Replacing urls in QGIS attribute table with images using python

Question

With the help of python, I managed to build a small script that replaces all URLs in a text column with images using a delegate. The images where loaded from Microsoft SharePoint using an adapted version of request_ntlm.

import PyQt4
from PyQt4 import QtGui,QtCore
import requests
from requests_ntlm import HttpNtlmAuth, HttpNtlmSspiAuth
from PyQt4.QtGui import QApplication, QTableView

class ImageDelegate(QtGui.QStyledItemDelegate):
    def __init__(self, parent):
        QtGui.QStyledItemDelegate.__init__(self, parent)

    def paint(self, painter, option, index):
        # Get Item Data
        url = index.model().data(index, QtCore.Qt.EditRole)

        if url != '':
            style = QtGui.QApplication.style()
            opt = QtGui.QStyleOptionGraphicsItem()
            opt.rect = option.rect
            r = requests.get(url, auth=HttpNtlmSspiAuth())
            data = r.content

            pixmap = QtGui.QPixmap()
            pixmap.loadFromData(data)
            if option.rect.x() > 250:
                pixmap=pixmap.scaledToWidth(250)

            painter.drawPixmap(option.rect.x(), option.rect.y(),  pixmap)


dialog = iface.showAttributeTable(iface.activeLayer())
targetColumnIndex = 8 # how to find Index of column?
delegateImage = ImageDelegate(iface)

dialog.findChildren(QTableView)[0].setItemDelegateForColumn(targetColumnIndex, delegateImage)
dialog.findChildren(QTableView)[0].setColumnWidth(targetColumnIndex, 250 )
dialog.findChildren(QTableView)[0].verticalHeader().setDefaultSectionSize(200)

What I couldn't manage by now: how to retrieve the index of a given column (see hardcoded targetColumnIndex in the code above) in the attribute table (QTableView) even when "colxy" is moved or some columns are hidden?

Answer 1

If someone is interested, here's the answer:

dialog = iface.showAttributeTable(iface.activeLayer())

delegateImage = ImageDelegate(iface)
tableView = dialog.findChildren(QTableView)[0]
model = tableView.horizontalHeader().model()
for column in range(model.columnCount()):
    title = tableView.model().children()[0].headerData(column,QtCore.Qt.Horizontal,0)
    if title == 'colxy':
        targetColumnIndex = column
        break

Unfortunately, that brings me only a little step further.

Next question that comes to mind:
How can I respond to any index change of the image column? (i.e. when other columns are hidden or the column is moved) Are there any signals available? Or can I disable the context menu of the table header?