In-line control in QTableModel

moravas

Hi Folks,

in my application I have to use QTableViews, and they content is coming from SQL database via QSqlTableModel and every records could be deleted or duplicated depends on the user.
The following is only a sample image from google to represent what I want:
http://www.apphp.com/php-datagrid/images/screenshots/inline_editing.png

Please consider the rightmost column: it is only for display the "delete" control, and I guess that isn't the part of the data model.

The question is how can I extend the model behind of the view to store additional columns for my "delete" and "copy" buttons?

Regards,
Norbert

SGaist

Hi,

Usually you would put a proxy model between your original model and the view so you don't fiddle with the QSqlRelationalTableModel that handles the data from your database. In that model you will return a column count higher than the original model to put your additional columns.

Hope it helps

moravas

Hi,

thanks for the reply, it sounds good enough. Which methods and how should I implement / reimplement for use QAbsrtactProxyModel in a QTableView? As I see, its sublcassing from QAbstractItemModel (which is a general model for every view classes, like lists and grids as well) as the QAbstractTableModel as well, but as I know, the QAbstractTableModel were designed to use in grids.

Could you provide any example, where the QAbsrtactProxyModel class is subclassed to create model for grids?

SGaist

The proxy model doesn't (and shouldn't) care what the underlying model is. Whether it's a list or table model doesn't really mater. It's a man in the middle. Take a look at QIdentityProxyModel. It's just a layer between the view and the model.

moravas

Hi SGaist,

thank you for your suggestions. I change my application regarding them, and I got something like this:

    _models.append(TableModelPtr(new QIdentityProxyModel()));
    QSqlTableModel* dataModel = new QSqlTableModel(this, ProjectManager::get().database());
    dataModel->setTable(partition.name);
    dataModel->setEditStrategy(QSqlTableModel::OnManualSubmit);
    dataModel->select();
    _models.last()->setSourceModel(dataModel);
    if(partition.enumerable) {
        _models.last()->insertRow(dataModel->rowCount());
        _models.last()->insertColumn(dataModel->columnCount());
        _models.last()->setHeaderData(dataModel->columnCount() - 1, Qt::Horizontal, "Action");
    }
    else if(0 == dataModel->rowCount()) {
        dataModel->insertRow(0);
    }

The "_models" variable is an array of models, where the user can select the desired model from.
You see, I try to insert a row and column into the proxymodel (whitin the conditions), but as I see, they will be inserted into the sourcemodel instead of to be present in the QIdentityModel instance.
I don't know, how can I avoid this? The newly inserted columns targets the view to draw QPushButton onto them by the following code:

    const QModelIndex modelIndex = _models[_currentIndex]->index(_models[_currentIndex]->rowCount() - 1, _models[_currentIndex]->columnCount() - 1);
    _ui->_TVPartitions->setIndexWidget(modelIndex, createAddControl());

How can I solve this task? Could you provide and example, suggestions, or whatever else?

Regards,
Norbert

SGaist

You should subclass QIdentityProxyModel and re-implement column count to return the source model count + 1 and data to handle that new column and otherwise return the source model data. So you will make the view think there's a new column.

Watch out about setIndexWidget, if your model contains lots of data you'll have a performance hit. having e.g. a thousand entries will yield the creation of a thousand widgets.

moravas

This post is deleted!