对于项目的复选框与其文本,如何区别对待点击事件? (PyQt的/ PySide / QT)

时间:2015-04-15 02:05:40

标签: qt pyqt pyside

我有一个QStandardItemModel,其中每个项目都是可检查的。当我单击项目的复选框时,我希望调用不同的插槽,而另一方面,当我单击其文本时,我需要调用另一个插槽。我的最终目标是进行文字修改,并在复选框状态中进行更改,然后单独转到QUndoStack

在我clicked的重新实现中,我希望以不同方式处理复选框点击和文字点击。到目前为止,我发现QCheckBox QStandardItem.QCheckBox toggled无法区分这些事件,而itemChangedclicked信号我可以使用,I我不确定如何专门听取文本区域的点击。

我试图避免手动设置坐标,然后在项目视图的不同区域中听取点击。

这似乎不像调用{{1}}之类的东西那么简单,因为这只会给你项目的 new 状态,而不是之前的状态。基于之前的问题,我相信您需要一些方法将先前的状态打包到撤消堆栈中,以便您知道要恢复的内容。这就是我的目标{{1}},但可能有更好的方法。

这个问题依赖于本系列的前两部分,其中我试图弄清楚如何在模型中撤消事物:

2 个答案:

答案 0 :(得分:3)

基于ekhumoro's suggestion和代码块,我构建了一个QStandardItemModel的树视图,当项目发生变化时会发出自定义信号。代码区分文本与通过setData中的角色更改的复选框(对于文本,使用Qt.EditRole,对于复选框状态更改使用Qt.CheckStateRole):

# -*- coding: utf-8 -*-

from PySide import QtGui, QtCore
import sys

class CommandTextEdit(QtGui.QUndoCommand):
    def __init__(self, tree, item, oldText, newText, description):
        QtGui.QUndoCommand.__init__(self, description)
        self.item = item
        self.tree = tree
        self.oldText = oldText
        self.newText = newText

    def redo(self):      
        self.item.model().itemDataChanged.disconnect(self.tree.itemDataChangedSlot) 
        self.item.setText(self.newText)
        self.item.model().itemDataChanged.connect(self.tree.itemDataChangedSlot) 

    def undo(self):
        self.item.model().itemDataChanged.disconnect(self.tree.itemDataChangedSlot) 
        self.item.setText(self.oldText)
        self.item.model().itemDataChanged.connect(self.tree.itemDataChangedSlot) 


class CommandCheckStateChange(QtGui.QUndoCommand):
    def __init__(self, tree, item, oldCheckState, newCheckState, description):
        QtGui.QUndoCommand.__init__(self, description)
        self.item = item
        self.tree = tree
        self.oldCheckState = QtCore.Qt.Unchecked if oldCheckState == 0 else QtCore.Qt.Checked
        self.newCheckState = QtCore.Qt.Checked if oldCheckState == 0 else QtCore.Qt.Unchecked

    def redo(self): #disoconnect to avoid recursive loop b/w signal-slot
        self.item.model().itemDataChanged.disconnect(self.tree.itemDataChangedSlot) 
        self.item.setCheckState(self.newCheckState)
        self.item.model().itemDataChanged.connect(self.tree.itemDataChangedSlot) 

    def undo(self):
        self.item.model().itemDataChanged.disconnect(self.tree.itemDataChangedSlot)
        self.item.setCheckState(self.oldCheckState)
        self.item.model().itemDataChanged.connect(self.tree.itemDataChangedSlot) 


class StandardItemModel(QtGui.QStandardItemModel):
    itemDataChanged = QtCore.Signal(object, object, object, object)


class StandardItem(QtGui.QStandardItem):
    def setData(self, newValue, role=QtCore.Qt.UserRole + 1):
        if role == QtCore.Qt.EditRole:
            oldValue = self.data(role)
            QtGui.QStandardItem.setData(self, newValue, role)
            model = self.model()
            #only emit signal if newvalue is different from old
            if model is not None and oldValue != newValue:
                model.itemDataChanged.emit(self, oldValue, newValue, role)
            return True
        if role == QtCore.Qt.CheckStateRole:
            oldValue = self.data(role)
            QtGui.QStandardItem.setData(self, newValue, role)
            model = self.model()
            if model is not None and oldValue != newValue:
                model.itemDataChanged.emit(self, oldValue, newValue, role)
            return True
        QtGui.QStandardItem.setData(self, newValue, role)


