likscan: Prefer pkg-config for libsane detection

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>

libkscan/ConfigureChecks.cmake

@@ -9,46 +9,54 @@
 #
 #################################################
 
-if( NOT HAVE_SANE )
-  message( STATUS "checking for 'sane'..." )
+if( NOT SANE_FOUND )
+  pkg_search_module( SANE sane-backends )
 endif( )
 
-# find sane-config
-find_program( SANE_EXECUTABLE NAMES sane-config )
-if( NOT SANE_EXECUTABLE )
-  tde_message_fatal( "sane-config is NOT found.\n sane library is installed?" )
-endif( )
+if( NOT SANE_FOUND )
+  message( STATUS "checking for 'sane'..." )
 
-macro( __run_sane_config  __type __var )
-  execute_process(
-    COMMAND ${SANE_EXECUTABLE} --${__type}
-    OUTPUT_VARIABLE ${__var}
-    RESULT_VARIABLE __result
-    OUTPUT_STRIP_TRAILING_WHITESPACE )
-  if( _result )
-    tde_message_fatal( "Unable to run ${SANE_EXECUTABLE}!\n sane library is correctly installed?\n Path to sane-config is corect?" )
+  # find sane-config
+  find_program( SANE_EXECUTABLE NAMES sane-config )
+  if( NOT SANE_EXECUTABLE )
+    tde_message_fatal( "sane-config is NOT found.\n sane library is installed?" )
   endif( )
-endmacro( )
 
-__run_sane_config( version SANE_VERSION )
-__run_sane_config( cflags SANE_INCLUDE_DIRS )
-__run_sane_config( libs SANE_LIBRARIES )
+  macro( __run_sane_config  __type __var )
+    execute_process(
+      COMMAND ${SANE_EXECUTABLE} --${__type}
+      OUTPUT_VARIABLE ${__var}
+      RESULT_VARIABLE __result
+      OUTPUT_STRIP_TRAILING_WHITESPACE )
+    if( _result )
+      tde_message_fatal( "Unable to run ${SANE_EXECUTABLE}!\n sane library is correctly installed?\n Path to sane-config is corect?" )
+    endif( )
+  endmacro( )
 
-# cleanup
-if( SANE_INCLUDE_DIRS )
-  string( REGEX REPLACE "(^| )-I" ";" SANE_INCLUDE_DIRS "${SANE_INCLUDE_DIRS}" )
-endif( )
-if( SANE_LIBRARIES )
-  ## remove all spaces and replace whitespace with ';'
-  string( REGEX REPLACE "[ ]+" ";" SANE_LIBRARIES "${SANE_LIBRARIES}" )
-  ## remove all non-library information
-  string( REGEX REPLACE ";[-][^l]([^ ;])+" "" SANE_LIBRARIES "${SANE_LIBRARIES}" )
-  ## remove multiple ';'
-  string( REGEX REPLACE "[;]+" ";" SANE_LIBRARIES "${SANE_LIBRARIES}" )
-  ## remove '-l'
-  string( REGEX REPLACE "-l" "" SANE_LIBRARIES "${SANE_LIBRARIES}" )
-endif( )
+  __run_sane_config( version SANE_VERSION )
+  __run_sane_config( cflags SANE_INCLUDE_DIRS )
+  __run_sane_config( libs SANE_LIBRARIES )
 
-if( NOT HAVE_SANE )
+  # cleanup
+  if( SANE_INCLUDE_DIRS )
+    string( REGEX REPLACE "(^| )-I" ";" SANE_INCLUDE_DIRS "${SANE_INCLUDE_DIRS}" )
+  else( )
+    set( SANE_INCLUDE_DIRS "/usr/include" )
+  endif( )
+  if( SANE_LIBRARIES )
+    ## remove all spaces and replace whitespace with ';'
+    string( REGEX REPLACE "[ ]+" ";" SANE_LIBRARIES "${SANE_LIBRARIES}" )
+    ## remove all non-library information
+    string( REGEX REPLACE ";[-][^l]([^ ;])+" "" SANE_LIBRARIES "${SANE_LIBRARIES}" )
+    ## remove multiple ';'
+    string( REGEX REPLACE "[;]+" ";" SANE_LIBRARIES "${SANE_LIBRARIES}" )
+    ## remove '-l'
+    string( REGEX REPLACE "-l" "" SANE_LIBRARIES "${SANE_LIBRARIES}" )
+  endif( )
   message( STATUS "  found 'sane', version ${SANE_VERSION}" )
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args( SANE DEFAULT_MSG
+                                     SANE_LIBRARIES
+                                     SANE_INCLUDE_DIRS )
 endif( )