[solved] Newbie is confused.How to add dynamic data to TableView and parse through it send data to c++

[vishnu]

@p3c0
I am still getting the error.
ASSERT: "!isEmpty()" in file ......\Qt5.4.1\5.4\mingw491_32\include/QtCore/qlist.h, line 292
Invalid parameter passed to C runtime function.
Invalid parameter passed to C runtime function.
My main.cpp:

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    TCPCommunicationPort tcpCommunicationPort;
    auto root_context = engine.rootContext();
    root_context->setContextProperty("tcpCommunicationPort",&tcpCommunicationPort);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    QObject* root = engine.rootObjects().first();// error at this point
    return app.exec();
}

The same main code was working fine in another project but When i copied the same in new project it's again saying the same error. I have loaded main.qml before
QObject* root = engine.rootObjects().first();
May i know what's the mistake?

[p3c0]

@vishnu Can you post the QML part ? i.e main.qml

[vishnu]

@p3c0
main.qml

import QtQuick 2.3
import QtQuick.Window 2.2
import QtQuick.Controls 1.3

Window{
    id:window
    width: Screen.width
    height: Screen.height
    visible: true

    Item{
        id:mainUI
        anchors.fill: parent
        Header{
            id:header
        }
        CentralView{
            id:centralView
            anchors.top: header.bottom
            anchors.bottom: footer.top
        }
        //Model
        SetTable{
            id:setTable
            anchors.top: header.bottom
            anchors.bottom: footer.top
            visible: false
        }
        Footer {
            id: footer
            anchors.bottom: parent.bottom
        }
        states: [
            State {
                name: "MainView"
                PropertyChanges {target: centralView;cycRegVisible:false; ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:false; }
            },
            //setTable view state
            State {
                name: "SetTableView"
                PropertyChanges {target: centralView;centralViewVisible:false;}
                PropertyChanges {target: setTable;visible:true;}
                PropertyChanges {target: footer;forwardButtonvisible:false;}
            },
            State {
                name: "CyclicRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:true }
                PropertyChanges {target: footer;backButtonvisible:true}
                PropertyChanges {target: centralView;ctrlReg1Visible:false }
                PropertyChanges {target: centralView;ctrlReg2Visible:false }
                PropertyChanges {target: centralView;cmodeRegVisible:false }
                PropertyChanges {target: centralView;directModeRegVisible:false }
                PropertyChanges {target: centralView;trackingModeRegVisible:false }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "ControlRegister1View"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:true;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;trackingModeRegVisible:false }
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "ControlRegister2View"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:true;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;trackingModeRegVisible:false }
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "OperationModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:true;directModeRegVisible:false }
                PropertyChanges {target: centralView;trackingModeRegVisible:false ;homingModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "DirectModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:true}
                PropertyChanges {target: centralView;trackingModeRegVisible:false ;homingModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "SetTableModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:true;trackingModeRegVisible:false;homingModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "TrackingModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:true;homingModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "HomingModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:true}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "JoggingModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:true}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:false }
            },
            State {
                name: "SAcyclicRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:true }
            },
            State {
                name: "StatusRegister1View"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;statusReg1Visible:true }
            },
            State {
                name: "StatusRegister2View"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;statusReg2Visible:true }
            },
            State {
                name: "StatusRegister3View"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;statusReg3Visible:true }
            },
            State {
                name: "SOperationModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sOperationRegVisible:true }
            },
            State {
                name: "SDirectModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sDirectModeRegVisible:true }
            },
            State {
                name: "SSetTableModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sSetTableModeRegVisible:true }
            },
            State {
                name: "STrackingModeRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sTtrackingModeRegVisible:true }
            },
            State {
                name: "SHomingRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sHomingModeRegVisible:true }
            },
            State {
                name: "SJoggingRegisterView"
                PropertyChanges {target: centralView;cycRegVisible:false;ctrlReg1Visible:false;ctrlReg2Visible:false;cmodeRegVisible:false;directModeRegVisible:false}
                PropertyChanges {target: centralView;setTableModeRegVisible:false;trackingModeRegVisible:false;homingModeRegVisible:false;jogginModeRegVisible:false}
                PropertyChanges {target: footer;backButtonvisible:true; }
                PropertyChanges {target: centralView;displayViewVisible:true;controlViewVisible:false;sAcycRegVisible:false;sJogginModeRegVisible:true }
            }
        ]
        state: "MainView"
        Connections{
            target: centralView;
            onAcyclicButtonClicked:{
                //                console.log("switching to CyclicRegisterView")
                mainUI.state="CyclicRegisterView"

