从 QAction 触发器访问委托 class

Question

我有一个 QListWidget，它对项目及其子项目进行分类（它们都是可检查的）。

目前，虽然 checking/unchecking 类别项目适用于子项目，但我在上下文菜单中引入了该选项，其中该选项的工作方式与您选中和取消选中类别项目的方式相同。

但是在我的 update_opts - 上下文菜单中的 QAction 中，虽然它确实允许我 check/uncheck 类别项目，但它不会影响子项目的检查状态。

此外，QListWidgetItem 似乎没有 trigger 或 toggle 信号，我可以利用它来触发委托 [=27= 中的 editorEvent ].

IsCategoryRole = QtCore.Qt.UserRole
ParentRole = QtCore.Qt.UserRole + 1


class CategoryDelegate(QtGui.QStyledItemDelegate):
    def editorEvent(self, event, model, option, index):
        old_state = model.data(index, QtCore.Qt.CheckStateRole)
        res = super(CategoryDelegate, self).editorEvent(
            event, model, option, index
        )
        current_state = model.data(index, QtCore.Qt.CheckStateRole)
        if old_state != current_state:
            if index.data(IsCategoryRole):
                pix = QtCore.QPersistentModelIndex(index)
                for i in range(model.rowCount()):
                    ix = model.index(i, 0)
                    if pix == ix.data(ParentRole):
                        model.setData(
                            ix, current_state, QtCore.Qt.CheckStateRole
                        )
        return res


class ListWidget(QtGui.QListWidget):
    def __init__(self, parent=None):
        super(ListWidget, self).__init__(parent)
        delegate = CategoryDelegate(self)
        self.setItemDelegate(delegate)

    def addCategory(self, text):
        item = ListWidget.create_checkable_item(text)
        item.setData(IsCategoryRole, True)
        self.addItem(item)
        return item

    def addItemToCategory(self, category_item, text):
        item = ListWidget.create_checkable_item(text)
        item.setData(IsCategoryRole, False)
        ix = self.indexFromItem(category_item)
        pix = QtCore.QPersistentModelIndex(ix)
        item.setData(ParentRole, pix)
        self.addItem(item)
        return item

    @staticmethod
    def create_checkable_item(text):
        item = QtGui.QListWidgetItem(text)
        item.setFlags(
            item.flags()
            | QtCore.Qt.ItemIsUserCheckable
            | QtCore.Qt.ItemIsEditable
        )
        item.setCheckState(QtCore.Qt.Unchecked)
        return item

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.RightButton:
            list_menu = QtGui.QMenu(self)
            selected_item = self.currentItem()
            if selected_item.data(IsCategoryRole):
                update_cat_items = QtGui.QAction("Check all or none", self)
                update_cat_items.triggered.connect(self.update_opts)
                list_menu.addAction(update_cat_items)

            list_menu.exec_(QtGui.QCursor().pos())

        else:
            super(ListWidget, self).mousePressEvent(event)

    def update_opts(self):
        selected_item = self.currentItem() 
        state = selected_item.checkState() # It returns eith 0 or 2, instead of QtCore.Qt.Unchecked or QtCore.Qt.Checked

        if state == QtCore.Qt.Checked:
            # If opt is checked in the first place, set it to uncheck
            selected_item.setCheckState(QtCore.Qt.Unchecked)

        else:
            # If opt is unchecked in the first place, set it to check
            selected_item.setCheckState(QtCore.Qt.Checked)


class TestDialog(QtGui.QDialog):
    def __init__(self, parent=None):
        super(TestDialog, self).__init__()
        self.listWidget = ListWidget()

        all_num = self.listWidget.addCategory("-- All Nums --")
        num_items = ["One", "Two", "Three"]
        for num in num_items:
            self.listWidget.addItemToCategory(all_num, num)

        all_letters = self.listWidget.addCategory("-- All Letters --")

        letter_items = ["A", "B", "C"]
        for letter in letter_items:
            self.listWidget.addItemToCategory(all_letters, letter)

        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.listWidget)




if __name__ == "__main__":
    import sys

    app = QtGui.QApplication(sys.argv)
    w = TestDialog()
    w.show()
    sys.exit(app.exec_())

Answer 1

在我的中，考虑到 OP 只希望只有在用户按下复选框时才允许行为，现在使用新方法将扩展行为，为此不需要委托，但创建一个自定义 QListWidgetItem，其中该方法被覆盖 setData() 方法：

from PyQt4 import QtCore, QtGui

IsCategoryRole = QtCore.Qt.UserRole
ParentRole = QtCore.Qt.UserRole + 1


class ListWidgetItem(QtGui.QListWidgetItem):
    def setData(self, role, value):
        if role == QtCore.Qt.CheckStateRole and self.data(IsCategoryRole):
            lw = self.listWidget()
            index = lw.indexFromItem(self)
            pix = QtCore.QPersistentModelIndex(index)
            for r in range(lw.count()):
                print(r)
                it = lw.item(r)
                if pix == it.data(ParentRole):
                    it.setData(role, value)
        super(ListWidgetItem, self).setData(role, value)


class ListWidget(QtGui.QListWidget):
    def addCategory(self, text):
        item = ListWidget.create_checkable_item(text)
        item.setData(IsCategoryRole, True)
        self.addItem(item)
        return item

    def addItemToCategory(self, category_item, text):
        item = ListWidget.create_checkable_item(text)
        item.setData(IsCategoryRole, False)
        ix = self.indexFromItem(category_item)
        pix = QtCore.QPersistentModelIndex(ix)
        item.setData(ParentRole, pix)
        self.addItem(item)
        return item

    @staticmethod
    def create_checkable_item(text):
        item = ListWidgetItem(text)
        item.setFlags(
            item.flags()
            | QtCore.Qt.ItemIsUserCheckable
            | QtCore.Qt.ItemIsEditable
        )
        item.setCheckState(QtCore.Qt.Unchecked)
        return item

    def contextMenuEvent(self, event):
        list_menu = QtGui.QMenu()
        it = self.itemAt(self.viewport().mapFromGlobal(QtGui.QCursor().pos()))
        if it.data(IsCategoryRole):
            update_cat_items = QtGui.QAction("Check all or none", self)
            update_cat_items.triggered.connect(self.update_opts)
            list_menu.addAction(update_cat_items)
        list_menu.exec_(QtGui.QCursor().pos())

    def update_opts(self):
        it = self.itemAt(self.viewport().mapFromGlobal(QtGui.QCursor().pos()))
        it.setCheckState(
            QtCore.Qt.Unchecked
            if it.checkState() == QtCore.Qt.Checked
            else QtCore.Qt.Checked
        )


class TestDialog(QtGui.QDialog):
    def __init__(self, parent=None):
        super(TestDialog, self).__init__()
        self.listWidget = ListWidget()

        all_num = self.listWidget.addCategory("-- All Nums --")
        num_items = ["One", "Two", "Three"]
        for num in num_items:
            self.listWidget.addItemToCategory(all_num, num)

        all_letters = self.listWidget.addCategory("-- All Letters --")

        letter_items = ["A", "B", "C"]
        for letter in letter_items:
            self.listWidget.addItemToCategory(all_letters, letter)

        layout = QtGui.QVBoxLayout(self)
        layout.addWidget(self.listWidget)


if __name__ == "__main__":
    import sys

    app = QtGui.QApplication(sys.argv)
    w = TestDialog()
    w.show()
    sys.exit(app.exec_())

从 QAction 触发器访问委托 class

Access delegate class from QAction Trigger

python

pyqt

pyqt4