My QStateMachine API example won't transition

Jeff Barnes

Given the following code (headers omitted).

//threadedobject.cpp
#include "threadedobject.h"

ThreadedObject::ThreadedObject(QObject *parent) : QObject(parent)
{
}

void ThreadedObject::callSignalOne()
{
emit signal1();
}

void ThreadedObject::callSignalTwo()
{
emit signal2();
}

//statemachinemain.cpp
#include "statemachinemain.h"
#include <QDebug>
#include <QSignalTransition>
#include <QState>

StateMachineMain::StateMachineMain(ThreadedObject *threadedObject, QObject *parent)
: QObject(parent)
, m_threadedObject(threadedObject)

{
initStateMachine();
}

void StateMachineMain::onStateOneEntered()
{
qDebug() << "onStateOneEntered()";
}

void StateMachineMain::onStateTwoEntered()
{
qDebug() << "onStateTwoEntered()";
}

void StateMachineMain::onStateThreeEntered()
{
qDebug() << "onStateThreeEntered()";
}

void StateMachineMain::initStateMachine()
{
QState *state1 = new QState;
QState *state2 = new QState;
QState *state3 = new QState;

m_stateMachine.addState(state1);
m_stateMachine.addState(state2);
m_stateMachine.addState(state3);

state1->addTransition(m_threadedObject, SIGNAL(signal1()), state2);
QObject::connect(state2, SIGNAL(entered()), this, SLOT(onStateTwoEntered()));
state2->addTransition(m_threadedObject, SIGNAL(signal2()), state3);
QObject::connect(state3, SIGNAL(entered()), this, SLOT(onStateThreeEntered()));
QObject::connect(state1, SIGNAL(entered()), this, SLOT(onStateOneEntered()));

m_stateMachine.setInitialState(state1);
m_stateMachine.start();

}

//main.cpp
#include <QCoreApplication>
#include <QThread>

#include "statemachinemain.h"
#include "threadedobject.h"

int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);

ThreadedObject *obj = new ThreadedObject;
QThread t1;
QThread t2;
obj->moveToThread(&t2);
StateMachineMain *main = new StateMachineMain(obj);
main->moveToThread(&t1);
t1.start();
t2.start();
obj->callSignalOne();
obj->callSignalTwo();
return a.exec();

}

Output from running the application:
onStateOneEntered()

Expected:
onStateOneEntered()
onStateTwoEntered()
onStateThreeEntered()

Would appreciate any help.

SGaist

Hi,

You are emitting the signals before all the event loops have started.