cmake: add 'libdecoration' as external project

CMakeLists.txt

@@ -36,6 +36,8 @@ cmake_dependent_option(GLFW_USE_WAYLAND "Use Wayland for window creation" OFF
                        "UNIX;NOT APPLE" OFF)
 cmake_dependent_option(USE_MSVC_RUNTIME_LIBRARY_DLL "Use MSVC runtime library DLL" ON
                        "MSVC" OFF)
+cmake_dependent_option(GLFW_USE_LIBDECORATION "use libdecoration" ON
+                       "GLFW_USE_WAYLAND" OFF)
 
 if (BUILD_SHARED_LIBS AND UNIX)
     # On Unix-like systems, shared libraries can use the soname system.
@@ -55,6 +57,8 @@ endif()
 
 list(APPEND CMAKE_MODULE_PATH "${GLFW_SOURCE_DIR}/CMake/modules")
 
+include(ExternalProject)
+
 find_package(Threads REQUIRED)
 
 if (GLFW_BUILD_DOCS)

external/libdecoration.cmake

@@ -0,0 +1,13 @@
+ExternalProject_Add(libdecoration
+    GIT_REPOSITORY https://gitlab.gnome.org/jadahl/libdecoration.git
+    GIT_TAG master
+    PREFIX "${CMAKE_CURRENT_BINARY_DIR}/extern/libdecoration"
+    CONFIGURE_COMMAND meson --prefix "${CMAKE_CURRENT_BINARY_DIR}/install" --libdir "lib" ../libdecoration
+    BUILD_COMMAND ninja
+    INSTALL_COMMAND ninja install
+)
+
+target_include_directories(glfw PRIVATE "${CMAKE_CURRENT_BINARY_DIR}/install/include")
+target_link_libraries(glfw PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/install/lib/libdecoration${CMAKE_SHARED_LIBRARY_SUFFIX})
+
+add_dependencies(glfw libdecoration)

src/CMakeLists.txt

@@ -70,6 +70,11 @@ if (_GLFW_WAYLAND)
         "${WAYLAND_PROTOCOLS_PKGDATADIR}/unstable/idle-inhibit/idle-inhibit-unstable-v1.xml"
         BASENAME idle-inhibit-unstable-v1)
     target_sources(glfw PRIVATE ${GLFW_WAYLAND_PROTOCOL_SOURCES})
+
+    if (GLFW_USE_LIBDECORATION)
+        include("${CMAKE_SOURCE_DIR}/external/libdecoration.cmake")
+        add_definitions(-DWITH_DECORATION)
+    endif()
 endif()
 
 if (WIN32 AND BUILD_SHARED_LIBS)