transitions) const;
     QSet<QAbstractTransition*> selectTransitions(QEvent *event) const;
     void exitStates(QEvent *event, const QList<QAbstractState *> &statesToExit_sorted,