View source for Simple template for libraries in contrib

<big>'''These instructions only apply to YARP > 2.3.23 and iCub > 1.1.13 software versions'''</big>

''See [[Simple template for libraries in contrib old]] for older instructions''

CMake code for a library in contrib is quite similar to that required for modules.

 cmake_minimum_required(VERSION 2.8.7)
 
 project(mylibrary)

 #find packages, examples YARP and/or ICUB
 find_package(YARP REQUIRED)
 find_package(ICUB REQUIRED)
 find_package(ICUBcontrib REQUIRED)
  
 #optionally: use cmake find scripts provided by YARP and iCub
 list(APPEND CMAKE_MODULE_PATH ${YARP_MODULE_PATH} ${ICUB_MODULE_PATH} ${ICUBCONTRIB_MODULE_PATH})

 include(ICUBcontribHelpers)
 icubcontrib_set_default_prefix() #set CMAKE_INSTALL_PREFIX to the ICUBcontrib one; print warning if user modifies it

 ## useful options (i.e., rpath settings and name of debug libraries on msvc)
 include(ICUBcontribOptions)

 #find packages
 find_package(GSL)
 find_package(OpenCV)
 
 include_directories(${YARP_INCLUDE_DIRS})
 include_directories(${ICUB_INCLUDE_DIRS})

 include_directories(${GSL_INCLUDE_DIRS})
 include_directories(${OpenCV_INCLUDE_DIRS})

 set(folder_source src/file1.cpp src/file2.cpp)
 set(folder_header include/iCub/file1.h include/iCub/file2.h)
 
 # add local directory and other (optional) packages to to search path for 
 # header files 
 include_directories(${PROJECT_SOURCE_DIR}/include)
 
 source_group("Source Files" FILES ${folder_source})
 source_group("Header Files" FILES ${folder_header})
 
 add_library(${PROJECT_NAME} ${folder_source} ${folder_header})

 #link other packages, this is required to let cmake know dependencies
 #your code will compile without this, but you can have problems linking agains
 #your lib in modules using it
 target_link_libraries(${PROJECT_NAME} ${YARP_LIBRARIES} ${OpenCV_LIBRARIES} ${GSL_LIBRARIES})

if you want to link all the libraries in iCub, you can rely on the ICUB_LIBRARIES variable:

 #link against all libraries in the iCub build
 set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${ICUB_LINK_FLAGS}")	
 target_link_libraries(${PROJECT_NAME} ${ICUB_LIBRARIES})

but you might prefer to just link the one you actually need:

  #link against single libraries in the iCub package
  #Important: notice that we use the name of the project
  target_link_libraries(${PROJECT_NAME} ctrlLib)

Now, if you want your library to be imported by 3rd-party projects through CMake, you can export it with the
icubcontrib_export_library(...) macro. The paradigm is the same as for the [[ Better_Repository#Writing_a_library | icub_export_library(...) macro in the "main" iCub repository ]].
Example:
  icubcontrib_export_library(${PROJECT_NAME} INTERNAL_INCLUDE_DIRS ${PROJECT_SOURCE_DIR}/include 
                      EXTERNAL_INCLUDE_DIRS ${YARP_INCLUDE_DIRS}  # only list directory for headers that are included by the header files of the library you are exporting
                      DESTINATION include/iCub
                      FILES f${foler_header})

You can export multiple libraries within the same source tree, calling the icubcontrib_export_library(...) macro for each of them. In order to be able to all the libraries as a single package, you need to call then the icubcontrib_finalize_export(<packagename>) macro:
  icubcontrib_finalize_export(mylibraries).

This allows 3rd-party projects to find and use your library like this:
  find_package(mylibraries)
  include_directories(${mylibraries_INCLUDE_DIRS})
  ...
  target_link_libraries(my3dpartyproj mylibrary)

Note that:
* you need to call the icubcontrib_finalize_export macro even if you are only exporting one library (<packagename> can be the same as the library name)
* for 3d-party projects to be able to find your exported library, its exported configuration files should be in the CMake search list; if users do not install icub-contrib libraries to default system directories, they are advised to set the CMAKE_PREFIX_PATH environment variable to point to the ICUBcontrib installation path (see the Setup ICUBcontrib sections in the [[ ICub_Software_Installation | installation instructions]]).