setData() with QAbstractTableModel in QtQuick TableView

[zergedu]

Hey all,

I'm trying to connect a TableView in QtQuick Controls with a QAbstractTableModel in C++. The tableview correctly displays the model data, but I cannot figure out how to update the model data from the tableview. I've made a simple example in QML/C++ to illustrate my problem. There are 3 roles in the model, and a checkbox, a button, and a textfield in the tableview. I'd like to be able to write the checkbox state and the textfield text to the model. The model should be updated where the "*** Save X to model here! ***" comments are. Does any know how to do this?

/* main.qml */

import QtQuick 2.2
import QtQuick.Controls 1.1
 
ApplicationWindow {
    id: applicationWindow1
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
 
    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }
 
    TableView {
 
        id: metadataTaskTable
        anchors.fill: parent
        alternatingRowColors: false
        model: theModel
 
        // Row Delegate
        rowDelegate: Item {
 
            height: 20 + 15
            Rectangle {
                anchors {
                    left: parent.left
                    right: parent.right
                    verticalCenter: parent.verticalCenter
                }
                height: parent.height
                color: styleData.selected ? 'lightblue' : 'white'
            }
        }
 
        // Column 0
        TableViewColumn {
            role: "role_enable";
            width: 25;
            resizable: false;
 
            delegate:
            CheckBox {
                id: checkBoxDelegate
                anchors.verticalCenter: parent.verticalCenter
                anchors.left: parent.left
                anchors.right: parent.right
                anchors.margins: 5
                checked: styleData.value
 
                onCheckedChanged: {
 
                    // *** Save check state to model here! ***
 
                    // Print Model
                    theModel.print_rows()
                }
            }
        }
 
        // Column 1
        TableViewColumn {
            role: "role_m_one";
            width: 70
 
            delegate:
            Button {
                anchors.verticalCenter: parent.verticalCenter
                text: "Click Me!"
                width: parent.width
 
                onClicked: {
                    console.log(styleData.value)
                }
            }
        }
 
 
        // Column 2
        TableViewColumn {
            title: "Some Text";
            role: "role_m_two";
            width: 70
 
            delegate:
            TextField {
                anchors.fill: parent
                text: styleData.value
 
                onTextChanged: {
 
                    // *** Save text to model here! ***
 
                    // Print Model
                    theModel.print_rows()
                }
            }
        }
    }
}

import QtQuick 2.2
import QtQuick.Controls 1.1

ApplicationWindow {
    id: applicationWindow1
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }

    TableView {

        id: metadataTaskTable
        anchors.fill: parent
        alternatingRowColors: false
        model: theModel

        // Row Delegate
        rowDelegate: Item {

            height: 20 + 15
            Rectangle {
                anchors {
                    left: parent.left
                    right: parent.right
                    verticalCenter: parent.verticalCenter
                }
                height: parent.height
                color: styleData.selected ? 'lightblue' : 'white'
            }
        }

        // Column 0
        TableViewColumn {
            role: "role_enable";
            width: 25;
            resizable: false;

            delegate:
            CheckBox {
                id: checkBoxDelegate
                anchors.verticalCenter: parent.verticalCenter
                anchors.left: parent.left
                anchors.right: parent.right
                anchors.margins: 5
                checked: styleData.value

                onCheckedChanged: {

                    // *** Save check state to model here! ***

                    // Print Model
                    theModel.print_rows()
                }
            }
        }

        // Column 1
        TableViewColumn {
            role: "role_m_one";
            width: 70

            delegate:
            Button {
                anchors.verticalCenter: parent.verticalCenter
                text: "Click Me!"
                width: parent.width

                onClicked: {
                    console.log(styleData.value)
                }
            }
        }


        // Column 2
        TableViewColumn {
            title: "Some Text";
            role: "role_m_two";
            width: 70

            delegate:
            TextField {
                anchors.fill: parent
                text: styleData.value

                onTextChanged: {

                    // *** Save text to model here! ***

                    // Print Model
                    theModel.print_rows()
                }
            }
        }
    }
}

