Using Combobox in delegate does to trigger model to change data

Celal

Hello,

Recently I decided to try QML, but I have some problems. QML is soo cool but it looks like to me at the same time it is tricky too :)

Well, let's look at my problem. I have a ListModel that in c++ and set to TableView in QML. The model consists of 4 roles. When I use TextField in delegate everything is working as expected.

But What I want is Add Combobox for delegate to make selection and change data. Whenever I start use combo box I am no longer to change data in the model.

Working code with TextField:

  TableViewColumn {
                role: "name"
                title: "Name"
                width: 250
                delegate: TextField {
                    anchors.verticalCenter: parent.verticalCenter
                    text: model.name
                    onEditingFinished: model.name = text
                }
            }

Problematic code:

TableViewColumn {
                role: "name"
                title: "Name"
                width: 120
                delegate: ComboBox {
                    anchors.verticalCenter: parent.verticalCenter
                    model: ["Alice", "Bob"]
                    currentIndex: model.name === "Alice" ? 0 : 1
                    onCurrentTextChanged: {
                        console.log("from component", currentText)
                        model.name = currentText
                    }
                }
            }

What is the reason causing this problem?

Thanks in advance.

dheerendra

ComboBox itself has model. When you access the model, it is changing the model of combobox not the parent model.

Celal

@dheerendra thank you for your response. So what is the solution then? I cannot use combobox in MVC?

What is the alternative way to solve this problem?

Thanks

Eeli K

@Celal Try this idea (no full code here):

delegate: Item {
    id: i
    ComboBox {
        oncurrentTextChanged: {
            i.model.name = currentText
        }

Celal

@Eeli-K It does not work in your way. It was giving "Type error"

However, I like your approach. So then I tried something else.

Instead of id, I define a property for each row then I use property to assign the new value then it works

here is the solution:

  delegate: RowLayout {
                property var rmodel: model
                ComboBox {
                    model: ListModel {
                        ListElement {name : "9600"}
                        ListElement {name : "112500"}
                    }
                    textRole: "name"
                    currentIndex: rmodel.baudrate === "9600" ? 0 : 1
                    onCurrentTextChanged: {
                        rmodel.baudrate = currentText
                    }
                }

Thanks for help.

Celal