extending functionality of third-party module

[mzimmers]

Hi all -

I'm using this third-party module and need to add some functionality to it. Here's a snippet of the file I need to extend:

Item {
    id: control
    Item {
        id: handleItem
        MouseArea {
            id: trackMouse
            onReleased: sp.value = control.value // this is the line I'm adding.

I'd prefer not to modify the module if I can avoid it, but I don't see a way around it. Is there a way to "inject" the functionality of that added line without modifying the source?

Thanks...

[fcarney]

I would modify the control like this:

Item {
    id: control
  
    signal trackMouseRelease()

    Item {
        id: handleItem
        MouseArea {
            id: trackMouse
            onReleased: trackMouseRelease()

Then in the place you use CircularSlider:

CircularSlider {
  id: circSlider
  onTrackMouseRelease: {
    sp.value = circSlider.value
  }
}

This way your change is generic and the object is reusable.

[mzimmers]

@fcarney your idea is great, but it's still modifying the third-party QML, which is what I'm trying to avoid. (I realize that in this instance, it's no big deal, but I'm trying to find a solution in case I eventually utilize a much larger, more elaborate third-party product.) Is there some QML equivalent to C++ subclassing where I could add or override member behavior?

Thanks...

[fcarney]

There is nothing magic you can do here if a QML object doesn't expose what you need. The best you can do is add aliases to expose objects you need access to and submit a patch to the repository. If they agree on the changes then you helped make their code more flexible.

[fcarney]

Why don't you just go off of value changed? Aren't you just needing the value when it changes? Every property in QML has a changed event signal that is created:

CircularSlider {
  id: circSlider
  onValueChanged: {
    sp.value = circSlider.value
  }
}

value -> onValueChanged for the signal

[GrecKo]

there's a pressed property for the above CircularSlider, no need to modify it.
You can do

CircularSlider {
    onPressedChanged: {
        if (!pressed)
            sp.value = control.value;
    }
}

[mzimmers]

@GrecKo @fcarney thank you both -- this is exactly what I was looking for. But, for some reason, fcarney's solution seems to "miss" most (not all) of the changes, at least as reported by the WRITE property of my C++ object. @GrecKo 's solution catches all of the changes. Not sure why this is (not) happening with @fcarney's solution...