GLFW API to track system color scheme dark/light

Implemented only on macOS and Wayland.

glfw/cocoa_window.m

@@ -1010,6 +1010,18 @@ static const NSRange kEmptyRange = { NSNotFound, 0 };
     _glfwInputCursorEnter(window, true);
 }
 
+- (void)viewDidChangeEffectiveAppearance
+{
+    static int appearance = 0;
+    if (_glfw.callbacks.system_color_theme_change) {
+        int new_appearance = glfwGetCurrentSystemColorTheme();
+        if (new_appearance != appearance) {
+            appearance = new_appearance;
+            _glfw.callbacks.system_color_theme_change(appearance);
+        }
+    }
+}
+
 - (void)viewDidChangeBackingProperties
 {
     if (!window) return;
@@ -2957,6 +2969,19 @@ GLFWAPI void glfwCocoaRequestRenderFrame(GLFWwindow *w, GLFWcocoarenderframefun
     requestRenderFrame((_GLFWwindow*)w, callback);
 }
 
+GLFWAPI int glfwGetCurrentSystemColorTheme(void) {
+    int theme_type = 0;
+    NSAppearance *changedAppearance = NSApp.effectiveAppearance;
+    NSAppearanceName newAppearance = [changedAppearance bestMatchFromAppearancesWithNames:@[NSAppearanceNameAqua, NSAppearanceNameDarkAqua]];
+    if([newAppearance isEqualToString:NSAppearanceNameDarkAqua]){
+        theme_type = 1;
+    } else {
+        theme_type = 2;
+    }
+    return theme_type;
+}
+
+
 GLFWAPI uint32_t
 glfwGetCocoaKeyEquivalent(uint32_t glfw_key, int glfw_mods, int *cocoa_mods) {
     *cocoa_mods = 0;

glfw/glfw3.h

@@ -1368,6 +1368,22 @@ typedef void (* GLFWwindowclosefun)(GLFWwindow*);
  */
 typedef void (* GLFWapplicationclosefun)(int);
 
+/*! @brief The function pointer type for system color theme change callbacks.
+ *
+ *  This is the function pointer type for system color theme changes.
+ *  @code
+ *  void function_name(int theme_type)
+ *  @endcode
+ *
+ *  @param[in] theme_type 0 for unknown, 1 for dark and 2 for light
+ *
+ *  @sa @ref glfwSetSystemColorThemeChangeCallback
+ *
+ *  @ingroup window
+ */
+typedef void (* GLFWsystemcolorthemechangefun)(int);
+
+
 /*! @brief The function pointer type for window content refresh callbacks.
  *
  *  This is the function pointer type for window content refresh callbacks.
@@ -3906,6 +3922,8 @@ GLFWAPI GLFWwindowsizefun glfwSetWindowSizeCallback(GLFWwindow* window, GLFWwind
  */
 GLFWAPI GLFWwindowclosefun glfwSetWindowCloseCallback(GLFWwindow* window, GLFWwindowclosefun callback);
 GLFWAPI GLFWapplicationclosefun glfwSetApplicationCloseCallback(GLFWapplicationclosefun callback);
+GLFWAPI GLFWsystemcolorthemechangefun glfwSetSystemColorThemeChangeCallback(GLFWsystemcolorthemechangefun callback);
+GLFWAPI int glfwGetCurrentSystemColorTheme(void);
 
 /*! @brief Sets the refresh callback for the specified window.
  *

glfw/init.c

@@ -382,6 +382,14 @@ GLFWAPI GLFWapplicationclosefun glfwSetApplicationCloseCallback(GLFWapplicationc
     return cbfun;
 }
 
+GLFWAPI GLFWapplicationclosefun glfwSetSystemColorThemeChangeCallback(GLFWsystemcolorthemechangefun cbfun)
+{
+    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
+    _GLFW_SWAP_POINTERS(_glfw.callbacks.system_color_theme_change, cbfun);
+    return cbfun;
+}
+
+
 GLFWAPI GLFWdrawtextfun glfwSetDrawTextFunction(GLFWdrawtextfun cbfun)
 {
     _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

glfw/internal.h

@@ -632,13 +632,13 @@ struct _GLFWlibrary
         GLFWmonitorfun  monitor;
         GLFWjoystickfun joystick;
         GLFWapplicationclosefun application_close;
+        GLFWsystemcolorthemechangefun system_color_theme_change;
         GLFWdrawtextfun draw_text;
         GLFWcurrentselectionfun get_current_selection;
         GLFWhascurrentselectionfun has_current_selection;
         GLFWimecursorpositionfun get_ime_cursor_position;
     } callbacks;
 
-
     // This is defined in the window API's platform.h
     _GLFW_PLATFORM_LIBRARY_WINDOW_STATE;
     // This is defined in the context API's context.h

glfw/linux_desktop_settings.c

@@ -24,6 +24,11 @@ static uint32_t appearance = 0;
 static bool is_gnome = false;
 static bool cursor_theme_changed = false;
 
