How to use property change signal if used with setContextProperty()?

HorstJ

Hi everyone,

I have problems writing my first qml/c++ app. Maybe someone can lend me a helping hand?

My app should show some health states including network settings. Reading the "ipAddress" is no problem, but I get a parser error on "eth0.onIpAddressChanged", saying the eth0 is unknown. Couldn't be that much, but I havn't found the problem/a solution yet.

Thanks in advance,
Horst

cpp:
@class netData : public QObject {
Q_OBJECT
Q_PROPERTY(QString ipAddress READ getIpAddress WRITE setIpAddress NOTIFY ipAddressChanged)

QString getIpAddress(void) const;
void setIpAddress(QString address);

signals:
void ipAddressChanged(QString addr);
}@

main.cpp:
@...
context->setContextProperty("eth0", myNetData );@

qml:
@Rectangle {
width: 360
height: 360

Text {
    color: "#000000"
    height: 20
    x: 10
    y: 10
    id: text1
    text: "ipAddr: " + eth0.ipAddress
    font.weight: Font.Bold
    font.pixelSize: 11
    verticalAlignment: Text.AlignVCenter
}

eth0.onIpAddressChanged: {
   text1.text = "ipAddr: " + addr;
}

}@

sierdzio

You need to use that block (JS connect style) in a JavaScript block, for example in Component.onCompleted:
@
Rectangle {
// ...

function addressChange() {
text1.text = "ipAddr: " + eth0.ipAddress;
}

Component.onCompleted: {
eth0.ipAddressChanged.connect(addressChange);
}
@

Torgeir

What sierdzio said, or you may use a Connections element:

@Connections {
target: eth0
onIpAddressChanged: text1.text = "ipAddr:" + addr
}
@

HorstJ

Thanks both of you!

Is it possible to use the connection element like this:
@
Connections {
target: eth0
onIpAddressChanged: text1.text = "ipAddr:" + addr
onIpSubnetChanged: text1.text = "Subnet:" + mask
}@

Torgeir

yes, if the netData class has a signal ipSubnetChanged with parameter named mask, that should work nicely.