Add "al_is_native_dialog_addon_initialized"

Author: MarkOates

addons/native_dialog/allegro5/allegro_native_dialog.h

@@ -59,6 +59,7 @@ typedef struct ALLEGRO_MENU_INFO {
 #define ALLEGRO_END_OF_MENU                { NULL,          0, 0, NULL }
 
 ALLEGRO_DIALOG_FUNC(bool, al_init_native_dialog_addon, (void));
+ALLEGRO_DIALOG_FUNC(bool, al_is_native_dialog_addon_initialized, (void));
 ALLEGRO_DIALOG_FUNC(void, al_shutdown_native_dialog_addon, (void));
 
 ALLEGRO_DIALOG_FUNC(ALLEGRO_FILECHOOSER *, al_create_native_file_dialog, (char const *initial_path,

addons/native_dialog/dialog.c

@@ -27,6 +27,13 @@ bool al_init_native_dialog_addon(void)
    return true;
 }
 
+/* Function: al_is_native_dialog_addon_initialized
+ */
+bool al_is_native_dialog_addon_initialized(void)
+{
+   return inited_addon;
+}
+
 /* Function: al_shutdown_native_dialog_addon
  */
 void al_shutdown_native_dialog_addon(void)

docs/src/refman/native_dialog.txt

@@ -31,6 +31,10 @@ an error message if Allegro fails to initialise.
 
 See also: [al_shutdown_native_dialog_addon]
 
+## API: al_is_native_dialog_addon_initialized
+
+Returns true if the native dialog addon is initialized, otherwise returns false.
+
 ## API: al_shutdown_native_dialog_addon
 
 Shut down the native dialog addon.