SemiPieChart
SemiPieChart widget looks like on the picture below. It can be used to display data sets in form of pie where each data is represented as a semi ring (central or last data in set is show with zero inner radius semi ring) and points of data are represented as parts of the corresponding semi ring. The more Y value of the point the bigger part of the semi ring it fills.
This widget doesn't use custom renderer assigned to data set. Thus custom drawing is not supported.
X-coordinate of data points is not used by this widget.
