QAbstractTableModel + QML TableView: How to call setData?

[VRonin]

Name might be a reserved word. Try changing Name = 0, to colName = 0, and use text: colName and colName = text

[Bremenpl]

@VRonin Doesnt matter how I call it:

qrc:/UBasicTable.qml:109: Error: Invalid write to global property "colName"
qrc:/UBasicTable.qml:109: Error: Invalid write to global property "colName1" // this doesnt exist

Any other hints :/?

[Bremenpl]

Just BTW... Figured out why doesnt the dataChanged signal fire the table update. I was calling it like this:

emit dataChanged(index, index, {role});

and role was always Qt::EditRole. Now I call it without roles parameter:

emit dataChanged(index, index);

And the TableView cells are being updated! Thanks for the help @VRonin, it led me to the right place for this one.
I still havent figured out how to automatically call setData from the QML though (using the presented workaround). If you have any more ideas please let me know.

[VRonin]

Are you sure you are inside delegate:?
This is a minimal working example:

#include <QGuiApplication>
#include <QQmlContext>
#include <QQmlApplicationEngine>
#include <QStringListModel>
#include <QDebug>
class MyModel : public QStringListModel{
public:
    MyModel(QObject *parent = nullptr) : QStringListModel(parent)
    {}
    QHash<int, QByteArray> roleNames() const override
    {
        QHash<int, QByteArray> roles;

            roles[Qt::EditRole] = QByteArrayLiteral("TestRole");
            roles[Qt::DisplayRole] = QByteArrayLiteral("AnotherRole");

        return roles;
    }
};

int main(int argc, char *argv[])
{
#if defined(Q_OS_WIN)
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    MyModel model;
    QObject::connect(&model,&MyModel::dataChanged,[](const QModelIndex& idx){
        qDebug() << "Changed: " << idx.row() << " " << idx.data().toString();
    });
    model.setStringList(QStringList{"aaa","bbb","ccc"});
    engine.rootContext()->setContextProperty("mymodel", &model);
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;
    return app.exec();
}

import QtQml 2.2
import QtQuick 2.7
import QtQuick.Window 2.2
import QtQuick.Controls 2.3

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Test Edit")

        ListView {
            anchors.fill: parent;
            width: 200; height: 250
            model: mymodel
            delegate: TextInput  {
                text: TestRole
                onEditingFinished: {
                    TestRole = text
                }
            }
        }
}

[Bremenpl]

@VRonin Hmmm... Here is the thing- I am inside itemDelegate not delegate. delegate is available in different QtQuick.Controls version. If I switch to it, I will no longer have my other components available, ie Popup. Isnt itemDelegate and delegate the same thing?

Look at the docs, TableView has no delegate member: https://doc.qt.io/qt-5/qml-qtquick-controls-tableview.html#rowDelegate-prop

[VRonin]

Looks like you are still using Qt Quick controls 1.
Qt Quick controls 2 is already 3 years old.

If I switch to it, I will no longer have my other components available, ie Popup

Qt Quick Controls 2 has https://doc.qt.io/qt-5/qml-qtquick-controls2-popup.html

[Bremenpl]

@VRonin QtQuick.Controls 2.5 do have delegate but dont have TableViewColumn which I am using for columns setting. Is there a better way now?

[VRonin]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

Is there a better way now?

@VRonin said in QAbstractTableModel + QML TableView: How to call setData?:

Looks like columns and roles are the same thing here but since 1 year ago they are now 2 distinct things (as they are in QtWidgets): https://blog.qt.io/blog/2018/08/29/tableview/

[Bremenpl]

@VRonin Ok... So now everything I got ahead of with styleData is no longer working. This time I am really confused. Those links threat about animations the most and what I need for now is to be able to send/ receive data from the C++ model. Is there any example for that?

[VRonin]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

So now everything I got ahead of with styleData is no longer working.

What is styleData?

[Bremenpl]

@VRonin It was available in itemDelegate: https://doc.qt.io/qt-5/qml-qtquick-controls-tableview.html#itemDelegate-prop
One could use it to locate itself in the table as well as read model data.

[VRonin]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

One could use it to locate itself in the table as well as read model data.

now you don't need it anymore. you just access role names directly to read data and you can use index, row and column directly to locate yourself within the model

Btw, this doesnt call setData:

Yes it does. If the dataChanged signal is not enough to convince you you can add the below to MyModel

bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) override{
        qDebug() << "Called setData";
        return QStringListModel::setData(index,value,role);
    }

[Bremenpl]

@VRonin Ok, you are right! Thanks.
It feels like we are really close this time. So this is the components now:

		TableView
		{
			anchors.fill: parent;
			model: tableModel;

			delegate: TextInput
			{
				text: Name;

				onEditingFinished:
				{
					Name = text
				}
			}
		}

My columns and roles are still mixed together because of the obsolete behavior- this needs to be disconnected. In this case, what should the roleNames override method return actually?

[VRonin]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

hat should the roleNames override method return actually?

I would not override it at all and just use the default edit

				text: edit

				onEditingFinished:
				{
					edit = text
				}

[Bremenpl]

@VRonin , yeah I just came to realize that too. I did:

delegate: TextInput
			{
				text: display;

				onEditingFinished:
				{
					edit = text
				}
			}

Which I believe in this context gives the same effect.
Alright... Thank you very much for your feedback, you helped me a lot.
Now I only need to figure out either headerData can be utilized and that would be it.

[VRonin]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

Now I only need to figure out either headerData can be utilized and that would be it.

I'm afraid that part has not been developed by Qt yet

We’re also working on a TableHeader, TableModel, as well as a DelegateChooser.

[Bremenpl]

@VRonin So as for now, is there a way to set the column header at all?

[VRonin]

Not exactly what I would call a header. There's this: https://doc.qt.io/qt-5/qml-qtquick-tableview.html#overlays-and-underlays but it's far from anything that is actually useful

[Bremenpl]

@VRonin Yes, I have just checked this. It overlaps my first row... Do you know either rows inserting and removing work? Meaning- If I remove or insert a row at runtime, will it update the view?
This seems to still be a very beta thing, I wonder either old or new controls should be used.

[raven-worx]

@Bremenpl said in QAbstractTableModel + QML TableView: How to call setData?:

I also dont know how to force the QML TreeView to call the C++ headerData method

since you use QtQuick.Controls 1 TableView you need to use the TableViewColumn element, which only supports roles.
So you can add custom role names and forward those header roles to the headerData() method in the data() method.

virtual QHash<int, QByteArray> roleNames() const {
    QHash<int, QByteArray> rn = QAbstractItemModel::roleNames();
    rn[MyHeaderRole1] = QByteArrayLiteral("header1");
    return rn;
}

QVariantdata(const QModelIndex &index, int role = Qt::DisplayRole) const {
     switch( role )
     {
        case MyHeaderRole1:  return headerData(0, Qt::Horizontal);
        ...
     }
     return QVariant();
}