In a QTableView, how can I make horizontal header cells display vertical text?

Question

I wish to make horizontal header cells in a QTableView display text from top to bottom (i.e., vertically), how can I do this?

Example PyQt5 app which displays a QTableView with a horizontal header showing text in the normal direction:

from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
import sys

class TableModel(QAbstractTableModel):
    def __init__(self, parent):
        super(TableModel, self).__init__(parent)

    def headerData(self, section, orientation, role):
        if orientation != Qt.Horizontal:
            return
        if role != Qt.DisplayRole:
            return

        return 'Header Data'

    def data(self, index, role):
        if role != Qt.DisplayRole:
            return

        return 'Row Data'

    def rowCount(self, parent):
        return 1

    def columnCount(self, parent):
        return 1


class Window(QMainWindow):
    def __init__(self):
        super(Window, self).__init__()

        main_widget = QWidget(self)
        self.setCentralWidget(main_widget)
        layout = QVBoxLayout(main_widget)

        view = QTableView(main_widget)
        view.horizontalHeader().setVisible(True)
        view.verticalHeader().setVisible(False)
        layout.addWidget(view)
        model = TableModel(view)
        view.setModel(model)
        view.resizeColumnsToContents()

app = QApplication(sys.argv)
window = Window()
window.show()
app.exec_()

Answer 1

Simple use of delegate will not work here.

You need to subclass QHeaderView and override paintSection.
In implementation of it you need:

• rotate and translate painter
• calculate new rectange which wil take into acount above transformation
• call old implementation of paintSection with new values
• restore painter state (reverse transformation).