How to use the qtconsole.qt.QtCore function in qtconsole

def add_menu_action(self, menu, action, defer_shortcut=False):
        """Add action to menu as well as self
        
        So that when the menu bar is invisible, its actions are still available.
        
        If defer_shortcut is True, set the shortcut context to widget-only,
        where it will avoid conflict with shortcuts already bound to the
        widgets themselves.
        """
        menu.addAction(action)
        self.addAction(action)

        if defer_shortcut:
            action.setShortcutContext(QtCore.Qt.WidgetShortcut)

# Whether to override ShortcutEvents for the keybindings defined by this
    # widget (Ctrl+n, Ctrl+a, etc). Enable this if you want this widget to take
    # priority (when it has focus) over, e.g., window-level menu shortcuts.
    override_shortcuts = Bool(False)
    
    # ------ Custom Qt Widgets -------------------------------------------------
    
    # For other projects to easily override the Qt widgets used by the console
    # (e.g. Spyder)
    custom_control = None
    custom_page_control = None

    #------ Signals ------------------------------------------------------------

    # Signals that indicate ConsoleWidget state.
    copy_available = QtCore.Signal(bool)
    redo_available = QtCore.Signal(bool)
    undo_available = QtCore.Signal(bool)

    # Signal emitted when paging is needed and the paging style has been
    # specified as 'custom'.
    custom_page_requested = QtCore.Signal(object)

    # Signal emitted when the font is changed.
    font_changed = QtCore.Signal(QtGui.QFont)

    #------ Protected class variables ------------------------------------------

    # control handles
    _control = None
    _page_control = None
    _splitter = None

QtCore.Qt.Key_PageUp,
                                        QtCore.Qt.NoModifier)
            QtGui.qApp.sendEvent(self._page_control, new_event)
            return True

        # vi/less -like key bindings
        elif key == QtCore.Qt.Key_J:
            new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress,
                                        QtCore.Qt.Key_Down,
                                        QtCore.Qt.NoModifier)
            QtGui.qApp.sendEvent(self._page_control, new_event)
            return True

        # vi/less -like key bindings
        elif key == QtCore.Qt.Key_K:
            new_event = QtGui.QKeyEvent(QtCore.QEvent.KeyPress,
                                        QtCore.Qt.Key_Up,
                                        QtCore.Qt.NoModifier)
            QtGui.qApp.sendEvent(self._page_control, new_event)
            return True

        return False

def eventFilter(self, obj, event):
        """ Reimplemented to handle keyboard input and to auto-hide when the
            text edit loses focus.
        """
        if obj == self._text_edit:
            etype = event.type()
            if etype == QtCore.QEvent.KeyPress:
                key = event.key()
                if self._consecutive_tab == 0 and key in (QtCore.Qt.Key_Tab,):
                    return False
                elif self._consecutive_tab == 1 and key in (QtCore.Qt.Key_Tab,):
                    # ok , called twice, we grab focus, and show the cursor
                    self._consecutive_tab = self._consecutive_tab+1
                    self._update_list()
                    return True
                elif self._consecutive_tab == 2:
                    if key in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
                        self._complete_current()
                        return True
                    if key in (QtCore.Qt.Key_Tab,):
                        self.select_right()
                        self._update_list()
                        return True

"""

    #---------------------------------------------------------------------------
    # signals
    #---------------------------------------------------------------------------

    pasteRequested = QtCore.Signal(str, name = 'pasteRequested')
    """This signal is emitted when user wants to paste selected magic 
       command into the command line.
    """

    runRequested = QtCore.Signal(str, name = 'runRequested')
    """This signal is emitted when user wants to execute selected magic command
    """

    readyForUpdate = QtCore.Signal(name = 'readyForUpdate')
    """This signal is emitted when MagicHelper is ready to be populated.
       Since kernel querying mechanisms are out of scope of this class,
       it expects its owner to invoke MagicHelper.populate_magic_helper()
       as a reaction on this event.
    """

    #---------------------------------------------------------------------------
    # constructor
    #---------------------------------------------------------------------------

    def __init__(self, name, parent):
        super(MagicHelper, self).__init__(name, parent)

        self.data = None

        class MinListWidget(QtGui.QListWidget):

def eventFilter(self, obj, event):
        """ Reimplemented to handle keyboard input and to auto-hide when the
            text edit loses focus.
        """
        if obj == self._text_edit:
            etype = event.type()

            if etype in( QtCore.QEvent.KeyPress, QtCore.QEvent.FocusOut ):
                self.cancel_completion()

        return super(CompletionPlain, self).eventFilter(obj, event)

self._index = len(self._ring)
        return self.rotate()

    def rotate(self):
        """ Rotate the kill ring, then yank back the new top.

