docs: def _do_home_key(self, event=None, select=False):
          """ Performs home key action """
          # get nb char to first significative char
          delta = (self.textCursor().positionInBlock() -
                   TextHelper(self).line_indent())
          cursor = self.textCursor()
          move = QtGui.QTextCursor.MoveAnchor
          if select:
              move = QtGui.QTextCursor.KeepAnchor
          if delta > 0:
              cursor.movePosition(QtGui.QTextCursor.Left, move, delta)
          else:
              cursor.movePosition(QtGui.QTextCursor.StartOfBlock, move)
          self.setTextCursor(cursor)
          if event:
              event.accept()