item = QgsComposerScaleBar(c)
item.setStyle("Line Ticks Up") # optionally modify the style
item.setComposerMap(composerMap)
c.addItem(item)

brush = ScaleBar.brush()
brush.setColor(QColor(255, 0, 0, 0))
QgsComposerScaleBar.setBrush(brush)

scalebaritem = super(QgsComposerItem, ScaleBar)
scalebaritem.setBrush(QColor(0,0,0,0))

ScaleBar.font().toString()
PyQt4.QtCore.QString(u'Ubuntu,12,-1,5,50,0,0,0,0,0')
>>> ScaleBar.font().setPointSize(8)
>>> ScaleBar.font().pointSize()
12

f = ScaleBar.font()
f.setPointSize(8)
ScaleBar.setFont(f)

ScaleBar = QgsComposerScaleBar(c)
ScaleBar.setComposerMap(composerMap)
ScaleBar.setStyle('Line Ticks Middle') # optionally modify the style
ScaleBar.setFrame(False)
ScaleBar.setUnitLabeling(QString("km"))
ScaleBar.setNumMapUnitsPerScaleBarUnit(1000)

brush = ScaleBar.brush()
brush.setColor(QColor(255, 0, 0, 0))
QgsComposerScaleBar.setBrush(brush)

ScaleBar.setItemPosition(50,40)
ScaleBar.applyDefaultSize()
#ScaleBar.update()
c.addItem(ScaleBar)

ScaleBar.font().toString()
PyQt4.QtCore.QString(u'Ubuntu,12,-1,5,50,0,0,0,0,0')
>>> ScaleBar.font().setPointSize(8)
>>> ScaleBar.font().pointSize()
12