Linux/Wayland new feature: Accept native parent window handle

.github/workflows/cmake.yml

@@ -37,14 +37,15 @@ jobs:
 
   build-ubuntu:
 
-    name: Ubuntu ${{ matrix.os.name }} - ${{ matrix.compiler.name }}, ${{ matrix.portal.name }}, ${{ matrix.autoappend.name }}, ${{ matrix.casesensitive.name }}, ${{ matrix.shared_lib.name }}, C++${{ matrix.cppstd }}
+    name: Ubuntu ${{ matrix.os.name }} - ${{ matrix.compiler.name }}, ${{ matrix.portal.name }}, ${{ matrix.wayland.name }}, ${{ matrix.autoappend.name }}, ${{ matrix.casesensitive.name }}, ${{ matrix.shared_lib.name }}, C++${{ matrix.cppstd }}
     runs-on: ${{ matrix.os.label }}
 
     strategy:
       matrix:
         os: [ {label: ubuntu-latest, name: latest}, {label: ubuntu-22.04, name: 22.04} ]
         portal: [ {flag: OFF, dep: libgtk-3-dev, name: GTK}, {flag: ON, dep: libdbus-1-dev, name: Portal} ] # The NFD_PORTAL setting defaults to OFF (i.e. uses GTK)
         autoappend: [ {flag: OFF, name: NoAppendExtn} ] # By default the NFD_PORTAL mode does not append extensions, because it breaks some features of the portal
+        wayland: [ {flag: OFF, dep: , name: NoWayland} ]
         casesensitive: [ {flag: OFF, name: CaseInsensitive} ] # Case insensitive or case sensitive file filtering
         compiler: [ {c: gcc, cpp: g++, name: GCC}, {c: clang, cpp: clang++, name: Clang} ] # The default compiler is gcc/g++
         cppstd: [20, 11]
@@ -53,34 +54,47 @@ jobs:
         - os: {label: ubuntu-latest, name: latest}
           portal: {flag: ON, dep: libdbus-1-dev, name: Portal}
           autoappend: {flag: ON, name: AutoAppendExtn}
+          wayland: {flag: OFF, dep: , name: NoWayland}
           casesensitive: {flag: OFF, name: CaseInsensitive}
           compiler: {c: gcc, cpp: g++, name: GCC}
           cppstd: 11
           shared_lib: {flag: OFF, name: Static}
         - os: {label: ubuntu-latest, name: latest}
           portal: {flag: ON, dep: libdbus-1-dev, name: Portal}
           autoappend: {flag: ON, name: AutoAppendExtn}
+          wayland: {flag: OFF, dep: , name: NoWayland}
           casesensitive: {flag: OFF, name: CaseInsensitive}
           compiler: {c: clang, cpp: clang++, name: Clang}
           cppstd: 11
           shared_lib: {flag: OFF, name: Static}
         - os: {label: ubuntu-latest, name: latest}
           portal: {flag: ON, dep: libdbus-1-dev, name: Portal}
           autoappend: {flag: OFF, name: NoAppendExtn}
+          wayland: {flag: OFF, dep: , name: NoWayland}
           casesensitive: {flag: OFF, name: CaseInsensitive}
           compiler: {c: gcc, cpp: g++, name: GCC}
           cppstd: 11
           shared_lib: {flag: ON, name: Shared}
+        - os: {label: ubuntu-latest, name: latest}
+          portal: {flag: ON, dep: libdbus-1-dev, name: Portal}
+          autoappend: {flag: OFF, name: NoAppendExtn}
+          wayland: {flag: ON, dep: libwayland-dev libwayland-bin, name: Wayland}
+          casesensitive: {flag: OFF, name: CaseInsensitive}
