QState: how to add and/or remove properties added with QState::assignProperty?

[breezeight]

Hi,
If I want to know which properties are added with:

void QState::assignProperty ( QObject * object, const char * name, const QVariant & value )

void QState::assignProperty ( QObject * object, const char * name, const QVariant & value )

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Currently (qt 4.6.2) I've not found how to do it.

Some times could be useful also remove them...

Any idea?

Nicola

[bmhautz]

I'm not completely sure what you're asking, but here's an example of using properties with the state machine framework: http://qt.nokia.com/doc/4.6/statemac...ore-properties. As far as removing them, it doesn't seem like there is an API to specifically remove properties, but you could take a look at the restore properties section listed in the above documentation.

[JohannesMunk]

I think he wants to edit the list of properties that a specific state sets.

A quick look into QState.cpp reveals, that the list of properties to be set is stored in the private object. As far as I can see, there are no other access-members to d->propertyAssignments.

void QState::assignProperty(QObject *object, const char *name,
                            const QVariant &value)
{
    Q_D(QState);
    if (!object) {
        qWarning("QState::assignProperty: cannot assign property '%s' of null object", name);
        return;
    }
    for (int i = 0; i < d->propertyAssignments.size(); ++i) {
        QPropertyAssignment &assn = d->propertyAssignments[i];
        if ((assn.object == object) && (assn.propertyName == name)) {
            assn.value = value;
            return;
        }
    }
    d->propertyAssignments.append(QPropertyAssignment(object, name, value));
}

void QState::assignProperty(QObject *object, const char *name,
                            const QVariant &value)
{
    Q_D(QState);
    if (!object) {
        qWarning("QState::assignProperty: cannot assign property '%s' of null object", name);
        return;
    }
    for (int i = 0; i < d->propertyAssignments.size(); ++i) {
        QPropertyAssignment &assn = d->propertyAssignments[i];
        if ((assn.object == object) && (assn.propertyName == name)) {
            assn.value = value;
            return;
        }
    }
    d->propertyAssignments.append(QPropertyAssignment(object, name, value));
}

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Why don't you create a new state and replace the old one instead of trying to change it?

Johannes

[breezeight]

Yes It's what I mean. I could replace a state but I had to restore also all the transitions... a lot of work. But it seem the only way to do what I need, thank you!
Nicola

[wysota]

To me it seems that if you wish to change the properties for a particular state in reality the new set of properties and the old one correspond to two different states. You can make a state with two substates each holding a different set of property values and decide which substate will be entered when the parent state is entered based on which set of properties you want to consider "active".