Fix GIcon implementation

The "new rules" for GIcon say that we must support serialisation via
g_icon_serialize() and loadability via GLoadableIcon, so implement both
of those.

Serialise GdkPixbuf by emitting a GVariant that will result in a
png-encoded GBytesIcon when deserialized.  The GLoadableIcon interface
is similar: we return a stream that will read out as a png.

Test the serialisation by round-tripping an image through this process
and ensuring that it is pixel-perfect.

https://bugzilla.gnome.org/show_bug.cgi?id=688820

1 files changed, 60 insertions, 0 deletions

diff --git a/tests/pixbuf-icon-serialize.c b/tests/pixbuf-icon-serialize.c
new file mode 100644
index 000000000..7d35a20af
--- /dev/null
+++ b/tests/pixbuf-icon-serialize.c
@@ -0,0 +1,60 @@
+#include "config.h"
+#include "gdk-pixbuf/gdk-pixbuf.h"
+#include <string.h>
+#include <glib.h>
+
+static void
+test_serialize (void)
+{
+  GError *error = NULL;
+  GdkPixbuf *pixbuf;
+  GdkPixbuf *pixbuf2;
+  GVariant *data;
+  GIcon *icon;
+  GInputStream *stream;
+
+  pixbuf = gdk_pixbuf_new_from_file (ABS_SRCDIR "/test-image.png", &error);
+  g_assert_no_error (error);
+  g_assert (pixbuf != NULL);
+
+  /* turn it into a GVariant */
+  data = g_icon_serialize (G_ICON (pixbuf));
+
+  /* back to a GIcon, but this will be a GBytesIcon, not GdkPixbuf */
+  icon = g_icon_deserialize (data);
+  g_assert (G_IS_BYTES_ICON (icon));
+
+  /* but since that is a GLoadableIcon, we can load it again */
+  stream = g_loadable_icon_load (G_LOADABLE_ICON (icon), 0, NULL, NULL, &error);
+  g_assert_no_error (error);
+  pixbuf2 = gdk_pixbuf_new_from_stream (stream, NULL, &error);
+  g_assert_no_error (error);
+
+  /* make sure that the pixels are the same.
+   * our _serialize() uses png, so this should be perfect.
+   */
+  {
+    guchar *pixels_a, *pixels_b;
+    guint len_a, len_b;
+    pixels_a = gdk_pixbuf_get_pixels_with_length (pixbuf, &len_a);
+    pixels_b = gdk_pixbuf_get_pixels_with_length (pixbuf2, &len_b);
+    g_assert (len_a == len_b);
+    g_assert (memcmp (pixels_a, pixels_b, len_a) == 0);
+  }
+
+  g_object_unref (pixbuf2);
+  g_object_unref (pixbuf);
+  g_object_unref (stream);
+  g_variant_unref (data);
+
+}
+
+int
+main (int argc, char **argv)
+{
+  g_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/pixbuf/icon/serialize", test_serialize);
+
+  return g_test_run ();
+}