Add support to build using cmake config files installed by libzip

Add support to build using cmake config files installed by libzip.
Add and option that controls if config mode is to be used,
this is on per default on non windows systems.
The package name used by libzip is libzip not LIBZIP so add
a variable that holds this and use it where needed in
CMakeLists.txt and Config.cmake.in.
FindLIBZIP.cmake is unneeded in config mode so don't install
it if config mode is used.
This commit also includes changes due to line endings.
This the editor that saves in \n instead of \r\n.

Author: niclasr

CMakeLists.txt

@@ -23,21 +23,31 @@ if(NOT WIN32)
   set(CMAKE_CXX_FLAGS "-W -Wall -Wextra -ansi -pedantic -std=c++11")
   set(CMAKE_CXX_FLAGS_DEBUG "-g")
   set(CMAKE_CXX_FLAGS_RELEASE "-O3")
+  set(NOTWIN32 ON)
 endif()
 
 option(LIBZIPPP_INSTALL "Install library" ${is_root_project})
 option(LIBZIPPP_INSTALL_HEADERS "Install the headers" ${is_root_project})
 option(LIBZIPPP_BUILD_TESTS "Build unit tests" ${is_root_project})
 option(LIBZIPPP_ENABLE_ENCRYPTION "Build with encryption enabled" OFF)
+option(LIBZIPPP_CMAKE_CONFIG_MODE "Build with libzip installed cmake config files" ${NOTWIN32})
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
-find_package(LIBZIP MODULE REQUIRED)
+if(LIBZIPPP_CMAKE_CONFIG_MODE)
+  set(LIBZIP_PKGNAME "libzip")
+  set(fp_mode "CONFIG")
+else()
+  set(LIBZIP_PKGNAME "LIBZIP")
+  set(fp_mode "MODULE")
+endif()
+
+find_package(${LIBZIP_PKGNAME} ${fp_mode} REQUIRED)
 
 add_library(libzippp "src/libzippp.cpp")
 add_library(libzippp::libzippp ALIAS libzippp) # Convenience alias
-target_include_directories(libzippp 
-  PUBLIC  
+target_include_directories(libzippp
+  PUBLIC
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
     $<INSTALL_INTERFACE:include/libzippp>
 )
@@ -61,7 +71,7 @@ if(LIBZIPPP_BUILD_TESTS)
   add_executable(libzippp_test "tests/tests.cpp")
   target_link_libraries(libzippp_test PRIVATE libzippp)
   add_test(NAME libzippp_tests COMMAND libzippp_test)
-  
+
   if (BUILD_SHARED_LIBS)
     set_target_properties(libzippp_test PROPERTIES OUTPUT_NAME "libzippp_shared_test")
   else()
@@ -71,11 +81,11 @@ endif()
 
 if(LIBZIPPP_INSTALL)
   install(
-    TARGETS libzippp 
+    TARGETS libzippp
     EXPORT libzipppTargets
     LIBRARY DESTINATION lib
-    ARCHIVE DESTINATION lib 
-    RUNTIME DESTINATION bin 
+    ARCHIVE DESTINATION lib
+    RUNTIME DESTINATION bin
   )
 
   if(LIBZIPPP_INSTALL_HEADERS)
@@ -91,10 +101,10 @@ if(LIBZIPPP_INSTALL)
   else()
     set(configInstallDestination share/${PROJECT_NAME})
   endif()
-  
+
   configure_package_config_file(
-    "Config.cmake.in" 
-    ${PROJECT_CONFIG_FILE} 
+    "Config.cmake.in"
+    ${PROJECT_CONFIG_FILE}
     INSTALL_DESTINATION ${configInstallDestination}
   )
   write_basic_package_version_file(
@@ -103,7 +113,8 @@ if(LIBZIPPP_INSTALL)
   )
 
   install(
-    FILES ${PROJECT_CONFIG_FILE} ${PROJECT_VERSION_FILE} cmake/FindLIBZIP.cmake
+    FILES ${PROJECT_CONFIG_FILE} ${PROJECT_VERSION_FILE}
+    $<$<NOT:$<BOOL:"${LIBZIPPP_CMAKE_CONFIG_MODE}">>:cmake/FindLIBZIP.cmake>
     DESTINATION ${configInstallDestination}
   )
 

Config.cmake.in

@@ -1,10 +1,10 @@
 @PACKAGE_INIT@
 
-find_package(LIBZIP QUIET)
-if(NOT LIBZIP_FOUND)
+find_package(@LIBZIP_PKGNAME@ QUIET)
+if(NOT @LIBZIP_PKGNAME@_FOUND)
     list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
     include(CMakeFindDependencyMacro)
-    find_dependency(LIBZIP REQUIRED)
+    find_dependency(@LIBZIP_PKGNAME@ REQUIRED)
 endif()
 
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")