CMake: use the CMAKE_FOLDER variable instead of FOLDER property.

It limits the support for CMake 3.12+, but it's much less verbose and I
don't expect people to use ancient CMake versions with IDEs like Xcode
or VS anyway, so this should be fine.

src/Corrade/CMakeLists.txt

@@ -23,9 +23,12 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+# IDE folder in VS, Xcode etc. CMake 3.12+, older versions have only the FOLDER
+# property that would have to be set on each target separately.
+set(CMAKE_FOLDER "Corrade/Python")
+
 if(WITH_PYTHON)
     add_custom_target(CorradePython SOURCES PythonBindings.h)
-    set_target_properties(CorradePython PROPERTIES FOLDER "Corrade/Python")
     install(FILES PythonBindings.h DESTINATION ${CORRADE_INCLUDE_INSTALL_DIR})
 
     add_subdirectory(Containers)

src/Corrade/Containers/CMakeLists.txt

@@ -30,6 +30,5 @@ if(WITH_PYTHON)
         StridedArrayViewPythonBindings.h)
 
     add_custom_target(CorradeContainersPython SOURCES ${CorradeContainersPython_HEADERS})
-    set_target_properties(CorradeContainersPython PROPERTIES FOLDER "Corrade/Python")
     install(FILES ${CorradeContainersPython_HEADERS} DESTINATION ${CORRADE_INCLUDE_INSTALL_DIR}/Containers)
 endif()

src/Magnum/CMakeLists.txt

@@ -23,6 +23,10 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+# IDE folder in VS, Xcode etc. CMake 3.12+, older versions have only the FOLDER
+# property that would have to be set on each target separately.
+set(CMAKE_FOLDER "Magnum/Python")
+
 # Generate version header. If Git is found and this is a Git working copy,
 # extract values from there, otherwise use just MAGNUMBINDINGS_VERSION_YEAR /
 # MONTH that are set in project root CMakeLists.
@@ -55,7 +59,6 @@ install(FILES ${CMAKE_CURRENT_BINARY_DIR}/versionBindings.h DESTINATION ${MAGNUM
 
 if(WITH_PYTHON)
     add_custom_target(MagnumPython SOURCES PythonBindings.h)
-    set_target_properties(MagnumPython PROPERTIES FOLDER "Magnum/Python")
     install(FILES PythonBindings.h DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR})
 endif()
 

src/Magnum/GL/CMakeLists.txt

@@ -25,6 +25,5 @@
 
 if(WITH_PYTHON)
     add_custom_target(MagnumGLPython SOURCES PythonBindings.h)
-    set_target_properties(MagnumGLPython PROPERTIES FOLDER "Magnum/Python")
     install(FILES PythonBindings.h DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR}/GL)
 endif()

src/Magnum/SceneGraph/CMakeLists.txt

@@ -25,6 +25,5 @@
 
 if(WITH_PYTHON)
     add_custom_target(MagnumSceneGraphPython SOURCES PythonBindings.h)
-    set_target_properties(MagnumSceneGraphPython PROPERTIES FOLDER "Magnum/Python")
     install(FILES PythonBindings.h DESTINATION ${MAGNUM_INCLUDE_INSTALL_DIR}/SceneGraph)
 endif()

src/python/corrade/CMakeLists.txt

@@ -23,6 +23,10 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+# IDE folder in VS, Xcode etc. CMake 3.12+, older versions have only the FOLDER
+# property that would have to be set on each target separately.
+set(CMAKE_FOLDER "Corrade/Python")
+
 # *Not* REQUIRED
 find_package(Corrade COMPONENTS
     PluginManager)
@@ -50,7 +54,6 @@ if(NOT CORRADE_BUILD_STATIC)
         Corrade::Containers
         Corrade::Utility)
     set_target_properties(corrade_containers PROPERTIES
-        FOLDER "python/corrade"
         OUTPUT_NAME "containers"
         LIBRARY_OUTPUT_DIRECTORY ${output_dir}/corrade)
 
@@ -62,7 +65,6 @@ if(NOT CORRADE_BUILD_STATIC)
         target_link_libraries(corrade_pluginmanager PRIVATE
             Corrade::PluginManager)
         set_target_properties(corrade_pluginmanager PROPERTIES
-            FOLDER "python/corrade"
             OUTPUT_NAME "pluginmanager"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/corrade)
     endif()
@@ -90,7 +92,6 @@ target_include_directories(corrade PRIVATE
     ${PROJECT_BINARY_DIR}/src/python) # for static build
 target_link_libraries(corrade PRIVATE Corrade::Utility ${corrade_LIBS})
 set_target_properties(corrade PROPERTIES
-    FOLDER "python"
     OUTPUT_NAME "_corrade"
     LIBRARY_OUTPUT_DIRECTORY ${output_dir})
 

