python - PyQt:自定义属性的 QDataWidgetMapper 映射

Question

在 PyQt 中，我想使用 QAbstractItemModel 和 QDataWidgetMapper 将小部件映射到模型数据。对于 QLineEdit，它工作正常，但我想在 QButtonGroup(填充有多个 QRadioButton)和模型之间建立映射。因此我继承了 QGroupBox 并添加了一个自定义属性 selectedOption:

class ButtonGroupWidget(QGroupBox):
    def __init__(self, parent=None):
        super(ButtonGroupWidget, self).__init__(parent)
        self._selectedOption = -1
        self.buttonGroup = QButtonGroup()
        self.layoutGroupBox = QVBoxLayout(self)

    def addRadioButton(self,optionText,optionId):
        print(optionText)
        radioButton = QRadioButton(optionText)
        radioButton.clicked.connect(self.updateOptionSelected)
        self.layoutGroupBox.addWidget(radioButton)
        self.buttonGroup.addButton(radioButton,optionId)

    def updateOptionSelected(self):
        print(self.buttonGroup.checkedId()) # for test purpose
        self.selectedOption = self.buttonGroup.checkedId()
        print(self._selectedOption) # for test purpose

    def getSelectedOption(self):
        print("get selectedOption is called")
        return self._selectedOption

    def setSelectedOption(self,selectedOption):
        print("set selectedOption is called")
        self._selectedOption = selectedOption
        self.buttonGroup.button(selectedOption).setChecked(True)

    selectedOption = pyqtProperty(int,getSelectedOption,setSelectedOption)

在主小部件中，我创建了这个 ButtonGroupWidget 的一个实例:

class MainWidget(QWidget):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        ...

        # insert a button group widget
        self.buttonGroupWidget1 = ButtonGroupWidget(self)
        self.buttonGroupWidget1.setTitle("Select option")
        self.buttonGroupWidget1.addRadioButton("Option 1", 1)
        self.buttonGroupWidget1.addRadioButton("Option 2", 2)
        self.buttonGroupWidget1.addRadioButton("Option 3", 3)
        ...

        # Create the data model and map the model to the widgets.
        self._model = DataModel()
        ...

        self._dataMapper = QDataWidgetMapper()
        self._dataMapper.setModel(self._model)
        ...
        # mapping to custom property
        self._dataMapper.addMapping(self.buttonGroupWidget1,1,"selectedOption")

下面给出了完整的代码(最小的工作示例)。我的问题如下:如果模型发生变化(例如通过您在完整代码中看到的 lineEdit)，将调用 setSelectedOption 方法并将 self._selectedOption 设置为当前值并更新 radioButtons。但是如果我点击另一个单选按钮，我不知道如何更新模型。

是否有 QWidget 的数据更改事件之类的东西，它会更新模型？

有没有更好的方法将 QAbstractItemModel 映射到具有多个单选按钮的 GroupBox？

完整代码(最小示例，使用 Python 3.4 和 PyQt 5.4 测试):

import sys
from PyQt5.QtWidgets import QWidget, QLineEdit, QRadioButton, QButtonGroup, QApplication, QVBoxLayout, QGroupBox, QTreeView,QDataWidgetMapper
from PyQt5.QtCore import QAbstractItemModel,QModelIndex,Qt,pyqtProperty

"""Base class to provide some nodes fro a tree
At the moment each node contains two members: name and option"""
class Node(object):

    def __init__(self,name,parent=None):

        self._name = name
        self._children = []
        self._parent = parent
        self._option = 2

        if parent is not None:
            parent.addChild(self)

    def name(self):
        return self._name

    def setName(self, name):
        self._name = name

    def option(self):
        return self._option

    def setOption(self,option):
        self._option = option  

    def addChild(self,child):
        self._children.append(child)

    def insertChild(self, position, child):
        if position < 0 or position > len(self._children):
            return False
        self._children.insert(position, child)
        child._parent = self
        return True

    def removeChild(self, position):
        if position < 0 or position > len(self._children):
            return False
        child = self._children.pop(position)
        child._parent = None
        return True

    def child(self,row):
        return self._children[row]

    def childCount(self):
        return len(self._children)

    def parent(self):
        return self._parent

    def row(self):
        if self._parent is not None:
            return self._parent._children.index(self)

    def __repr__(self):
        return  self.log()


class ButtonGroupWidget(QGroupBox):
    def __init__(self, parent=None):
        super(ButtonGroupWidget, self).__init__(parent)
        self._selectedOption = -1
        self.buttonGroup = QButtonGroup()
        self.layoutGroupBox = QVBoxLayout(self)

    def addRadioButton(self,optionText,optionId):
        print(optionText)
        radioButton = QRadioButton(optionText)
        radioButton.clicked.connect(self.updateOptionSelected)
        self.layoutGroupBox.addWidget(radioButton)
        self.buttonGroup.addButton(radioButton,optionId)

    def updateOptionSelected(self):
        print(self.buttonGroup.checkedId()) # for test purpose
        self.selectedOption = self.buttonGroup.checkedId()
        print(self._selectedOption) # for test purpose

