def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
self.mainwindow = Ui_MainWindow()
self.mainwindow.setupUi(self)
it1 = Category(title='it1')
it2 = Page('it2', 'This is it2\'s content')
it3 = Page('it3', 'This is it3\'s content')
it1.setChild(it1.rowCount(), it2)
it1.setChild(it1.rowCount(), it3)
model = QStandardItemModel()
model.appendRow(it1)
tv = self.mainwindow.treeView
tv.setModel(model)
tv.setRootIsDecorated(True)
tv.setSelectionMode(QAbstractItemView.SingleSelection)
tv.setSelectionBehavior(QAbstractItemView.SelectItems)
tv.clicked.connect(self.printData)
