PyQt：自定义 QDataWidgetMapper 映射 属性
PyQt: QDataWidgetMapper mapping for custom property
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。
因此我将 QGroupBox 子类化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")
完整代码（工作最小示例）如下所示。
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radioButton，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()
模型将在单选按钮选项更改时更新，但只有在按下 return 或输入时才会更新。
这样做的原因是数据映射器使用项目委托来通知对模型的更改，并且该项目委托在映射的每个小部件上安装了事件过滤器。但是事件过滤器只监听按键和焦点变化，不监听鼠标点击，无论如何，它不能接收来自子部件的事件。
解决此限制的一种略显骇人听闻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))
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。 因此我将 QGroupBox 子类化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")
完整代码（工作最小示例）如下所示。 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radioButton，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()
模型将在单选按钮选项更改时更新，但只有在按下 return 或输入时才会更新。
这样做的原因是数据映射器使用项目委托来通知对模型的更改，并且该项目委托在映射的每个小部件上安装了事件过滤器。但是事件过滤器只监听按键和焦点变化，不监听鼠标点击，无论如何，它不能接收来自子部件的事件。
解决此限制的一种略显骇人听闻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))