#include <gtk/gtk.h>

static void
color_changed (GObject *o, GParamSpec *pspect, gpointer data)
{
  GdkRGBA color;

  gtk_color_chooser_get_rgba (GTK_COLOR_CHOOSER (o), &color);
  g_print ("color changed: %g %g %g %g\n",
           color.red, color.green, color.blue, color.alpha);
}

static void
dialog_response (GtkDialog *dialog, gint response)
{
  GdkRGBA color;

  switch (response)
    {
    case GTK_RESPONSE_OK:
      gtk_color_chooser_get_rgba (GTK_COLOR_CHOOSER (dialog), &color);
      g_print ("color accepted: %g %g %g %g\n",
           color.red, color.green, color.blue, color.alpha);
      break;
    default:
      g_print ("canceled\n");
      break;
    }

  gtk_main_quit ();
}

static void
show_editor_cb (GtkWidget *dialog, GParamSpec *pspec, GtkWidget *button)
{
  gboolean show_editor;

  g_object_get (dialog, "show-editor", &show_editor, NULL);
  gtk_widget_set_visible (button, show_editor);
}

static void
go_to_palette (GtkWidget *button, GtkWidget *dialog)
{
  g_object_set (dialog, "show-editor", FALSE, NULL);
}

int
main (int argc, char *argv[])
{
  GtkWidget *dialog;
  GtkWidget *button;
  GtkWidget *aa;
  GtkWidget *image;
  gint i;

  gtk_init (NULL, NULL);

  dialog = gtk_color_chooser_dialog_new ("Select a color", NULL);

  button = gtk_button_new ();
  image = gtk_image_new_from_icon_name ("view-grid-symbolic", GTK_ICON_SIZE_MENU);
  gtk_widget_show (image);
  gtk_container_add (GTK_CONTAINER (button), image);
  aa = gtk_dialog_get_action_area (GTK_DIALOG (dialog));
  gtk_container_add (GTK_CONTAINER (aa), button);
  gtk_widget_set_no_show_all (button, TRUE);
  gtk_button_box_set_child_secondary (GTK_BUTTON_BOX (aa), button, TRUE);
  gtk_button_box_set_child_non_homogeneous (GTK_BUTTON_BOX (aa), button, TRUE);
  gtk_widget_set_tooltip_text (button, "Show color palette");
  g_signal_connect (dialog, "notify::show-editor", G_CALLBACK (show_editor_cb), button);
  g_signal_connect (button, "clicked", G_CALLBACK (go_to_palette), dialog);

  for (i = 1; i < argc; i++)
    {
      if (g_strcmp0 (argv[i], "--no-alpha") == 0)
        {
          g_print ("turning alpha off\n");
          gtk_color_chooser_set_use_alpha (GTK_COLOR_CHOOSER (dialog), FALSE);
        }
      else if (g_strcmp0 (argv[i], "--edit") == 0)
        {
          g_print ("starting in edit mode\n");
          g_object_set (dialog, "show-editor", TRUE, NULL);
        }
      else if (g_strcmp0 (argv[i], "--palette") == 0)
        {
          const gchar *c[4] = { "red", "maroon", "yellow", "green" };
          GdkRGBA color;
          GdkRGBA colors[36];
          gint i,j;
          gdouble f[5] = { 0.2, 0.35, 0.5, 0.65, 0.8 };

          g_print ("setting custom palette\n");
          for (i = 0; i < 4; i++)
            {
              gdk_rgba_parse (&color, c[i]);
              for (j = 0; j < 5; j++)
                {
                  colors[i*9 + j].red   = f[j]*color.red;
                  colors[i*9 + j].green = f[j]*color.green;
                  colors[i*9 + j].blue  = f[j]*color.blue;
                  colors[i*9 + j].alpha = 1;
                }
              for (j = 5; j < 9; j++)
                {
                  colors[i*9 + j].red   = f[9-j]*color.red + (1-f[9-j]);
                  colors[i*9 + j].green = f[9-j]*color.green + (1-f[9-j]);
                  colors[i*9 + j].blue  = f[9-j]*color.blue + (1-f[9-j]);
                  colors[i*9 + j].alpha = 1;
                }
            }
          gtk_color_chooser_add_palette (GTK_COLOR_CHOOSER (dialog),
                                         FALSE,
                                         9, 36,
                                         colors);
        }
    }

  g_signal_connect (dialog, "notify::color", G_CALLBACK (color_changed), NULL);
  g_signal_connect (dialog, "response", G_CALLBACK (dialog_response), NULL);

  gtk_widget_show_all (dialog);

  gtk_main ();

  return 0;
}