class UndoableTree(QtGui.QWidget):
    def __init__(self, parent = None):
        QtGui.QWidget.__init__(self, parent = None)
        self.setAttribute(QtCore.Qt.WA_DeleteOnClose)
        self.view = QtGui.QTreeView()
        self.model = self.createModel()
        self.view.setModel(self.model)
        self.view.expandAll()
        self.undoStack = QtGui.QUndoStack(self)
        undoView = QtGui.QUndoView(self.undoStack)
        buttonLayout = self.buttonSetup()
        mainLayout = QtGui.QHBoxLayout(self)
        mainLayout.addWidget(undoView)
        mainLayout.addWidget(self.view)
        mainLayout.addLayout(buttonLayout)
        self.setLayout(mainLayout)
        self.makeConnections()

    def makeConnections(self):
        self.model.itemDataChanged.connect(self.itemDataChangedSlot)
        self.quitButton.clicked.connect(self.close)
        self.undoButton.clicked.connect(self.undoStack.undo)
        self.redoButton.clicked.connect(self.undoStack.redo)

    def itemDataChangedSlot(self, item, oldValue, newValue, role):
        if role == QtCore.Qt.EditRole:
            command = CommandTextEdit(self, item, oldValue, newValue,
                "Text changed from '{0}' to '{1}'".format(oldValue, newValue))
            self.undoStack.push(command)
            return True
        if role == QtCore.Qt.CheckStateRole:
            command = CommandCheckStateChange(self, item, oldValue, newValue, 
                "CheckState changed from '{0}' to '{1}'".format(oldValue, newValue))
            self.undoStack.push(command)
            return True

    def buttonSetup(self):
        self.undoButton = QtGui.QPushButton("Undo")
        self.redoButton = QtGui.QPushButton("Redo")
        self.quitButton = QtGui.QPushButton("Quit")
        buttonLayout = QtGui.QVBoxLayout()
        buttonLayout.addStretch()
        buttonLayout.addWidget(self.undoButton)
        buttonLayout.addWidget(self.redoButton)
        buttonLayout.addStretch()
        buttonLayout.addWidget(self.quitButton)
        return buttonLayout

    def createModel(self):
        model = StandardItemModel()
        model.setHorizontalHeaderLabels(['Titles', 'Summaries'])
        rootItem = model.invisibleRootItem()
        item0 = [StandardItem('Title0'), StandardItem('Summary0')]
        item00 = [StandardItem('Title00'), StandardItem('Summary00')]
        item01 = [StandardItem('Title01'), StandardItem('Summary01')]
        item0[0].setCheckable(True)
        item00[0].setCheckable(True)
        item01[0].setCheckable(True)
        rootItem.appendRow(item0)
        item0[0].appendRow(item00)
        item0[0].appendRow(item01)
        return model


def main():
    app = QtGui.QApplication(sys.argv)
    newTree = UndoableTree()
    newTree.show()
    sys.exit(app.exec_())    

if __name__ == "__main__":
    main()

答案 1 :(得分:2)

clicked信号似乎完全是跟踪变化的错误方式。你将如何处理通过键盘进行的更改?那么以编程方式进行的更改呢?要使撤消堆栈正常工作,必须记录每个更改,并且按照完全相同的顺序记录。

如果您使用QStandardItemModelitemChanged信号几乎就是您想要的信号。但是,它的主要问题是虽然它发送了更改的,但它不会为您提供有关 更改的信息。所以看起来你需要做一些子类化并发出一个自定义信号来做到这一点:

class StandardItemModel(QtGui.QStandardItemModel):
    itemDataChanged = QtCore.Signal(object, object, object)

class StandardItem(QtGui.QStandardItem):
    def setData(self, newValue, role=QtCore.Qt.UserRole + 1):
        oldValue = self.data(role)
        QtGui.QStandardItem.setData(self, newValue, role)
        model = self.model()
        if model is not None:
            model.itemDataChanged.emit(oldValue, newvValue, role)

请注意,只有在项目添加到模型后所做的更改才会发出信号。