[cairo] warning while executing gtk_widget_draw

[RAVI NANJUNDAPPA]

Hi, 

U can try this : This works fine for me.

#include <cairo.h>
#include <gtk/gtk.h>

static gboolean on_draw_event(GtkWidget *widget, cairo_t *cr, 
    gpointer user_data)
{      
gtk_widget_draw(widget, cr );
  return FALSE;
}

main()
{
    GtkDrawingArea *statistics;
    cairo_surface_t *surface;
    cairo_t *cr;
    GtkWindow *main_window;


    gtk_init( NULL, NULL );
    statistics = (GtkDrawingArea*)gtk_drawing_area_new();
    surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 120, 120);
    cr = cairo_create ( surface );
    cairo_surface_write_to_png( surface, "one.png" );
    main_window = (GtkWindow*)gtk_window_new(GTK_WINDOW_TOPLEVEL);

  g_signal_connect(G_OBJECT(main_window), "draw", G_CALLBACK(on_draw_event), NULL); 

g_signal_connect(G_OBJECT(main_window),"destroy",G_CALLBACK(gtk_main_quit),NULL);
    gtk_container_add (GTK_CONTAINER (main_window),(GtkWidget*)statistics);

    gtk_widget_show_all((GtkWidget*)main_window);

    gtk_main();
}

Thanks and Best Regards, 
N Ravi

------- Original Message -------
Sender : Lokesh Chakka<lvenkatakumarchakka at gmail.com>
Date : Aug 12, 2014 13:24 (GMT+05:30)
Title : [cairo] warning while executing gtk_widget_draw



Hello,


I have written one program and I am seeing the following warning:

Gtk-CRITICAL **: gtk_widget_draw: assertion '!widget->priv->alloc_needed' failed

program is as follows:

main()
{
    GtkDrawingArea *statistics;
    cairo_surface_t *surface;
    cairo_t *cr;
    GtkWindow *main_window;


    gtk_init( NULL, NULL );
    statistics = (GtkDrawingArea*)gtk_drawing_area_new();
    surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 120, 120);
    cr = cairo_create ( surface );
    gtk_widget_draw( (GtkWidget*)statistics, cr );
    cairo_surface_write_to_png( surface, "one.png" );
    main_window = (GtkWindow*)gtk_window_new(GTK_WINDOW_TOPLEVEL);
    g_signal_connect(G_OBJECT(main_window),"destroy",G_CALLBACK(gtk_main_quit),NULL);
    gtk_container_add (GTK_CONTAINER (main_window),(GtkWidget*)statistics);
    gtk_widget_show_all((GtkWidget*)main_window);

    gtk_main();
}


can some one please tell me the problem in the above program ?



Thanks & Regards
--
Lokesh Chakka,
Mobile: 9731023458