Fix version detection in Findhidapi.cmake (#4215)

* Findhidapi.cmake: Fix detection of Version 0 digits

Co-authored-by: Be-ing <be@mixxx.org>

* Improve messages when linking hidapi

* Remove unreachable error message

* Introduced a MINIMUM_hidapi_VERSION variable to avoid repeat the version number literaly

* Make use of FindPackageHandleStandardArgs() to format user message

Co-authored-by: Be-ing <be@mixxx.org>

CMakeLists.txt

@@ -2605,9 +2605,8 @@ find_package(LibUSB)
 # USB HID controller support
 option(HID "USB HID controller support" ON)
 if(HID)
-  find_package(hidapi)
-  # hidapi_VERSION is only available starting with 0.10.0
-  if(NOT hidapi_FOUND OR NOT hidapi_VERSION OR hidapi_VERSION VERSION_LESS 0.10.1)
+  find_package(hidapi 0.10.1)
+  if(NOT hidapi_FOUND)
     message(STATUS "Linking internal libhidapi statically")
     add_library(mixxx-hidapi STATIC EXCLUDE_FROM_ALL)
     target_include_directories(mixxx-hidapi SYSTEM PUBLIC lib/hidapi/hidapi)
@@ -2630,10 +2629,6 @@ if(HID)
     endif()
     target_link_libraries(mixxx-lib PRIVATE mixxx-hidapi)
   else()
-    message(STATUS "Linking libhidapi dynamically")
-    if(NOT HIDAPI_FOUND)
-      message(FATAL_ERROR "USB HID controller support requires libhidapi-libusb and its development headers.")
-    endif()
     target_link_libraries(mixxx-lib PRIVATE hidapi::hidapi)
   endif()
   target_sources(mixxx-lib PRIVATE

cmake/modules/Findhidapi.cmake

@@ -62,29 +62,36 @@ find_library(hidapi_LIBRARY
 )
 mark_as_advanced(hidapi_LIBRARY)
 
+
+# Version detection
+if(DEFINED PC_hidapi_VERSION)
+  set(hidapi_VERSION "${PC_hidapi_VERSION}")
+else()
+  if (EXISTS "${hidapi_INCLUDE_DIR}/hidapi.h")
+      file(READ "${hidapi_INCLUDE_DIR}/hidapi.h" hidapi_H_CONTENTS)
+      string(REGEX MATCH "#define HID_API_VERSION_MAJOR ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
+      set(hidapi_VERSION_MAJOR "${CMAKE_MATCH_1}")
+      string(REGEX MATCH "#define HID_API_VERSION_MINOR ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
+      set(hidapi_VERSION_MINOR "${CMAKE_MATCH_1}")
+      string(REGEX MATCH "#define HID_API_VERSION_PATCH ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
+      set(hidapi_VERSION_PATCH "${CMAKE_MATCH_1}")
+      # hidapi_VERSION is only available starting with 0.10.0
+      # Simply using if(NOT) does not work because 0 is a valid value, so compare to empty string.
+    if (NOT hidapi_VERSION_MAJOR STREQUAL "" AND
+        NOT hidapi_VERSION_MINOR STREQUAL "" AND
+        NOT hidapi_VERSION_PATCH STREQUAL "")
+        set(hidapi_VERSION "${hidapi_VERSION_MAJOR}.${hidapi_VERSION_MINOR}.${hidapi_VERSION_PATCH}")
+      endif()
+  endif()
+endif ()
+
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(
   hidapi
-  DEFAULT_MSG
-  hidapi_LIBRARY
-  hidapi_INCLUDE_DIR
+  REQUIRED_VARS hidapi_LIBRARY hidapi_INCLUDE_DIR
+  VERSION_VAR hidapi_VERSION
 )
 
-# Version detection
-if (EXISTS "${hidapi_INCLUDE_DIR}/hidapi.h")
-    file(READ "${hidapi_INCLUDE_DIR}/hidapi.h" hidapi_H_CONTENTS)
-    string(REGEX MATCH "#define HID_API_VERSION_MAJOR ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
-    set(hidapi_VERSION_MAJOR "${CMAKE_MATCH_1}")
-    string(REGEX MATCH "#define HID_API_VERSION_MINOR ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
-    set(hidapi_VERSION_MINOR "${CMAKE_MATCH_1}")
-    string(REGEX MATCH "#define HID_API_VERSION_PATCH ([0-9]+)" _dummy "${hidapi_H_CONTENTS}")
-    set(hidapi_VERSION_PATCH "${CMAKE_MATCH_1}")
-    # hidapi_VERSION is only available starting with 0.10.0
-    if (hidapi_VERSION_MAJOR AND hidapi_VERSION_MINOR AND hidapi_VERSION_PATCH)
-      set(hidapi_VERSION "${hidapi_VERSION_MAJOR}.${hidapi_VERSION_MINOR}.${hidapi_VERSION_PATCH}")
-    endif()
-endif ()
-
 if(hidapi_FOUND)
   set(hidapi_LIBRARIES "${hidapi_LIBRARY}")
   set(hidapi_INCLUDE_DIRS "${hidapi_INCLUDE_DIR}")