fix(cmake): fix installation with cmake --install (lvgl#7161)

Author: etag4048

env_support/cmake/custom.cmake

@@ -99,26 +99,25 @@ if("${INC_INSTALL_DIR}" STREQUAL "")
   set(INC_INSTALL_DIR "include/lvgl")
 endif()
 
-set(CMAKE_INSTALL_PREFIX .)
 
 #Install headers
 install(
   DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src"
-  DESTINATION "${CMAKE_INSTALL_PREFIX}/${INC_INSTALL_DIR}/"
+  DESTINATION "${INC_INSTALL_DIR}"
   FILES_MATCHING
   PATTERN "*.h")
 
 # Install headers from the LVGL_PUBLIC_HEADERS variable
 install(
   FILES ${LVGL_PUBLIC_HEADERS}
-  DESTINATION "${CMAKE_INSTALL_PREFIX}/${INC_INSTALL_DIR}/"
+  DESTINATION "${INC_INSTALL_DIR}/"
 )
 
 # install example headers
 if(NOT LV_CONF_BUILD_DISABLE_EXAMPLES)
   install(
     DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/examples"
-    DESTINATION "${CMAKE_INSTALL_PREFIX}/${INC_INSTALL_DIR}/"
+    DESTINATION "${INC_INSTALL_DIR}"
     FILES_MATCHING
     PATTERN "*.h")
 endif()
@@ -127,7 +126,7 @@ endif()
 if(NOT LV_CONF_BUILD_DISABLE_DEMOS)
   install(
     DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/demos"
-    DESTINATION "${CMAKE_INSTALL_PREFIX}/${INC_INSTALL_DIR}/"
+    DESTINATION "${INC_INSTALL_DIR}"
     FILES_MATCHING
     PATTERN "*.h")
 endif()
@@ -138,17 +137,16 @@ configure_file("${LVGL_ROOT_DIR}/lv_version.h.in" ${CMAKE_CURRENT_BINARY_DIR}/lv
 
 install(
   FILES "${CMAKE_CURRENT_BINARY_DIR}/lvgl.pc"
-  DESTINATION "${LIB_INSTALL_DIR}/pkgconfig/")
+  DESTINATION "share/pkgconfig/")
 
 # Install library
 set_target_properties(
   lvgl
   PROPERTIES OUTPUT_NAME lvgl
              VERSION ${LVGL_VERSION}
              SOVERSION ${LVGL_SOVERSION}
-             ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-             LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-             RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
+             ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
+             LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
              PUBLIC_HEADER "${LVGL_PUBLIC_HEADERS}")
 
 install(
@@ -166,9 +164,8 @@ if(NOT LV_CONF_BUILD_DISABLE_THORVG_INTERNAL)
     PROPERTIES OUTPUT_NAME lvgl_thorvg
                VERSION ${LVGL_VERSION}
                SOVERSION ${LVGL_SOVERSION}
-               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
+               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
+               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
                PUBLIC_HEADER "${LVGL_PUBLIC_HEADERS}")
 
   install(
@@ -186,9 +183,8 @@ if(NOT LV_CONF_BUILD_DISABLE_DEMOS)
     PROPERTIES OUTPUT_NAME lvgl_demos
                VERSION ${LVGL_VERSION}
                SOVERSION ${LVGL_SOVERSION}
-               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
+               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
+               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
                PUBLIC_HEADER "${LVGL_PUBLIC_HEADERS}")
 
   install(
@@ -206,9 +202,8 @@ if(NOT LV_CONF_BUILD_DISABLE_EXAMPLES)
     PROPERTIES OUTPUT_NAME lvgl_examples
                VERSION ${LVGL_VERSION}
                SOVERSION ${LVGL_SOVERSION}
-               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib"
-               RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
+               ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
+               LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib"
                PUBLIC_HEADER "${LVGL_PUBLIC_HEADERS}")
 
   install(