def keyPressEvent(self, event):
        #HOT KEYS

        if self.video_reader is None:
            # break no file open, nothing to do here
            return

        key = event.key()
        if key == Qt.Key_Minus:
            self.mainImage.zoom(-1)
        elif key == Qt.Key_Plus:
            self.mainImage.zoom(1)

        super().keyPressEvent(event)

    # frame spin box 

def left(self):
        self.widget.switch_page(right=False)
        
        
        
    #def keyPressEvent(self, event):
        #这里event.key（）显示的是按键的编码
        #print("按下：" + str(event.key()))
        # 举例，这里Qt.Key_A注意虽然字母大写，但按键事件对大小写不敏感
        #if (event.key() == Qt.Key_Left):
        #    self.widget.switch_page(right=False)
        #elif (event.key() == Qt.Key_Right):
        #    self.widget.switch_page(right=True)
        #elif (event.modifiers() == Qt.CTRL and event.key() == Qt.Key_Plus):
        #    self.widget.zoom_book(plus=True)
        #elif (event.modifiers() == Qt.CTRL and event.key() == Qt.Key_Minus):
        #    self.widget.zoom_book(plus=False) 

def _qtKeyToUMKey(self, key):
        if key == Qt.Key_Shift:
            return KeyEvent.ShiftKey
        elif key == Qt.Key_Control:
            return KeyEvent.ControlKey
        elif key == Qt.Key_Alt:
            return KeyEvent.AltKey
        elif key == Qt.Key_Space:
            return KeyEvent.SpaceKey
        elif key == Qt.Key_Meta:
            return KeyEvent.MetaKey
        elif key == Qt.Key_Enter or key == Qt.Key_Return:
            return KeyEvent.EnterKey
        elif key == Qt.Key_Up:
            return KeyEvent.UpKey
        elif key == Qt.Key_Down:
            return KeyEvent.DownKey
        elif key == Qt.Key_Left:
            return KeyEvent.LeftKey
        elif key == Qt.Key_Right:
            return KeyEvent.RightKey
        elif key == Qt.Key_Minus:
            return KeyEvent.MinusKey
        elif key == Qt.Key_Underscore:
            return KeyEvent.UnderscoreKey
        elif key == Qt.Key_Plus:
            return KeyEvent.PlusKey
        elif key == Qt.Key_Equal:
            return KeyEvent.EqualKey

        return key 

def keyPressEvent(self, event):
        if self.vid is not None:
            # break no file open, nothing to do here
            return
        key = event.key()
        if key == Qt.Key_Minus:
            self.twoViews.zoom(-1)
        elif key == Qt.Key_Plus:
            self.twoViews.zoom(1)

        else:
            QMainWindow.keyPressEvent(self, event) 

def __init__(self, filename=None, parent=None):
        super(SpectraViewer, self).__init__(parent)
        self.ui = Ui_SpectraViewer()
        self.ui.setupUi(self)
        self.sf = 7200
        self.k0 = 0
        self.dsf = 0
        self.dk0 = 0
        self.ita = None
        self.fig = self.ui.mpl.canvas.fig
        self.canvas = self.ui.mpl.canvas
        self.ax = self.fig.add_subplot(111)
        self.nextMass = QShortcut(Qt.Key_Plus, self)
        self.prevMass = QShortcut(Qt.Key_Minus, self)
        self.nextMass.activated.connect(self.next_mass)
        self.prevMass.activated.connect(self.prev_mass)
        self.ui.pushButton_2.clicked.connect(self.toggleMassCal)
        self.ui.pushButton.clicked.connect(self.removeMassCalItem)
        self.ui.show_mass.clicked.connect(self.yAxisScaleChanged)
        self.canvas.mpl_connect('motion_notify_event', self.on_motion)
        self.canvas.mpl_connect('button_press_event', self.onMousePress)
        self.canvas.mpl_connect('button_release_event', self.onMouseRelease)
        self.canvas.mpl_connect("scroll_event", self.scrolling)
        self.labels = []
        self.action = None
        self.lab_lines = []
        self.MassCal = []
        self.open(filename)