The problem was with the resizeEvent(). I need to also invoke the method in the QTableView class that I derived from to force a refresh on vertical resizing. Amended method looks like this:
void DDUTableView::resizeEvent(QResizeEvent* ev)
{
int num_columns = NUM_ELEMENTS(COLUMN_WIDTHS);
if (num_columns > 0) {
int width = ev->size().width();
int used_width = 0;
// Set our widths to be a percentage of the available width
for (int i = 0; i < num_columns - 1; i++) {
int column_width = (width * COLUMN_WIDTHS[i]) / 100;
this->setColumnWidth(i, column_width);
used_width += column_width;
}
// Set our last column to the remaining width
this->setColumnWidth(num_columns - 1, width - used_width);
}
QTableView::resizeEvent(ev);
}