tray:unix: Rework the tray structures to have an 'internal' member

Currently, the SDL_Tray* structs in the unix backend are subclassed for each
implementation (only dbus so far). This means that the DBus-specific members
are in their own structs (SDL_Tray*DBus), which all are required to have the
corresponding 'parent' struct as their first member, so that they can be cast
easily and used in the more generic code.

However, other SDL systems which have pluggable backends work the other way
around: the 'generic' struct has an 'internal' member, which individual
drivers can use to store a pointer to any internal state. This is a bit
simpler to wrap one's head around -- particularly because it's consistent --
but does typically involve more memory allocations.

Change the unix/DBus tray implementations to use an 'internal' pointer to
match other subsystems.

src/tray/unix/SDL_dbustray.c

@@ -34,15 +34,11 @@
 
 typedef struct SDL_TrayDriverDBus
 {
-    SDL_TrayDriver class_parent;
-
     SDL_DBusContext *dbus;
 } SDL_TrayDriverDBus;
 
 typedef struct SDL_TrayDBus
 {
-    SDL_Tray class_parent;
-
     DBusConnection *connection;
     char *service_name;
 
@@ -59,8 +55,6 @@ typedef struct SDL_TrayDBus
 
 typedef struct SDL_TrayMenuDBus
 {
-    SDL_TrayMenu class_parent;
-
     SDL_ListNode *menu;
     const char *menu_path;
 
@@ -69,10 +63,8 @@ typedef struct SDL_TrayMenuDBus
 
 typedef struct SDL_TrayEntryDBus
 {
-    SDL_TrayEntry class_parent;
-
     SDL_MenuItem *item;
-    SDL_TrayMenuDBus *sub_menu;
+    SDL_TrayMenu *sub_menu;
 } SDL_TrayEntryDBus;
 
 #define SNI_INTERFACE         "org.kde.StatusNotifierItem"
@@ -95,7 +87,7 @@ static DBusHandlerResult TrayHandleGetAllProps(SDL_Tray *tray, SDL_TrayDBus *tra
     dbus_uint32_t uint32_val;
     dbus_bool_t bool_value;
 
-    menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     empty = "";
     driver->dbus->message_iter_init(msg, &iter);
@@ -156,7 +148,7 @@ static DBusHandlerResult TrayHandleGetAllProps(SDL_Tray *tray, SDL_TrayDBus *tra
     driver->dbus->message_iter_close_container(&dict_iter, &entry_iter);
 
     key = "ItemIsMenu";
-    menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
     if (menu_dbus && menu_dbus->menu_path) {
         bool_value = TRUE;
     } else {
@@ -241,7 +233,7 @@ static DBusHandlerResult TrayHandleGetProp(SDL_Tray *tray, SDL_TrayDBus *tray_db
     const char *empty;
     dbus_bool_t bool_value;
 
-    menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     empty = "";
     driver->dbus->message_iter_init(msg, &iter);
@@ -347,8 +339,8 @@ static DBusHandlerResult TrayMessageHandler(DBusConnection *connection, DBusMess
     DBusMessage *reply;
 
     tray = user_data;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
 
     if (driver->dbus->message_is_method_call(msg, "org.freedesktop.DBus.Properties", "Get")) {
         return TrayHandleGetProp(tray, tray_dbus, driver, msg);
@@ -425,6 +417,7 @@ SDL_Tray *CreateTray(SDL_TrayDriver *driver, SDL_PropertiesID props)
 #define CLEANUP()                           \
     SDL_free(tray_dbus->tooltip);           \
     SDL_DestroySurface(tray_dbus->surface); \
+    SDL_free(tray);                         \
     SDL_free(tray_dbus)
 #define CLEANUP2()                                              \
     dbus_driver->dbus->connection_close(tray_dbus->connection); \
@@ -436,14 +429,19 @@ SDL_Tray *CreateTray(SDL_TrayDriver *driver, SDL_PropertiesID props)
 
     /* Allocate the tray structure */
     tray_dbus = SDL_malloc(sizeof(SDL_TrayDBus));
-    tray = &tray_dbus->class_parent;
     if (!tray_dbus) {
         return NULL;
     }
+    tray = SDL_malloc(sizeof(SDL_Tray));
+    if (!tray) {
+        CLEANUP();
+        return NULL;
+    }
 
     /* Populate */
     tray->menu = NULL;
     tray->driver = driver;
+    tray->internal = tray_dbus;
     if (tooltip) {
         tray_dbus->tooltip = SDL_strdup(tooltip);
     } else {
@@ -453,7 +451,7 @@ SDL_Tray *CreateTray(SDL_TrayDriver *driver, SDL_PropertiesID props)
     tray_dbus->block = false;
 
