QTableWidget 和 setCellWidget：调整大小问题

Posted 2023-02-16

【中文标题】QTableWidget 和 setCellWidget：调整大小问题

【英文标题】：QTableWidget and setCellWidget: resize problem

【发布时间】：2020-06-28 16:17:59

【问题描述】：

我尝试在 QTableWidget 的某个单元格中插入一些 QRadioButton。情况类似于this post 的情况。特别是@eyllanesc 的解决方案，PySide2 如下

import sys

from PySide2.QtWidgets import QApplication, QTableWidget, QTableWidgetItem, \
    QButtonGroup, QRadioButton

app = QApplication(sys.argv)

searchView = QTableWidget(0, 4)
colsNames = ['A', 'B', 'C']
searchView.setHorizontalHeaderLabels(['DIR'] + colsNames)
dirNames = 'A': ['/tmp', '/tmp/dir1'], 'B': ['/tmp/dir2'],
            'C': ['/tmp/dir3']

rowCount = sum(len(v) for (name, v) in dirNames.items())
searchView.setRowCount(rowCount)

index = 0

for letter, paths in dirNames.items():
    for path in paths:
        it = QTableWidgetItem(path)
        searchView.setItem(index, 0, it)
        group = QButtonGroup(searchView)
        for i, name in enumerate(colsNames):
            button = QRadioButton()
            group.addButton(button)
            searchView.setCellWidget(index, i + 1, button)
            if name == letter:
                button.setChecked(True)
        index += 1

searchView.show()
sys.exit(app.exec_())

在调整列或行的大小时，我注意到一个奇怪的行为：当我按下鼠标按钮并调整列或原始大小时，QRadioButtons 仍然在它们的位置，导致一些冲突；然后，当我最终松开鼠标按钮时，每个 QRadioButton 都会到位。有没有办法避免在调整大小的过程中也让 QRadioButtons 移动？

【参考方案1】：

由于我之前的解决方案会产生其他问题，因此在此解决方案中，我将展示另一种选择：

使用 Qt :: CheckStateRole 通过委托实现排除逻辑。 QProxyStyle 可用于绘画

import sys

from PySide2.QtCore import Qt, QEvent
from PySide2.QtWidgets import (
    QApplication,
    QTableWidget,
    QTableWidgetItem,
    QStyledItemDelegate,
    QStyle,
    QStyleOptionViewItem,
    QProxyStyle,
)


class RadioButtonDelegate(QStyledItemDelegate):
    def editorEvent(self, event, model, option, index):
        flags = model.flags(index)
        if (
            not (flags & Qt.ItemIsUserCheckable)
            or not (option.state & QStyle.State_Enabled)
            or not (flags & Qt.ItemIsEnabled)
        ):
            return False
        state = index.data(Qt.CheckStateRole)
        if state is None:
            return False
        widget = option.widget
        style = widget.style() if widget is not None else QApplication.style()
        # make sure that we have the right event type
        if (
            (event.type() == QEvent.MouseButtonRelease)
            or (event.type() == QEvent.MouseButtonDblClick)
            or (event.type() == QEvent.MouseButtonPress)
        ):
            viewOpt = QStyleOptionViewItem(option)
            self.initStyleOption(viewOpt, index)
            checkRect = style.subElementRect(
                QStyle.SE_ItemViewItemCheckIndicator, viewOpt, widget
            )
            me = event
            if me.button() != Qt.LeftButton or not checkRect.contains(me.pos()):
                return False
            if (event.type() == QEvent.MouseButtonPress) or (
                event.type() == QEvent.MouseButtonDblClick
            ):
                return True
        else:
            return False

        if state != Qt.Checked:
            for c in range(model.columnCount()):
                if c not in (0, index.column()):
                    ix = model.index(index.row(), c)
                    model.setData(ix, Qt.Unchecked, Qt.CheckStateRole)
            return model.setData(index, Qt.Checked, Qt.CheckStateRole)
        return False


class Radiostyle(QProxyStyle):
    def drawPrimitive(self, element, option, painter, widget=None):
        if element == QStyle.PE_IndicatorItemViewItemCheck:
            element = QStyle.PE_IndicatorRadioButton
        super().drawPrimitive(element, option, painter, widget)


app = QApplication(sys.argv)

searchView = QTableWidget(0, 4)
style = RadioStyle(searchView.style())
searchView.setStyle(style)

delegate = RadioButtonDelegate(searchView)
searchView.setItemDelegate(delegate)

colsNames = ["A", "B", "C"]
searchView.setHorizontalHeaderLabels(["DIR"] + colsNames)
dirNames = "A": ["/tmp", "/tmp/dir1"], "B": ["/tmp/dir2"], "C": ["/tmp/dir3"]

rowCount = sum(len(v) for (name, v) in dirNames.items())
searchView.setRowCount(rowCount)

index = 0

for letter, paths in dirNames.items():
    for path in paths:
        it = QTableWidgetItem(path)
        searchView.setItem(index, 0, it)
        for i, name in enumerate(colsNames):
            it = QTableWidgetItem()
            searchView.setItem(index, i + 1, it)
            it.setCheckState(Qt.Checked if name == letter else Qt.Unchecked)
        index += 1

searchView.show()
sys.exit(app.exec_())

【讨论】：

不错的解决方案，因为我是初学者，所以我必须研究它。一个问题：“原始”解决方案有什么问题？调整大小过程中的奇怪行为是错误还是类似的东西？ （只是为了理解和学习）

@MaPo 似乎只有在释放鼠标时才通知单元格小部件的大小（宽度）变化，虽然这个问题可以解决我更喜欢实现更优化的解决方案跨度>

只是循序渐进地学习，我应该阅读什么来修改原始示例以避免'延迟'发布通知？