simple_pebble_watchface/src/main.c

#include <pebble.h>
#include <inttypes.h>
#include "pebble_utils.h"


#define KEY_TEMPERATURE 0
#define KEY_CONDITIONS  1
#define KEY_ROOM_TEMP   2
#define WEATHER_TIME    0


// Function signatures
static void update_time();
static void tick_handler(struct tm *tick_time, TimeUnits units_changed);
static void main_window_load(Window *window);
static void main_window_unload(Window *window);
static void init();
static void deinit();
static void inbox_received_callback(DictionaryIterator *iterator, void *context);
static void inbox_dropped_callback(AppMessageResult reason, void *context);
static void outbox_failed_callback(DictionaryIterator *iterator, AppMessageResult reason, void *context);
static void outbox_sent_callback(DictionaryIterator *iterator, void *context);


// Global variables
static Window      *s_main_window;
static TextLayer   *s_time_layer;
static TextLayer   *s_weather_layer;
static TextLayer   *s_room_layer;
static TextLayer   *s_daymonth_layer;
static GFont        s_time_font;
static GFont        s_weather_font;
static GFont        s_date_font;
static BitmapLayer *s_background_layer;
static GBitmap     *s_background_bitmap;



int main(void) {

  init();
  app_event_loop();
  deinit();

}


static void update_time() {

  // Get a tm structure
  const time_t temp = time(NULL);
  const struct tm *tick_time = localtime(&temp);

  // Create a long-lived buffer
  static char buffer[] = "00:00";

  // Write the current hours and minutes into the buffer
  if (clock_is_24h_style()) {
    // Use 24 hour format
    strftime(buffer, sizeof(buffer), "%H:%M", tick_time);
  } else {
    // Use 12 hour format
    strftime(buffer, sizeof(buffer), "%I:%M", tick_time);
  }

  // Display this time on the TextLayer
  text_layer_set_text(s_time_layer, buffer);

}


static void update_date() {

  // Get a tm structure
  const time_t temp = time(NULL);
  const struct tm *tick_time = localtime(&temp);

  // Create a long-lived buffer
  static char buffer_daymonth[] = "00.000";

  // Write the current hours and minutes into the buffer
  strftime(buffer_daymonth, sizeof(buffer_daymonth), "%e.%b", tick_time);

  // Display this time on the TextLayer
  text_layer_set_text(s_daymonth_layer, buffer_daymonth);

}


static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {

  update_time();
  if (units_changed & DAY_UNIT) {
    update_date();
  }

  if (persist_exists(WEATHER_TIME)) {
    (void) persist_delete(WEATHER_TIME);
  }

  // Get weather update every 30 minutes
  if (tick_time->tm_min % 30 == 0) {
    // Begin dictionary
    DictionaryIterator *iter;
    app_message_outbox_begin(&iter);

    // Add a key-value pair
    dict_write_value(iter, 0, (uint8_t)0);

    // Send the message!
    app_message_outbox_send();
  }

}


static void inbox_received_callback(DictionaryIterator *iterator, void *context) {

  // Store incoming information
  static char temperature_buffer[8];
  static char conditions_buffer[32];
  static char room_buffer[32];
  static char weather_layer_buffer[32];
  bool   got_weather = false;
  bool   got_room = false;

  // Read first item
  Tuple *t = dict_read_first(iterator);

  // For all items
  while(t != NULL) {

    // Which key was received?
    switch(t->key) {
      case KEY_TEMPERATURE:
        snprintf(temperature_buffer, sizeof(temperature_buffer), "%d", (int)t->value->int32);
        break;

      case KEY_CONDITIONS:
        snprintf(conditions_buffer, sizeof(conditions_buffer), "%s", t->value->cstring);
        got_weather = true;
        break;

      case KEY_ROOM_TEMP:
        snprintf(room_buffer, sizeof(room_buffer), "%s", t->value->cstring);
        got_room = true;
        break;

      default:
        APP_LOG(APP_LOG_LEVEL_ERROR, "Key %d not recognized!", (int)t->key);
        break;
    }

    // Look for next item
    t = dict_read_next(iterator);
  }

  // Assemble full string and display
  if (got_weather) {
    snprintf(weather_layer_buffer, sizeof(weather_layer_buffer), "%s°C, %s", temperature_buffer, conditions_buffer);
    text_layer_set_text(s_weather_layer, weather_layer_buffer);
  }

  if (got_room) {
    text_layer_set_text(s_room_layer, room_buffer);
  }

}


static void inbox_dropped_callback(AppMessageResult reason, void *context) {
  APP_LOG(APP_LOG_LEVEL_ERROR, "Message dropped!");
}


static void outbox_failed_callback(DictionaryIterator *iterator, AppMessageResult reason, void *context) {
  APP_LOG(APP_LOG_LEVEL_ERROR, "Outbox send failed!");
}


static void outbox_sent_callback(DictionaryIterator *iterator, void *context) {
  APP_LOG(APP_LOG_LEVEL_INFO, "Outbox send success!");
}


static void main_window_load(Window *window) {

  // Create GBitmap, then set to created BitmapLayer
  s_background_bitmap = gbitmap_create_with_resource(RESOURCE_ID_TUTORIAL_BACKGROUND);
  s_background_layer = bitmap_layer_create(GRect(0, 0, 144, 168));
  bitmap_layer_set_bitmap(s_background_layer, s_background_bitmap);

