I have a QTableWidget with a number of columns that are only checkboxes (and some that aren't). I am trying to implement a feature so that when the user right clicks on a header item related to a "checkbox only" column, they are presented with the option to "uncheck all" or "check all".

So far, I've managed to implement a `customContextMenu` via the following signals:

```
self.headers = self.tblData.horizontalHeader()
self.headers.setContextMenuPolicy(Qt.CustomContextMenu)
self.headers.customContextMenuRequested.connect(self.show_header_context_menu)
self.headers.setSelectionMode(QAbstractItemView.SingleSelection)

```

Which leads to the following context menu call:

```
def show_header_context_menu(self, position):
    menu = QMenu()
    deselect = menu.addAction("Clear Checked")
    ac = menu.exec_(self.tblData.mapToGlobal(position))
    if ac == deselect:
        pass
        #Actually do stuff here, of course

```

This pops up a context menu, however I cannot find any way to get the index of the header that was right-clicked, I've tried `self.headers.selectedIndexes()` as well as `self.headers.currentIndex()` but these seem to only relate to the actual table selections, and not the headers.

Once I manage to get the right-clicked header index, I can easily restrict the menu to show only when the right indexes are selected (those columns with only checkboxes), so that's an additional thing, really.

What am I missing? Thanks in advance for any help.