QML Combobox not updating with dataChanged signal

[Andreas.S]

Hi!

I have a QML Combobox that does not update the current selected value when the model value is changed by another QML component.
However, if I open the Combobox, I see the element with the updated value. Selecting the same element will not change the current selected to the correct value, but selecting another value, and then jumping back updates the current selected value correctly.

The signal dataChanged is emitted each time the model data is changed.

Is there another signal ComboBox listens to when it comes to updating the current selected value?

I'm using Qt5.3, QtQuick 2.3 and QtQuick.Controls 1.2

QML Combobox code:

 ComboBox {
        id: myComboBox
        height: 20
        width: 300
        textRole: "nameRole"

        model: myModel
    }

myModel is defined in c++ like this:

class MyModel: public QAbstractListModel

Where the setData function is implemented like:

bool MyModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    if (!index.isValid() || index.row() >= dataList_.count())
        return false;

    switch(role) {
    case NameRole:
        if(dataList_.at(index.row())->->name() != value.toString())
        {
            dataList_.at(index.row())->setName(value.toString());
            emit dataChanged(index, index);
        }

and roleNames:

QHash<int, QByteArray> MyModel::roleNames() const
{
    QHash<int, QByteArray> roles;
    roles[NameRole] = "nameRole";

[Andreas.S]

@Andreas.S

Reproduced problem with QStringListModel. When changing element in model, ComboBox is not updated correctly.

int main(int argc, char** argv)
{
    QApplication app(argc, argv);

    QQuickView view;

    QStringListModel nameModel(QStringList() << "One" << "Two" << "Three");

    view.rootContext()->setContextProperty("_nameModel", &nameModel);

    QString loc = "qrc:///main.qml";
    view.setSource(QUrl(loc));

    view.show();


    return app.exec();
}

And QML:

import QtQuick 2.3
import QtQuick.Controls 1.2

Item {
    id: root
    width: 560
    height: 360

    ComboBox {
        id: comboBox
        model: _nameModel
        textRole: "edit"
    }

    Component
    {
        id: editNameDelegate

        Rectangle
        {
            id: editNameBox
            visible: comboBox.currentIndex===index ? true: false
            color: "transparent"

            Rectangle {
                id: changeNameBox
                border.color: "black"

                height: 30
                width: 360

                anchors.top: parent.top
                anchors.topMargin: 2
                anchors.left: parent.left
                Text
                {
                    text: "Change Name"
                    font.pixelSize: 18
                    anchors.left: parent.left
                    anchors.leftMargin: 8
                    anchors.verticalCenter: parent.verticalCenter
                }
                Rectangle
                {
                    border.color: "black"
                    height: 25
                    width: 200
                    anchors.right: parent.right
                    anchors.rightMargin: 5
                    anchors.verticalCenter: parent.verticalCenter

                    TextInput
                    {
                        anchors.fill: parent
                        anchors.leftMargin: 3
                        id: changeNameInput
                        text: model.edit
                        Keys.onReturnPressed: {
                            model.edit = text
                            Qt.inputMethod.hide();
                        }
                    }
                }
            }
        }
    }
    ListView {
        anchors.top: comboBox.bottom
        height: 30
        width: 500
        id: editNameAList
        model: _nameModel
        delegate: editNameDelegate
        interactive: false
    }
}

[Andreas.S]

Found a workaround:
Connect a slot that updates the model completely using either beginInsertRows or ResetModel. This should be called each time data that the combobox displays is changed.

[dheerendra]

This post is deleted!