  // Create time TextLayer
  s_time_layer = text_layer_create(GRect(5, 52, 139, 50));
  text_layer_set_background_color(s_time_layer, GColorClear);
  text_layer_set_text_color(s_time_layer, GColorBlack);

  // Create temperature Layer
  s_weather_layer = text_layer_create(GRect(0, 130, 144, 20));
  text_layer_set_background_color(s_weather_layer, GColorClear);
  text_layer_set_text_color(s_weather_layer, GColorWhite);
  text_layer_set_text(s_weather_layer, "Loading...");

  // Create room temperature Layer
  s_room_layer = text_layer_create(GRect(0, 150, 144, 20));
  text_layer_set_background_color(s_room_layer, GColorClear);
  text_layer_set_text_color(s_room_layer, GColorWhite);
  text_layer_set_text(s_room_layer, "Loading...");

  // Create day-month TextLayer
  s_daymonth_layer = text_layer_create(GRect(5, 12, 139, 30));
  text_layer_set_background_color(s_daymonth_layer, GColorBlack);
  text_layer_set_text_color(s_daymonth_layer, GColorWhite);

  // Create GFont
  s_time_font = fonts_load_custom_font(resource_get_handle(RESOURCE_ID_FONT_PERFECT_DOS_48));
  s_weather_font = fonts_load_custom_font(resource_get_handle(RESOURCE_ID_FONT_PERFECT_DOS_16));
  s_date_font = fonts_load_custom_font(resource_get_handle(RESOURCE_ID_FONT_PERFECT_DOS_24));

  // Apply to TextLayer
  text_layer_set_font(s_time_layer, s_time_font);
  text_layer_set_font(s_weather_layer, s_weather_font);
  text_layer_set_font(s_room_layer, s_weather_font);
  text_layer_set_font(s_daymonth_layer, s_date_font);

  // Improve the layout to be more like a watchface
  text_layer_set_text_alignment(s_time_layer, GTextAlignmentCenter);
  text_layer_set_text_alignment(s_weather_layer, GTextAlignmentCenter);
  text_layer_set_text_alignment(s_room_layer, GTextAlignmentCenter);
  text_layer_set_text_alignment(s_daymonth_layer, GTextAlignmentCenter);

  // Add it as a child layer to the Window's root layer
  layer_add_child(window_get_root_layer(window), bitmap_layer_get_layer(s_background_layer));
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_time_layer));
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_weather_layer));
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_room_layer));
  layer_add_child(window_get_root_layer(window), text_layer_get_layer(s_daymonth_layer));

}


static void main_window_unload(Window *window) {

  // Destroy TextLayer
  text_layer_destroy(s_time_layer);
  text_layer_destroy(s_weather_layer);
  text_layer_destroy(s_room_layer);
  text_layer_destroy(s_daymonth_layer);

  // Unload GFont
  fonts_unload_custom_font(s_time_font);
  fonts_unload_custom_font(s_weather_font);
  fonts_unload_custom_font(s_date_font);

  // Destroy GBitmap
  gbitmap_destroy(s_background_bitmap);

  // Destroy BitmapLayer
  bitmap_layer_destroy(s_background_layer);

}


static void init() {

  // Create main Window element and assign to pointer
  s_main_window = window_create();

  // Set handlers to manage the elements inside the Window
  window_set_window_handlers(s_main_window, (WindowHandlers){
    .load = main_window_load,
    .unload = main_window_unload
  });

  // Show the Window on the watch, with animated=true
  window_stack_push(s_main_window, true);

  // Register with TickTimerService
  tick_timer_service_subscribe((MINUTE_UNIT | DAY_UNIT), tick_handler);

  // Register AppMessage callbacks
  app_message_register_inbox_received(inbox_received_callback);
  app_message_register_inbox_dropped(inbox_dropped_callback);
  app_message_register_outbox_failed(outbox_failed_callback);
  app_message_register_outbox_sent(outbox_sent_callback);

  // Open AppMessage
  app_message_open(app_message_inbox_size_maximum(), app_message_outbox_size_maximum());

  update_time();
  update_date();

}


static void deinit() {

  // Destroy Window
  window_destroy(s_main_window);

}