            }
            onControlRegister1ButtonClicked:{
                //                console.log("switching to Control Register1View")
                mainUI.state="ControlRegister1View"
            }
            onControlRegister2ButtonClicked:{
                //                console.log("switching to Control Register2View")
                mainUI.state="ControlRegister2View"
            }
            onOperationModeRegisterClicked:{
                //                console.log("switching to CMODE or operation mode register view")
                mainUI.state="OperationModeRegisterView"
            }
            onDirectModeRegisterClicked:{
                //                console.log("switching to direct mode register view")
                mainUI.state="DirectModeRegisterView"
            }
            onSetTableModeRegisterClicked:{
                //                console.log("switching to settable mode register view")
                mainUI.state="SetTableModeRegisterView"
            }
            onTrackingModeRegisterClicked:{
                //                console.log("switching to trakingmode register view")
                mainUI.state="TrackingModeRegisterView"
            }
            onHomingModeRegisterClicked:{
                //                console.log("switching to homing register view")
                mainUI.state="HomingModeRegisterView"
            }
            onJoggingModeRegisterClicked:{
                //                console.log("switching to joggin register view")
                mainUI.state="JoggingModeRegisterView"
            }
            onSAcyclicButtonClicked:{
                //                console.log("switching to display acyclic register view")
                mainUI.state="SAcyclicRegisterView"
            }
            onSStatusRegister1ButtonClicked:{
                mainUI.state="StatusRegister1View"
            }
            onSStatusRegister2ButtonClicked:{
                mainUI.state="StatusRegister2View"
            }
            onSStatusRegister3ButtonClicked:{
                mainUI.state="StatusRegister3View"
            }
            onSOperationModeRegisterClicked:{
                mainUI.state="SOperationModeRegisterView"
            }
            onSDirectModeRegisterClicked:{
                mainUI.state="SDirectModeRegisterView"
            }
            onSSetTableModeRegisterClicked:{
                mainUI.state="SSetTableModeRegisterView"
            }
            onSTrackingModeRegisterClicked:{
                mainUI.state="STrackingModeRegisterView"
            }
            onSHomingModeRegisterClicked:{
                mainUI.state="SHomingRegisterView"
            }
            onSJoggingModeRegisterClicked:{
                mainUI.state="SJoggingRegisterView"
            }
        }
        Connections{
            target: footer
            onBackButtoncliked:{
                //                console.log("switching to MainView")
                mainUI.state="MainView"
            }
            onForwardButtonClicked:{
                mainUI.state="SetTableView"
            }
        }
    }
}

Sorry for the lengthy one. my model is in SetTable.qml

import QtQuick 2.3
import QtQuick.Window 2.2
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1
Rectangle {
    id:root
    anchors.fill: parent
    Row{
        id:buttons
        anchors.top: root.top
        Button{
            id:addNewRowButton
            text: "ADD"
            onClicked: {
                setTableModel.append({x_position: 0,
                                         y_position:0,
                                         z_position:0,
                                         velocity :0,
                                         acceleration:0,
                                         deceleration:0,
                                         tool:0,
                                         tracking_x:0,
                                         tracking_y:0,
                                         tracking_z:0}
                                     )
            }
        }
        Button{
            id:deleteRowButton
            text: "DELETE"
            onClicked: {
                setTableModel.remove(setTableView.currentRow)
            }
        }

    }
    ListModel{
        id:setTableModel

        ListElement{
            x_position: 1000
            y_position: 200
            z_position: 300
            velocity: 28
            acceleration:34
            deceleration:14
            tool:1
            tracking_x: 400
            tracking_y:500
            tracking_z:5
        }
        ListElement{
            x_position: 1000
            y_position: 200
            z_position: 300
            velocity: 28
            acceleration:34
            deceleration:14
            tool:1
            tracking_x: 400
            tracking_y:500
            tracking_z:5
        }
        ListElement{
            x_position: 100
            y_position: 200
            z_position: 300
            velocity: 28
            acceleration:34
            deceleration:14
            tool:1
            tracking_x: 400
            tracking_y:500
            tracking_z:555
        }
    }

    TableView{
        id:setTableView
        objectName: "setTableView"
        model: setTableModel
        width: parent.width
        height: parent.height-buttons.height
        Layout.minimumWidth: 400
        Layout.minimumHeight: 240
        Layout.preferredWidth: 600
        Layout.preferredHeight: 400
        anchors.top: buttons.bottom
        TableViewColumn {
            role: "x_position"
            title: "X mm"
            width: 80
        }
        TableViewColumn {
            role: "y_position"
            title: "Y mm"
            width: 80
        }
        TableViewColumn {
            role: "z_position"
            title: "Z mm"
            width: 80
        }
        TableViewColumn {
            role: "velocity"
            title: "V m/s"
            width: 80
        }
        TableViewColumn {
            role: "acceleration"
            title: "A m/s2"
            width: 80
        }
        TableViewColumn {
            role: "deceleration"
            title: "D m/s2"
            width: 80
        }
        TableViewColumn {
            role: "tool"
            title: "Tool"
            width: 80
            delegate:
                TextInput {
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                renderType: Text.NativeRendering
                validator: IntValidator {bottom: 0; top: 1;}
                text: styleData.value
            }
        }

