You are writing a game in, say GLFW or SDL. Somehow you want to show a fatal error message to the user, preferrably in native style. How?
MessageBox() to show such message.Just compile it without any flags should work.
# Use gcc
g++ message-box.cpp
./a.out
# Use clang
clang++ message-box.cpp
./a.outIf there are any linking error, you may need to supply -ldl to the compiler.
| #include <dlfcn.h> | |
| #include <assert.h> | |
| namespace gtk | |
| { | |
| struct Object; | |
| using Unref = auto (Object*) -> void; | |
| using Try_Init = auto () -> bool; | |
| using Iterate_Main_Context = auto (Object*, bool) -> bool; | |
| using New_Alert_Dialog = auto (char const* fmt, ...) -> Object*; | |
| using Show_Alert_Dialog = auto (Object* self, Object* parent) -> void; | |
| using Set_Alert_Dialog_Detail = auto (Object*, char const*) -> void; | |
| using Count_List_Items = auto (Object*) -> unsigned; | |
| using List_Toplevels = auto () -> Object*; | |
| auto show_messgage_box(char const* title, char const* message) -> void | |
| { | |
| auto lib = dlopen("/usr/lib/libgtk-4.so", RTLD_LAZY | RTLD_LOCAL); | |
| assert(lib); | |
| auto unref = (gtk::Unref*) dlsym(lib, "g_object_unref"); | |
| auto iterate_main_context = (gtk::Iterate_Main_Context*) dlsym(lib, "g_main_context_iteration"); | |
| auto try_init = (gtk::Try_Init*) dlsym(lib, "gtk_init_check"); | |
| auto new_alert_dialog = (gtk::New_Alert_Dialog*) dlsym(lib, "gtk_alert_dialog_new"); | |
| auto show_alert_dialog = (gtk::Show_Alert_Dialog*) dlsym(lib, "gtk_alert_dialog_show"); | |
| auto set_alert_dialog_detail = (gtk::Set_Alert_Dialog_Detail*) dlsym(lib, "gtk_alert_dialog_set_detail"); | |
| auto list_toplevels = (gtk::List_Toplevels*) dlsym(lib, "gtk_window_get_toplevels"); | |
| auto count_list_items = (gtk::Count_List_Items*) dlsym(lib, "g_list_model_get_n_items"); | |
| assert(unref); | |
| assert(iterate_main_context); | |
| assert(try_init); | |
| assert(new_alert_dialog); | |
| assert(show_alert_dialog); | |
| assert(set_alert_dialog_detail); | |
| assert(list_toplevels); | |
| assert(count_list_items); | |
| if (!try_init()) return; | |
| auto dialog = new_alert_dialog("%s", title); | |
| set_alert_dialog_detail(dialog, message); | |
| show_alert_dialog(dialog, nullptr); | |
| while (count_list_items(list_toplevels()) > 0u) { | |
| iterate_main_context(nullptr, true); | |
| } | |
| unref(dialog); | |
| dlclose(lib); | |
| } | |
| } | |
| int main() | |
| { | |
| gtk::show_messgage_box("Hi", "Hello world!"); | |
| gtk::show_messgage_box("Fatal Error", "Something bad happened.\nThere is nothing you can do."); | |
| } | |