#include <stdlib.h>
#include <clutter/clutter.h>

typedef struct
{
  ClutterActor    *stage;
  ClutterActor    *group;
  ClutterAnimator *animator;
} State;

static const ClutterColor stage_color = { 0x33, 0x33, 0x55, 0xff };
static const ClutterColor red_color = { 0xff, 0x00, 0x00, 0xff };
static const ClutterColor green_color = { 0x00, 0xff, 0x00, 0xff };
static const ClutterColor blue_color = { 0x00, 0x00, 0xff, 0xff };

/* add keys to the animator such that the actor is moved
 * to a random x position
 */
static void
add_keys_for_actor (ClutterActor *actor,
                    gpointer      user_data)
{
  ClutterAnimator *animator = CLUTTER_ANIMATOR (user_data);

  gfloat x, end_x;

  x = clutter_actor_get_x (actor);

  end_x = 50.0;
  if (x == 50.0)
    end_x = 225.0 + (100.0 * rand () / (RAND_MAX + 1.0));

  clutter_animator_set (animator,
                        actor, "x", CLUTTER_LINEAR, 0.0, x,
                        actor, "x", CLUTTER_EASE_OUT_CUBIC, 1.0, end_x,
                        NULL);
}

static gboolean
move_actors (ClutterActor *actor,
             ClutterEvent *event,
             gpointer      user_data)
{
  State *state = (State *) user_data;

  /* do nothing if the animator is already running */
  if (clutter_timeline_is_playing (clutter_animator_get_timeline (state->animator)))
    return TRUE;

  /* remove all keys from the animator */
  clutter_animator_remove_key (state->animator, NULL, NULL, -1);

  /* add keys for all actors in the group */
  clutter_container_foreach (CLUTTER_CONTAINER (state->group),
                             add_keys_for_actor,
                             state->animator);

  /* start the animation */
  clutter_animator_start (state->animator);

  return TRUE;
}

int
main (int   argc,
      char *argv[])
{
  /* seed random number generator */
  srand ((unsigned int) time (NULL));

  State *state = g_new0 (State, 1);

  ClutterActor *red;
  ClutterActor *green;
  ClutterActor *blue;

  clutter_init (&argc, &argv);

  state->animator = clutter_animator_new ();
  clutter_animator_set_duration (state->animator, 500);

  state->stage = clutter_stage_get_default ();
  clutter_actor_set_size (state->stage, 400, 350);
  clutter_stage_set_color (CLUTTER_STAGE (state->stage), &stage_color);
  g_signal_connect (state->stage,
                    "destroy",
                    G_CALLBACK (clutter_main_quit),
                    NULL);

  state->group = clutter_group_new ();

  red = clutter_rectangle_new_with_color (&red_color);
  clutter_actor_set_size (red, 50, 50);
  clutter_actor_set_position (red, 50, 50);

  green = clutter_rectangle_new_with_color (&green_color);
  clutter_actor_set_size (green, 50, 50);
  clutter_actor_set_position (green, 50, 150);

  blue = clutter_rectangle_new_with_color (&blue_color);
  clutter_actor_set_size (blue, 50, 50);
  clutter_actor_set_position (blue, 50, 250);

  g_signal_connect (state->stage,
                    "key-press-event",
                    G_CALLBACK (move_actors),
                    state);

  clutter_container_add (CLUTTER_CONTAINER (state->group),
                         red,
                         green,
                         blue,
                         NULL);
  clutter_container_add_actor (CLUTTER_CONTAINER (state->stage), state->group);

  clutter_actor_show (state->stage);

  clutter_main ();

  g_object_unref (state->animator);
  g_free (state);

  return EXIT_SUCCESS;
}
