Adding Interfaces to Orca

Note:

Reviewed for release 2.9.0

See also:

Adding Source Code to Orca.

How to write an interface file

Orca interfaces are written in Slice interface definition language. There are no restrictions on what an Orca interface should or should not contain.

A Slice interface is defined as a set operations. Operations can contain input and output parameters. These parameters can be represented in different ways listed here in order of increasing complexity:

• struct
  • In C++, this becomes a simple structure.
  • Use these unless there is a good reason not to.
• class with member variables only
  • In C++, this becomes a smart pointer to class.
  • Use these if you need inheritance in object definition.
• interface
  • In C++, this becomes a proxy to a remote interface.
  • Use these if you need to return an address of another interface.
• class with member variables and functions
  • Same as class without functions but requires implementing factories.
  • Use these if you need to perform local operations using remote objects.

For more information read the chapter on Slice in the Ice Manual [download]

How to add an interface to the build system

1. Write a Slice file (*.ice) which defines an interface.
   • Slice files are in [ORCA_SRC]/src/interfaces/slice/orca
   • To create a new interface start by copying a similar file.
2. Add the filename of the new file to the list of Slice sources
   • Edit file [ORCA_SRC]/src/interfaces/slice/orca/slice_sources.cmake

Adding support for you interface

Optionally, consider adding support for you interface in libraries and utilities. Library libOrcaObjects has many functions specialized for data objects, e.g. setSane(). The following tools have a plug-in architecture, with a plug-in per interface:

• OrcaView2d
• LogRecorder
• LogPlayer
• Probe
• orca_component_orcamon