     /* Connect */
-    dbus_driver = (SDL_TrayDriverDBus *)driver;
+    dbus_driver = (SDL_TrayDriverDBus *)driver->internal;
     dbus_driver->dbus->error_init(&err);
     tray_dbus->connection = dbus_driver->dbus->bus_get_private(DBUS_BUS_SESSION, &err);
     if (dbus_driver->dbus->error_is_set(&err)) {
@@ -487,7 +485,7 @@ SDL_Tray *CreateTray(SDL_TrayDriver *driver, SDL_PropertiesID props)
     /* Create object */
     object_path = SNI_OBJECT_PATH;
     vtable.message_function = TrayMessageHandler;
-    bool_status = dbus_driver->dbus->connection_try_register_object_path(tray_dbus->connection, object_path, &vtable, tray_dbus, &err);
+    bool_status = dbus_driver->dbus->connection_try_register_object_path(tray_dbus->connection, object_path, &vtable, tray, &err);
     if (dbus_driver->dbus->error_is_set(&err)) {
         SDL_SetError("Unable to create tray: %s", err.message);
         dbus_driver->dbus->error_free(&err);
@@ -531,7 +529,7 @@ void DestroyMenu(SDL_TrayMenu *menu)
         return;
     }
 
-    menu_dbus = (SDL_TrayMenuDBus *)menu;
+    menu_dbus = (SDL_TrayMenuDBus *)menu->internal;
 
     if (menu_dbus->menu) {
         SDL_ListNode *cursor;
@@ -539,14 +537,16 @@ void DestroyMenu(SDL_TrayMenu *menu)
         cursor = menu_dbus->menu;
         while (cursor) {
             SDL_MenuItem *item;
-            SDL_TrayEntryDBus *entry;
+            SDL_TrayEntry *entry;
+            SDL_TrayEntryDBus *entry_dbus;
 
             item = cursor->entry;
             entry = item->udata;
+            entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
 
-            if (entry->sub_menu) {
-                DestroyMenu((SDL_TrayMenu *)entry->sub_menu);
-                entry->sub_menu = NULL;
+            if (entry_dbus->sub_menu) {
+                DestroyMenu(entry_dbus->sub_menu);
+                entry_dbus->sub_menu = NULL;
             }
             SDL_free(item);
             SDL_free(entry);
@@ -561,6 +561,7 @@ void DestroyMenu(SDL_TrayMenu *menu)
     }
 
     SDL_free(menu_dbus);
+    SDL_free(menu);
 }
 
 void DestroyTray(SDL_Tray *tray)
@@ -568,8 +569,8 @@ void DestroyTray(SDL_Tray *tray)
     SDL_TrayDBus *tray_dbus;
     SDL_TrayDriverDBus *driver;
 
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    tray_dbus = (SDL_TrayDBus *)tray;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
 
     /* Destroy connection */
     driver->dbus->connection_flush(tray_dbus->connection);
@@ -596,8 +597,8 @@ void UpdateTray(SDL_Tray *tray)
     SDL_TrayDBus *tray_dbus;
     SDL_TrayDriverDBus *driver;
 
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    tray_dbus = (SDL_TrayDBus *)tray;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
 
     if (!SDL_ObjectValid(tray, SDL_OBJECT_TYPE_TRAY)) {
         return;
@@ -627,8 +628,8 @@ void SetTrayIcon(SDL_Tray *tray, SDL_Surface *surface)
     SDL_TrayDriverDBus *driver;
     DBusMessage *signal;
 
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    tray_dbus = (SDL_TrayDBus *)tray;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
 
     if (tray_dbus->surface) {
         SDL_DestroySurface(tray_dbus->surface);
@@ -647,8 +648,8 @@ void SetTrayTooltip(SDL_Tray *tray, const char *text)
     SDL_TrayDriverDBus *driver;
     DBusMessage *signal;
 
