Definition
The display context is a class containing general visualization attributes.
Use
As with other attribute bundles the application can create an instance of the class, a customizing bundle. The application can assign this customizing bundle to a port in the graphics proxy.
You can use the display context in one of two ways:
The display context can be used for different purposes with different classes. For example, it could be used to set the color of the title for the drawing area and the line attributes for gridlines.
Example
The attribute bundle CL_CU_DRAWING_AREA has the contexts CO_DISPLAY_CONTEXT, CO_TITLE_CONTEXT and CO_LEGEND_CONTEXT each of which contains a subset of the attributes in CL_CU_DISPLAY_CONTEXT.
Structure
The display context contains six types of attribute:
Border
Line
Area
Text
Marker
Miscellaneous
Integration
Those attributes (in customizing bundles) with the suffix _CONTEXT refer to the display context.
The application does not have to save the display context separately because it is saved along with the customizing bundle that contains it. It is also loaded along with the customizing bundle that contains it.
The display context is copied, not referenced, so changing an attribute in CL_CU_DISPLAY_CONTEXT does not automatically change the customizing objects that have already been instantiated.
Just as there is a hierarchy of ports so too there is a hierarchy of display contexts. For more information, see
Hierarchy of Display Contexts.