QTableView not updating despite attention to flags and explicit emit of dataChanged

[buckler]

Hello,
My first forum post so hopefully I will be clear.
I have an editable QTableView, or so I am trying to have.
I can select and type in fields, and internal debug tells me that setData is being called and the model internal values are updated. I do emit dataChanged, or so I think I do, but the data function never gets called and the values don't change.

Here is my model class:

class workItemListViewingModel : public QAbstractTableModel
{
  Q_OBJECT

public:
  workItemListViewingModel(workItem *workItemParent) { parent = workItemParent; };
  int rowCount(const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;
  int columnCount(const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;
  QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const Q_DECL_OVERRIDE;
  QVariant headerData(int section, Qt::Orientation orientation, int role) const Q_DECL_OVERRIDE;
  bool setData(const QModelIndex & index, const QVariant & value, int role = Qt::EditRole) Q_DECL_OVERRIDE;
  Qt::ItemFlags flags(const QModelIndex & index) const Q_DECL_OVERRIDE { 
    return Qt::ItemIsSelectable |  Qt::ItemIsEditable | Qt::ItemIsEnabled | QAbstractTableModel::flags(index) | QAbstractItemModel::flags(index); 
  }

signals:

private:
  workItem *parent;
};

Note that I do not have any slots... this seems wrong to me, since I guess data is a slot? But none of the online examples show exploit indication of this. I have surmised it is due to the fact that the setData can actually trigger multiple data calls, with a range of cells rather than just the one it was called with, by setting this range on the emit call. (In fact I need to use this, so great.)

Here is my setData code:

bool workItemListViewingModel::setData(const QModelIndex & index, const QVariant & value, int role)
{
  workItemListEntry entry = parent->workItemList().at(index.row());
  if (role == Qt::EditRole) {
    switch (index.column()) {
      case subjectID_col: { entry.setSubjectID(value.toString()); break; }
      case indication_col: { entry.setIndication(value.toString()); break; }
      default: {
        QErrorMessage *error = new QErrorMessage (0);
        error->showMessage(tr("Warning: Cannot edit this field in the application, need to change it at the source."));
        return false;
      }
    }
  }
  emit dataChanged(index,index);
  return true;
}

Can anyone help?

Many thanks,
Andy

[edit: added missing coding tags ``` SGaist]

[SGaist]

Hi and welcome to devnet,

No, setData is not a slot. You can see that in the documentation.

As for your code, are you sure that setData is called for the Edit Role ? In any case, you are modifying the local copy of entry, not what you have in workItemList.

On a side note, in your flags override, you should only call QAbstractTableModel::flags(index), that's the base class of your model.

[buckler]

@SGaist Thank you. Yes, I am sure that setData is being called, I have debug statement sheer. Entry is in workItem List; the table rows are entries, and the columns are fields in each entry.

Here is a little more of the code to try to give more to go on, since I still have the problem.

First is workItemListEntry class:
class workItemListEntry
{
public:
workItemListEntry() {};

void setSubjectID(QString str) { subjectID = str; qDebug() << "in setSubjecId " << subjectID;};
const QString getSubjectID() const { return subjectID; qDebug() << "in getSubjecId " << subjectID;};

void setIndication(QString str) { indication = str; };
const QString getIndication() const { return indication; };

private:
QString subjectID, indication;
};

and here is the "data" function in the model:
QVariant workItemListViewingModel::data(const QModelIndex &index, int role) const
{
if (role == Qt::DisplayRole)
{
switch (index.column()) {
case subjectID_col: return parent->workItemList().at(index.row()).getSubjectID();
case indication_col: return parent->workItemList().at(index.row()).getIndication();
(there are more cases and a default, but I am trying to simplify to focus on the issue)
}
}
return QVariant();
}

The code which sets the model in the first place is in the constructor of an over-arching class which has the workItemList:
workItem::workItem(QWidget *parent) :
QWidget(parent),
ui(new Ui::workItem)
{
ui->setupUi(this);
workItemListEntries.clear();
(more in here, which sets up the list and gets the first view of the table coming out perfectly, before trying to edit it)
workItemListViewingModel *wiListModel = new workItemListViewingModel(this);
ui->workItemList->setModel( wiListModel );
ui->workItemList->selectionModel()->selectedRows();
ui->workItemList->verticalHeader()->setVisible(false);
ui->workItemList->horizontalHeader()->setVisible(true);
ui->workItemList->verticalHeader()->setSectionResizeMode(QHeaderView::Stretch);
ui->workItemList->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch);

}:

the over-arching class, which is the one with the table view widget in it:
class workItem : public QWidget
{
Q_OBJECT

QString tabLabel;
int sessionItemIndex;
workItemListProvenance listProvenance;
QList<workItemListEntry> workItemListEntries;

public:
explicit workItem(QWidget *parent = 0);
~workItem();
Ui::workItem *ui;
QList<workItemListEntry> &workItemList() { return workItemListEntries; };
void setSessionItemIndex(int index) { sessionItemIndex = index; }
void newWorkItemList();
enum saveFormat { Json, Binary };
bool loadWorkItemListFromFile(saveFormat saveFormat);
bool saveWorkItemListToFile(saveFormat saveFormat) const;
void readWorkItemList(const QJsonObject &json);
void writeWorkItemList(QJsonObject &json) const;
void logListProvenanceUpdate(QString step);

public slots:
QString getTabLabel() { return(tabLabel); }

signals:
void selectWorkItemButton_clicked(int sessionItemIndex);

private slots:
void on_selectWorkItemButton_clicked() { emit selectWorkItemButton_clicked(sessionItemIndex); }
void on_targetPath_clicked() { QString pathFile=QFileDialog::getOpenFileName(this, tr("Path File"), "", tr("Path files (*.pth)")); };
void on_seriesFolder_clicked() { QString seriesFolder=QFileDialog::getExistingDirectory(this, tr("Series Folder"), ""); };
void on_seriesTypeSelector_activated(const QString &arg1) { std::cout << "selected " << std::endl; };
void on_addWorkItemButton_clicked() {};
void on_listFileNameButton_clicked() ;
void on_labelTabsWithWorkItemID_clicked() { labelTabsWith = WORKITEMID; };
void on_labelTabsWithPatientID_clicked() { labelTabsWith = PATIENTID; };
void on_labelTabsWithPatientName_clicked() { labelTabsWith = PATIENTNAME; };
void on_labelTabsWithSubjectID_clicked() { labelTabsWith = SUBJECTID; };
void on_labelTabsWithAlsoKnownAs_clicked() { labelTabsWith = ALSOKNOWNAS; };

private:
QString workItemListFileName;
enum field { WORKITEMID, PATIENTID, PATIENTNAME, SUBJECTID, ALSOKNOWNAS } labelTabsWith;
};

[bsomervi]

In your setData overide:

workItemListEntry entry = parent->workItemList().at(index.row());

is making a copy so you are not updating your underlying data for your model.

Try using:

auto& entry = parent->workItemList()[index.row()];

[buckler]

@bsomervi wow... that is great. Of course I see it now, but would not have without your help. Both of you who replied! Thank you :-)

[SGaist]

You're welcome !

Since you have it working now, please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)

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