BehaviorTree#10 Export CMake config

- Add cmake export to generate BehaviorTreeConfig.cmake
- Install config cmake file
- Update C++11 by target property

Signed-off-by: Uilian Ries <uilianries@gmail.com>

CMakeLists.txt

@@ -1,13 +1,6 @@
 cmake_minimum_required(VERSION 2.8.12) # version on Ubuntu Trusty
 project(behaviortree_cpp)
 
-if(NOT CMAKE_VERSION VERSION_LESS 3.1)
-    set(CMAKE_CXX_STANDARD 11)
-    set(CMAKE_CXX_STANDARD_REQUIRED ON)
-else()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-endif()
-
 set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 
 
@@ -105,15 +98,31 @@ list(APPEND BT_SOURCE
 set(BEHAVIOR_TREE_LIBRARY ${PROJECT_NAME})
 
 add_library(${BEHAVIOR_TREE_LIBRARY} ${BT_SOURCE} )
-target_link_libraries(${BEHAVIOR_TREE_LIBRARY}  ${BEHAVIOR_TREE_EXTERNAL_LIBRARIES} ${catkin_LIBRARIES})
-target_include_directories(${BEHAVIOR_TREE_LIBRARY} PUBLIC include 3rdparty ${catkin_INCLUDE_DIRS})
+target_link_libraries(${BEHAVIOR_TREE_LIBRARY} PUBLIC ${BEHAVIOR_TREE_EXTERNAL_LIBRARIES} ${catkin_LIBRARIES})
+target_include_directories(${BEHAVIOR_TREE_LIBRARY} PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/3rdparty>
+    $<INSTALL_INTERFACE:3rdparty>
+    ${catkin_INCLUDE_DIRS})
+set_property(TARGET ${BEHAVIOR_TREE_LIBRARY} PROPERTY CXX_STANDARD 11)
+set_property(TARGET ${BEHAVIOR_TREE_LIBRARY} PROPERTY CXX_STANDARD_REQUIRED ON)
 
 if(MSVC)
   target_compile_options(${BEHAVIOR_TREE_LIBRARY} PRIVATE /W4 /WX)
 else()
   target_compile_options(${BEHAVIOR_TREE_LIBRARY} PRIVATE -Wall -Wextra -Werror=return-type)
 endif()
 
+######################################################
+# EXPORTS
+
+set(PROJECT_NAMESPACE BehaviorTree)
+set(PROJECT_CONFIG ${PROJECT_NAMESPACE}Config)
+export(TARGETS ${PROJECT_NAME}
+       NAMESPACE ${PROJECT_NAMESPACE}::
+       FILE "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_CONFIG}.cmake")
+
 ######################################################
 # TESTS
 
@@ -163,6 +172,7 @@ else()
 endif()
 
 INSTALL(TARGETS ${BEHAVIOR_TREE_LIBRARY}
+    EXPORT ${PROJECT_CONFIG}
     ARCHIVE DESTINATION ${BEHAVIOR_TREE_LIB_DESTINATION}
     LIBRARY DESTINATION ${BEHAVIOR_TREE_LIB_DESTINATION}
     )
@@ -171,6 +181,10 @@ INSTALL( DIRECTORY ${CMAKE_SOURCE_DIR}/include/
     DESTINATION ${BEHAVIOR_TREE_INC_DESTINATION}
     FILES_MATCHING PATTERN "*.h*")
 
+install(EXPORT ${PROJECT_CONFIG}
+    DESTINATION "${CMAKE_INSTALL_LIBDIR}/${PROJECT_NAMESPACE}/cmake"
+    NAMESPACE ${PROJECT_NAMESPACE}::)
+
 ######################################################
 # EXAMPLES and TOOLS