Meson build: Make it possible to use cairomm as a subproject

cairo and sigc++ can be subprojects of cairomm.

9 files changed, 49 insertions, 14 deletions

diff --git a/Makefile.am b/Makefile.am
index f78ac02..63bf2f1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -50,6 +50,8 @@ EXTRA_DIST = \
   docs/reference/meson.build \
   cairomm/meson.build \
   examples/meson.build \
+  subprojects/cairo.wrap \
+  subprojects/sigc++-3.0.wrap \
   tests/meson.build \
   untracked/README
 
diff --git a/cairomm/meson.build b/cairomm/meson.build
index 1c3304b..488e4fd 100644
--- a/cairomm/meson.build
+++ b/cairomm/meson.build
@@ -2,7 +2,7 @@
 
 # Input: cairomm_build_dep, cairomm_pcname, cairomm_libversion, cairomm_rc,
 #        is_msvc, cairomm_libname, macos_darwin_versions
-# Output: source_h_files, cairomm_dep
+# Output: source_h_files, cairomm_own_dep
 
 # There are no built source files in cairomm.
 
@@ -89,9 +89,9 @@ cairomm_library = library(cairomm_libname,
   install: true,
 )
 
-# This is useful in the main project when cairomm is used as a subproject.
-# It's also used when building example programs and test programs.
-cairomm_dep = declare_dependency(
+# This is used when building example programs and test programs.
+# It's also a part of cairomm_dep, when cairomm is a subproject.
+cairomm_own_dep = declare_dependency(
   link_with: cairomm_library,
   include_directories: extra_include_dirs,
   dependencies: cairomm_build_dep
diff --git a/data/meson.build b/data/meson.build
index 509ed36..90813aa 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -2,7 +2,7 @@
 
 # Input: install_prefix, install_libdir, install_datadir, install_includedir,
 #        install_pkgconfigdir, cairomm_pcname, cairomm_api_version,
-#        cairomm_requires, msvc14x_toolset_ver
+#        cairomm_requires, msvc14x_toolset_ver, cairo_dep
 # Output: -
 
 pkg_conf_data = configuration_data()
@@ -33,6 +33,9 @@ foreach cairomm_mod : ['ft', 'pdf', 'png', 'ps', 'quartz', 'quartz-font',
   # Install the module only if there is a corresponding cairo module.
   if cairo_dep.type_name() == 'pkgconfig'
     do_install = dependency('cairo-' + cairomm_mod, required: false).found()
+  elif cairo_dep.type_name() == 'internal'
+    do_install = dependency('cairo-' + cairomm_mod, fallback: 'cairo',
+                            required: false).found()
   else
     if cairomm_mod == 'png'
       do_install = cpp_compiler.has_function('cairo_surface_write_to_png',
diff --git a/docs/reference/meson.build b/docs/reference/meson.build
index ba8a41a..91bf6e2 100644
--- a/docs/reference/meson.build
+++ b/docs/reference/meson.build
@@ -3,7 +3,7 @@
 # Input: project_build_root, project_source_root, cairomm_pcname,
 #        build_documentation, source_h_files, install_datadir, python3,
 #        doc_reference_py
-# Output: install_docdir, install_devhelpdir, book_name
+# Output: install_docdir, install_devhelpdir, book_name, tag_file
 
 # There are no built source files in cairomm.
 
@@ -16,9 +16,9 @@ docinstall_flags = []
 foreach module : tag_file_modules
   depmod = dependency(module, required: false)
   if depmod.found()
-    doxytagfile = depmod.get_pkgconfig_variable('doxytagfile')
-    htmlrefpub = depmod.get_pkgconfig_variable('htmlrefpub', default: '')
-    htmlrefdir = depmod.get_pkgconfig_variable('htmlrefdir', default: '')
+    doxytagfile = depmod.get_variable(pkgconfig: 'doxytagfile', internal: 'doxytagfile')
+    htmlrefpub = depmod.get_variable(pkgconfig: 'htmlrefpub', internal: 'htmlrefpub', default_value: '')
+    htmlrefdir = depmod.get_variable(pkgconfig: 'htmlrefdir', internal: 'htmlrefdir', default_value: '')
     if htmlrefpub == ''
       htmlrefpub = htmlrefdir
     elif htmlrefdir == ''
diff --git a/examples/meson.build b/examples/meson.build
index 1f60aea..c383432 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -1,6 +1,6 @@
 # examples
 
