[Solved] Calculation in a QML file?

Thanana

Hello all,

I got the following code that doesn't work (in a QML file - PixelAdapter.qml) :

@Item {
id: pixelAdapterId

property int in
property int alpha
property int out

out = in * 10 + alpha

}@

I tried :

@pixelAdapterId.out = pixelAdapterId.in * 10 + pixelAdapterId.alpha

PixelAdapter.out: PixelAdapter.in * 10 + PixelAdapter.alpha@

but everything doesn't work. I feel like I'm not doing something usual in QML but I HAVE to do some calculations with my properties, and "bind" the result of it to another property.
What do I have to modify ?

Thanks in advance for any help,
Gui

vsorokin

@Item {
id: pixelAdapterId

property int in: 10
property int alpha: 20
property int out: in * 10 + alpha

Component.onCompleted: {
console.log(out);
}
}@

This example print 120 to console

Thanana

This seems to work but it doesn't... I'll try to explain.
The thing is that in my software uses 2 bindings with this QML file. One binding is on the "in" value and the other on the "out" value.
And when I start my software, when I FIRST change my "in" value, the bind on the "out" value gets the new value. This works.
But when I change the value again, the "out" doesn't update... and the thing is that the value will constantly change in my software :/

Does someone got an idea about it ?

vsorokin

For every property in QML you automatically get chadged signal, so you can try use something like:

@Item {
id: pixelAdapterId

property int in
property int alpha: 20
property int out
.....
function calcOut() {
   out = in * 10 + aplha
}
onInChanged: {
   calcOut()
}
.....

}@

sierdzio

[quote author="Thanana" date="1318406351"]This seems to work but it doesn't... I'll try to explain.
The thing is that in my software uses 2 bindings with this QML file. One binding is on the "in" value and the other on the "out" value.
And when I start my software, when I FIRST change my "in" value, the bind on the "out" value gets the new value. This works.
But when I change the value again, the "out" doesn't update... and the thing is that the value will constantly change in my software :/

Does someone got an idea about it ?[/quote]

Use @Behaviour on in { /* some code here */ }@ It will be invoked every time when you change "in".

Thanana

Both works, thanks a lot to both of you :)