+          compiler: {c: gcc, cpp: g++, name: GCC}
+          cppstd: 11
+          shared_lib: {flag: ON, name: Static}
         - os: {label: ubuntu-latest, name: latest}
           portal: {flag: OFF, dep: libgtk-3-dev, name: GTK}
           autoappend: {flag: OFF, name: NoAppendExtn}
+          wayland: {flag: OFF, dep: , name: NoWayland}
           casesensitive: {flag: ON, name: CaseSensitive}
           compiler: {c: gcc, cpp: g++, name: GCC}
           cppstd: 11
           shared_lib: {flag: OFF, name: Static}
         - os: {label: ubuntu-latest, name: latest}
           portal: {flag: ON, dep: libdbus-1-dev, name: Portal}
           autoappend: {flag: OFF, name: NoAppendExtn}
+          wayland: {flag: OFF, dep: , name: NoWayland}
           casesensitive: {flag: ON, name: CaseSensitive}
           compiler: {c: gcc, cpp: g++, name: GCC}
           cppstd: 11
@@ -89,16 +103,18 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v4
+      with:
+        submodules: true
     - name: Install Dependencies
-      run: sudo apt-get update && sudo apt-get install ${{ matrix.portal.dep }}
+      run: sudo apt-get update && sudo apt-get install ${{ matrix.portal.dep }} ${{ matrix.wayland.dep }}
     - name: Configure
-      run: mkdir build && mkdir install && cd build && cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=${{ matrix.compiler.c }} -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cpp }} -DCMAKE_CXX_STANDARD=${{ matrix.cppstd }} -DCMAKE_C_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DNFD_PORTAL=${{ matrix.portal.flag }} -DNFD_APPEND_EXTENSION=${{ matrix.autoappend.flag }} -DNFD_CASE_SENSITIVE_FILTER=${{ matrix.casesensitive.flag }} -DBUILD_SHARED_LIBS=${{ matrix.shared_lib.flag }} -DNFD_BUILD_TESTS=ON ..
+      run: mkdir build && mkdir install && cd build && cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=${{ matrix.compiler.c }} -DCMAKE_CXX_COMPILER=${{ matrix.compiler.cpp }} -DCMAKE_CXX_STANDARD=${{ matrix.cppstd }} -DCMAKE_C_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DNFD_PORTAL=${{ matrix.portal.flag }} -DNFD_WAYLAND=${{ matrix.wayland.flag }} -DNFD_APPEND_EXTENSION=${{ matrix.autoappend.flag }} -DNFD_CASE_SENSITIVE_FILTER=${{ matrix.casesensitive.flag }} -DBUILD_SHARED_LIBS=${{ matrix.shared_lib.flag }} -DNFD_BUILD_TESTS=ON ..
     - name: Build
       run: cmake --build build --target install
     - name: Upload test binaries
       uses: actions/upload-artifact@v4
       with:
-        name: Ubuntu ${{ matrix.os.name }} - ${{ matrix.compiler.name }}, ${{ matrix.portal.name }}, ${{ matrix.autoappend.name }}, ${{ matrix.casesensitive.name }}, ${{ matrix.shared_lib.name }}, C++${{ matrix.cppstd }}
+        name: Ubuntu ${{ matrix.os.name }} - ${{ matrix.compiler.name }}, ${{ matrix.portal.name }}, ${{ matrix.wayland.name }}, ${{ matrix.autoappend.name }}, ${{ matrix.casesensitive.name }}, ${{ matrix.shared_lib.name }}, C++${{ matrix.cppstd }}
         path: |
           build/src/*
           build/test/*
@@ -208,26 +224,29 @@ jobs:
 
