def __init__(self, parent=None):
QAbstractItemView.__init__(self, parent)
self.horizontalScrollBar().setRange(0, 0)
self.verticalScrollBar().setRange(0, 0)
self.validItems = 1
self.totalValue = 0.0
self.setMouseTracking(True)
self.highlight = None
self.old_highlight = None
self.fm = None
