New feature: Accept native parent window handle

This is necessary for platforms to present the dialog properly, e.g. ensuring that the dialog never goes behind the parent window.

.github/workflows/cmake.yml

@@ -189,3 +189,29 @@ jobs:
         path: |
           build/src/*
           build/test/*
+
+  build-ubuntu-sdl2:
+
+    name: Ubuntu latest - GCC, ${{ matrix.portal.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)
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - name: Installing Dependencies
+      run: sudo apt-get update && sudo apt-get install ${{ matrix.portal.dep }} libsdl2-dev
+    - name: Configure
+      run: mkdir build && mkdir install && cd build && cmake -DCMAKE_INSTALL_PREFIX="../install" -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-Wall -Wextra -Werror -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -Werror -pedantic" -DNFD_PORTAL=${{ matrix.portal.flag }} -DNFD_APPEND_EXTENSION=OFF -DNFD_BUILD_SDL2_TESTS=ON ..
+    - name: Build
+      run: cmake --build build --target install
+    - name: Upload test binaries
+      uses: actions/upload-artifact@v2
+      with:
+        name: Ubuntu latest - GCC, ${{ matrix.portal.name }}, Static, SDL2
+        path: |
+          build/src/*
+          build/test/*

CMakeLists.txt

@@ -8,6 +8,7 @@ endif ()
 
 option(BUILD_SHARED_LIBS "Build a shared library instead of static" OFF)
 option(NFD_BUILD_TESTS "Build tests for nfd" ${nfd_ROOT_PROJECT})
+option(NFD_BUILD_SDL2_TESTS "Build SDL2 tests for nfd" OFF)
 option(NFD_INSTALL "Generate install target for nfd" ${nfd_ROOT_PROJECT})
 
 set(nfd_PLATFORM Undefined)
@@ -48,6 +49,6 @@ endif()
 
 add_subdirectory(src)
 
-if(${NFD_BUILD_TESTS})
+if(${NFD_BUILD_TESTS} OR ${NFD_BUILD_SDL2_TESTS})
   add_subdirectory(test)
 endif()

src/include/nfd.h

@@ -93,19 +93,39 @@ typedef struct {
 typedef nfdu8filteritem_t nfdnfilteritem_t;
 #endif  // _WIN32
 
+// The native window handle type.
+enum {
+    NFD_WINDOW_HANDLE_TYPE_UNSET = 0,
+    // Windows: handle is HWND (the Windows API typedefs this to void*)
+    NFD_WINDOW_HANDLE_TYPE_WINDOWS = 1,
+    // Cocoa: handle is NSWindow*
+    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
+};
+// The native window handle.  If using a platform abstraction framework (e.g. SDL), this should be
+// obtained using the corresponding NFD glue header (e.g. nfd_sdl.h).
+typedef struct {
+    size_t type;  // this is one of the values of the enum above
+    void* handle;
+} nfdwindowhandle_t;
+
 typedef size_t nfdversion_t;
 
 typedef struct {
     const nfdu8filteritem_t* filterList;
     nfdfiltersize_t filterCount;
     const nfdu8char_t* defaultPath;
+    nfdwindowhandle_t parentWindow;
 } nfdopendialogu8args_t;
 
 #ifdef _WIN32
 typedef struct {
     const nfdnfilteritem_t* filterList;
     nfdfiltersize_t filterCount;
     const nfdnchar_t* defaultPath;
+    nfdwindowhandle_t parentWindow;
 } nfdopendialognargs_t;
 #else
 typedef nfdopendialogu8args_t nfdopendialognargs_t;
@@ -116,6 +136,7 @@ typedef struct {
     nfdfiltersize_t filterCount;
     const nfdu8char_t* defaultPath;
     const nfdu8char_t* defaultName;
+    nfdwindowhandle_t parentWindow;
 } nfdsavedialogu8args_t;
 
 #ifdef _WIN32
@@ -124,18 +145,21 @@ typedef struct {
     nfdfiltersize_t filterCount;
     const nfdnchar_t* defaultPath;
     const nfdnchar_t* defaultName;
+    nfdwindowhandle_t parentWindow;
 } nfdsavedialognargs_t;
 #else
 typedef nfdsavedialogu8args_t nfdsavedialognargs_t;
 #endif  // _WIN32
 
 typedef struct {
     const nfdu8char_t* defaultPath;
+    nfdwindowhandle_t parentWindow;
 } nfdpickfolderu8args_t;
 
