QML ListView currentIndex Not Working With c++

khislop

I'm trying to create a voltage selector in QML using a ListView as a base. The list itself just needs to be a list of text elements but the number of items in the list needs to be able to be changed at run time. If I set the model to a number (model: 4) or a mathematical expression (model: (1200-800)/100) then everything works as expected. When I try to set the model based on a c++ integer variable exposed to the QML (model: myCppClass.intProperty) it seemes to work since I get the correct number of elements. However setting the currentIndex does not seem to do anything, it will always start at index 0. If I increment the currentIndex during run time (by a button press for example) it changes correctly. However I need have a default setting larger than index 0 which doesn't seem to work once I add a c++ integer to the model number calculation.

My voltage selector:


        // Using ListView
        Rectangle {
            width: 540; height: 94
            x: 711
            y: 117
            color: "transparent"
            clip: true

            ListView {
                id: voltageList
                width: 540; height: 94
//                property var itemCount: (mainScreen.maxVoltage - mainScreen.minVoltage) / 100 + 1
                model: (mainScreen.maxVoltage - mainScreen.minVoltage) / 100 + 1
//                model: (1200 - 800) / 100
//                model: itemCount
//                model: 5
                preferredHighlightBegin: 270 - 50
                preferredHighlightEnd: 270 + 50
                highlightRangeMode: PathView.StrictlyEnforceRange
                currentIndex: 2
//                currentIndex: (manager.mode == 0) ? (manager.getVoltageDefaultWave()-mainScreen.minVoltage)/100 : (manager.getVoltageDefaultFlex()-mainScreen.minVoltage)/100
                orientation: Qt.Horizontal

                delegate: Item {
                    width: 100
                    height: 100
                    property bool currentItem: ListView.view.currentIndex == index
                    property alias text : textNumList.text
                    Text {
                        id: textNumList
                        anchors.centerIn: parent
//                        text: ((index + 12) / 10).toFixed(1)
                        text: ((index*manager.getVoltageResolution() + mainScreen.minVoltage) / 1000).toFixed(1)
//                        text: mainScreen.maxVoltage

                        opacity: currentItem? 1 : 0.5
                        font.pixelSize: currentItem ? 65 : 34

                        font.family: nizzoli.name
                        color: "#7ED1F2"

                    }
                }

//                onCurrentIndexChanged: mainScreen.setVoltage(currentIndex*manager.getVoltageResolution() + mainScreen.minVoltage)
                onMovementEnded: mainScreen.setVoltage(currentIndex*manager.getVoltageResolution() + mainScreen.minVoltage)
            }
        }

Here's what I expose to QML in my C++ mainScreen header:

    Q_PROPERTY(int voltage READ voltage NOTIFY voltageChanged)
    Q_PROPERTY(int minVoltage READ minVoltage NOTIFY minVoltageChanged)
    Q_PROPERTY(int maxVoltage READ maxVoltage NOTIFY maxVoltageChanged)

IntruderExcluder

When model changes it will reload whole ListView and drop currentIndex to a default value (0). You can save current index somehere else before updating model and then restore it:

onModelChanged: currentIndex = someSavedValue