#include <gtk/gtk.h>

#include <clutter/clutter.h>

#include <math.h>

#include <clutter-gtk/clutter-gtk.h>

#define MAX_NWIDGETS   4

#define WINWIDTH   400

#define WINHEIGHT  400

#define RADIUS     80

static ClutterActor *group = NULL;

static ClutterActor *widgets[MAX_NWIDGETS];

static gboolean do_rotate = TRUE;

static int nwidgets;

/* Timeline handler */

void

frame_cb (ClutterTimeline *timeline,

	  gint             msecs,

	  gpointer         data)

{

  double rotation = clutter_timeline_get_progress (timeline) * 360.0;

  gint i;

  if (!do_rotate)

    return;

  /* Rotate everything clockwise about stage center */

  clutter_actor_set_rotation_angle (group, CLUTTER_Z_AXIS, rotation);

  for (i = 0; i < nwidgets; i++)

    {

      clutter_actor_set_rotation_angle (widgets[i], CLUTTER_Z_AXIS, - 2 * rotation);

      clutter_actor_set_opacity (widgets[i], 50 * sin (2 * M_PI * rotation / 360) + (255 - 50));

    }

}

static void

button_clicked (GtkWidget *button,

		GtkWidget *vbox)

{

  GtkWidget *label;

  g_print ("button clicked\n");

  label = gtk_label_new ("A new label");

  gtk_widget_show (label);

  gtk_box_pack_start (GTK_BOX (vbox), label, FALSE, FALSE, 0);

}

static ClutterActor *

create_gtk_actor (int i)

{

  GtkWidget       *button, *vbox, *entry, *bin;

  ClutterActor    *gtk_actor;

  gtk_actor = gtk_clutter_actor_new ();

  bin = gtk_clutter_actor_get_widget (GTK_CLUTTER_ACTOR (gtk_actor));

  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);

  gtk_container_add (GTK_CONTAINER (bin), vbox);

  button = gtk_button_new_with_label ("A Button");

  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);

  g_signal_connect (button, "clicked", G_CALLBACK (button_clicked), vbox);

  button = gtk_check_button_new_with_label ("Another button");

  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);

  entry = gtk_entry_new ();

  gtk_box_pack_start (GTK_BOX (vbox), entry, FALSE, FALSE, 0);

  gtk_widget_show_all (bin);

  return gtk_actor;

}

static void

add_clutter_actor (ClutterActor *actor,

		   ClutterActor *container,

		   int           i)

{

  float x, y, w, h;

  /* Add to our group group */

  clutter_actor_add_child (container, actor);

  /* Place around a circle */

  w = clutter_actor_get_width (widgets[0]);

  h = clutter_actor_get_height (widgets[0]);

  x = WINWIDTH / 2  + RADIUS * cosf (i * 2 * M_PI / (MAX_NWIDGETS)) - w / 2;

  y = WINHEIGHT / 2 + RADIUS * sinf (i * 2 * M_PI / (MAX_NWIDGETS)) - h / 2;

  clutter_actor_set_position (actor, x, y);

  clutter_actor_set_pivot_point (actor, 0.5, 0.5);

}

static gboolean

add_or_remove_timeout (gpointer user_data)

{

  if (nwidgets == MAX_NWIDGETS)

    {

      /* Removing an item */

      clutter_actor_remove_child (group, widgets[MAX_NWIDGETS - 1]);

      widgets[MAX_NWIDGETS - 1] = NULL;

      nwidgets--;

    }

  else

    {

      /* Adding an item */

      widgets[MAX_NWIDGETS - 1] = create_gtk_actor (MAX_NWIDGETS - 1);

      nwidgets++;

      add_clutter_actor (widgets[MAX_NWIDGETS - 1], group, MAX_NWIDGETS - 1);

    }

  return G_SOURCE_CONTINUE;

}

int

main (int argc, char *argv[])

{

  ClutterTimeline *timeline;

  ClutterActor    *stage;

  ClutterColor     stage_color = { 0x61, 0x64, 0x8c, 0xff };

  GtkWidget       *window, *clutter;

  GtkWidget       *button, *vbox;

  gint             i;

  if (gtk_clutter_init_with_args (&argc, &argv, NULL, NULL, NULL, NULL) != CLUTTER_INIT_SUCCESS)

    g_error ("Unable to initialize GtkClutter");

  if (argc != 1)

    do_rotate = FALSE;

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);

  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);

  gtk_container_add (GTK_CONTAINER (window), vbox);

  clutter = gtk_clutter_embed_new ();

  gtk_widget_set_size_request (clutter, WINWIDTH, WINHEIGHT);

  gtk_box_pack_start (GTK_BOX (vbox), clutter, TRUE, TRUE, 0);

  stage = gtk_clutter_embed_get_stage (GTK_CLUTTER_EMBED (clutter));

  button = gtk_button_new_with_mnemonic ("_Quit");

  g_signal_connect_swapped (button, "clicked",

			    G_CALLBACK (gtk_widget_destroy),

			    window);

  gtk_box_pack_end (GTK_BOX (vbox), button, FALSE, FALSE, 0);

  clutter_actor_set_background_color (stage, &stage_color);

  nwidgets = 0;

  /* create a new group to hold multiple actors in a group */

  group = clutter_actor_new ();

  clutter_actor_set_pivot_point (group, 0.5, 0.5);

  for (i = 0; i < MAX_NWIDGETS; i++)

    {

      widgets[i] = create_gtk_actor (i);

      nwidgets++;

      add_clutter_actor (widgets[i], group, i);

    }

  /* Add the group to the stage and center it*/

  clutter_actor_add_child (stage, group);

  clutter_actor_add_constraint (group, clutter_align_constraint_new (stage, CLUTTER_ALIGN_BOTH, 0.5));

  gtk_widget_show_all (window);

  /* Create a timeline to manage animation */

  timeline = clutter_timeline_new (6000);

  clutter_timeline_set_repeat_count (timeline, -1);

  /* fire a callback for frame change */

  g_signal_connect (timeline, "new-frame",  G_CALLBACK (frame_cb), stage);

  /* and start it */

  clutter_timeline_start (timeline);

  g_timeout_add_seconds (3, add_or_remove_timeout, NULL);

  gtk_main();

  return 0;

}