Main Loop

Handling Input

With the input callback now processing our new events, we can start utilizing them in our main loop.

Let's do that, and write a simple control flow.

int32_t box_mover_app(void* p){
    UNUSED(p);

    BoxMover* box_mover = box_mover_alloc();

    InputEvent event;
    for(bool processing = true; processing;){
        // Pops a message off the queue and stores it in `event`.
        // No message priority denoted by NULL, and 100 ticks of timeout.
        osStatus_t status =  osMessageQueueGet(box_mover->event_queue, &event, NULL, 100);
        furi_check(osMutexAcquire(box_mover->model_mutex, osWaitForever) == osOK);
        if(status==osOK){
            if(event.type==InputTypePress){
                switch(event.key){
                    case InputKeyUp:
                        box_mover->model->y-=2;
                        break;
                    case InputKeyDown:
                        box_mover->model->y+=2;
                        break;
                    case InputKeyLeft:
                        box_mover->model->x-=2;
                        break;
                    case InputKeyRight:
                        box_mover->model->x+=2;
                        break;
                    case InputKeyOk:
                    case InputKeyBack:
                        processing = false;
                        break;
                }
            }
        }
        osMutexRelease(box_mover->model_mutex);
        view_port_update(box_mover->view_port); // signals our draw callback
    } 
    box_mover_free(box_mover);
    return 0;
}

As you can see, because of our struct-oriented approach, this makes our final client calls much easier, and these skills and structure will transfer very well to other GUI Paradigms.

Unsure of your code?

Check out the code so far for this section!