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/* mymodel.h */

#ifndef MYMODEL_H
#define MYMODEL_H
 
#include <QAbstractTableModel>
#include <QDebug>
 
 
struct SimpleData {
    bool enable;
    QString m_one;
    QString m_two;
 
    SimpleData() {
        enable = true;
        m_one = "1";
        m_two = "2";
    }
 
    SimpleData(bool enable, const QString m_one, const QString m_two) :
    enable(enable), m_one(m_one), m_two(m_two) {}
};
 
 
class MyModel : public QAbstractTableModel
{
    Q_OBJECT
 
public:
    explicit MyModel(QObject *parent = 0);
 
    int rowCount(const QModelIndex &parent = QModelIndex()) const ;
    int columnCount(const QModelIndex &parent = QModelIndex()) const;
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
    bool setData(const QModelIndex & index, const QVariant &value, int role = Qt::EditRole);
    QHash<int, QByteArray> roleNames() const;
 
    QList<SimpleData*> m_data_list;
 
    enum MyRoles {
        RoleOne = Qt::UserRole + 1,
        RoleTwo,
        RoleThree
    };
 
signals:
 
public slots:
    void print_rows();
};
 
#endif // MYMODEL_H

#ifndef MYMODEL_H
#define MYMODEL_H

#include <QAbstractTableModel>
#include <QDebug>


struct SimpleData {
    bool enable;
    QString m_one;
    QString m_two;

    SimpleData() {
        enable = true;
        m_one = "1";
        m_two = "2";
    }

    SimpleData(bool enable, const QString m_one, const QString m_two) :
    enable(enable), m_one(m_one), m_two(m_two) {}
};


class MyModel : public QAbstractTableModel
{
    Q_OBJECT

public:
    explicit MyModel(QObject *parent = 0);

    int rowCount(const QModelIndex &parent = QModelIndex()) const ;
    int columnCount(const QModelIndex &parent = QModelIndex()) const;
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const;
    bool setData(const QModelIndex & index, const QVariant &value, int role = Qt::EditRole);
    QHash<int, QByteArray> roleNames() const;

    QList<SimpleData*> m_data_list;

    enum MyRoles {
        RoleOne = Qt::UserRole + 1,
        RoleTwo,
        RoleThree
    };

signals:

public slots:
    void print_rows();
};

#endif // MYMODEL_H

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/* mymodel.cpp */

#include "mymodel.h"
 
MyModel::MyModel(QObject *parent) : QAbstractTableModel(parent) {
 
    SimpleData *m_simpledata;
 
    // Create junk model data
    m_simpledata = new SimpleData(true, "a1", "b1");
    m_data_list.append(m_simpledata);
    m_simpledata = new SimpleData(false, "a2", "b2");
    m_data_list.append(m_simpledata);
}
 
int MyModel::rowCount(const QModelIndex & /*parent*/) const {
   return m_data_list.length();
}
 
int MyModel::columnCount(const QModelIndex & /*parent*/) const {
    return 3;
}
 
QVariant MyModel::data(const QModelIndex &index, int role) const {
 
    switch(role)
    {
        case RoleOne:
            return m_data_list.at(index.row())->enable;
        case RoleTwo:
            return m_data_list.at(index.row())->m_one;
        case RoleThree:
            return m_data_list.at(index.row())->m_two;
    }
 
    return QVariant();
}
 
bool MyModel::setData(const QModelIndex & index, const QVariant & value, int role) {
 
    qDebug() << "setData() called with:" << value;
 
    switch(role)
    {
        case RoleOne:
            m_data_list[index.row()]->enable = value.toBool();
        case RoleTwo:
            m_data_list[index.row()]->m_one = value.toString();
        case RoleThree:
            m_data_list[index.row()]->m_two = value.toString();
    }
 