   build-ubuntu-sdl2:
 
-    name: Ubuntu latest - GCC, ${{ matrix.portal.name }}, Static, SDL2
+    name: Ubuntu latest - GCC, ${{ matrix.portal.name }}, ${{ matrix.wayland.name }}, Static, SDL2
     runs-on: ubuntu-latest
 
     strategy:
       matrix:
         portal: [ {flag: OFF, dep: libgtk-3-dev, name: GTK}, {flag: ON, dep: libdbus-1-dev, name: Portal} ] # The NFD_PORTAL setting defaults to OFF (i.e. uses GTK)
+        wayland: [ {flag: OFF, dep: , name: NoWayland}, {flag: ON, dep: libwayland-dev libwayland-bin, name: Wayland} ]
 
     steps:
     - name: Checkout
       uses: actions/checkout@v4
+      with:
+        submodules: true
     - name: Install Dependencies
-      run: sudo apt-get update && sudo apt-get install ${{ matrix.portal.dep }} libsdl2-dev libsdl2-ttf-dev
+      run: sudo apt-get update && sudo apt-get install ${{ matrix.portal.dep }} ${{ matrix.wayland.dep }} libsdl2-dev libsdl2-ttf-dev
     - name: Configure
-      run: mkdir build && mkdir install && cd build && cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DNFD_PORTAL=${{ matrix.portal.flag }} -DNFD_APPEND_EXTENSION=OFF -DNFD_BUILD_TESTS=OFF -DNFD_BUILD_SDL2_TESTS=ON ..
+      run: mkdir build && mkdir install && cd build && cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -Wshadow -Werror -pedantic" -DNFD_PORTAL=${{ matrix.portal.flag }} -DNFD_WAYLAND=${{ matrix.wayland.flag }} -DNFD_APPEND_EXTENSION=OFF -DNFD_BUILD_TESTS=OFF -DNFD_BUILD_SDL2_TESTS=ON ..
     - name: Build
       run: cmake --build build --target install
     - name: Upload test binaries
       uses: actions/upload-artifact@v4
       with:
-        name: Ubuntu latest - GCC, ${{ matrix.portal.name }}, Static, SDL2
+        name: Ubuntu latest - GCC, ${{ matrix.portal.name }}, ${{ matrix.wayland.name }}, Static, SDL2
         path: |
           build/src/*
           build/test/*

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "3ps/wayland-protocols"]
+	path = 3ps/wayland-protocols
+	url = https://gitlab.freedesktop.org/wayland/wayland-protocols.git

src/CMakeLists.txt

@@ -18,13 +18,33 @@ if(nfd_PLATFORM STREQUAL PLATFORM_LINUX)
   option(NFD_PORTAL "Use xdg-desktop-portal instead of GTK" OFF)
   if(NOT NFD_PORTAL)
     pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
-    message("Using GTK version: ${GTK3_VERSION}")
+    message(STATUS "Using GTK version: ${GTK3_VERSION}")
     list(APPEND SOURCE_FILES nfd_gtk.cpp)
   else()
     pkg_check_modules(DBUS REQUIRED dbus-1)
-    message("Using DBUS version: ${DBUS_VERSION}")
+    message(STATUS "Using D-Bus version: ${DBUS_VERSION}")
     list(APPEND SOURCE_FILES nfd_portal.cpp)
   endif()
+
+  # for Linux, we support X11, Wayland, or both
+  option(NFD_X11 "Support X11 on Linux" ON)
+  option(NFD_WAYLAND "Support Wayland on Linux" ON)
+  if(NFD_WAYLAND)
+    pkg_check_modules(WAYLAND REQUIRED wayland-client)
+    message(STATUS "Using Wayland version: ${WAYLAND_VERSION}")
+    set(NFD_WAYLAND_PROTOCOL_XDG_FOREIGN ${CMAKE_CURRENT_SOURCE_DIR}/../3ps/wayland-protocols/unstable/xdg-foreign/xdg-foreign-unstable-v1.xml)
+    add_custom_command(
+      OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.h
+      COMMAND wayland-scanner client-header < ${NFD_WAYLAND_PROTOCOL_XDG_FOREIGN} > ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.h
+      MAIN_DEPENDENCY ${NFD_WAYLAND_PROTOCOL_XDG_FOREIGN}
+    )
+    add_custom_command(
+      OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.c
+      COMMAND wayland-scanner private-code < ${NFD_WAYLAND_PROTOCOL_XDG_FOREIGN} > ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.c
+      MAIN_DEPENDENCY ${NFD_WAYLAND_PROTOCOL_XDG_FOREIGN}
+    )
+    list(APPEND SOURCE_FILES ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.h ${CMAKE_CURRENT_BINARY_DIR}/xdg-foreign-unstable-v1.c)
+  endif()
 endif()
 
 if(nfd_PLATFORM STREQUAL PLATFORM_MACOS)
@@ -94,10 +114,21 @@ if(nfd_PLATFORM STREQUAL PLATFORM_LINUX)
   if(NFD_APPEND_EXTENSION)
     target_compile_definitions(${TARGET_NAME} PRIVATE NFD_APPEND_EXTENSION)
   endif()
+
   option(NFD_CASE_SENSITIVE_FILTER "Make filters case sensitive" OFF)
   if(NFD_CASE_SENSITIVE_FILTER)
     target_compile_definitions(${TARGET_NAME} PRIVATE NFD_CASE_SENSITIVE_FILTER)
   endif()
+
+  if(NFD_X11)
+    target_compile_definitions(${TARGET_NAME} PRIVATE NFD_X11)
+  endif()
+  if(NFD_WAYLAND)
+    target_include_directories(${TARGET_NAME} PRIVATE ${WAYLAND_INCLUDE_DIRS})
+    target_link_libraries(${TARGET_NAME} PRIVATE ${WAYLAND_LINK_LIBRARIES})
+    target_compile_definitions(${TARGET_NAME} PRIVATE NFD_WAYLAND)
+    target_include_directories(${TARGET_NAME} PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+  endif()
 endif()
 