        Returns
        -------
        A text string or None.
        """
        self._index -= 1
        if self._index >= 0:
            return self._ring[self._index]
        return None

class QtKillRing(QtCore.QObject):
    """ A kill ring attached to Q[Plain]TextEdit.
    """

    #--------------------------------------------------------------------------
    # QtKillRing interface
    #--------------------------------------------------------------------------

    def __init__(self, text_edit):
        """ Create a kill ring attached to the specified Qt text edit.
        """
        assert isinstance(text_edit, (QtGui.QTextEdit, QtGui.QPlainTextEdit))
        super(QtKillRing, self).__init__()

        self._ring = KillRing()
        self._prev_yank = None
        self._skip_cursor = False

info = "Would you like to quit the Kernel and close all attached Consoles as well?"
                    justthis = QtGui.QPushButton("&No, just this Tab", self)
                    justthis.setShortcut('N')
                    closeall = QtGui.QPushButton("&Yes, close all", self)
                    closeall.setShortcut('Y')
                    # allow ctrl-d ctrl-d exit, like in terminal
                    closeall.setShortcut('Ctrl+D')
                    box = QtGui.QMessageBox(QtGui.QMessageBox.Question,
                                            title, msg)
                    box.setInformativeText(info)
                    box.addButton(cancel)
                    box.addButton(justthis, QtGui.QMessageBox.NoRole)
                    box.addButton(closeall, QtGui.QMessageBox.YesRole)
                    box.setDefaultButton(closeall)
                    box.setEscapeButton(cancel)
                    pixmap = QtGui.QPixmap(self._app.icon.pixmap(QtCore.QSize(64,64)))
                    box.setIconPixmap(pixmap)
                    reply = box.exec_()
                    if reply == 1: # close All
                        for slave in slave_tabs:
                            background(slave.kernel_client.stop_channels)
                            self.tab_widget.removeTab(self.tab_widget.indexOf(slave))
                        kernel_manager.shutdown_kernel()
                        self.tab_widget.removeTab(current_tab)
                        background(kernel_client.stop_channels)
                    elif reply == 0: # close Console
                        if not closing_widget._existing:
                            # Have kernel: don't quit, just close the tab
                            closing_widget.execute("exit True")
                        self.tab_widget.removeTab(current_tab)
                        background(kernel_client.stop_channels)
                else:

# Signal emitted when paging is needed and the paging style has been
    # specified as 'custom'.
    custom_page_requested = QtCore.Signal(object)

    # Signal emitted when the font is changed.
    font_changed = QtCore.Signal(QtGui.QFont)

    #------ Protected class variables ------------------------------------------

    # control handles
    _control = None
    _page_control = None
    _splitter = None

    # When the control key is down, these keys are mapped.
    _ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
                         QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
                         QtCore.Qt.Key_A : QtCore.Qt.Key_Home,
                         QtCore.Qt.Key_P : QtCore.Qt.Key_Up,
                         QtCore.Qt.Key_N : QtCore.Qt.Key_Down,
                         QtCore.Qt.Key_H : QtCore.Qt.Key_Backspace, }
    if not sys.platform == 'darwin':
        # On OS X, Ctrl-E already does the right thing, whereas End moves the
        # cursor to the bottom of the buffer.
        _ctrl_down_remap[QtCore.Qt.Key_E] = QtCore.Qt.Key_End

    # The shortcuts defined by this widget. We need to keep track of these to
    # support 'override_shortcuts' above.
    _shortcuts = set(_ctrl_down_remap.keys()) | \
                     { QtCore.Qt.Key_C, QtCore.Qt.Key_G, QtCore.Qt.Key_O,
                       QtCore.Qt.Key_V }