#include <gtk/gtk.h>

static GtkWidget *draw_area;
static GtkWidget *hruler;
static GtkWidget *vruler;

static int num_events;
static int num_paints;

static int xpos, ypos;
static int old_timestamp = 0;

static guint refresh_timeout_id = 0;

#define FRAMES_PER_SECOND 60

#define MSECS_BETWEEN_UPDATES (1000 / FRAMES_PER_SECOND)

static void
refresh_rulers (int x, int y)
{
	gtk_ruler_set_range (GTK_RULER (hruler),
			     0, draw_area->allocation.width,
			     x,
			     10);
	gtk_ruler_set_range (GTK_RULER (vruler),
			     0, draw_area->allocation.height,
			     y,
			     10);

	num_paints++;
}

static gboolean
refresh_timeout_cb (gpointer data)
{
	refresh_rulers (xpos, ypos);

	refresh_timeout_id = 0;
	return FALSE;
}

static gboolean
draw_area_motion_notify_event_cb (GtkWidget *widget,
				  GdkEventMotion *event,
				  gpointer data)
{
	int new_timestamp;

	xpos = event->x;
	ypos = event->y;
	new_timestamp = event->time;

	if (new_timestamp > old_timestamp + MSECS_BETWEEN_UPDATES) {
		if (refresh_timeout_id != 0) {
			g_source_remove (refresh_timeout_id);
			refresh_timeout_id = 0;
		}

		refresh_rulers (xpos, ypos);
	} else {
		if (refresh_timeout_id == 0)
			refresh_timeout_id = g_timeout_add (MSECS_BETWEEN_UPDATES, refresh_timeout_cb, NULL);
	}

	old_timestamp = new_timestamp;

	num_events++;
	return TRUE;
}

static gboolean
timeout_cb (gpointer data)
{
	g_print ("events: %d\tpaints: %d\n", num_events, num_paints);
	return TRUE;
}

int
main (int argc, char **argv)
{
	GtkWidget *window;
	GtkWidget *table;

	gtk_init (&argc, &argv);

	window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

	table = gtk_table_new (2, 2, FALSE);
	gtk_container_add (GTK_CONTAINER (window), table);

	draw_area = gtk_drawing_area_new ();
	gtk_widget_add_events (draw_area, GDK_POINTER_MOTION_MASK);
	gtk_table_attach (GTK_TABLE (table), draw_area,
			  1, 2, 1, 2,
			  GTK_EXPAND | GTK_FILL, GTK_EXPAND | GTK_FILL,
			  0, 0);
	g_signal_connect (draw_area, "motion-notify-event",
			  G_CALLBACK (draw_area_motion_notify_event_cb), NULL);

	hruler = gtk_hruler_new ();
	gtk_table_attach (GTK_TABLE (table), hruler,
			  1, 2, 0, 1,
			  GTK_EXPAND | GTK_FILL, 0,
			  0, 0);

	vruler = gtk_vruler_new ();
	gtk_table_attach (GTK_TABLE (table), vruler,
			  0, 1, 1, 2,
			  0, GTK_EXPAND | GTK_FILL,
			  0, 0);

	num_events = num_paints = 0;
	xpos = ypos = 0;
	g_timeout_add (1000, timeout_cb, NULL);

	gtk_widget_show_all (window);
	gtk_main ();

	return 0;
}