Detect when the content of a cell of QTableView is changed

[qt_developer]

Hi all,

I need monitoring the changes in the data content of a cell of QTableView.

I have a QTableView widget into QMainWindow.

I have tried with the QAbstractItemView signals, the slots are called in my QMainWindow class, but neither of them accomplish the target that I need.

I have tried with the currentChanged( const QModelIndex & current, const QModelIndex & previous ) signal of QItemSelectionModel, as above the slot is called, but itsn't accomplish the target that I need too.

I make the connects like this:

connect(ui->myTableView->selectionModel(), SIGNAL(currentChanged ( QModelIndex const&, QModelIndex const& )), this, SLOT(onCurrentChanged(QModelIndex con7st&, QModelIndex const&)));
connect(ui->myTableView, SIGNAL(pressed(const QModelIndex &)), this, SLOT(onPressed(const QModelIndex &)));

connect(ui->myTableView->selectionModel(), SIGNAL(currentChanged ( QModelIndex const&, QModelIndex const& )), this, SLOT(onCurrentChanged(QModelIndex con7st&, QModelIndex const&)));
connect(ui->myTableView, SIGNAL(pressed(const QModelIndex &)), this, SLOT(onPressed(const QModelIndex &)));

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There are any signal / slot / method or similar that I could use to accomplish my target?

Best regards.

[ChrisW67]

You are looking in the wrong direction. To get a signal when the data changes you need to be looking at the data model not the view: QAbstractItemModel::dataChanged() for example.

[ShapeShiftme]

When i first started i tried QTableView and had endless problems myself

I then switched to Qtable Widget. And cell changed events and so forth are much easier to use.

Hope this helps

[qt_developer]

You are looking in the wrong direction. To get a signal when the data changes you need to be looking at the data model not the view: QAbstractItemModel::dataChanged() for example.

Hi ChrisW67,

I have used this new code:

connect(ui->myTableView->model(), SIGNAL(dataChanged(const QModelIndex&, const QModelIndex&)), this, SLOT(onDataChanged(const QModelIndex&, const QModelIndex&)));
 
...
 
void myClass::onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight)
{
    qDebug() << "the cell has changed";
}

connect(ui->myTableView->model(), SIGNAL(dataChanged(const QModelIndex&, const QModelIndex&)), this, SLOT(onDataChanged(const QModelIndex&, const QModelIndex&)));

...

void myClass::onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight)
{
    qDebug() << "the cell has changed";
}

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And works fine!

Thank you.

[sbabadag]

Hi ChrisW67,

I have used this new code:

connect(ui->myTableView->model(), SIGNAL(dataChanged(const QModelIndex&, const QModelIndex&)), this, SLOT(onDataChanged(const QModelIndex&, const QModelIndex&)));
 
...
 
void myClass::onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight)
{
    qDebug() << "the cell has changed";
}

connect(ui->myTableView->model(), SIGNAL(dataChanged(const QModelIndex&, const QModelIndex&)), this, SLOT(onDataChanged(const QModelIndex&, const QModelIndex&)));

...

void myClass::onDataChanged(const QModelIndex& topLeft, const QModelIndex& bottomRight)
{
    qDebug() << "the cell has changed";
}

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And works fine!

Thank you.

Hi can you give the whole code ?

[d_stranz]

Hi can you give the whole code ?

What you do in response to a dataChanged() signal is specific to your application. Any "whole code" for this thread would probably have no meaning in your application.

I suggest you start with reading about Qt Model/View Programming in the documentation, look at the Model/View tutorial, and finally look at some of the 19 examples of Model/View programming that come with Qt.

You will probably learn enough in that to understand how to use the QAbstractItemModel::dataChanged() signal in your own application.