improve the events demo

demos/events.c

@@ -121,7 +121,7 @@ static void control_change(unsigned char controller, unsigned char value, void *
 
 static void create_window(void *user_data) {
 	struct demo *demo = user_data;
-	struct gral_window_interface window_interface = {
+	struct gral_window_interface interface = {
 		&close,
 		&draw,
 		&resize,
@@ -139,18 +139,15 @@ static void create_window(void *user_data) {
 		&focus_enter,
 		&focus_leave
 	};
-	demo->window = gral_window_create(demo->application, 600, 400, "gral events demo", &window_interface, demo);
-	demo->timer = gral_timer_create(1000, &timer, demo);
-	struct gral_midi_interface midi_interface = {
-		&note_on,
-		&note_off,
-		&control_change
-	};
-	demo->midi = gral_midi_create(demo->application, "gral events demo", &midi_interface, demo);
+	demo->window = gral_window_create(demo->application, 600, 400, "gral events demo", &interface, demo);
 }
 
 static void start(void *user_data) {
 	printf("start\n");
+	struct demo *demo = user_data;
+	demo->timer = gral_timer_create(1000, &timer, demo);
+	struct gral_midi_interface midi_interface = {&note_on, &note_off, &control_change};
+	demo->midi = gral_midi_create(demo->application, "gral events demo", &midi_interface, demo);
 }
 
 static void open_empty(void *user_data) {
@@ -165,14 +162,15 @@ static void open_file(char const *path, void *user_data) {
 
 static void quit(void *user_data) {
 	printf("quit\n");
+	struct demo *demo = user_data;
+	gral_midi_delete(demo->midi);
 }
 
 int main(int argc, char **argv) {
 	struct demo demo;
 	struct gral_application_interface interface = {&start, &open_empty, &open_file, &quit};
 	demo.application = gral_application_create("com.github.eyelash.libgral.demos.events", &interface, &demo);
 	int result = gral_application_run(demo.application, argc, argv);
-	gral_midi_delete(demo.midi);
 	gral_window_delete(demo.window);
 	gral_application_delete(demo.application);
 	return result;