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    tray_dbus = (SDL_TrayDBus *)tray;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
 
     if (tray_dbus->tooltip) {
         SDL_free(tray_dbus->tooltip);
@@ -671,16 +672,22 @@ SDL_TrayMenu *CreateTrayMenu(SDL_Tray *tray)
     SDL_TrayMenuDBus *menu_dbus;
 
     menu_dbus = SDL_malloc(sizeof(SDL_TrayMenuDBus));
-    tray->menu = &menu_dbus->class_parent;
     if (!menu_dbus) {
         SDL_SetError("Unable to create tray menu: allocation failure!");
         return NULL;
     }
+    tray->menu = SDL_malloc(sizeof(SDL_TrayMenu));
+    if (!tray->menu) {
+        SDL_free(menu_dbus);
+        SDL_SetError("Unable to create tray menu: allocation failure!");
+        return NULL;
+    }
 
     menu_dbus->menu = NULL;
     menu_dbus->menu_path = NULL;
     tray->menu->parent_tray = tray;
     tray->menu->parent_entry = NULL;
+    tray->menu->internal = menu_dbus;
     menu_dbus->array_representation = NULL;
 
     return tray->menu;
@@ -692,19 +699,25 @@ SDL_TrayMenu *CreateTraySubmenu(SDL_TrayEntry *entry)
     SDL_TrayMenu *menu;
     SDL_TrayEntryDBus *entry_dbus;
 
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
     menu_dbus = SDL_malloc(sizeof(SDL_TrayMenuDBus));
-    menu = &menu_dbus->class_parent;
     if (!menu_dbus) {
         SDL_SetError("Unable to create tray submenu: allocation failure!");
         return NULL;
     }
+    menu = SDL_malloc(sizeof(SDL_TrayMenu));
+    if (!menu) {
+        SDL_free(menu_dbus);
+        SDL_SetError("Unable to create tray submenu: allocation failure!");
+        return NULL;
+    }
 
     menu_dbus->menu = NULL;
     menu_dbus->menu_path = NULL;
     menu->parent_tray = entry->parent->parent_tray;
     menu->parent_entry = entry;
-    entry_dbus->sub_menu = menu_dbus;
+    menu->internal = menu_dbus;
+    entry_dbus->sub_menu = menu;
     menu_dbus->array_representation = NULL;
 
     return menu;
@@ -714,18 +727,17 @@ SDL_TrayMenu *GetTraySubmenu(SDL_TrayEntry *entry)
 {
     SDL_TrayEntryDBus *entry_dbus;
 
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
 
-    return (SDL_TrayMenu *)entry_dbus->sub_menu;
+    return entry_dbus->sub_menu;
 }
 
 bool TrayRightClickHandler(SDL_ListNode *menu, void *udata)
 {
-    SDL_TrayDBus *tray_dbus;
-
-    tray_dbus = (SDL_TrayDBus *)udata;
+    SDL_Tray *tray = (SDL_Tray *)udata;
+    SDL_TrayDBus *tray_dbus = (SDL_TrayDBus *)tray->internal;
 
-    return tray_dbus->r_cb(tray_dbus->udata, (SDL_Tray *)tray_dbus);
+    return tray_dbus->r_cb(tray_dbus->udata, tray);
 }
 
 void TraySendNewMenu(SDL_Tray *tray, const char *new_path)
@@ -735,9 +747,9 @@ void TraySendNewMenu(SDL_Tray *tray, const char *new_path)
     SDL_TrayMenuDBus *menu_dbus;
     DBusMessage *signal;
 
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     driver->dbus->connection_flush(tray_dbus->connection);
 
@@ -807,18 +819,24 @@ SDL_TrayEntry *InsertTrayEntryAt(SDL_TrayMenu *menu, int pos, const char *label,
     bool update;
 
     tray = menu->parent_tray;
-    menu_dbus = (SDL_TrayMenuDBus *)menu;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
+    menu_dbus = (SDL_TrayMenuDBus *)menu->internal;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
 
     entry_dbus = SDL_malloc(sizeof(SDL_TrayEntryDBus));
-    entry = &entry_dbus->class_parent;
     if (!entry_dbus) {
         SDL_SetError("Unable to create tray entry: allocation failure!");
         return NULL;
     }
+    entry = SDL_malloc(sizeof(SDL_TrayEntry));
+    if (!entry) {
+        SDL_free(entry_dbus);
+        SDL_SetError("Unable to create tray entry: allocation failure!");
+        return NULL;
+    }
 
     entry->parent = menu;
+    entry->internal = entry_dbus;
     entry_dbus->item = SDL_DBus_CreateMenuItem();
     entry_dbus->item->utf8 = label;
     if (!label) {
@@ -832,7 +850,7 @@ SDL_TrayEntry *InsertTrayEntryAt(SDL_TrayMenu *menu, int pos, const char *label,
     entry_dbus->item->cb_data = NULL;
     entry_dbus->item->cb = NULL;
     entry_dbus->item->sub_menu = NULL;
-    entry_dbus->item->udata = entry_dbus;
+    entry_dbus->item->udata = entry;
     entry_dbus->sub_menu = NULL;
 
     if (menu_dbus->menu) {
@@ -850,14 +868,14 @@ SDL_TrayEntry *InsertTrayEntryAt(SDL_TrayMenu *menu, int pos, const char *label,
     if (menu->parent_entry) {
         SDL_TrayEntryDBus *parent_entry_dbus;
 
