From 1ca0c2a6d1ce7477b4c31c507603c870f298c79d Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@linux.intel.com>
Date: Sun, 8 Aug 2010 19:17:14 +0100
Subject: [PATCH] state: Return a boolean when getting the key value

Since the copy might fail, we should return a boolean value and not just
warn on the console - similarly to what ClutterAnimator does.
---
 clutter/clutter-state.c | 26 ++++++++++++++++++--------
 clutter/clutter-state.h |  2 +-
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/clutter/clutter-state.c b/clutter/clutter-state.c
index bafd6ca1c..5ebfa8005 100644
--- a/clutter/clutter-state.c
+++ b/clutter/clutter-state.c
@@ -1403,20 +1403,26 @@ clutter_state_key_get_mode (const ClutterStateKey *state_key)
  * @state_key: a #ClutterStateKey
  * @value: a #GValue initialized with the correct type for the @state_key
  *
- * Copies of the value for a #ClutterStateKey into @value
+ * Retrieves a copy of the value for a #ClutterStateKey.
  *
  * The #GValue needs to be already initialized for the value type
- * of the property or to a transformable type
+ * of the property or to a type that allow transformation from the value
+ * type of the key.
+ *
+ * Use g_value_unset() when done.
+ *
+ * Return value: %TRUE if the value was successfully retrieved,
+ *   and %FALSE otherwise
  *
  * Since: 1.4
  */
-void
+gboolean
 clutter_state_key_get_value (const ClutterStateKey *state_key,
                              GValue                *value)
 {
-  g_return_if_fail (state_key != NULL);
-  g_return_if_fail (value != NULL);
-  g_return_if_fail (G_VALUE_TYPE (value) != G_TYPE_INVALID);
+  g_return_val_if_fail (state_key != NULL, FALSE);
+  g_return_val_if_fail (value != NULL, FALSE);
+  g_return_val_if_fail (G_VALUE_TYPE (value) != G_TYPE_INVALID, FALSE);
 
   if (!g_type_is_a (G_VALUE_TYPE (&state_key->value), G_VALUE_TYPE (value)))
     {
@@ -1424,14 +1430,14 @@ clutter_state_key_get_value (const ClutterStateKey *state_key,
                                    G_VALUE_TYPE (value)))
         {
           g_value_copy (&state_key->value, value);
-          return;
+          return TRUE;
         }
 
       if (g_value_type_transformable (G_VALUE_TYPE (&state_key->value),
                                       G_VALUE_TYPE (value)))
         {
           if (g_value_transform (&state_key->value, value))
-            return;
+            return TRUE;
         }
 
       g_warning ("%s: Unable to convert from %s to %s for the "
@@ -1441,9 +1447,13 @@ clutter_state_key_get_value (const ClutterStateKey *state_key,
                  g_type_name (G_VALUE_TYPE (value)),
                  state_key->property_name,
                  G_OBJECT_TYPE_NAME (state_key->object));
+
+      return FALSE;
     }
   else
     g_value_copy (&state_key->value, value);
+
+  return TRUE;
 }
 
 /**
diff --git a/clutter/clutter-state.h b/clutter/clutter-state.h
index 414ea247e..9a2904d45 100644
--- a/clutter/clutter-state.h
+++ b/clutter/clutter-state.h
@@ -147,7 +147,7 @@ GType                 clutter_state_key_get_type              (void) G_GNUC_CONS
 gdouble               clutter_state_key_get_pre_delay         (const ClutterStateKey *state_key);
 gdouble               clutter_state_key_get_post_delay        (const ClutterStateKey *state_key);
 gulong                clutter_state_key_get_mode              (const ClutterStateKey *state_key);
-void                  clutter_state_key_get_value             (const ClutterStateKey *state_key,
+gboolean              clutter_state_key_get_value             (const ClutterStateKey *state_key,
                                                                GValue                *value);
 GType                 clutter_state_key_get_property_type     (const ClutterStateKey *key);
 GObject *             clutter_state_key_get_object            (const ClutterStateKey *state_key);