From 4a21425f4837798d01f4435b68582faf9029c61c Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@linux.intel.com>
Date: Sun, 13 Dec 2009 01:23:54 +0000
Subject: [PATCH] layout: Let begin_animation() return the Alpha

When beginning a new animation for a LayoutManager, the implementation
should return the ClutterAlpha used. This allows controlling the
timeline and/or modifying the animation parameters on the fly.
---
 clutter/clutter-box-layout.c     |  5 +++--
 clutter/clutter-layout-manager.c | 30 ++++++++++++++++++++++--------
 clutter/clutter-layout-manager.h |  5 +++--
 3 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/clutter/clutter-box-layout.c b/clutter/clutter-box-layout.c
index 00b16256a..f9a7dbb0d 100644
--- a/clutter/clutter-box-layout.c
+++ b/clutter/clutter-box-layout.c
@@ -967,7 +967,7 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
   g_list_free (children);
 }
 
-static void
+static ClutterAlpha *
 clutter_box_layout_begin_animation (ClutterLayoutManager *manager,
                                     guint                 duration,
                                     gulong                easing)
@@ -982,7 +982,8 @@ clutter_box_layout_begin_animation (ClutterLayoutManager *manager,
 
   /* we want the default implementation */
   parent_class = CLUTTER_LAYOUT_MANAGER_CLASS (clutter_box_layout_parent_class);
-  parent_class->begin_animation (manager, duration, easing);
+
+  return parent_class->begin_animation (manager, duration, easing);
 }
 
 static void
diff --git a/clutter/clutter-layout-manager.c b/clutter/clutter-layout-manager.c
index 251f3e647..35b624f1d 100644
--- a/clutter/clutter-layout-manager.c
+++ b/clutter/clutter-layout-manager.c
@@ -226,7 +226,7 @@ layout_manager_real_get_child_meta_type (ClutterLayoutManager *manager)
   return G_TYPE_INVALID;
 }
 
-static void
+static ClutterAlpha *
 layout_manager_real_begin_animation (ClutterLayoutManager *manager,
                                      guint                 duration,
                                      gulong                mode)
@@ -236,7 +236,14 @@ layout_manager_real_begin_animation (ClutterLayoutManager *manager,
 
   alpha = g_object_get_qdata (G_OBJECT (manager), quark_layout_alpha);
   if (alpha != NULL)
-    return;
+    {
+      timeline = clutter_alpha_get_timeline (alpha);
+      clutter_timeline_set_duration (timeline, duration);
+
+      clutter_alpha_set_mode (alpha, mode);
+
+      return alpha;
+    };
 
   timeline = clutter_timeline_new (duration);
   alpha = clutter_alpha_new_full (timeline, mode);
@@ -254,6 +261,8 @@ layout_manager_real_begin_animation (ClutterLayoutManager *manager,
                            (GDestroyNotify) g_object_unref);
 
   clutter_timeline_start (timeline);
+
+  return alpha;
 }
 
 static gdouble
@@ -1004,19 +1013,24 @@ clutter_layout_manager_list_child_properties (ClutterLayoutManager *manager,
  *
  * The result of this function depends on the @manager implementation
  *
+ * Return value: (transfer none): The #ClutterAlpha created by the
+ *   layout manager; the returned instance is owned by the layout
+ *   manager and should not be unreferenced
+ *
  * Since: 1.2
  */
-void
+ClutterAlpha *
 clutter_layout_manager_begin_animation (ClutterLayoutManager *manager,
                                         guint                 duration,
                                         gulong                mode)
 {
-  g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
-  g_return_if_fail (duration > 0 && duration < 1000);
+  ClutterLayoutManagerClass *klass;
 
-  CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager)->begin_animation (manager,
-                                                               duration,
-                                                               mode);
+  g_return_val_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager), NULL);
+
+  klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
+
+  return klass->begin_animation (manager, duration, mode);
 }
 
 /**
diff --git a/clutter/clutter-layout-manager.h b/clutter/clutter-layout-manager.h
index 1271a3db4..e249b6b1a 100644
--- a/clutter/clutter-layout-manager.h
+++ b/clutter/clutter-layout-manager.h
@@ -30,6 +30,7 @@
 #define __CLUTTER_LAYOUT_MANAGER_H__
 
 #include <clutter/clutter-actor.h>
+#include <clutter/clutter-alpha.h>
 #include <clutter/clutter-container.h>
 #include <clutter/clutter-types.h>
 
@@ -126,7 +127,7 @@ struct _ClutterLayoutManagerClass
                                                  ClutterContainer       *container,
                                                  ClutterActor           *actor);
 
-  void               (* begin_animation)        (ClutterLayoutManager   *manager,
+  ClutterAlpha *     (* begin_animation)        (ClutterLayoutManager   *manager,
                                                  guint                   duration,
                                                  gulong                  mode);
   gdouble            (* get_animation_progress) (ClutterLayoutManager   *manager);
@@ -198,7 +199,7 @@ void               clutter_layout_manager_child_get_property    (ClutterLayoutMa
                                                                  const gchar            *property_name,
                                                                  GValue                 *value);
 
-void               clutter_layout_manager_begin_animation       (ClutterLayoutManager   *manager,
+ClutterAlpha *     clutter_layout_manager_begin_animation       (ClutterLayoutManager   *manager,
                                                                  guint                   duration,
                                                                  gulong                  mode);
 void               clutter_layout_manager_end_animation         (ClutterLayoutManager   *manager);