-        parent_entry_dbus = (SDL_TrayEntryDBus *)menu->parent_entry;
+        parent_entry_dbus = (SDL_TrayEntryDBus *)menu->parent_entry->internal;
         parent_entry_dbus->item->sub_menu = menu_dbus->menu;
     }
 
     if (update) {
         SDL_TrayMenuDBus *main_menu_dbus;
 
-        main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+        main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
         SDL_DBus_UpdateMenu(driver->dbus, tray_dbus->connection, main_menu_dbus->menu, main_menu_dbus->menu_path, TrayNewMenuOnMenuUpdateCallback, tray, SDL_DBUS_UPDATE_MENU_FLAGS_NONE);
     } else {
         menu_dbus->menu_path = SDL_DBus_ExportMenu(driver->dbus, tray_dbus->connection, menu_dbus->menu);
@@ -882,7 +900,7 @@ SDL_TrayEntry **GetTrayEntries(SDL_TrayMenu *menu, int *count)
     int sz;
     int i;
 
-    menu_dbus = (SDL_TrayMenuDBus *)menu;
+    menu_dbus = (SDL_TrayMenuDBus *)menu->internal;
 
     if (menu_dbus->array_representation) {
         SDL_free(menu_dbus->array_representation);
@@ -922,11 +940,11 @@ void RemoveTrayEntry(SDL_TrayEntry *entry)
     const char *old_path;
 
     tray = entry->parent->parent_tray;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
-    menu_dbus = (SDL_TrayMenuDBus *)entry->parent;
-    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
+    menu_dbus = (SDL_TrayMenuDBus *)entry->parent->internal;
+    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     tray_dbus->block = true;
     if (menu_dbus->menu->entry == entry_dbus->item && menu_dbus->menu->next) {
@@ -939,9 +957,10 @@ void RemoveTrayEntry(SDL_TrayEntry *entry)
     }
 
     driver->dbus->connection_flush(tray_dbus->connection);
-    DestroyMenu((SDL_TrayMenu *)entry_dbus->sub_menu);
+    DestroyMenu(entry_dbus->sub_menu);
     SDL_ListRemove(&menu_dbus->menu, entry_dbus->item);
     SDL_free(entry_dbus->item);
+    SDL_free(entry_dbus);
     SDL_free(entry);
 
     if (old_path) {
@@ -969,10 +988,10 @@ void SetTrayEntryCallback(SDL_TrayEntry *entry, SDL_TrayCallback callback, void
     SDL_TrayMenuDBus *main_menu_dbus;
 
     tray = entry->parent->parent_tray;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
-    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
+    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     entry_dbus->item->cb = EntryCallback;
     entry_dbus->item->cb_data = userdata;
@@ -990,10 +1009,10 @@ void SetTrayEntryLabel(SDL_TrayEntry *entry, const char *label)
     SDL_TrayMenuDBus *main_menu_dbus;
 
     tray = entry->parent->parent_tray;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
-    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
+    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     entry_dbus->item->utf8 = label;
 
@@ -1002,7 +1021,7 @@ void SetTrayEntryLabel(SDL_TrayEntry *entry, const char *label)
 
 const char *GetTrayEntryLabel(SDL_TrayEntry *entry)
 {
-    return ((SDL_TrayEntryDBus *)entry)->item->utf8;
+    return ((SDL_TrayEntryDBus *)entry->internal)->item->utf8;
 }
 
 void SetTrayEntryChecked(SDL_TrayEntry *entry, bool val)
@@ -1014,10 +1033,10 @@ void SetTrayEntryChecked(SDL_TrayEntry *entry, bool val)
     SDL_TrayMenuDBus *main_menu_dbus;
 
     tray = entry->parent->parent_tray;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
-    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
+    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     if (val) {
         entry_dbus->item->flags |= SDL_MENU_ITEM_FLAGS_CHECKED;
@@ -1030,7 +1049,7 @@ void SetTrayEntryChecked(SDL_TrayEntry *entry, bool val)
 
 bool GetTrayEntryChecked(SDL_TrayEntry *entry)
 {
-    return ((SDL_TrayEntryDBus *)entry)->item->flags & SDL_MENU_ITEM_FLAGS_CHECKED;
+    return ((SDL_TrayEntryDBus *)entry->internal)->item->flags & SDL_MENU_ITEM_FLAGS_CHECKED;
 }
 