    return true;
}
 
QHash<int, QByteArray> MyModel::roleNames() const {
 
    QHash<int, QByteArray> roles;
    roles[RoleOne] = "role_enable";
    roles[RoleTwo] = "role_m_one";
    roles[RoleThree] = "role_m_two";
    return roles;
}
 
void MyModel::print_rows() {
 
    qDebug() << "Model Data:";
 
    for (int i=0; i < m_data_list.length(); i++) {
        qDebug() << "At" << i << ":" << m_data_list.at(i)->enable << m_data_list.at(i)->m_one << m_data_list.at(i)->m_two;
    }
 
}

#include "mymodel.h"

MyModel::MyModel(QObject *parent) : QAbstractTableModel(parent) {

    SimpleData *m_simpledata;

    // Create junk model data
    m_simpledata = new SimpleData(true, "a1", "b1");
    m_data_list.append(m_simpledata);
    m_simpledata = new SimpleData(false, "a2", "b2");
    m_data_list.append(m_simpledata);
}

int MyModel::rowCount(const QModelIndex & /*parent*/) const {
   return m_data_list.length();
}

int MyModel::columnCount(const QModelIndex & /*parent*/) const {
    return 3;
}

QVariant MyModel::data(const QModelIndex &index, int role) const {

    switch(role)
    {
        case RoleOne:
            return m_data_list.at(index.row())->enable;
        case RoleTwo:
            return m_data_list.at(index.row())->m_one;
        case RoleThree:
            return m_data_list.at(index.row())->m_two;
    }

    return QVariant();
}

bool MyModel::setData(const QModelIndex & index, const QVariant & value, int role) {

    qDebug() << "setData() called with:" << value;

    switch(role)
    {
        case RoleOne:
            m_data_list[index.row()]->enable = value.toBool();
        case RoleTwo:
            m_data_list[index.row()]->m_one = value.toString();
        case RoleThree:
            m_data_list[index.row()]->m_two = value.toString();
    }

    return true;
}

QHash<int, QByteArray> MyModel::roleNames() const {

    QHash<int, QByteArray> roles;
    roles[RoleOne] = "role_enable";
    roles[RoleTwo] = "role_m_one";
    roles[RoleThree] = "role_m_two";
    return roles;
}

void MyModel::print_rows() {

    qDebug() << "Model Data:";

    for (int i=0; i < m_data_list.length(); i++) {
        qDebug() << "At" << i << ":" << m_data_list.at(i)->enable << m_data_list.at(i)->m_one << m_data_list.at(i)->m_two;
    }

}

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/* main.cpp */

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
 
#include "mymodel.h"
 
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QQmlApplicationEngine engine;
    MyModel model;
 
    engine.rootContext()->setContextProperty("theModel", &model);
    engine.load(QUrl(QStringLiteral("qrc:///main.qml")));
 
    return app.exec();
}

#include <QApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>

#include "mymodel.h"


int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QQmlApplicationEngine engine;
    MyModel model;

    engine.rootContext()->setContextProperty("theModel", &model);
    engine.load(QUrl(QStringLiteral("qrc:///main.qml")));

    return app.exec();
}

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Thanks!

[anda_skoa]

You can either create one method for each thing you want to change, e.g. setEnabled(int row, int column, bool enabled), or a more generic form, e.g. setData(int row, int column, const QString &role, const QVariant &value).

Either as Q_INVOKABLE or as a slot.

Cheers,
_

[zergedu]

Edit: *** Nevermind *** That information is in the styleData. Thanks!!

Ok, thanks! I had thought of doing it this way, but I wasn't sure how to determine the row/col from the TableView. I tried using TableView.currentRow, but that only works if I click the row 1st and then item I want to change. Any thoughts?

[wysota]

Each delegate contains a property "index" which points to the row number in the model the delegate represents.