code: def get_item_size(self, content):
          
          strings = []
          if content:
              for rich_text in content:
                  label = QLabel(rich_text)
                  label.setTextFormat(Qt.PlainText)
                  strings.append(label.text())
                  fm = label.fontMetrics()
  
              return (max([fm.width(s) * 1.3 for s in strings]), fm.height())
docs: Get the max size (width and height) for the elements of a list of
          strings as a QLabel.