QStateMachine, not getting entered()

[jimiq]

Hi,

I have set up a QStateMachine but I am not getting an entered() signal from any of the states and Creator editor is not even showing this in the class list as I type it in the connect function. I only get destroyed, polished and finished in the list. function code below.

What am I doing wrong? ....any suggestions.

Many thanks

Jim

connectionMachine = new QStateMachine(this);
disconnected_SM = new QState();
connecting_SM = new QState();
connected_SM = new QState();
statusCheck_SM = new QState();
commsReady_SM = new QState();
 
disconnected_SM->addTransition(this, SIGNAL(connectToHost_SM()), connecting_SM);
connecting_SM->addTransition(&commandSequencer, SIGNAL(connected()), connected_SM);
connected_SM->addTransition(this, SIGNAL(updatingStatus_SM()), statusCheck_SM);
 
connectionMachine->addState(disconnected_SM);
connectionMachine->addState(connecting_SM);
connectionMachine->addState(connected_SM);
connectionMachine->addState(statusCheck_SM);
 
connect(connecting_SM, SIGNAL(entered()), this, SLOT(debugConnecting())); 
connect(connected_SM, SIGNAL(entered()), this, SLOT(updateStatus()));
 
connectionMachine->setInitialState(disconnected_SM);
connectionMachine->start();

connectionMachine = new QStateMachine(this);
disconnected_SM = new QState();
connecting_SM = new QState();
connected_SM = new QState();
statusCheck_SM = new QState();
commsReady_SM = new QState();
 
disconnected_SM->addTransition(this, SIGNAL(connectToHost_SM()), connecting_SM);
connecting_SM->addTransition(&commandSequencer, SIGNAL(connected()), connected_SM);
connected_SM->addTransition(this, SIGNAL(updatingStatus_SM()), statusCheck_SM);
 
connectionMachine->addState(disconnected_SM);
connectionMachine->addState(connecting_SM);
connectionMachine->addState(connected_SM);
connectionMachine->addState(statusCheck_SM);
 
connect(connecting_SM, SIGNAL(entered()), this, SLOT(debugConnecting())); 
connect(connected_SM, SIGNAL(entered()), this, SLOT(updateStatus()));
 
connectionMachine->setInitialState(disconnected_SM);
connectionMachine->start();

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[wysota]

Does connectToHost_SM() signal get emitted? Also check your console logs to see if there are any warnings from Qt.

[jimiq]

Hi wysota,

I put in a connect() for the connectToHost_SM to output under qDebug and that works so it seems as though it is emitted. The logs at runtime and compile time don't show any warnigns or errors.

Jim

[wysota]

connect() means it is connected, not that it is emitted.

[jimiq]

No, no....what I mean is that I put in

connect(this, SIGNAL(connectToHost_SM()), this, SLOT(debugConnectToHost_SM()));

connect(this, SIGNAL(connectToHost_SM()), this, SLOT(debugConnectToHost_SM()));

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in order to see if connectToHost_SM() is emitted and debugConnectToHost_SM() just outputs a qDebug message so I can see that at runtime connectToHost_SM() is emitted.

jim

[wysota]

Please provide a minimal compilable example reproducing the problem. The code you pasted looks correct so the problem is probably elsewhere. Try isolating it from the rest of your code.

[jimiq]

I haven't got round to getting a compiled version to post but I have noticed that the state machine does start. I have put a qDebug line after the .start() to check if the state machine is running but it comes back as not running!!!! any suggestions?

[wysota]

It's an asynchronous call. The machine will start next time Qt enters the event loop.

[jimiq]

I have no other events running at that time.
I checked if it was running later in the app and it still comes back with stopped

[wysota]

As already said, provide a minimal compilable example reproducing the problem. I can't help you without knowing what you did.

[jimiq]

I managed to find the problem. When you mentioned about it being an asynchronous call got me thinking. I found that I was calling the state machine in the constructor of my dialog and was trying to trigger it too early. I then added a slot/signal combination to wait for the started() signal from the state machine before trying to create the TCP socket and now all appears fine.

Thanks for your help.
Jim