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Documentation for the Ev3Wrap library

If you have not read the first part, go read that first.

This page continues exploring the library’s CMake structure, in particular everything in the examples folder(s)

The CMakeLists.txt file in the examples folder: 

include_directories(
    ${PROJECT_SOURCE_DIR}/lib/
    ${PROJECT_SOURCE_DIR}/lib/blockable/
    ${PROJECT_SOURCE_DIR}/lib/button/
    ${PROJECT_SOURCE_DIR}/lib/color/
    ${PROJECT_SOURCE_DIR}/lib/compass/
    ${PROJECT_SOURCE_DIR}/lib/gyro/
    ${PROJECT_SOURCE_DIR}/lib/irseeker/
    ${PROJECT_SOURCE_DIR}/lib/motor/
    ${PROJECT_SOURCE_DIR}/lib/motorpair/
    ${PROJECT_SOURCE_DIR}/lib/omnirobot/
    ${PROJECT_SOURCE_DIR}/lib/touch/
    ${PROJECT_SOURCE_DIR}/lib/ultrasonic/
    ${PROJECT_SOURCE_DIR}/lib/utilities/
)

This tells the examples where to find the library source files, more importantly, where to find the headers.

add_subdirectory(spin_a_motor)
add_subdirectory(move_until_distance)
add_subdirectory(compass_calibration)
add_subdirectory(ir_source_facer)
add_subdirectory(press_n_spin)

Add each of the example folders. Each example folder contains 1 example (1 executable), and 1 CMakeLists.txt file for managing its build process.

Every CMakeLists.txt file in the individual example folders all follow the same template, with only a different project name.

The template for each CMakeLists.txt file in the example subfolders 

project(PROJECT_NAME_HERE VERSION 1.0)

declares the project. Note that every example has a different PROJECT_NAME_HERE

add_executable(
    ${PROJECT_NAME}
    ${PROJECT_NAME}.cpp
)

Add the example .cpp file to the project. (build an executable)

target_link_libraries(
    ${PROJECT_NAME}
    PRIVATE
    ${LIBNAME}
)

Link the library to the example executable. Here, ${LIBNAME} is the name of the library. (refer to the previous page) for more details

set_target_properties(
    ${PROJECT_NAME}
    PROPERTIES
    OUTPUT_NAME ${PROJECT_NAME}.elf
)

Set the executable’s output file name

add_dependencies(${EVERYTHING_BUILT_TARGET} ${PROJECT_NAME})
add_custom_target(
    ${PROJECT_NAME}_TARGET ALL
)
add_dependencies(${PROJECT_NAME}_TARGET ${EVERYTHING_BUILT_TARGET})

Make the EVERYTHING_BUILT_TARGET target depend on this project (be built after this project). Make a new target named ${PROJECT_NAME}_TARGET, then make it so that the ${PROJECT_NAME}_TARGET target depend on the EVERYTHING_BUILT_TARGET target.

This means the ${PROJECT_NAME}_TARGET will be finished once everything else is finished

add_custom_command(
    TARGET ${PROJECT_NAME}_TARGET POST_BUILD
    COMMAND sudo mkdir -p ${WRAPPER_BIN_EXAMPLES_DIR}/${PROJECT_NAME}/
    COMMAND sudo cp ${WRAPPER_BIN_DIR}/examples/${PROJECT_NAME}/${PROJECT_NAME}.elf ${WRAPPER_BIN_EXAMPLES_DIR}/${PROJECT_NAME}/${PROJECT_NAME}.elf
    COMMAND sudo bash ${WRAPPER_SCRIPTS_DIR}/post_build.sh ${PROJECT_NAME} 500 ${WRAPPER_BIN_EXAMPLES_DIR}/${PROJECT_NAME}/${PROJECT_NAME}.elf 50
    USES_TERMINAL
)

Copy the built binary to the correct folder, then run post_build.sh to check its size once ${PROJECT_NAME}_TARGET is finished.

variables used here such as ${WRAPPER_BIN_EXAMPLES_DIR} are defined in higher up CMakeLists.txt files.

add_dependencies(${LIB_BUILT_TARGET} ${PROJECT_NAME}_TARGET)

Ensure that LIB_BUILT_TARGET finishes after this example has been built.