qtscxml: connect to signals

larry104

I'm playing with qtscxml and I'm running into a problem - here is a simple state machine

<?xml version="1.0" encoding="UTF-8"?>

<scxml xmlns="http://www.w3.org/2005/07/scxml" xmlns:qt="http://theqtcompany.com/scxml/2015/06/" version="1.0" name="KeyboardStateMachine" initial="s1">

<state id="s1">
    <onentry>
      <log expr="Now in s1" />
      <send event="enter_state1"/>
    </onentry>
    <transition event="key_pressed" target="s2"/>
</state>
<state id="s2">
    <onentry>
        <log expr="Now in s2" />
        <send event="enter_state2"/>
    </onentry>
    <transition event="key_released" target="s1"/>
</state>

</scxml>

I want to connect to the signals enter_state1 and enter_state2 on the c++ side.

QObject::connect(machine, SIGNAL(enter_state1()), this, SLOT(keyLedOff()));
QObject::connect(machine, SIGNAL(enter_state1()), this, SLOT(lkeyLedOon()));

but I get an error: QObject::connect: No such signal KeyboardStateMachine::enter_state1()

What I'm I doing wrong here?

mrjj

@larry104 said:
Hi
The normal cause for this error is
1: forgot
Q_OBJECT macro in a QObject subclass ( your KeyboardStateMachine)

2:
Using visual studio and qmake/moc.exe is not run.

Update:
Did you check the files generated by
qscxmlc
that they do in fact contain such signals?

larry104

1: is done
#ifndef KEYBOARD_H
#define KEYBOARD_H

#include <QObject>
#include <QHash>
#include <QColor>
#include <QDebug>
#include "statemachine.h"

class Keyboard : public QObject
{
Q_OBJECT

public:
explicit Keyboard(QHash<QString, QObject*> keys, QObject *parent = 0);

signals:

public slots:
void ledOn();
void ledOff();
void keyPressed();
void keyReleased();

private:
KeyboardStateMachine m_machine;
QHash<QString, QObject> m_keys;
};

#endif // KEYBOARD_H

2: I'm using qt5.7.0 on ubuntu with qtcreator. My .pro file looks like this:

QT += qml quick scxml
CONFIG += c++11
SOURCES += main.cpp
keyboard.cpp
STATECHARTS = statemachine.scxml
load(qscxmlc)
RESOURCES += qml.qrc
QML_IMPORT_PATH =
include(deployment.pri)
HEADERS +=
keyboard.h

It's interesting the statmachine.h gets only created if I run the compile from commandline. How can I tell qtcreator to run the compile of the statemachine so it finds the .h file - but that's a different issue.

But to answer the question the statemachine.h file create when calling qscxmlc statemachine.scxml does not contain the signals -
qscxmlc --version is: qscxmlc 1 (Qt 5.7.0)

mrjj

Hmm, seems to follow the docs closely so should be ok.
STATECHARTS should make qmake run tool. ?

I wonder how connect can possible work then if no signals generated. are they somehow exported from QML?

Sorry, i have never used this new module so Im afraid we must
hope for others to have better suggestions :)

larry104

I found the problem - to create a qt signal I need to set the following:

mrjj

@larry104
good found :)