#include typedef enum { EventTypeTick, EventTypeKey, // add your events type } EventType; typedef struct { union { InputEvent input; // add your events payload } value; EventType type; } Event; typedef struct { // describe state here } State; static void render_callback(Canvas* canvas, void* ctx) { State* state = (State*)acquire_mutex((ValueMutex*)ctx, 25); canvas_clear(canvas); // draw your app release_mutex((ValueMutex*)ctx, state); } static void input_callback(InputEvent* input_event, void* ctx) { osMessageQueueId_t event_queue = (QueueHandle_t)ctx; Event event; event.type = EventTypeKey; event.value.input = *input_event; osMessageQueuePut(event_queue, &event, 0, 0); } void template_app(void* p) { osMessageQueueId_t event_queue = osMessageQueueNew(1, sizeof(Event), NULL); State _state; /* init state here */ ValueMutex state_mutex; if(!init_mutex(&state_mutex, &_state, sizeof(State))) { printf("cannot create mutex\n"); furiac_exit(NULL); } Widget* widget = widget_alloc(); widget_draw_callback_set(widget, render_callback, &state_mutex); widget_input_callback_set(widget, input_callback, event_queue); // Open GUI and register widget Gui* gui = furi_record_open("gui"); if(gui == NULL) { printf("gui is not available\n"); furiac_exit(NULL); } gui_add_widget(gui, widget, /* specify UI layer */); Event event; while(1) { osStatus_t event_status = osMessageQueueGet( event_queue, &event, NULL, /* specify timeout */ ); State* state = (State*)acquire_mutex_block(&state_mutex); if(event_status == osOK) { if(event.type == EventTypeKey) { // press events if(event.value.input.state && event.value.input.input == InputBack) { } if(event.value.input.state && event.value.input.input == InputUp) { } if(event.value.input.state && event.value.input.input == InputDown) { } if(event.value.input.state && event.value.input.input == InputLeft) { } if(event.value.input.state && event.value.input.input == InputRight) { } if(event.value.input.input == InputOk) { } } } else { // event timeout } // common code, for example, force update UI // widget_update(widget); release_mutex(&state_mutex, state); } }