Problem with gtk_drawing_area

[Dani Mezher <dany mezher fi usj edu lb>]

    Hello,

     I'm working on the colorsel exemple and I'm trying to initialize
the drawing area
with a different color.
I can't do so since "drawingarea->window" is NULL in main whereas it is
not NULL in
color_changed_cb

Here is the code, I inserted to lines of code to print the values of
"drawingarea->window".

Can any body help me??

Regards
Dany Mezher

==================================================================

/* example-start colorsel colorsel.c */

#include <glib.h>
#include <gdk/gdk.h>
#include <gtk/gtk.h>

GtkWidget *colorseldlg = NULL;
GtkWidget *drawingarea = NULL;

/* Color changed handler */

void color_changed_cb( GtkWidget         *widget,
                       GtkColorSelection *colorsel )
{
  gdouble color[3];
  GdkColor gdk_color;
  GdkColormap *colormap;

  /* Get drawingarea colormap */

  colormap = gdk_window_get_colormap (drawingarea->window);

  /* Get current color */

  gtk_color_selection_get_color (colorsel,color);

  /* Fit to a unsigned 16 bit integer (0..65535) and
   * insert into the GdkColor structure */

  gdk_color.red = (guint16)(color[0]*65535.0);
  gdk_color.green = (guint16)(color[1]*65535.0);
  gdk_color.blue = (guint16)(color[2]*65535.0);

  /* Allocate color */

  gdk_color_alloc (colormap, &gdk_color);

  /* Set window background color */

  printf("drawingarea->window=%p\n",drawingarea->window);

  gdk_window_set_background (drawingarea->window, &gdk_color);

  /* Clear window */

  gdk_window_clear (drawingarea->window);
}

/* Drawingarea event handler */

gint area_event( GtkWidget *widget,
                 GdkEvent  *event,
                 gpointer   client_data )
{
  gint handled = FALSE;
  GtkWidget *colorsel;

  /* Check if we've received a button pressed event */

  if (event->type == GDK_BUTTON_PRESS && colorseldlg == NULL)
    {
      /* Yes, we have an event and there's no colorseldlg yet! */

      handled = TRUE;

      /* Create color selection dialog */

      colorseldlg = gtk_color_selection_dialog_new("Select background
color");

      /* Get the ColorSelection widget */

      colorsel = GTK_COLOR_SELECTION_DIALOG(colorseldlg)->colorsel;

      /* Connect to the "color_changed" signal, set the client-data
       * to the colorsel widget */

      gtk_signal_connect(GTK_OBJECT(colorsel), "color_changed",
        (GtkSignalFunc)color_changed_cb, (gpointer)colorsel);

      /* Show the dialog */

      gtk_widget_show(colorseldlg);
    }

  return handled;
}

/* Close down and exit handler */

gint destroy_window( GtkWidget *widget,
                     GdkEvent  *event,
                     gpointer   client_data )
{
  gtk_main_quit ();
  return(TRUE);
}

/* Main */

gint main( gint   argc,
           gchar *argv[] )
{
  GtkWidget *window;

  /* Initialize the toolkit, remove gtk-related commandline stuff */

  gtk_init (&argc,&argv);

  /* Create toplevel window, set title and policies */

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  gtk_window_set_title (GTK_WINDOW(window), "Color selection test");
  gtk_window_set_policy (GTK_WINDOW(window), TRUE, TRUE, TRUE);

  /* Attach to the "delete" and "destroy" events so we can exit */

  gtk_signal_connect (GTK_OBJECT(window), "delete_event",
    (GtkSignalFunc)destroy_window, (gpointer)window);

  /* Create drawingarea, set size and catch button events */

  drawingarea = gtk_drawing_area_new ();

  gtk_drawing_area_size (GTK_DRAWING_AREA(drawingarea), 200, 200);

  gtk_widget_set_events (drawingarea, GDK_BUTTON_PRESS_MASK);

  gtk_signal_connect (GTK_OBJECT(drawingarea), "event",
    (GtkSignalFunc)area_event, (gpointer)drawingarea);




 printf("drawingarea->window=%p\n",drawingarea->window);

  /* Add drawingarea to window, then show them both */

  gtk_container_add (GTK_CONTAINER(window), drawingarea);

  gtk_widget_show (drawingarea);
  gtk_widget_show (window);

  /* Enter the gtk main loop (this never returns) */

  gtk_main ();

  /* Satisfy grumpy compilers */

  return(0);
}
/* example-end */