First column not populating in QTableView

egefeyzioglu

Hi,
I have a QTableView that is connected to a QAbstractTableModel. The QTableView is set as the widget for a QDockWidget and added to my main window object. My problem is that the first column of the table is not populated. By adding some debug statements, I noticed that the data() method of the QAbstractTableModel is not called with Qt::DisplayRole for any cell in the first column. It's called with other roles, but not with the display role. I tried adding the QTableView as the central widget and even calling show() on it directly,and the same problem persists.

Here's the relevant portions of my code:

// mainwindow.cpp

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    this -> setWindowTitle(kWindowTitle.data());
    this -> setWindowIcon(QIcon(":/resources/img/icon.xpm"));
    this -> resize(1200,600);

    // Set up the base widgets
    setUpMemoryTable(memory_view);

    // Set up the dock widgets
    memory_tab = new QDockWidget("Memory");

    memory_tab -> setWidget(memory_view);

    // Add everything to the window
    this -> addDockWidget(Qt::LeftDockWidgetArea, memory_tab);
    memory_view -> setShowGrid(true);
    memory_view -> setCornerButtonEnabled(false);
    memory_view -> setSelectionBehavior(QAbstractItemView::SelectionBehavior::SelectItems);
    memory_view -> setSelectionMode(QAbstractItemView::SelectionMode::SingleSelection);

    this -> show();
}

void MainWindow::setUpMemoryTable(QTableView *&memory_view){
    memory_view = new QTableView();
    memory_model = new MemoryModel(emulator -> memory, emulator->kMemorySize, this);
    memory_view -> setModel(memory_model);
}

// memorymodel.cpp

MemoryModel::MemoryModel(uint8_t *memory, size_t kMemorySize, QObject *parent) : QAbstractTableModel{parent}, memory{memory}, kMemorySize{kMemorySize} {}

int MemoryModel::rowCount(const QModelIndex &parent) const{
    return kMemorySize/0x10;
}

int MemoryModel::columnCount(const QModelIndex &parent) const{
    return 0x10;
}

QVariant MemoryModel::data(const QModelIndex &index, int role) const{
    // Only want the display role
    if(role != Qt::DisplayRole){
        return QVariant();
    }

    if(index.isValid() && index.row() < rowCount() && index.row() >= 0 && index.column() < columnCount() && index.column() > 0){
        auto ret = QVariant(QString::fromStdString(std::to_string(memory[(index.row()) * columnCount() + index.column()])));
        return ret;
    } else {
        return QVariant();
    }
}

Qt::ItemFlags MemoryModel::flags(const QModelIndex &index) const{
    return Qt::ItemIsEnabled | Qt::ItemIsEditable;
}

Thanks in advance for any help!

ChrisW67

@egefeyzioglu said in First column not populating in QTableView:

    if(index.isValid() && index.row() < rowCount() && index.row() >= 0 && index.column() < columnCount() && index.column() > 0){
        ...
    } else {
        return QVariant();
    }

You explicitly exclude column 0 from returning a value i.e. column must be greater than 0. So I suspect it is called but it is returning a null QVariant.

egefeyzioglu

@ChrisW67 oh my god... Yes that was it thank you 😂