 if(nfd_PLATFORM STREQUAL PLATFORM_MACOS)
@@ -122,7 +153,7 @@ if(nfd_COMPILER STREQUAL COMPILER_CLANGCL)
 endif()
 
 if(nfd_COMPILER STREQUAL COMPILER_GNU)
-  target_compile_options(${TARGET_NAME} PRIVATE -nostdlib -fno-exceptions -fno-rtti)
+  target_compile_options(${TARGET_NAME} PRIVATE -nostdlib -fno-exceptions $<$<COMPILE_LANGUAGE:CXX>:-fno-rtti>)
 endif()
 
 set_target_properties(${TARGET_NAME} PROPERTIES

src/include/nfd.h

@@ -105,7 +105,8 @@ enum {
     NFD_WINDOW_HANDLE_TYPE_COCOA = 2,
     // X11: handle is Window
     NFD_WINDOW_HANDLE_TYPE_X11 = 3,
-    // Wayland support will be implemented separately in the future
+    // Wayland: handle is wl_surface*
+    NFD_WINDOW_HANDLE_TYPE_WAYLAND = 4,
 };
 // The native window handle.  If using a platform abstraction framework (e.g. SDL2), this should be
 // obtained using the corresponding NFD glue header (e.g. nfd_sdl2.h).
@@ -190,6 +191,11 @@ NFD_API nfdresult_t NFD_Init(void);
 /** Call this to de-initialize NFD, if NFD_Init returned NFD_OKAY. */
 NFD_API void NFD_Quit(void);
 
+struct wl_display;
+/** Sets or updates the Wayland display used by your application. Use NULL to remove an existing
+ * display. Only defined on Linux. */
+NFD_API nfdresult_t NFD_SetWaylandDisplay(struct wl_display*);
+
 /** Single file open dialog
  *
  *  It's the caller's responsibility to free `outPath` via NFD_FreePathN() if this function returns

src/include/nfd_sdl2.h

@@ -26,6 +26,20 @@ extern "C" {
 #define NFD_INLINE static inline
 #endif  // __cplusplus
 
+NFD_INLINE bool NFD_SetDisplayPropertiesFromSDLWindow(SDL_Window* sdlWindow) {
+#if defined(SDL_VIDEO_DRIVER_WAYLAND)
+    SDL_SysWMinfo info;
+    SDL_VERSION(&info.version);
+    if (!SDL_GetWindowWMInfo(sdlWindow, &info) || info.subsystem != SDL_SYSWM_WAYLAND) {
+        return false;
+    }
+    return NFD_SetWaylandDisplay(info.info.wl.display) == NFD_OKAY;
+#else
+    (void)sdlWindow;
+    return true;
+#endif
+}
+
 /**
  *  Converts an SDL window handle to a native window handle that can be passed to NFDe.
  *  @param sdlWindow The SDL window handle.
@@ -59,6 +73,12 @@ NFD_INLINE bool NFD_GetNativeWindowFromSDLWindow(SDL_Window* sdlWindow,
             nativeWindow->type = NFD_WINDOW_HANDLE_TYPE_X11;
             nativeWindow->handle = (void*)info.info.x11.window;
             return true;
+#endif
+#if defined(SDL_VIDEO_DRIVER_WAYLAND)
+        case SDL_SYSWM_WAYLAND:
+            nativeWindow->type = NFD_WINDOW_HANDLE_TYPE_WAYLAND;
+            nativeWindow->handle = (void*)info.info.wl.surface;
+            return true;
 #endif
         default:
             // Silence the warning in case we are not using a supported backend.

src/nfd_gtk.cpp

@@ -549,6 +549,12 @@ nfdresult_t NFD_Init(void) {
     }
     return NFD_OKAY;
 }
+
+nfdresult_t NFD_SetWaylandDisplay(wl_display*) {
+    // TODO do something with the display
+    return NFD_OKAY;
+}
+
 void NFD_Quit(void) {
     // do nothing, GTK cannot be de-initialized
 }