        TableViewColumn {
            role: "tracking_x"
            title: "Tx mm"
            width: 80
        }
        TableViewColumn {
            role: "tracking_y"
            title: "Ty mm"
            width: 80
        }
        TableViewColumn {
            role: "tracking_z"
            title: "Tz mm"
            width: 80
        }
        itemDelegate: Item {
            TextInput {
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                renderType: Text.NativeRendering
                text: styleData.value
            }
        }
    }
}

But the same piece of code as main.cpp is working fine in another project. I think something is wrong with my main.qml. May i know what's the mistake? Thanks

[p3c0]

@vishnu No idea. Seems closer to this QTBUG-44859.
Can you try trimming down the main.qml i.e removing some component and then executing ?

[vishnu]

@p3c0
Okay, Any other way to access the TableView model in C++ side?

[p3c0]

@vishnu AFAIK. no. But that error is not related to TableView or ListModel.

[vishnu]

@p3c0
Got it.The error was due to the wrong import statement in qml.
Now How do I capture the changes?
If reading the entire model is the solution (ofcourse not efficient).
How can I call this public slot getModel when ever there is a change in TableView in qml? What is the signal I get from the model/view which tells me that there is a change ?

void TCPCommunicationPort::getModel(QQmlApplicationEngine &engine)
{
    QObject* root = engine.rootObjects().first(); //get the root object as usual
    QObject* list = root->findChild<QObject*>("setTableView"); //get the ListView

    QVariant qmlmodel = list->property("model"); //access model property of ListView
    QAbstractListModel *model = qvariant_cast<QAbstractListModel *>(qmlmodel); //convert to QAbstractListModel
.....//data is handled here

[p3c0]

@vishnu As we casted it to QAbstractListModel we can connect to its signal dataChanged from C++. Thus when anything changes the slot will be called.

QAbstractListModel *model = qvariant_cast<QAbstractListModel *>(qmlmodel);
QObject::connect(model,SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
                     &myclass,SLOT(onDataChanged(QModelIndex,QModelIndex,QVector<int>)));

Access the changed data in slot

void MyClass::onDataChanged(const QModelIndex &topLeft, 
             const QModelIndex &bottomRight, const QVector<int> &roles)
{
    qDebug() << "Data Changed :" << topLeft.data(roles[0]) << topLeft.data(roles[1]);
}

[vishnu]

@p3c0
I don't know why but the SLOT is not called when the data changes.
I did the connection in main itself.
main.qml

QQmlApplicationEngine engine;
    TCPCommunicationPort tcpCommunicationPort;
    auto root_context = engine.rootContext();
    root_context->setContextProperty("tcpCommunicationPort",&tcpCommunicationPort);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
//    tcpCommunicationPort.getModel(engine);
    QObject* root = engine.rootObjects().first(); //get the root object as usual
    QObject* list = root->findChild<QObject*>("setTableView"); //get the ListView

    QVariant qmlmodel = list->property("model"); //access model property of ListView
    QAbstractListModel *model = qvariant_cast<QAbstractListModel *>(qmlmodel); //convert to QAbstractListModel

    QObject::connect(model,SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
                         &tcpCommunicationPort,SLOT(onDataChanged(QModelIndex,QModelIndex,QVector<int>)));

In header file

public slots:
void onDataChanged(const QModelIndex &topLeft,
                            const QModelIndex &bottomRight, const QVector<int> &roles);

May i know why the slot is not called?I even don't know whether the signal is raised or not.How to know whether the signal is emitted not in this case?

[p3c0]

@vishnu

May i know why the slot is not called?I even don't know whether the signal is raised or not.How to know whether the signal is emitted not in this case?

Since you are using ListModel use onDataChanged signal handler.

ListModel {
    id: myModel

    onDataChanged: console.log("Data Changed")
}

thus verify whether the data is changed.

[vishnu]

@p3c0
nice hint. unfortunatelly onDataChanged singal is not emitted. when ever I am changing data,adding new row. That means problem is on my QML side.Again this is code for my model,View:
setTable.qml

import QtQuick 2.3
import QtQuick.Window 2.2
import QtQuick.Controls 1.3
import QtQuick.Layouts 1.1
Rectangle {
    id:root
    anchors.fill: parent
    Row{
        id:buttons
        anchors.top: root.top
        Button{
            id:addNewRowButton
            text: "ADD"
            onClicked: {
                setTableModel.append({x_position: 0,
                                         y_position:0,
                                         z_position:0,
                                         velocity :0,
                                         acceleration:0,
                                         deceleration:0,
                                         tool:0,
                                         tracking_x:0,
                                         tracking_y:0,
                                         tracking_z:0}
                                     )
            }
        }
        Button{
            id:deleteRowButton
            text: "DELETE"
            onClicked: {
                setTableModel.remove(setTableView.currentRow)
            }
        }

