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c++qtqtableviewqitemdelegate

QStyledItemDelegate's sizeHint method not called for a QTableView row

I have QTableView using a QSqlQueryModel (it fetches data from SQLite).

There is a QStyledItemDelegate subclass called MiniItemDelegate that I use as a delegate for the items. I set up a sizeHint() method like this:

QSize MiniItemDelegate::sizeHint(const QStyleOptionViewItem &option,
                                 const QModelIndex &index) const
{
    // just for testing...breakpoint shows this line never gets called
    return QSize(256,256);  
}

I'm not sure why this method isn't called when I run the following code:

m_pMiniItemDelegate = new MiniItemDelegate(this);
ui->PList_tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
ui->PList_tableView->setSelectionMode(QAbstractItemView::SingleSelection);
ui->PList_tableView->setItemDelegate(m_pMiniItemDelegate);
ui->PList_tableView->setAlternatingRowColors(true);
ui->PList_tableView->setModel(ListMiniSqlModel::instance());

This also doesn't work:

ui->PList_tableView->resizeColumnsToContents();
ui->PList_tableView->resizeRowsToContents();

Nor does this:

QHeaderView* headerView = ui->PList_tableView->horizontalHeader();
headerView->setResizeMode(QHeaderView::ResizeToContents);
Solution

  • QStyledItemDelegate::sizeHint is useful only when QTableView::resizeRowsToContents, QTableView::resizeRowToContents, QTableView::resizeColumnsToContents and QTableView::resizeColumnToContents are called. or use 

    QHeaderView* headerView = tableView->horizontalHeader();
headerView->setResizeMode(QHeaderView::ResizeToContents);