#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); } int32_t template_app(void* p) { osMessageQueueId_t event_queue = osMessageQueueNew(8, sizeof(Event), NULL); State _state; /* init state here */ ValueMutex state_mutex; if(!init_mutex(&state_mutex, &_state, sizeof(State))) { printf("cannot create mutex\r\n"); return 255; } ViewPort* view_port = view_port_alloc(); view_port_draw_callback_set(view_port, render_callback, &state_mutex); view_port_input_callback_set(view_port, input_callback, event_queue); // Open GUI and register view_port Gui* gui = furi_record_open("gui"); if(gui == NULL) { printf("gui is not available\r\n"); return 255; } gui_add_view_port(gui, view_port, /* 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.type == InputTypeShort && event.value.input.key == InputKeyBack) { } if(event.value.input.type == InputTypeShort && event.value.input.key == InputKeyUp) { } if(event.value.input.type == InputTypeShort && event.value.input.key == InputKeyDown) { } if(event.value.input.type == InputTypeShort && event.value.input.key == InputKeyLeft) { } if(event.value.input.type == InputTypeShort && event.value.input.key == InputKeyRight) { } if(event.value.input.key == InputKeyOk) { } } } else { // event timeout } // common code, for example, force update UI // view_port_update(view_port); release_mutex(&state_mutex, state); } return 0; }