gtk: implement -full-screen

Aiming for GTK as replacement for SDL, a feature like -full-screen should also
be implemented.

Bringing the window into full-screen mode is done by activating the "Fullscreen"
menu item. This is done after showing the windows to make the cursor and menu
hidden.

v2: drop -no-frame implementation, use booleans instead of ints and ensure
    consistency between ui state and menu.

Signed-off-by: Peter Wu <lekensteyn@gmail.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

include/ui/console.h

@@ -339,6 +339,6 @@ int index_from_keycode(int code);
 
 /* gtk.c */
 void early_gtk_display_init(void);
-void gtk_display_init(DisplayState *ds);
+void gtk_display_init(DisplayState *ds, bool full_screen);
 
 #endif

ui/gtk.c

@@ -1435,7 +1435,7 @@ static const DisplayChangeListenerOps dcl_ops = {
     .dpy_cursor_define = gd_cursor_define,
 };
 
-void gtk_display_init(DisplayState *ds)
+void gtk_display_init(DisplayState *ds, bool full_screen)
 {
     GtkDisplayState *s = g_malloc0(sizeof(*s));
     char *filename;
@@ -1511,6 +1511,10 @@ void gtk_display_init(DisplayState *ds)
 
     gtk_widget_show_all(s->window);
 
+    if (full_screen) {
+        gtk_menu_item_activate(GTK_MENU_ITEM(s->full_screen_item));
+    }
+
     register_displaychangelistener(&s->dcl);
 
     global_state = s;

vl.c

@@ -4348,7 +4348,7 @@ int main(int argc, char **argv, char **envp)
 #endif
 #if defined(CONFIG_GTK)
     case DT_GTK:
-        gtk_display_init(ds);
+        gtk_display_init(ds, full_screen);
         break;
 #endif
     default: