[gdm] user-chooser: try to find fallback icon more aggressively

[Ray Strode <halfline src gnome org>]

commit 8a52950e5101a32cd8f9efd4854b0f63c0ccf1c3
Author: Ray Strode <rstrode redhat com>
Date:   Wed Jan 19 12:06:42 2011 -0500

    user-chooser: try to find fallback icon more aggressively
    
    Some themes won't give you the nearest icon at the requested size,
    so first look up the available sizes and choose the closest
    available one ourselves.
    
    If it fails, just fallback to an empty square of the right size.

 gui/simple-greeter/gdm-user-chooser-widget.c |   35 ++++++++++++++++++++++++-
 1 files changed, 33 insertions(+), 2 deletions(-)
---
diff --git a/gui/simple-greeter/gdm-user-chooser-widget.c b/gui/simple-greeter/gdm-user-chooser-widget.c
index 8df255f..6d03c38 100644
--- a/gui/simple-greeter/gdm-user-chooser-widget.c
+++ b/gui/simple-greeter/gdm-user-chooser-widget.c
@@ -833,6 +833,9 @@ get_pixbuf_from_icon_names (GdmUserChooserWidget *widget,
         int          size;
         const char  *icon_name;
         va_list      argument_list;
+        gint        *sizes;
+        gint         candidate_size;
+        int          i;
 
         array = g_ptr_array_new ();
 
@@ -849,9 +852,29 @@ get_pixbuf_from_icon_names (GdmUserChooserWidget *widget,
 
         size = get_icon_height_for_widget (GTK_WIDGET (widget));
 
+        sizes = gtk_icon_theme_get_icon_sizes (widget->priv->icon_theme, first_name);
+
+        candidate_size = 0;
+        for (i = 0; sizes[i] != 0; i++) {
+
+                /* scalable */
+                if (sizes[i] == -1) {
+                        candidate_size = sizes[i];
+                        break;
+                }
+
+                if (ABS (size - sizes[i]) < ABS (size - candidate_size)) {
+                        candidate_size = sizes[i];
+                }
+        }
+
+        if (candidate_size == 0) {
+                candidate_size = size;
+        }
+
         icon_info = gtk_icon_theme_choose_icon (widget->priv->icon_theme,
                                                 (const char **) array->pdata,
-                                                size,
+                                                candidate_size,
                                                 GTK_ICON_LOOKUP_GENERIC_FALLBACK);
         g_ptr_array_free (array, FALSE);
 
@@ -868,8 +891,16 @@ get_pixbuf_from_icon_names (GdmUserChooserWidget *widget,
                         g_error_free (error);
                 }
         } else {
+                GdkPixbuf *scaled_pixbuf;
+
+                guchar pixel = 0x00000000;
+
                 g_warning ("Could not find icon '%s' or fallbacks", first_name);
-                pixbuf = NULL;
+                pixbuf = gdk_pixbuf_new_from_data (&pixel, GDK_COLORSPACE_RGB,
+                                                   TRUE, 8, 1, 1, 1, NULL, NULL);
+                scaled_pixbuf = gdk_pixbuf_scale_simple (pixbuf, size, size, GDK_INTERP_NEAREST);
+                g_object_unref (pixbuf);
+                scaled_pixbuf = pixbuf;
         }
 
         return pixbuf;