I have just compiled a c program that is supposed to simply display an about dialog box but I am getting an error on the output.

Error:

about.c: In function ‘main’:
about.c:26: warning: unused variable ‘about’

Here's the code:

#include <gtk/gtk.h>

void show_about(GtkWidget *widget, gpointer data)
{

  GdkPixbuf *pixbuf = gdk_pixbuf_new_from_file("battery.png", NULL);

  GtkWidget *dialog = gtk_about_dialog_new();
  gtk_about_dialog_set_name(GTK_ABOUT_DIALOG(dialog), "Battery");
  gtk_about_dialog_set_version(GTK_ABOUT_DIALOG(dialog), "0.9"); 
  gtk_about_dialog_set_copyright(GTK_ABOUT_DIALOG(dialog), "(c) Jan Bodnar");
  gtk_about_dialog_set_comments(GTK_ABOUT_DIALOG(dialog), "Battery is a simple tool for battery checking.");
  gtk_about_dialog_set_website(GTK_ABOUT_DIALOG(dialog), "http://www.batteryhq.net");
  gtk_about_dialog_set_logo(GTK_ABOUT_DIALOG(dialog), pixbuf);
  g_object_unref(pixbuf), pixbuf = NULL;
  gtk_dialog_run(GTK_DIALOG (dialog));
  gtk_widget_destroy(dialog);

}


int main( int argc, char *argv[])
{

  GtkWidget *window;
  GtkWidget *about;
  GdkPixbuf *battery;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
  gtk_window_set_default_size(GTK_WINDOW(window), 220, 150);
  gtk_window_set_title(GTK_WINDOW(window), "Battery");

  gtk_container_set_border_width(GTK_CONTAINER(window), 15);
  gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);

  battery = gtk_image_get_pixbuf(GTK_IMAGE(
  gtk_image_new_from_file("battery.jpeg")));

  g_signal_connect(G_OBJECT(window), "button-press-event", 
  G_CALLBACK(show_about), (gpointer) window); 

  g_signal_connect_swapped(G_OBJECT(window), "destroy",
  G_CALLBACK(gtk_main_quit), G_OBJECT(window));

  gtk_widget_show_all(window);

  gtk_main();

  return 0;
}

Can someone help find the problem?

Thanks guys!
-Brian

You create a reference with

GtkWidget *about;

but it is not used in the function.

And you don't get an error, you get a warning.
The warning is there mainly to raise your awareness on a "not so optimal" thing.
Here, that you reserve system resources for something you don't use.

...Still having problems trying to fix this, can someone be a bit more informative with the solution?

just remove the reference and the warning will go away.

Originally Posted by chrishirst

just remove the reference and the warning will go away.

Maybe I am missing the reference part of the script, because when I tried removing the part, the output would just be a blank window. Nothing else is displaying like it should,

not even the text.

Excuse me on that one, the title in the window does display, but not the rest of the code...

Just give "about" some pointless value then.

Ok, I figure it out, but what I want to eliminate is the need to first click on the empty window to display the actual script. So another words, when I run the script, I get a blank window, then I have to click the blank window for a new window to come up with the content. How do I remove the first empty window?

Thanks again!
-Brian

run it in debug and trace the execution.

Thanks chris, that was a good thought...Don't know why I didn't think of that before.

Been there many times

Staring at lines of code and thinking "Well THAT shouldn't happen"!!

I had smoke coming off a microcontroller one day because I didn't allow for the possibility of having no devices on the comms, and the code went into a locked loop looking for nothing to "talk" to.

I guess computer too, need another to talk to sometimes...Loneliness is not just for humanoids any more. LoL

Edit: Going to run debug on the code right now