Call a function every time a variable is changed

[tobben24]

Hi,

Is it possible to automatically call a function every time a specified variable is changed?

[shifty]

I believe there is a way if it is a "property" inside a QML component, then you get a onVariableNameChanged and you can call whatever you would like there

Ex:

property string myVar: "default_value"

onMyVarChanged: { // call your function here }

Hope this helps!!

[andre]

No, there is not. If you want that, then you should make your variable private to a class, and create a public accessor method for it. So:
@
//old situation
public:
int value;

//somewhere in code
value = 10;

//new situation:
private:
int value;
public:
void setValue(int newValue) {value = newValue; /* whatever else you need to do*/}

//somewhere in code:
setValue(10);
@

[tobben24]

Okay. Thanks for the replies:) I think I will go with the last one.

[shifty]

Oh, haha one was using QML, the other Qt C++,

If you want to go the C++ route there is this page "Qt Bindings":http://doc.qt.nokia.com/4.7-snapshot/qtbinding.html

Which may help you... I believe they use signals inside the C++ code as well as using the Q_PROPERTY macro