 #ifdef _WIN32
 typedef struct {
     const nfdnchar_t* defaultPath;
+    nfdwindowhandle_t parentWindow;
 } nfdpickfoldernargs_t;
 #else
 typedef nfdpickfolderu8args_t nfdpickfoldernargs_t;

src/include/nfd_glfw.h

@@ -0,0 +1,69 @@
+/*
+  Native File Dialog Extended
+  Repository: https://github.com/btzy/nativefiledialog-extended
+  License: Zlib
+  Authors: Bernard Teo
+
+  This header contains a function to convert a GLFW window handle to a native window handle for
+  passing to NFDe.
+ */
+
+#ifndef _NFD_GLFW_H
+#define _NFD_GLFW_H
+
+#include <GLFW/glfw3native.h>
+#include <nfd.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+/**
+ *  Converts a GLFW window handle to a native window handle that can be passed to NFDe.
+ *  @param sdlWindow The GLFW window handle.
+ *  @param[out] nativeWindow The output native window handle, populated if and only if this function
+ *  returns true.
+ *  @return Either true to indicate success, or false to indicate failure.  It is intended that
+ * users ignore the error and simply pass a value-initialized nfdwindowhandle_t to NFDe if this
+ * function fails. */
+inline bool NFD_GetNativeWindowFromGLFWWindow(GLFWwindow* glfwWindow,
+                                              nfdwindowhandle_t* nativeWindow) {
+    GLFWerrorfun* oldCallback = glfwSetErrorCallback(NULL);
+    bool success = false;
+#if defined(GLFW_EXPOSE_NATIVE_WIN32)
+    if (!success) {
+        const HWND hwnd = glfwGetWin32Window(glfwWindow);
+        if (hwnd) {
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_WINDOWS, hwnd};
+            success = true;
+        }
+    }
+#endif
+#if defined(GLFW_EXPOSE_NATIVE_COCOA)
+    if (!success) {
+        NSWindow* const cocoa_window = glfwGetCocoaWindow(glfwWindow);
+        if (cocoa_window) {
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_COCOA, cocoa_window};
+            success = true;
+        }
+    }
+#endif
+#if defined(NFD_WINDOW_HANDLE_TYPE_X11)
+    if (!success) {
+        const Window x11_window = glfwGetX11Window(glfwWindow);
+        if (x11_window != None) {
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_X11, x11_window};
+            success = true;
+        }
+    }
+#endif
+    glfwSetErrorCallback(oldCallback);
+    return success;
+}
+
+#ifdef __cplusplus
+}
+#endif  // __cplusplus
+
+#endif  // _NFD_GLFW_H

src/include/nfd_sdl.h

@@ -0,0 +1,66 @@
+/*
+  Native File Dialog Extended
+  Repository: https://github.com/btzy/nativefiledialog-extended
+  License: Zlib
+  Authors: Bernard Teo
+
+  This header contains a function to convert an SDL window handle to a native window handle for
+  passing to NFDe.
+
+  This is meant to be used with SDL2, but if there are incompatibilities with future SDL versions,
+  we can conditionally compile based on SDL_MAJOR_VERSION.
+ */
+
+#ifndef _NFD_SDL_H
+#define _NFD_SDL_H
+
+#include <SDL_error.h>
+#include <SDL_syswm.h>
+#include <nfd.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+/**
+ *  Converts an SDL window handle to a native window handle that can be passed to NFDe.
+ *  @param sdlWindow The SDL window handle.
+ *  @param[out] nativeWindow The output native window handle, populated if and only if this function
+ *  returns true.
+ *  @return Either true to indicate success, or false to indicate failure.  If false is returned,
+ * you can call SDL_GetError() for more information.  However, it is intended that users ignore the
+ * error and simply pass a value-initialized nfdwindowhandle_t to NFDe if this function fails. */
+inline bool NFD_GetNativeWindowFromSDLWindow(SDL_Window* sdlWindow,
+                                             nfdwindowhandle_t* nativeWindow) {
+    SDL_GetWindowWMInfo info;
+    SDL_VERSION(&info.version);
+    if (SDL_GetWindowWMInfo(window, &info)) {
+        return false;
+    }
+    switch (info.subsystem) {
+#if defined(SDL_VIDEO_DRIVER_WINDOWS)
+        case SDL_SYSWM_WINDOWS:
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_WINDOWS, info.info.win.window};
+            return true;
+#endif
+#if defined(SDL_VIDEO_DRIVER_COCOA)
+        case SDL_SYSWM_COCOA:
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_COCOA, info.info.cocoa.window};
+            return true;
+#endif
+#if defined(SDL_VIDEO_DRIVER_X11)
+        case SDL_SYSWM_X11:
+            *nativeWindow = {NFD_WINDOW_HANDLE_TYPE_X11, info.info.x11.window};
+            return true;
+#endif
+        default:
+            SDL_SetError("Unsupported native window type.");
+            return false;
+    }
+}
+
+#ifdef __cplusplus
+}
+#endif  // __cplusplus
+
+#endif  // _NFD_SDL_H

src/nfd_cocoa.m

@@ -174,6 +174,13 @@ static nfdresult_t CopyUtf8String(const char* utf8Str, nfdnchar_t** out) {
     return NFD_ERROR;
 }
 
