custom model isn't completely working

[mzimmers]

@JoeCFD I don't assign any role to anything in the drawer. I'm not sure how I'd even do that as it relates to the Switch it contains.

[J.Hilk]

@mzimmers said in custom model isn't completely working:

Does the act of opening a drawer force an update to its contents?

possibly that opening the drawer recreates the drawer content, forcing a reload of the data each time its opened

[mzimmers]

@J-Hilk well, in a sense, that's good news -- it would mean that my model isn't properly signaling changes at all, so at least the problem is consistent.

This is so weird -- it's almost as though the Switches on the different screens are independent of each other. Everything in the model seems to be working, from messaging the server, to accepting the response and (seemingly) sending the appropriate signals to QML.

I know this idea is a cheat, and I wouldn't want to use it in production, but...is there a way to force a QML component to update every time it becomes visible?

[JoeCFD]

@mzimmers

 onVisibleChanged: {
      console.log( " visible =", visible )
      //do update if visible is true 
 }

[mzimmers]

@JoeCFD the Creator doesn't like the "do update" construct; am I supposed to replace update with something?

[JoeCFD]

@mzimmers these are only texts. You do your update there.

[mzimmers]

@JoeCFD OK, but what is the command to force the update?

Here's what's happening: in my model, I make the change at the appropriate time:

if (m_list->setItemAt(i, itemFromList)) {
    QModelIndex qmi = index(i, 0, QModelIndex());
    setData(qmi, itemFromList.powerState(), StateRole);
    qDebug() << __PRETTY_FUNCTION__ << "changed powerState to" << itemFromList.powerState();
}

And in a qml screen, I have this code:

Text { text: "equipmentModel.getEquipmentItem(pumpUuid).powerState is " + equipmentModel.getEquipmentItem(pumpUuid).powerState }

This line is NOT reflecting the change made above. Somewhere there's a disconnect between the change, and the QML, but it seems like the model is doing everything correctly.

[JoeCFD]

@mzimmers in my code above you can print out the data value. If it is right, set it. If not, you have to find out the reason.

[mzimmers]

@JoeCFD oh, OK, I got it.

Text { text: "equipmentModel.getEquipmentItem(pumpUuid).powerState is " + equipmentModel.getEquipmentItem(pumpUuid).powerState }

Switch_custom {
    id: sw
    checked: equipmentModel.getEquipmentItem(pumpUuid).powerState === 1
    onClicked: {
        if (switchState === 1) {
            switchState = 0;
        } else {
            switchState = 1;
        }
        equipmentModel.sendSwitchChange(pumpUuid, switchState)
        console.log("Infoscreen.qml: new switch state is " + switchState)
    }
    onVisibleChanged: {
        console.log( "InfoScreen: Switch_custom visible =", visible)
        if (visible) {
            checked = equipmentModel.getEquipmentItem(pumpUuid).powerState === 1
        }
    }
}

The forced update to the checked property of the Switch is working, so the powerState value is good. But the line of text above it (which should reflect the same value) still shows the old value of powerState.

It almost seems that my equipmentItem (the class that the list is composed of) needs to emit a signal when something changes, but my equipmentItem is just a Q_GADGET, so it can't emit signals. In the example, the list item is just a struct, so it's obviously not emitting a signal.

Aargh...

[mzimmers]

Hi all -

Thanks for all the assistance. I'm going to close this topic, even though it's not solved, because I've come to realize that my model is overly complicated, and it make it difficult for me to explain here (there are parts of it that I still don't understand).

So, I'm going to make the following changes to my model:

• use an internal QList instead of using a separate class (currently EquipmentList) for my data list.

• replace the EquipmentItem class with a struct, and eliminate all the now-unnecessary getters and setters.

Hopefully these changes will make it a lot easier to follow what's happening. If I run into trouble, I'll start a new topic...thanks again.