    }
    ListModel{
        id:setTableModel

        ListElement{
            x_position: 0
            y_position: 300
            z_position: 500
            velocity: 100
            acceleration:100
            deceleration:0
            tool:0
            tracking_x: 0
            tracking_y:0
            tracking_z:0
        }
        onDataChanged: {
            console.log("Data changed")
        }
    }

    TableView{
        id:setTableView
        objectName: "setTableView"
        model: setTableModel
        width: parent.width
        height: parent.height-buttons.height
        Layout.minimumWidth: 400
        Layout.minimumHeight: 240
        Layout.preferredWidth: 600
        Layout.preferredHeight: 400
        anchors.top: buttons.bottom
        TableViewColumn {
            role: "x_position"
            title: "X mm"
            width: 80
        }
        TableViewColumn {
            role: "y_position"
            title: "Y mm"
            width: 80
        }
        TableViewColumn {
            role: "z_position"
            title: "Z mm"
            width: 80
        }
        TableViewColumn {
            role: "velocity"
            title: "V m/s"
            width: 80
        }
        TableViewColumn {
            role: "acceleration"
            title: "A m/s2"
            width: 80
        }
        TableViewColumn {
            role: "deceleration"
            title: "D m/s2"
            width: 80
        }
        TableViewColumn {
            role: "tool"
            title: "Tool"
            width: 80
            delegate:
                TextInput {
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                renderType: Text.NativeRendering
                validator: IntValidator {bottom: 0; top: 1;}
                text: styleData.value
            }
        }
        TableViewColumn {
            role: "tracking_x"
            title: "Tx mm"
            width: 80
        }
        TableViewColumn {
            role: "tracking_y"
            title: "Ty mm"
            width: 80
        }
        TableViewColumn {
            role: "tracking_z"
            title: "Tz mm"
            width: 80
        }
        itemDelegate: Item {
            TextInput {
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                renderType: Text.NativeRendering
                text: styleData.value
            }
        }
    }
}

[p3c0]

@vishnu AFAICS You are just adding and removing the data but not updating it. In this case dataChanged wont be called.

[vishnu]

@p3c0
Any hint or example on how to update the data? Thanks a lot

[p3c0]

@vishnu Make use rowsInserted of rowsRemoved signals. Connect them to their respective slots as shown previously for dataChanged.

[vishnu]

@p3c0
I have already added 3 rows with default value. when ever I change default value to someother value. I am not getting the updated value to c++ side.
QObject::connect(model,SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)), &myclass,SLOT(onDataChanged(QModelIndex,QModelIndex,QVector<int>)));
This is not working? As you said since I am not updating the model, just appending and removing the rows.I feel like there has to be done more in my QML part.May I know what is wrong or missing in my Model and View (QML) ?Thanks

[p3c0]

@vishnu

I have already added 3 rows with default value. when ever I change default value to someother value. I am not getting the updated value to c++ side.

how are you changing the default value ?

[vishnu]

@p3c0
I can change my default values because my delegate is a TextInput.

 TableViewColumn {
            role: "tool"
            title: "Tool"
            width: 80
            delegate:
                TextInput {
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                renderType: Text.NativeRendering
                validator: IntValidator {bottom: 0; top: 1;}
                text: styleData.value
            }
        }

[p3c0]

@vishnu Im asking how do you change the items added in ListModel ? That signal will only be updated only when you update the existing items in the model.
For eg:

ListModel {
    id: myModel

    ListElement {
        name: "abc"
        age: 12
    }

    onDataChanged: console.log("Changed")
}

//updating the list model
myModel.set(0, { "name" : "xyz" } )

So here the signal dataChanged will be triggered and hence the slot onDataChanged in QML will be invoked. Same will work for C++ slot too.

Now in your earlier code you are just adding and removing the rows so those signals (mentioned earlier) will be triggered.

[vishnu]

@p3c0
I am no where doing that kind of updating. I am assuming that ListModel.append method does updating the model as well as view.

Button{
                id:addNewRowButton
                text: "ADD"
                onClicked: {
                    setTableModel.append({"x_position": 0,
                                             "y_position":0,
                                             "z_position":0,
                                             "velocity":0,
                                             "acceleration":0,
                                             "deceleration":0,
                                             "tool":0,
                                             "tracking_x":0,
                                             "tracking_y":0,
                                             "tracking_z":0}
                                         )
                }
            }

[p3c0]

@vishnu No that is not updating. That wont invoke the data changed signal.
As said earlier if you use append or remove use rowsInserted or rowsRemoved signals repectively.