+static NSWindow* GetNativeWindowHandle(const nfdwindowhandle_t* parentWindow) {
+    if (parentWindow->type != NFD_WINDOW_HANDLE_TYPE_COCOA) {
+        return NULL;
+    }
+    return (NSWindow*)parentWindow->handle;
+}
+
 /* public */
 
 const char* NFD_GetError(void) {
@@ -230,7 +237,12 @@ nfdresult_t NFD_OpenDialogN_With_Impl(nfdversion_t version,
 
     nfdresult_t result = NFD_CANCEL;
     @autoreleasepool {
-        NSWindow* keyWindow = [[NSApplication sharedApplication] keyWindow];
+        NSWindow* keyWindow = GetNativeWindowHandle(&args->parentWindow);
+        if (keyWindow) {
+            [keyWindow makeKeyAndOrderFront:nil];
+        } else {
+            keyWindow = [[NSApplication sharedApplication] keyWindow];
+        }
 
         NSOpenPanel* dialog = [NSOpenPanel openPanel];
         [dialog setAllowsMultipleSelection:NO];
@@ -285,7 +297,12 @@ nfdresult_t NFD_OpenDialogMultipleN_With_Impl(nfdversion_t version,
 
     nfdresult_t result = NFD_CANCEL;
     @autoreleasepool {
-        NSWindow* keyWindow = [[NSApplication sharedApplication] keyWindow];
+        NSWindow* keyWindow = GetNativeWindowHandle(&args->parentWindow);
+        if (keyWindow) {
+            [keyWindow makeKeyAndOrderFront:nil];
+        } else {
+            keyWindow = [[NSApplication sharedApplication] keyWindow];
+        }
 
         NSOpenPanel* dialog = [NSOpenPanel openPanel];
         [dialog setAllowsMultipleSelection:YES];
@@ -347,7 +364,12 @@ nfdresult_t NFD_SaveDialogN_With_Impl(nfdversion_t version,
 
     nfdresult_t result = NFD_CANCEL;
     @autoreleasepool {
-        NSWindow* keyWindow = [[NSApplication sharedApplication] keyWindow];
+        NSWindow* keyWindow = GetNativeWindowHandle(&args->parentWindow);
+        if (keyWindow) {
+            [keyWindow makeKeyAndOrderFront:nil];
+        } else {
+            keyWindow = [[NSApplication sharedApplication] keyWindow];
+        }
 
         NSSavePanel* dialog = [NSSavePanel savePanel];
         [dialog setExtensionHidden:NO];
@@ -404,7 +426,12 @@ nfdresult_t NFD_PickFolderN_With_Impl(nfdversion_t version,
 
     nfdresult_t result = NFD_CANCEL;
     @autoreleasepool {
-        NSWindow* keyWindow = [[NSApplication sharedApplication] keyWindow];
+        NSWindow* keyWindow = GetNativeWindowHandle(&args->parentWindow);
+        if (keyWindow) {
+            [keyWindow makeKeyAndOrderFront:nil];
+        } else {
+            keyWindow = [[NSApplication sharedApplication] keyWindow];
+        }
 
         NSOpenPanel* dialog = [NSOpenPanel openPanel];
         [dialog setAllowsMultipleSelection:NO];
@@ -451,7 +478,12 @@ nfdresult_t NFD_PickFolderMultipleN_With_Impl(nfdversion_t version,
 
     nfdresult_t result = NFD_CANCEL;
     @autoreleasepool {
-        NSWindow* keyWindow = [[NSApplication sharedApplication] keyWindow];
+        NSWindow* keyWindow = GetNativeWindowHandle(&args->parentWindow);
+        if (keyWindow) {
+            [keyWindow makeKeyAndOrderFront:nil];
+        } else {
+            keyWindow = [[NSApplication sharedApplication] keyWindow];
+        }
 
         NSOpenPanel* dialog = [NSOpenPanel openPanel];
         [dialog setAllowsMultipleSelection:YES];