def mark_poi(self, times=None):
        """Mark selected signal, from list of start and end times.
        
        Parameters
        ----------
        times : list of tuple of float
            start and end times, in sec form rec start
        """
        y_pos = BARS['quality']['pos0']
        height = 5
        
        for rect in self.idx_poi:
            self.scene.removeItem(rect)
        self.idx_poi = []
        
        if not times:
            return
        
        for beg, end in times:
            rect = QGraphicsRectItem(beg, y_pos, end - beg, height)
            rect.setPen(NoPen)
            rect.setBrush(Qt.darkRed)
            self.scene.addItem(rect)
            self.idx_poi.append(rect) 

def paint_drop_indicator(self, painter):
        if self.drag_active:
            opt = QStyleOption()
            opt.initFrom(self)
            opt.rect = self.drop_indicator_rect
            rect = opt.rect

            brush = QBrush(QColor(Qt.darkRed))

            if rect.height() == 0:
                pen = QPen(brush, 2, Qt.SolidLine)
                painter.setPen(pen)
                painter.drawLine(rect.topLeft(), rect.topRight())
            else:
                pen = QPen(brush, 2, Qt.SolidLine)
                painter.setPen(pen)
                painter.drawRect(rect) 

def __init__(self, ui):
        super().__init__(ui)

        self.food_coordinates = None
        self.wlabC = {
            WLAB['U']: Qt.white,
            WLAB['WORM']: Qt.green,
            WLAB['WORMS']: Qt.blue,
            WLAB['BAD']: Qt.darkRed,
            WLAB['GOOD_SKE']: Qt.darkCyan
            } 
        self.ui.checkBox_showFood.stateChanged.connect(self.updateImage)
        self.ui.checkBox_showFood.setEnabled(False)
        self.ui.checkBox_showFood.setChecked(True) 

def paint_drop_indicator(self, painter):
        brush = QBrush(QColor(Qt.darkRed))
        pen = QPen(brush, 2, Qt.SolidLine)
        painter.setPen(pen)
        rect = self.boundingRect()

        if self.drop_indicator_position == QAbstractItemView.AboveItem:
            painter.drawLine(QLineF(rect.topLeft(), rect.topRight()))
        else:
            painter.drawLine(QLineF(rect.bottomLeft(), rect.bottomRight())) 

def paint_drop_indicator(self, painter):
        painter.setPen(QPen(Qt.darkRed, 2, Qt.SolidLine))
        painter.setBrush(Qt.NoBrush)
        rect = self.boundingRect()

        if self.drop_indicator_position == QAbstractItemView.AboveItem:
            painter.drawLine(QLineF(rect.topLeft(), rect.topRight()))
        elif self.drop_indicator_position == QAbstractItemView.OnItem:
            painter.drawRect(rect)
        else:
            painter.drawLine(QLineF(rect.bottomLeft(), rect.bottomRight()))