Modernize FindITK module (#11494)

Use the Config mode of find_package to search for ITKConfig.  This makes
FindITK a thin-wrapper around a standard find_package, bringing benefits
like searching lib64 paths when appropriate.  This does for FindITK what
commit 2c1a01dc (Modernize FindVTK module, 2009-10-07) did for FindVTK.

1 files changed, 17 insertions, 61 deletions

diff --git a/Modules/FindITK.cmake b/Modules/FindITK.cmake
index 244ce54..5f43dd9 100644
--- a/Modules/FindITK.cmake
+++ b/Modules/FindITK.cmake
@@ -21,7 +21,7 @@
 #                 instead.
 
 #=============================================================================
-# Copyright 2001-2009 Kitware, Inc.
+# Copyright 2001-2010 Kitware, Inc.
 #
 # Distributed under the OSI-approved BSD License (the "License");
 # see accompanying file Copyright.txt for details.
@@ -33,67 +33,23 @@
 # (To distribute this file outside of CMake, substitute the full
 #  License text for the above reference.)
 
-SET(ITK_DIR_STRING "directory containing ITKConfig.cmake.  This is either the root of the build tree, or PREFIX/lib/InsightToolkit for an installation.")
+# Use the Config mode of the find_package() command to find ITKConfig.
+# If this succeeds (possibly because ITK_DIR is already set), the
+# command will have already loaded ITKConfig.cmake and set ITK_FOUND.
+IF(NOT ITK_FOUND)
+  FIND_PACKAGE(ITK QUIET NO_MODULE
+    NAMES ITK InsightToolkit
+    CONFIGS ITKConfig.cmake
+    )
+ENDIF()
 
-# Search only if the location is not already known.
-IF(NOT ITK_DIR)
-  # Get the system search path as a list.
-  IF(UNIX)
-    STRING(REGEX MATCHALL "[^:]+" ITK_DIR_SEARCH1 "$ENV{PATH}")
-  ELSE(UNIX)
-    STRING(REGEX REPLACE "\\\\" "/" ITK_DIR_SEARCH1 "$ENV{PATH}")
-  ENDIF(UNIX)
-  STRING(REGEX REPLACE "/;" ";" ITK_DIR_SEARCH2 ${ITK_DIR_SEARCH1})
-
-  # Construct a set of paths relative to the system search path.
-  SET(ITK_DIR_SEARCH "")
-  FOREACH(dir ${ITK_DIR_SEARCH2})
-    SET(ITK_DIR_SEARCH ${ITK_DIR_SEARCH} "${dir}/../lib/InsightToolkit")
-  ENDFOREACH(dir)
-
-  #
-  # Look for an installation or build tree.
-  #
-  FIND_PATH(ITK_DIR ITKConfig.cmake
-    # Look for an environment variable ITK_DIR.
-    $ENV{ITK_DIR}
-
-    # Look in places relative to the system executable search path.
-    ${ITK_DIR_SEARCH}
-
-    # Look in standard UNIX install locations.
-    /usr/local/lib/InsightToolkit
-    /usr/lib/InsightToolkit
-
-    # Read from the CMakeSetup registry entries.  It is likely that
-    # ITK will have been recently built.
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild1]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild2]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild3]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild4]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild5]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild6]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild7]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild8]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild9]
-    [HKEY_CURRENT_USER\\Software\\Kitware\\CMakeSetup\\Settings\\StartPath;WhereBuild10]
-
-    # Help the user find it if we cannot.
-    DOC "The ${ITK_DIR_STRING}"
-  )
-ENDIF(NOT ITK_DIR)
-
-# If ITK was found, load the configuration file to get the rest of the
-# settings.
-IF(ITK_DIR)
-  SET(ITK_FOUND 1)
-  INCLUDE(${ITK_DIR}/ITKConfig.cmake)
+SET(ITK_DIR_MESSAGE "Please set ITK_DIR to the directory containing ITKConfig.cmake.  This is either the root of the build tree, or PREFIX/lib/InsightToolkit for an installation.")
 
+IF(ITK_FOUND)
   # Set USE_ITK_FILE for backward-compatability.
   SET(USE_ITK_FILE ${ITK_USE_FILE})
-ELSE(ITK_DIR)
-  SET(ITK_FOUND 0)
-  IF(ITK_FIND_REQUIRED)
-    MESSAGE(FATAL_ERROR "Please set ITK_DIR to the ${ITK_DIR_STRING}")
-  ENDIF(ITK_FIND_REQUIRED)
-ENDIF(ITK_DIR)
+ELSEIF(ITK_FIND_REQUIRED)
+  MESSAGE(FATAL_ERROR ${ITK_DIR_MESSAGE})
+ELSEIF(NOT ITK_FIND_QUIETLY)
+  MESSAGE(STATUS ${ITK_DIR_MESSAGE})
+ENDIF()