Improve Doxygen support

Except Graphviz's `dot` Doxygen may use few other utilities like
`mscgen` (Message Sequence Chart) and `dia` (Diagram Editor).

Now this module allows to manage Doxygen settings from `CMakeLists.txt`
and forget about `Doxyfile`s. Also it provides a helper function
to add a target to generate documentation: `doxygen_add_docs`.

Implement code review notes:

- Introduce `COMPONENTS` to find: `dot`, `mscgen` and `dia`;
- Deprecate variables `DOXYGEN_SKIP_DOT`, `DOXYGEN_EXECUTABLE`,
  `DOXYGEN_DOT_EXECUTABLE`, `DOXYGEN_DOT_FOUND` in favour of
  `doxygen_add_docs ` usage instead;
- Properly handle paths to found tools in Windows;
- Prevent adding a custom target if Doxygen was not really found;
- Introduce exported (executable) targets for found components.

Co-Author: Craig Scott <craig.scott@crascit.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/Tests/FindDoxygen/CMakeLists.txt b/Tests/FindDoxygen/CMakeLists.txt
new file mode 100644
index 0000000..daceaa3
--- /dev/null
+++ b/Tests/FindDoxygen/CMakeLists.txt
@@ -0,0 +1,20 @@
+add_test(NAME FindDoxygen.SimpleTest COMMAND
+  ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
+  --build-and-test
+  "${CMake_SOURCE_DIR}/Tests/FindDoxygen/SimpleTest"
+  "${CMake_BINARY_DIR}/Tests/FindDoxygen/SimpleTest"
+  --build-target allDocTargets
+  ${build_generator_args}
+  --build-options ${build_options}
+)
+
+if(CMake_TEST_FindDoxygen_Dot)
+  add_test(NAME FindDoxygen.DotComponentTest COMMAND
+    ${CMAKE_CTEST_COMMAND} -C $<CONFIGURATION>
+    --build-and-test
+    "${CMake_SOURCE_DIR}/Tests/FindDoxygen/DotComponentTestTest"
+    "${CMake_BINARY_DIR}/Tests/FindDoxygen/DotComponentTestTest"
+    ${build_generator_args}
+    --build-options ${build_options}
+  )
+endif()