pebble-faces.c

#include <pebble.h>
#include "netdownload.h"

static Window *window;
static TextLayer *text_layer;
static BitmapLayer *bitmap_layer;
static GBitmap *current_bmp;

static char *images[] = {
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/cherie.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/mtole.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/chris.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/heiko.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/thomas.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/matt.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/katharine.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/katherine.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/alex.png",
  "http://assets.getpebble.com.s3-website-us-east-1.amazonaws.com/pebble-faces/lukasz.png"
};

static unsigned long image = 0;

void show_next_image() {
  // show that we are loading by showing no image
  bitmap_layer_set_bitmap(bitmap_layer, NULL);

  text_layer_set_text(text_layer, "Loading...");

  // Unload the current image if we had one and save a pointer to this one
  if (current_bmp) {
    gbitmap_destroy(current_bmp);
    current_bmp = NULL;
  }

  netdownload_request(images[image]);

  image++;
  if (image >= sizeof(images)/sizeof(char*)) {
    image = 0;
  }
}

static 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, "Shake it!");
  text_layer_set_text_alignment(text_layer, GTextAlignmentCenter);
  layer_add_child(window_layer, text_layer_get_layer(text_layer));

  bitmap_layer = bitmap_layer_create(bounds);
  layer_add_child(window_layer, bitmap_layer_get_layer(bitmap_layer));
  current_bmp = NULL;
}

static void window_unload(Window *window) {
  text_layer_destroy(text_layer);
  bitmap_layer_destroy(bitmap_layer);
  gbitmap_destroy(current_bmp);
}

void download_complete_handler(NetDownload *download) {
  printf("Loaded image with %lu bytes", download->length);
  printf("Heap free is %u bytes", heap_bytes_free());

  GBitmap *bmp = gbitmap_create_from_png_data(download->data, download->length);
  bitmap_layer_set_bitmap(bitmap_layer, bmp);

  // Save pointer to currently shown bitmap (to free it)
  if (current_bmp) {
    gbitmap_destroy(current_bmp);
  }
  current_bmp = bmp;

  // Free the memory now
  free(download->data);

  // We null it out now to avoid a double free
  download->data = NULL;
  netdownload_destroy(download);
}

void tap_handler(AccelAxisType accel, int32_t direction) {
  show_next_image();
}

static void init(void) {
  // Need to initialize this first to make sure it is there when
  // the window_load function is called by window_stack_push.
  netdownload_initialize(download_complete_handler);

  window = window_create();
  window_set_window_handlers(window, (WindowHandlers) {
    .load = window_load,
    .unload = window_unload,
  });
  window_stack_push(window, true);

  accel_tap_service_subscribe(tap_handler);
}

static void deinit(void) {
  netdownload_deinitialize(); // call this to avoid 20B memory leak
  window_destroy(window);
}

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