除了使用QIcon之外，如何将DecorationRole形状更改为圆形？

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QPalette, QColor
from PyQt5.QtWidgets import QStyledItemDelegate, QApplication, QListView


class CircleDelegate(QStyledItemDelegate):
    def paint(self, painter, option, index):
        if index.data(Qt.DecorationRole):
            # 获取DecorationRole的内容
            icon = index.data(Qt.DecorationRole).pixmap(option.decorationSize)
            # 获取圆形的位置和大小
            circle_rect = option.rect
            circle_rect.setWidth(circle_rect.height())

            # 设置画笔
            painter.setPen(Qt.NoPen)
            # 设置画刷颜色为透明
            painter.setBrush(QColor(0, 0, 0, 0))
            # 绘制圆形
            painter.drawEllipse(circle_rect)

            # 在圆形内绘制图标
            icon_rect = circle_rect
            icon_rect.adjust(2, 2, -2, -2)  # 调整图标位置
            painter.drawPixmap(icon_rect, icon)

        # 绘制其他内容
        super().paint(painter, option, index)


if __name__ == "__main__":
    import sys

    app = QApplication(sys.argv)
    view = QListView()
    delegate = CircleDelegate(view)
    view.setItemDelegate(delegate)
    view.show()

    sys.exit(app.exec_())