src/python/corrade/test/CMakeLists.txt

@@ -23,11 +23,13 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+# IDE folder in VS, Xcode etc. CMake 3.12+, older versions have only the FOLDER
+# property that would have to be set on each target separately.
+set(CMAKE_FOLDER "Corrade/Python/Test")
+
 foreach(_test optional stridedarrayview)
     pybind11_add_module(test_${_test} ${pybind11_add_module_SYSTEM} test_${_test}.cpp)
     target_include_directories(test_${_test} PRIVATE ${PROJECT_SOURCE_DIR}/src)
     target_link_libraries(test_${_test} PRIVATE Corrade::Containers)
-    set_target_properties(test_${_test} PROPERTIES
-        FOLDER "python"
-        LIBRARY_OUTPUT_DIRECTORY ${output_dir})
+    set_target_properties(test_${_test} PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${output_dir})
 endforeach()

src/python/magnum/CMakeLists.txt

@@ -23,6 +23,10 @@
 #   DEALINGS IN THE SOFTWARE.
 #
 
+# IDE folder in VS, Xcode etc. CMake 3.12+, older versions have only the FOLDER
+# property that would have to be set on each target separately.
+set(CMAKE_FOLDER "Magnum/Python")
+
 # *Not* REQUIRED
 find_package(Magnum COMPONENTS
     GL
@@ -89,7 +93,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_gl PRIVATE Magnum::GL)
         set_target_properties(magnum_gl PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "gl"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -99,7 +102,6 @@ if(NOT MAGNUM_BUILD_STATIC)
         target_include_directories(magnum_meshtools PRIVATE ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_meshtools PRIVATE Magnum::MeshTools)
         set_target_properties(magnum_meshtools PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "meshtools"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -109,7 +111,6 @@ if(NOT MAGNUM_BUILD_STATIC)
         target_include_directories(magnum_primitives PRIVATE ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_primitives PRIVATE Magnum::Primitives)
         set_target_properties(magnum_primitives PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "primitives"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -121,7 +122,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_scenegraph PRIVATE Magnum::SceneGraph)
         set_target_properties(magnum_scenegraph PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "scenegraph"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -133,7 +133,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_shaders PRIVATE Magnum::Shaders)
         set_target_properties(magnum_shaders PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "shaders"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -145,7 +144,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src/python)
         target_link_libraries(magnum_trade PRIVATE Magnum::Trade)
         set_target_properties(magnum_trade PROPERTIES
-            FOLDER "python"
             OUTPUT_NAME "trade"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum)
     endif()
@@ -220,7 +218,6 @@ target_include_directories(magnum PRIVATE
     ${PROJECT_BINARY_DIR}/src/python) # for static build
 target_link_libraries(magnum PRIVATE Magnum::Magnum ${magnum_LIBS})
 set_target_properties(magnum PROPERTIES
-    FOLDER "python"
     OUTPUT_NAME "_magnum"
     LIBRARY_OUTPUT_DIRECTORY ${output_dir})
 

src/python/magnum/platform/CMakeLists.txt

@@ -31,7 +31,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src
             ${PROJECT_SOURCE_DIR}/src/python)
         set_target_properties(magnum_platform_glfw PROPERTIES
-            FOLDER "python/platform"
             OUTPUT_NAME "glfw"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum/platform)
     endif()
@@ -43,7 +42,6 @@ if(NOT MAGNUM_BUILD_STATIC)
             ${PROJECT_SOURCE_DIR}/src
             ${PROJECT_SOURCE_DIR}/src/python)
         set_target_properties(magnum_platform_sdl2 PROPERTIES
-            FOLDER "python/platform"
             OUTPUT_NAME "sdl2"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum/platform)
     endif()
@@ -53,7 +51,6 @@ if(NOT MAGNUM_BUILD_STATIC)
         target_link_libraries(magnum_platform_egl PRIVATE Magnum::WindowlessEglApplication)
         target_include_directories(magnum_platform_egl PRIVATE ${PROJECT_SOURCE_DIR}/src/python)
         set_target_properties(magnum_platform_egl PROPERTIES
-            FOLDER "python/platform"
             OUTPUT_NAME "egl"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum/platform)
     endif()
@@ -63,7 +60,6 @@ if(NOT MAGNUM_BUILD_STATIC)
         target_link_libraries(magnum_platform_glx PRIVATE Magnum::WindowlessGlxApplication)
         target_include_directories(magnum_platform_glx PRIVATE ${PROJECT_SOURCE_DIR}/src/python)
         set_target_properties(magnum_platform_glx PROPERTIES
-            FOLDER "python/platform"
             OUTPUT_NAME "glx"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum/platform)
     endif()
@@ -73,7 +69,6 @@ if(NOT MAGNUM_BUILD_STATIC)
         target_link_libraries(magnum_platform_wgl PRIVATE Magnum::WindowlessWglApplication)
         target_include_directories(magnum_platform_wgl PRIVATE ${PROJECT_SOURCE_DIR}/src/python)
         set_target_properties(magnum_platform_wgl PROPERTIES
-            FOLDER "python/platform"
             OUTPUT_NAME "wgl"
             LIBRARY_OUTPUT_DIRECTORY ${output_dir}/magnum/platform)
     endif()