[Bug]: Change background of ListWidget item

[AmirMahdaviAM]

What happened?

how can i change item list background?

use setBackground but it will break all other visuals

item = QListWidgetItem(itemText)
setFont(item)
item.setBackground(QColor(255, 255, 255, 10))
self.taskList.addItem(item)

and then edited background color in qss file and apply it but background still unchanged
(i know applied because of padding changed)

#taskList::item {
    background: rgba(255, 255, 255, 0.100);
    padding-left: 15px;
    padding-right: 15px;
    padding-top: 15px;
    padding-bottom: 15px;
}

Operation System

Windows11 22h2

Python Version

3.10.6

PyQt/PySide Version

PyQt 5.15.9

PyQt/PySide-Fluent-Widgets Version

1.5.6

How to Reproduce?

ListWidget::item {
background: rgba(255, 255, 255, 0.100);
}

item.setBackground(QColor(255, 255, 255, 10))

Minimum code

self.taskList = ListWidget(self)
self.taskList.setObjectName("taskList")

item = QListWidgetItem(itemText)
setFont(item)
item.setBackground(QColor(255, 255, 255, 10))
self.taskList.addItem(item)

[AlexZhu2001]

I don't think it's easy to do this in the current version. If you want to set background for widget item, you should inherit ListItemDelegate, rewrite _drawBackground or paint fuction. Here is an simple example:

# coding: utf-8
import sys

from PySide6.QtCore import *
from PySide6.QtGui import *
from PySide6.QtWidgets import *

from qfluentwidgets import *

class MyListItemDelegate(ListItemDelegate):
    def __init__(self, parent: QListView):
        super().__init__(parent)

    def _drawBackground(self, painter: QPainter, option: QStyleOptionViewItem, index: QModelIndex):
        painter.save()
        isHover = self.hoverRow == index.row()
        isPressed = self.pressedRow == index.row()
        if index.row() not in self.selectedRows:
            if isPressed:
                painter.setBrush(QColor(0x66, 0xcc, 0xff, 0xff))
            elif isHover:
                painter.setBrush(QColor(0x66, 0xcc, 0xff, 0x88))
            else:
                painter.setBrush(QColor(0x66, 0xcc, 0xff, 0x44))
        else:
            painter.setBrush(QColor(0x66, 0xcc, 0xff, 0xff))
        painter.drawRoundedRect(option.rect, 5, 5)
        painter.restore()

class Demo(QWidget):

    def __init__(self):
        super().__init__()
        # setTheme(Theme.DARK)

        self.hBoxLayout = QHBoxLayout(self)
        self.listWidget = ListWidget(self)
        self.listWidget.setItemDelegate(MyListItemDelegate(self.listWidget))
        # self.listWidget.setAlternatingRowColors(True)

        # self.listWidget.setSelectRightClickedRow(True)

        stands = [
            '白金之星', '绿色法皇', "天堂制造", "绯红之王",
            '银色战车', '疯狂钻石', "壮烈成仁", "败者食尘",
            "黑蚊子多", '杀手皇后', "金属制品", "石之自由",
            "砸瓦鲁多", '钢链手指', "臭氧宝宝", "华丽挚爱",
            "隐者之紫", "黄金体验", "虚无之王", "纸月之王",
            "骇人恶兽", "男子领域", "20世纪男孩", "牙 Act 4",
            "铁球破坏者", "性感手枪", 'D4C • 爱之列车', "天生完美",
            "软又湿", "佩斯利公园", "奇迹于你", "行走的心",
            "护霜旅行者", "十一月雨", "调情圣手", "片刻静候"
        ]
        for stand in stands:
            item = QListWidgetItem(stand)
            self.listWidget.addItem(item)


        self.setStyleSheet("Demo{background: rgb(249, 249, 249)} ")
        self.hBoxLayout.setContentsMargins(0, 0, 0, 0)
        self.hBoxLayout.addWidget(self.listWidget)
        self.resize(300, 400)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    w = Demo()
    w.show()
    app.exec()

But this example did not consider the dark theme, you can refer to the source code of TableItemDelegate to get more detail about how this package draw item background.

[AmirMahdaviAM]

thank you, worked like charm

class MyListItemDelegate(ListItemDelegate):

    def __init__(self, parent: QListView):
        super().__init__(parent)

    def _drawBackground(self, painter: QPainter, option: QStyleOptionViewItem, index: QModelIndex):
        painter.save()
        isHover = self.hoverRow == index.row()
        isPressed = self.pressedRow == index.row()

        if isDarkTheme():
            pressBrush = QColor(255, 255, 255, 10)
            hoverBrush = QColor(255, 255, 255, 15)
            otherBrush = QColor(255, 255, 255, 5)
        else:
            pressBrush = QColor(0, 0, 0, 15)
            hoverBrush = QColor(0, 0, 0, 30)
            otherBrush = QColor(0, 0, 0, 10)

        if index.row() not in self.selectedRows:
            if isPressed:
                painter.setBrush(pressBrush)
            elif isHover:
                painter.setBrush(hoverBrush)
            else:
                painter.setBrush(otherBrush)

        painter.drawRoundedRect(option.rect, 5, 5)
        painter.restore()