 void SetTrayEntryEnabled(SDL_TrayEntry *entry, bool val)
@@ -1042,10 +1061,10 @@ void SetTrayEntryEnabled(SDL_TrayEntry *entry, bool val)
     SDL_TrayMenuDBus *main_menu_dbus;
 
     tray = entry->parent->parent_tray;
-    tray_dbus = (SDL_TrayDBus *)tray;
-    driver = (SDL_TrayDriverDBus *)tray->driver;
-    entry_dbus = (SDL_TrayEntryDBus *)entry;
-    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+    tray_dbus = (SDL_TrayDBus *)tray->internal;
+    driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+    entry_dbus = (SDL_TrayEntryDBus *)entry->internal;
+    main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
     if (!val) {
         entry_dbus->item->flags |= SDL_MENU_ITEM_FLAGS_DISABLED;
@@ -1058,7 +1077,7 @@ void SetTrayEntryEnabled(SDL_TrayEntry *entry, bool val)
 
 bool GetTrayEntryEnabled(SDL_TrayEntry *entry)
 {
-    return !(((SDL_TrayEntryDBus *)entry)->item->flags & SDL_MENU_ITEM_FLAGS_DISABLED);
+    return !(((SDL_TrayEntryDBus *)entry->internal)->item->flags & SDL_MENU_ITEM_FLAGS_DISABLED);
 }
 
 void ClickTrayEntry(SDL_TrayEntry *entry)
@@ -1066,7 +1085,7 @@ void ClickTrayEntry(SDL_TrayEntry *entry)
     SDL_TrayEntryDBus *dbus_entry;
     SDL_TrayCallback entry_cb;
 
-    dbus_entry = (SDL_TrayEntryDBus *)entry;
+    dbus_entry = (SDL_TrayEntryDBus *)entry->internal;
     if (dbus_entry->item->type == SDL_MENU_ITEM_TYPE_CHECKBOX) {
         SDL_Tray *tray;
         SDL_TrayDriverDBus *driver;
@@ -1074,9 +1093,9 @@ void ClickTrayEntry(SDL_TrayEntry *entry)
         SDL_TrayMenuDBus *main_menu_dbus;
 
         tray = entry->parent->parent_tray;
-        tray_dbus = (SDL_TrayDBus *)tray;
-        driver = (SDL_TrayDriverDBus *)tray->driver;
-        main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu;
+        tray_dbus = (SDL_TrayDBus *)tray->internal;
+        driver = (SDL_TrayDriverDBus *)tray->driver->internal;
+        main_menu_dbus = (SDL_TrayMenuDBus *)tray->menu->internal;
 
         dbus_entry->item->flags ^= SDL_MENU_ITEM_FLAGS_CHECKED;
         SDL_DBus_UpdateMenu(driver->dbus, tray_dbus->connection, main_menu_dbus->menu, main_menu_dbus->menu_path, TrayNewMenuOnMenuUpdateCallback, tray, SDL_DBUS_UPDATE_MENU_FLAGS_NONE);
@@ -1143,13 +1162,18 @@ SDL_TrayDriver *SDL_Tray_CreateDBusDriver(void)
 
     /* Allocate the driver struct */
     dbus_driver = SDL_malloc(sizeof(SDL_TrayDriverDBus));
-    driver = &dbus_driver->class_parent;
     if (!dbus_driver) {
         return NULL;
     }
+    driver = SDL_malloc(sizeof(SDL_TrayDriver));
+    if (!driver) {
+        SDL_free(dbus_driver);
+        return NULL;
+    }
 
     /* Populate */
     dbus_driver->dbus = ctx;
+    driver->internal = dbus_driver;
     driver->name = "dbus";
     driver->count = 0;
     driver->CreateTray = CreateTray;

src/tray/unix/SDL_unixtray.h

@@ -54,17 +54,23 @@ typedef struct SDL_TrayDriver
     void (*SetTrayEntryCallback)(SDL_TrayEntry *, SDL_TrayCallback, void *);
 
     void (*DestroyDriver)(struct SDL_TrayDriver *);
+
+    void *internal;
 } SDL_TrayDriver;
 
 struct SDL_TrayMenu
 {
     SDL_Tray *parent_tray;
     SDL_TrayEntry *parent_entry;
+
+    void *internal;
 };
 
 struct SDL_TrayEntry
 {
     SDL_TrayMenu *parent;
+
+    void *internal;
 };
 
 struct SDL_Tray
@@ -72,6 +78,8 @@ struct SDL_Tray
     SDL_TrayDriver *driver;
 
     SDL_TrayMenu *menu;
+
+    void *internal;
 };
 
 #ifdef SDL_USE_LIBDBUS