    def getSelectedOption(self):
        print("get selectedOption is called")
        return self._selectedOption

    def setSelectedOption(self,selectedOption):
        print("set selectedOption is called")
        self._selectedOption = selectedOption
        self.buttonGroup.button(selectedOption).setChecked(True)

    selectedOption = pyqtProperty(int,getSelectedOption,setSelectedOption)


class DataModel(QAbstractItemModel):

    def __init__(self, parent=None):
        super(DataModel, self).__init__(parent)
        self._rootNode = Node("Root Node")
        childNode1 = Node("Child 1",self._rootNode)
        childNode2 = Node("Child 2",self._rootNode)
        childNode3 = Node("Child 3",self._rootNode)

    def __eq__(self, other): 
        return self.__dict__ == other.__dict__

    def isNull(self):
        nullObject = DataModel()
        if self.__eq__(nullObject):
            return True
        else:
            return False

    def rowCount(self, parent):
        if not parent.isValid():
            parentNode = self._rootNode
        else:
            parentNode = parent.internalPointer()
        return parentNode.childCount()

    def columnCount(self, parent):
        return 1

    def data(self,index,role):
        if not index.isValid():
            return None
        node = index.internalPointer()
        if role == Qt.DisplayRole or role == Qt.EditRole:
            if index.column() == 0:
                return node.name()
            if index.column() == 1:
                return node.option()

    def setData(self,index,value, role=Qt.EditRole):
        if index.isValid():
            node = index.internalPointer()
            if role == Qt.EditRole:
                if index.column() == 0:
                    node.setName(value)
                if index.column() == 1:
                    node.setOption(value)
                self.dataChanged.emit(index,index)
                return True            
        return False   

    def headerData(self, section, orientation, role):
        if role == Qt.DisplayRole:
            if section == 0:
                return "Select Child"

    def flags(self, index):
        return Qt.ItemIsEnabled | Qt.ItemIsSelectable | Qt.ItemIsEditable

    def parent(self, index):
        node = index.internalPointer()
        parentNode = node.parent()
        if parentNode == self._rootNode:
            return QModelIndex()
        return self.createIndex(parentNode.row(), 0, parentNode)

    def index(self, row, column, parent):

        if not parent.isValid():
            parentNode = self._rootNode
        else:
            parentNode = parent.internalPointer()

        childItem = parentNode.child(row)

        if childItem:
            return self.createIndex(row, column, childItem)
        else:
            return QModelIndex()

    def getNode(self, index):
        if index.isValid():
            node = index.internalPointer()
            if node:
                return node

        return self._rootNode

class MainWidget(QWidget):

    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        # define tree view
        self.treeView = QTreeView(self)

        # insert line edit
        self.lineEdit1 = QLineEdit(self)
        self.lineEdit2 = QLineEdit(self)

        # insert a button group widget
        self.buttonGroupWidget1 = ButtonGroupWidget(self)
        self.buttonGroupWidget1.setTitle("Select option")
        self.buttonGroupWidget1.addRadioButton("Option 1", 1)
        self.buttonGroupWidget1.addRadioButton("Option 2", 2)
        self.buttonGroupWidget1.addRadioButton("Option 3", 3)

        layoutMain = QVBoxLayout(self)
        layoutMain.addWidget(self.treeView)
        layoutMain.addWidget(self.lineEdit1)
        layoutMain.addWidget(self.lineEdit2)
        layoutMain.addWidget(self.buttonGroupWidget1)

        # Create the data model and map the model to the widgets.
        self._model = DataModel()
        self.treeView.setModel(self._model)

        self._dataMapper = QDataWidgetMapper()
        self._dataMapper.setModel(self._model)
        # the mapping works fine for line edits and combo boxes
        self._dataMapper.addMapping(self.lineEdit1, 0)
        self._dataMapper.addMapping(self.lineEdit2, 1)
        # mapping to custom property
        self._dataMapper.addMapping(self.buttonGroupWidget1,1,"selectedOption")

        self.treeView.selectionModel().currentChanged.connect(self.setSelection)

    def setSelection(self, current):

        parent = current.parent()
        self._dataMapper.setRootIndex(parent)
        self._dataMapper.setCurrentModelIndex(current) 


def main():
    app = QApplication(sys.argv)
    form = MainWidget()
    form.show()
    app.exec_()

main() 

Answer 1

模型将在单选按钮选项更改时更新，但前提是按下回车或回车。

这样做的原因是，数据映射器使用一个项目委托(delegate)来通知模型的更改，并且这个项目委托(delegate)在每个映射的小部件上安装一个事件过滤器。但是事件过滤器只监控按键和焦点变化，不监控鼠标点击，而且在任何情况下，它都不能接收来自子部件的事件。

绕过此限制的一种稍微老套的方法是在单击单选按钮时模拟适当的按键操作:

    def updateOptionSelected(self):
        self.selectedOption = self.buttonGroup.checkedId()
        QApplication.postEvent(
            self, QKeyEvent(QEvent.KeyPress, Qt.Key_Enter, Qt.NoModifier))