def onListImageFilesContextMenuRequested(self, point):
        current_item = self.ui.listWidgetImageFiles.currentItem()
        if current_item is None:
            return

        pop_menu = QtGui.QMenu()
        delete_action = QtGui.QAction(u'删除', self)
        pop_menu.addAction(delete_action)
        delete_action.triggered.connect(self.DeletePatternItem)
        modify_action = QtGui.QAction(u'修改', self)
        pop_menu.addAction(modify_action)
        modify_action.triggered.connect(self.ModifyPatternItem)
        cancel_modify_action = QtGui.QAction(u'取消修改', self)
        pop_menu.addAction(cancel_modify_action)
        cancel_modify_action.triggered.connect(self.CancelModifyPatternItem)
        pop_menu.exec_(QtGui.QCursor.pos()) 

def __init__(self, sandbox, *args, **kwargs):
            QtWidgets.QMenu.__init__(self)
            self.setTitle('Add Source')
            self.sandbox = sandbox

            backends = set(src.display_backend for src in __sources__)

            for ibe, be in enumerate(backends):
                self.addSection(be)

                for src in [s for s in __sources__
                            if s.display_backend == be]:
                    self.addSourceDelegate(src)

                if ibe is not len(backends) - 1:
                    self.addSeparator() 

def __init__(self, parent, idx, *args, **kwargs):
            QtGui.QMenu.__init__(self, *args, **kwargs)
            self.parent = parent
            self.sandbox = parent.sandbox
            self.idx = idx

            def removeSource():
                self.sandbox.sources.removeSource(self.idx)

            editAction = self.addAction(
                'Edit', lambda: self.parent.editSource(self.idx))

            self.addMenu(
                SourcesAddButton.SourcesAddMenu(self.sandbox, self))
            self.addSeparator()

            removeAction = self.addAction(
                self.style().standardIcon(
                    QtGui.QStyle.SP_DialogCloseButton),
                'Remove', removeSource)

            if self.sandbox.sources.rowCount(QtCore.QModelIndex()) == 0:
                editAction.setEnabled(False)
                removeAction.setEnabled(False) 

def _setup_menu(self):
        """ Sets up the main menu.
        """
        # file_menu = self.menuBar().addMenu("&File")
        self.menu = QtGui.QMenu(self)
        self.menu.addAction("C&lose", self.close_window, "Ctrl+W")
        self.menu.addAction("E&xit", self.quit_application, "Ctrl+Q")
        if DEBUGGING is True:
            self.menu.addSeparator()
            self.menu.addAction("&Test", self.my_test, "Ctrl+T")

        self.show_cols_submenu = self.menu.addMenu("Table columns")
        self.menu.addAction(self.toggle_callable_action)
        self.menu.addAction(self.toggle_special_attribute_action)

        self.titleBar().settingDownButton.setMenu(self.menu)
        self.titleBar().settingMenuShowed.connect(
            self.titleBar().settingDownButton.showMenu) 

def classifier(parent):
    main_menu = parent.menuBar()
    # classifier menu
    parent.trainfiles = []
    parent.statlabels = None
    parent.loadMenu = QtGui.QMenu("Load", parent)
    parent.loadClass = QtGui.QAction("from file", parent)
    parent.loadClass.triggered.connect(lambda: classgui.load_classifier(parent))
    parent.loadClass.setEnabled(False)
    parent.loadMenu.addAction(parent.loadClass)
    parent.loadUClass = QtGui.QAction("default classifier", parent)
    parent.loadUClass.triggered.connect(lambda: classgui.load_default_classifier(parent))
    parent.loadUClass.setEnabled(False)
    parent.loadMenu.addAction(parent.loadUClass)
    parent.loadSClass = QtGui.QAction("built-in classifier", parent)
    parent.loadSClass.triggered.connect(lambda: classgui.load_s2p_classifier(parent))
    parent.loadSClass.setEnabled(False)
    parent.loadMenu.addAction(parent.loadSClass)
    parent.loadTrain = QtGui.QAction("Build", parent)
    parent.loadTrain.triggered.connect(lambda: classgui.load_list(parent))
    parent.loadTrain.setEnabled(False)
    parent.saveDefault = QtGui.QAction("Save loaded as default", parent)
    parent.saveDefault.triggered.connect(lambda: classgui.class_default(parent))
    parent.saveDefault.setEnabled(False)
    parent.resetDefault = QtGui.QAction("Reset default to built-in", parent)
    parent.resetDefault.triggered.connect(lambda: classgui.reset_default(parent))
    parent.resetDefault.setEnabled(True)
    class_menu = main_menu.addMenu("&Classifier")
    class_menu.addMenu(parent.loadMenu)
    class_menu.addAction(parent.loadTrain)
    class_menu.addAction(parent.resetDefault)
    class_menu.addAction(parent.saveDefault)