-# input: cairomm_dep, build_examples
+# input: cairomm_own_dep, build_examples
 
 examples = [
 # [[dir-name], exe-name, [sources]]
@@ -26,7 +26,7 @@ foreach ex : examples
 
   executable(ex_name, ex_sources,
     cpp_args: '-DCAIROMM_DISABLE_DEPRECATED',
-    dependencies: cairomm_dep,
+    dependencies: cairomm_own_dep,
     gui_app: false,
     build_by_default: build_examples
   )
diff --git a/meson.build b/meson.build
index 5b25206..66d10c7 100644
--- a/meson.build
+++ b/meson.build
@@ -6,7 +6,8 @@ project('cairomm', 'cpp',
   default_options: [
     'cpp_std=c++17',
   ],
-  meson_version: '>= 0.50.0', # required for python3.path()
+  meson_version: '>= 0.54.0', # required for meson.override_dependency()
+                              # and dep.get_variable(internal:)
 )
 
 cairomm_api_version = '1.16'
@@ -283,6 +284,19 @@ if not meson.is_subproject()
     'untracked' / 'build_scripts',
     dont_distribute,
   )
+else
+  # This is a subproject.
+  cairomm_dep = declare_dependency(
+    dependencies: cairomm_own_dep,
+    variables: {
+      'doxytagfile': tag_file.full_path(),
+      'htmlrefdir': install_prefix / install_docdir / 'reference' / 'html',
+      'htmlrefpub': 'http://www.cairographics.org/documentation/cairomm/reference'
+    }
+  )
+
+  # A main project that looks for cairomm_pcname.pc shall find cairomm_dep.
+  meson.override_dependency(cairomm_pcname, cairomm_dep)
 endif
 
 # Print a summary.
diff --git a/subprojects/cairo.wrap b/subprojects/cairo.wrap
new file mode 100644
index 0000000..954daa3
--- /dev/null
+++ b/subprojects/cairo.wrap
@@ -0,0 +1,8 @@
+[wrap-git]
+directory=cairo
+url=https://gitlab.freedesktop.org/cairo/cairo.git
+revision=master
+depth=1
+
+[provide]
+dependency_names = cairo
diff --git a/subprojects/sigc++-3.0.wrap b/subprojects/sigc++-3.0.wrap
new file mode 100644
index 0000000..8d8c543
--- /dev/null
+++ b/subprojects/sigc++-3.0.wrap
@@ -0,0 +1,8 @@
+[wrap-git]
+directory=libsigcplusplus
+url=https://github.com/libsigcplusplus/libsigcplusplus.git
+revision=master
+depth=1
+
+[provide]
+dependency_names = sigc++-3.0
diff --git a/tests/meson.build b/tests/meson.build
index 530eb73..9aa6742 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -1,6 +1,6 @@
 # tests
 
-# input: cairomm_dep, build_tests, can_test, test_dep, USE_SHARED_BOOST
+# input: cairomm_own_dep, build_tests, can_test, test_dep, USE_SHARED_BOOST
 
 cairomm_tests_extra_cppargs = []
 if USE_SHARED_BOOST
@@ -34,7 +34,7 @@ if can_test
     boost_test_modname_flag = [ '-DBOOST_TEST_MODULE=@0@'.format(ex[1]) ]
     exe_file = executable(ex_name, ex_sources,
       cpp_args: ex[3] + boost_test_modname_flag + cairomm_tests_extra_cppargs,
-      dependencies: [cairomm_dep, test_dep],
+      dependencies: [cairomm_own_dep, test_dep],
       gui_app: false,
       build_by_default: build_tests,
     )