Pebble - Comunication between the pebble smartwatch and a smartphone

PebbleCommunicationToSmartPhone02C

#include <pebble.h>

static Window *window;
static TextLayer *text_layer;

enum {
	KEY_EXCHANGEDATA = 0,
};

// END Interaction with JS
static void in_received_handler(DictionaryIterator *iter, void *context)
{
	(void) context;
	Tuple *t = dict_read_first(iter);
	while (t != NULL)
	{
		process_tuple(t);
		t = dict_read_next(iter);
	}
}
void process_tuple(Tuple *t)
{
	int key = t->key;
	int value = t->value->int32;
  char string_value[32];
  strcpy(string_value, t->value->cstring);
	switch (key) {
    case KEY_EXCHANGEDATA:
    snprintf(sample_buffer, sizeof("XX button: \u00B0C"), "%d button: \u00B0C", value);
    text_layer_set_text(text_layer, (char*) &sample_buffer);
    break;
	}
}

void send_int(uint8_t key, uint8_t cmd)
{
	DictionaryIterator *iter;
  app_message_outbox_begin(&iter);
	Tuplet value = TupletInteger(key, cmd);
	dict_write_tuplet(iter, &value);
  app_message_outbox_send();
}
// END Interaction with JS


void select_click_handler(ClickRecognizerRef recognizer, void *context) {
	APP_LOG(APP_LOG_LEVEL_DEBUG, "click SELECT");
  text_layer_set_text(text_layer, "Select");
		send_int(0, 1);
}

void up_click_handler(ClickRecognizerRef recognizer, void *context) {
	APP_LOG(APP_LOG_LEVEL_DEBUG, "click UP");
  text_layer_set_text(text_layer, "Up");
		send_int(0, 2);
}

void down_click_handler(ClickRecognizerRef recognizer, void *context) {
	APP_LOG(APP_LOG_LEVEL_DEBUG, "click DOWN");
  text_layer_set_text(text_layer, "Down");
		send_int(0, 3);
}

void click_config_provider(void *context) {
  window_single_click_subscribe(BUTTON_ID_SELECT, select_click_handler);
  window_single_click_subscribe(BUTTON_ID_UP, up_click_handler);
  window_single_click_subscribe(BUTTON_ID_DOWN, down_click_handler);
}

void window_load(Window *window) {
  Layer *window_layer = window_get_root_layer(window);
  GRect bounds = layer_get_bounds(window_layer);

  text_layer = text_layer_create((GRect) { .origin = { 0, 72 }, .size = { bounds.size.w, 20 } });
  text_layer_set_text(text_layer, "Press a button");
  text_layer_set_text_alignment(text_layer, GTextAlignmentCenter);
  layer_add_child(window_layer, text_layer_get_layer(text_layer));
}

void window_unload(Window *window) {
  text_layer_destroy(text_layer);
}

void init(void) {
  window = window_create();
  window_set_click_config_provider(window, click_config_provider);
  window_set_window_handlers(window, (WindowHandlers) {
	.load = window_load,
    .unload = window_unload,
  });
  const bool animated = true;
  window_stack_push(window, animated);
  
  //Register AppMessage events
	app_message_register_inbox_received(in_received_handler);
	app_message_open(app_message_inbox_size_maximum(), app_message_outbox_size_maximum());    //Largest possible input and output buffer sizes
}

void deinit(void) {
  window_destroy(window);
}

int main(void) {
  init();
  app_event_loop();
  deinit();
}

PebbleCommunicationToSmartPhone02JS

Pebble.addEventListener('ready',
    function (e) {
        console.log("JS4 Pebble.addEventListener ready ");
    });

Pebble.addEventListener("appmessage",
  function (e) {
      try {
        var selectedButton = "undefined";
        console.log(JSON.stringify(e.payload));
        if (e.payload["exchangeData"] == 1) 
        {
          console.log("Button SELECT");
          selectedButton = "SELECT";
        }
        if (e.payload["exchangeData"] == 2) 
        {
          console.log("Button UP");
          selectedButton = "UP";
        }
        if (e.payload["exchangeData"] == 3) 
        {
          console.log("Button DOWN");
          selectedButton = "DOWN";
        }
        
        Pebble.sendAppMessage({ exchangeData: selectedButton },
                              function (e) {
                                console.log("Successfully delivered message with transactionId=" + e.data.transactionId);
                              },
                              function (e) {
                                console.log("Unable to deliver message with transactionId=" + e.data.transactionId + " Error is: " + e.error.message);
                              }
                             );
      } catch (exc) {
          console.log("exception" + exc.message);
      }
  }
);