Add SDL_IsTraySupported

include/SDL3/SDL_tray.h

@@ -96,6 +96,25 @@ typedef Uint32 SDL_TrayEntryFlags;
  */
 typedef void (SDLCALL *SDL_TrayCallback)(void *userdata, SDL_TrayEntry *entry);
 
+/**
+ * Check whether or not tray icons can be created.
+ *
+ * Note that this function does not guarantee that SDL_CreateTray() will or will
+ * not work; you should still check SDL_CreateTray() for errors.
+ *
+ * Using tray icons require the video subsystem.
+ *
+ * \returns true if trays are available, false otherwise.
+ *
+ * \threadsafety This function should only be called on the main thread. It will
+ *               return false if not called on the main thread.
+ *
+ * \since This function is available since SDL 3.4.0.
+ *
+ * \sa SDL_CreateTray
+ */
+extern SDL_DECLSPEC bool SDLCALL SDL_IsTraySupported(void);
+
 /**
  * Create an icon to be placed in the operating system's tray, or equivalent.
  *

src/dynapi/SDL_dynapi.sym

@@ -1254,6 +1254,7 @@ SDL3_0.0.0 {
     SDL_SetAudioIterationCallbacks;
     SDL_GetEventDescription;
     SDL_PutAudioStreamDataNoCopy;
+    SDL_IsTraySupported;
     # extra symbols go here (don't modify this line)
   local: *;
 };

src/dynapi/SDL_dynapi_overrides.h

@@ -1279,3 +1279,4 @@
 #define SDL_SetAudioIterationCallbacks SDL_SetAudioIterationCallbacks_REAL
 #define SDL_GetEventDescription SDL_GetEventDescription_REAL
 #define SDL_PutAudioStreamDataNoCopy SDL_PutAudioStreamDataNoCopy_REAL
+#define SDL_IsTraySupported SDL_IsTraySupported_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -1287,3 +1287,4 @@ SDL_DYNAPI_PROC(bool,SDL_PutAudioStreamPlanarData,(SDL_AudioStream *a,const void
 SDL_DYNAPI_PROC(bool,SDL_SetAudioIterationCallbacks,(SDL_AudioDeviceID a,SDL_AudioIterationCallback b,SDL_AudioIterationCallback c,void *d),(a,b,c,d),return)
 SDL_DYNAPI_PROC(int,SDL_GetEventDescription,(const SDL_Event *a,char *b,int c),(a,b,c),return)
 SDL_DYNAPI_PROC(bool,SDL_PutAudioStreamDataNoCopy,(SDL_AudioStream *a,const void *b,int c,SDL_AudioStreamDataCompleteCallback d,void *e),(a,b,c,d,e),return)
+SDL_DYNAPI_PROC(bool,SDL_IsTraySupported,(void),(),return)

src/tray/cocoa/SDL_tray.m

@@ -82,6 +82,16 @@ void SDL_UpdateTrays(void)
 {
 }
 
+bool SDL_IsTraySupported(void)
+{
+    if (!SDL_IsMainThread()) {
+        SDL_SetError("This function should be called on the main thread");
+        return false;
+    }
+
+    return true;
+}
+
 SDL_Tray *SDL_CreateTray(SDL_Surface *icon, const char *tooltip)
 {
     if (!SDL_IsMainThread()) {

src/tray/dummy/SDL_tray.c

@@ -29,6 +29,11 @@ void SDL_UpdateTrays(void)
 {
 }
 
+bool SDL_IsTraySupported(void)
+{
+    return false;
+}
+
 SDL_Tray *SDL_CreateTray(SDL_Surface *icon, const char *tooltip)
 {
     SDL_Unsupported();

src/tray/unix/SDL_tray.c

@@ -413,6 +413,24 @@ void SDL_UpdateTrays(void)
     }
 }
 
+bool SDL_IsTraySupported(void)
+{
+    if (!SDL_IsMainThread()) {
+        SDL_SetError("This function should be called on the main thread");
+        return false;
+    }
+
+    static bool has_trays = false;
+    static bool has_been_detected_once = false;
+
+    if (!has_been_detected_once) {
+        has_trays = init_gtk();
+        has_been_detected_once = true;
+    }
+
+    return has_trays;
+}
+
 SDL_Tray *SDL_CreateTray(SDL_Surface *icon, const char *tooltip)
 {
     if (!SDL_IsMainThread()) {

src/tray/windows/SDL_tray.c

@@ -216,6 +216,16 @@ void SDL_UpdateTrays(void)
 {
 }
 
+bool SDL_IsTraySupported(void)
+{
+    if (!SDL_IsMainThread()) {
+        SDL_SetError("This function should be called on the main thread");
+        return false;
+    }
+
+    return true;
+}
+
 SDL_Tray *SDL_CreateTray(SDL_Surface *icon, const char *tooltip)
 {
     if (!SDL_IsMainThread()) {