#include <stdlib.h>

#include <gtk/gtk.h>

#include <time.h>

#include <string.h>

GtkWidget *selection_button;

GtkWidget *selection_widget;

/* Callback when the user toggles the selection */

static void selection_toggled( GtkWidget *widget,

                               gint      *have_selection )

{

  if (GTK_TOGGLE_BUTTON (widget)->active)

    {

      *have_selection = gtk_selection_owner_set (selection_widget,

						 GDK_SELECTION_PRIMARY,

						 GDK_CURRENT_TIME);

      /* if claiming the selection failed, we return the button to

	 the out state */

      if (!*have_selection)

	gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (widget), FALSE);

    }

  else

    {

      if (*have_selection)

	{

	  /* Before clearing the selection by setting the owner to NULL,

	     we check if we are the actual owner */

	  if (gdk_selection_owner_get (GDK_SELECTION_PRIMARY) == widget->window)

	    gtk_selection_owner_set (NULL, GDK_SELECTION_PRIMARY,

				     GDK_CURRENT_TIME);

	  *have_selection = FALSE;

	}

    }

}

/* Called when another application claims the selection */

static gboolean selection_clear( GtkWidget         *widget,

                                 GdkEventSelection *event,

                                 gint              *have_selection )

{

  *have_selection = FALSE;

  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (selection_button), FALSE);

  return TRUE;

}

/* Supplies the current time as the selection. */

static void selection_handle( GtkWidget        *widget,

                              GtkSelectionData *selection_data,

                              guint             info,

                              guint             time_stamp,

                              gpointer          data )

{

  gchar *timestr;

  time_t current_time;

  current_time = time (NULL);

  timestr = asctime (localtime (&current_time));

  /* When we return a single string, it should not be null terminated.

     That will be done for us */

  gtk_selection_data_set (selection_data, GDK_SELECTION_TYPE_STRING,

			  8, timestr, strlen (timestr));

}

int main( int   argc,

          char *argv[] )

{

  GtkWidget *window;

  static int have_selection = FALSE;

  gtk_init (&argc, &argv);

  /* Create the toplevel window */

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

  gtk_window_set_title (GTK_WINDOW (window), "Event Box");

  gtk_container_set_border_width (GTK_CONTAINER (window), 10);

  g_signal_connect (window, "destroy",

		    G_CALLBACK (exit), NULL);

  /* Create a toggle button to act as the selection */

  selection_widget = gtk_invisible_new ();

  selection_button = gtk_toggle_button_new_with_label ("Claim Selection");

  gtk_container_add (GTK_CONTAINER (window), selection_button);

  gtk_widget_show (selection_button);

  g_signal_connect (selection_button, "toggled",

		    G_CALLBACK (selection_toggled), &have_selection);

  g_signal_connect (selection_widget, "selection-clear-event",

		    G_CALLBACK (selection_clear), &have_selection);

  gtk_selection_add_target (selection_widget,

			    GDK_SELECTION_PRIMARY,

			    GDK_SELECTION_TYPE_STRING,

		            1);

  g_signal_connect (selection_widget, "selection-get",

		    G_CALLBACK (selection_handle), &have_selection);

  gtk_widget_show (selection_button);

  gtk_widget_show (window);

  gtk_main ();

  return 0;

}