Qt on maemo DBus

[mrudulpen]

Hi,

I am trying to use Qt4 on maemo 4.x. (I am an absolute beginner to linux world.)

I am trying to capture event when the device goes in dimmed state. I understand we need to use DBus for it.
Following is the information I get when dbus-monitor is run on the device

signal sender=:1.5 -> dest=(null destination) path=/com/nokia/mce/signal; interface=com.nokia.mce.signal; member=display_status_ind
string "dimmed"

based on that I am writing following code

bool success = conn.connect("com.nokia.mce.signal","/com/nokia/mce/signal","com.nokia.mce.signal", "display_status_ind",halObj, SLOT(listenInactivity(string)));
    qDebug() << "SUCCESS : " << success;

bool success = conn.connect("com.nokia.mce.signal","/com/nokia/mce/signal","com.nokia.mce.signal", "display_status_ind",halObj, SLOT(listenInactivity(string)));
    qDebug() << "SUCCESS : " << success;

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where halObj class is as follows
class HalObj : public QObject
{
Q_OBJECT
public:
HalObj (QObject * parent = 0);
virtual ~ HalObj() {}
public slots:
void listenInactivity(QString aStr);
};
But for some reason, my slot never gets called. Also second problem, that I am facing is that, I want to listen for this signal continuously, but it seems, I dont seem to loop by itself, I need to wrap my function call in an infinite while loop.
Here is my main.cpp

void fun()
{
    qDebug()<<"Step1";
//Step 1
    /* Register previously declared types with DBus */
    qDBusRegisterMetaType<Property>();
    qDBusRegisterMetaType< QList<Property> >();
qDebug()<<"Step2";
  //Step 2
    /* This object is used to listen for and react to events */
HalObj * halObj = new HalObj();
 
/* HAL stores everything on the system bus */
QDBusConnection conn = QDBusConnection::systemBus();
 
/* Connect to the HAL Manager device to find all devices */
QDBusInterface battery("com.nokia.bme.signal","/com/nokia/bme/signal","com.nokia.bme.signal",conn);
 
qDebug()<<"Step5";
    //Step 5
    /* Listen for any ’display_status_ind’ events from this battery
    * on DBus
    */
    bool success = conn.connect("com.nokia.mce.signal","/com/nokia/mce/signal","com.nokia.mce.signal", "display_status_ind",halObj, SLOT(listenInactivity(string)));
    qDebug() << "SUCCESS : " << success;
 
qDebug()<<"Step7";
}
 
int main(int argc, char *argv[])
{
while(1)
    {
    fun();
    sleep(2);
}
    QCoreApplication a(argc, argv);
    return a.exec();
}

void fun()
{
    qDebug()<<"Step1";
//Step 1
    /* Register previously declared types with DBus */
    qDBusRegisterMetaType<Property>();
    qDBusRegisterMetaType< QList<Property> >();
qDebug()<<"Step2";
  //Step 2
    /* This object is used to listen for and react to events */
HalObj * halObj = new HalObj();

/* HAL stores everything on the system bus */
QDBusConnection conn = QDBusConnection::systemBus();

/* Connect to the HAL Manager device to find all devices */
QDBusInterface battery("com.nokia.bme.signal","/com/nokia/bme/signal","com.nokia.bme.signal",conn);

qDebug()<<"Step5";
    //Step 5
    /* Listen for any ’display_status_ind’ events from this battery
    * on DBus
    */
    bool success = conn.connect("com.nokia.mce.signal","/com/nokia/mce/signal","com.nokia.mce.signal", "display_status_ind",halObj, SLOT(listenInactivity(string)));
    qDebug() << "SUCCESS : " << success;

qDebug()<<"Step7";
}

int main(int argc, char *argv[])
{
while(1)
    {
    fun();
    sleep(2);
}
    QCoreApplication a(argc, argv);
    return a.exec();
}

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Please let me know how to go about this problem.

Another signal I am looking for is charger connected.
The DBus monitor shows following:

signal sender=:1.2 -> dest=(null destination) path=/com/nokia/bme/signal; interface=com.nokia.bme.signal; member=charger_connected

My question is
In the above signal,
Service is: com.nokia.bme.signal
Path is: /com/nokia/bme/signal
Interface is: com.nokia.bme.signal
Method/Signal is : charger_connected
Parameter to slot: void

Is my assumption correct?

any help would be highly appreciated

Kind Regards

Mrudul