|The SDL Component Suite is an industry leading collection of components supporting scientific and engineering computing. Please visit the SDL Web site for more information....|
|Home ChartPack PolChart Class numbers|
|See also: ClassDefault, ClassVisible, RemoveItemsByClass, MarkAllItems, MarkItemsInWindow|
When handling scientific or technical graphs it is often necessary to treat some of the graphics elements differently from others. This can be easily achieved with TPolChart by assigning a class number to each graphics element which belongs to a certain group. The class number is set to the ClassDefault value when an item is entered into the data container. Selected classes may be "switched on and off" by the array property ClassVisible.
The class numbers can take values between 0 and 254. A value of 255 is reserved as a place holder for all classes. The class numbers can be manipulated by some methods, such as SetItemParams, MarkItemsInWindow, or MarkAllItems.