+int
+glfw_current_system_color_theme(void) {
+    return appearance;
+}
+
 #define HANDLER(name) static void name(DBusMessage *msg, const char* errmsg, void *data) { \
     (void)data; \
     if (errmsg) { \
@@ -155,6 +160,9 @@ on_color_scheme_change(DBusMessage *message) {
                 if (val > 2) val = 0;
                 if (val != appearance) {
                     appearance = val;
+                    if (_glfw.callbacks.system_color_theme_change) {
+                        _glfw.callbacks.system_color_theme_change(appearance);
+                    }
                 }
             }
             break;

glfw/linux_desktop_settings.h

@@ -12,3 +12,4 @@
 
 void glfw_initialize_desktop_settings(void);
 void glfw_current_cursor_theme(const char **theme, int *size);
+int glfw_current_system_color_theme(void);

glfw/wl_init.c

@@ -789,6 +789,10 @@ glfwWaylandCheckForServerSideDecorations(void) {
     return has_ssd ? "YES" : "NO";
 }
 
+GLFWAPI int glfwGetCurrentSystemColorTheme(void) {
+    return glfw_current_system_color_theme();
+}
+
 //////////////////////////////////////////////////////////////////////////
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////

glfw/x11_init.c

@@ -614,6 +614,10 @@ Cursor _glfwCreateCursorX11(const GLFWimage* image, int xhot, int yhot)
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////
 
+GLFWAPI int glfwGetCurrentSystemColorTheme(void) {
+    return 0;
+}
+
 int _glfwPlatformInit(void)
 {
     XInitThreads();

kitty/glfw-wrapper.c

@@ -239,6 +239,12 @@ load_glfw(const char* path) {
     *(void **) (&glfwSetApplicationCloseCallback_impl) = dlsym(handle, "glfwSetApplicationCloseCallback");
     if (glfwSetApplicationCloseCallback_impl == NULL) fail("Failed to load glfw function glfwSetApplicationCloseCallback with error: %s", dlerror());
 
+    *(void **) (&glfwSetSystemColorThemeChangeCallback_impl) = dlsym(handle, "glfwSetSystemColorThemeChangeCallback");
+    if (glfwSetSystemColorThemeChangeCallback_impl == NULL) fail("Failed to load glfw function glfwSetSystemColorThemeChangeCallback with error: %s", dlerror());
+
+    *(void **) (&glfwGetCurrentSystemColorTheme_impl) = dlsym(handle, "glfwGetCurrentSystemColorTheme");
+    if (glfwGetCurrentSystemColorTheme_impl == NULL) fail("Failed to load glfw function glfwGetCurrentSystemColorTheme with error: %s", dlerror());
+
     *(void **) (&glfwSetWindowRefreshCallback_impl) = dlsym(handle, "glfwSetWindowRefreshCallback");
     if (glfwSetWindowRefreshCallback_impl == NULL) fail("Failed to load glfw function glfwSetWindowRefreshCallback with error: %s", dlerror());
 

kitty/glfw-wrapper.h

@@ -1106,6 +1106,22 @@ typedef void (* GLFWwindowclosefun)(GLFWwindow*);
  */
 typedef void (* GLFWapplicationclosefun)(int);
 
+/*! @brief The function pointer type for system color theme change callbacks.
+ *
+ *  This is the function pointer type for system color theme changes.
+ *  @code
+ *  void function_name(int theme_type)
+ *  @endcode
+ *
+ *  @param[in] theme_type 0 for unknown, 1 for dark and 2 for light
+ *
+ *  @sa @ref glfwSetSystemColorThemeChangeCallback
+ *
+ *  @ingroup window
+ */
+typedef void (* GLFWsystemcolorthemechangefun)(int);
+
+
 /*! @brief The function pointer type for window content refresh callbacks.
  *
  *  This is the function pointer type for window content refresh callbacks.
@@ -1928,6 +1944,14 @@ typedef GLFWapplicationclosefun (*glfwSetApplicationCloseCallback_func)(GLFWappl
 GFW_EXTERN glfwSetApplicationCloseCallback_func glfwSetApplicationCloseCallback_impl;
 #define glfwSetApplicationCloseCallback glfwSetApplicationCloseCallback_impl
 
+typedef GLFWsystemcolorthemechangefun (*glfwSetSystemColorThemeChangeCallback_func)(GLFWsystemcolorthemechangefun);
+GFW_EXTERN glfwSetSystemColorThemeChangeCallback_func glfwSetSystemColorThemeChangeCallback_impl;
+#define glfwSetSystemColorThemeChangeCallback glfwSetSystemColorThemeChangeCallback_impl
+
+typedef int (*glfwGetCurrentSystemColorTheme_func)(void);
+GFW_EXTERN glfwGetCurrentSystemColorTheme_func glfwGetCurrentSystemColorTheme_impl;
+#define glfwGetCurrentSystemColorTheme glfwGetCurrentSystemColorTheme_impl
+
 typedef GLFWwindowrefreshfun (*glfwSetWindowRefreshCallback_func)(GLFWwindow*, GLFWwindowrefreshfun);
 GFW_EXTERN glfwSetWindowRefreshCallback_func glfwSetWindowRefreshCallback_impl;
 #define glfwSetWindowRefreshCallback glfwSetWindowRefreshCallback_impl