P4
In the for-loop beginning at line 613 of PieChart, there is a redundant if (null check followed by instanceof). The consequence of this if does not enclose enough code. It is possible to get out of this if with no value in the variable arc, which causes NPE at line 626. It appears that the if should end after line 641.
I have a panel structure AnchorPane/BorderPane/SplitPane/(PieChart,BarChart). This runs fine in its own window. When I embed this in a larger FXML structure and change the data in the PieChart, NPE occurs if there is more than one slice of the pie, apparently because there is no Data item past the first one when running in this larger context. Fixing the error described explicitly above may fix this problem, or it may simply unmask another one. BTW I would be able to give you more information, but there are variables and methods in this class and its superclasses marked private or package, which makes it really-hard-to-impossible to make useful subclasses that might help with debugging.
I have a panel structure AnchorPane/BorderPane/SplitPane/(PieChart,BarChart). This runs fine in its own window. When I embed this in a larger FXML structure and change the data in the PieChart, NPE occurs if there is more than one slice of the pie, apparently because there is no Data item past the first one when running in this larger context. Fixing the error described explicitly above may fix this problem, or it may simply unmask another one. BTW I would be able to give you more information, but there are variables and methods in this class and its superclasses marked private or package, which makes it really-hard-to-impossible to make useful subclasses that might help with debugging.