constraint: Add ClutterConstraint base class

The Constraint base, abstract class should be used to implement Actor
modifiers that affect the way an actor is sized or positioned inside a
fixed layout manager.

clutter/Makefile.am

@@ -88,6 +88,7 @@ source_h =					\
 	$(srcdir)/clutter-child-meta.h		\
 	$(srcdir)/clutter-clone.h		\
 	$(srcdir)/clutter-color.h		\
+	$(srcdir)/clutter-constraint.h		\
 	$(srcdir)/clutter-container.h		\
 	$(srcdir)/clutter-deprecated.h		\
 	$(srcdir)/clutter-device-manager.h	\
@@ -165,6 +166,7 @@ source_c = \
 	$(srcdir)/clutter-child-meta.c		\
 	$(srcdir)/clutter-clone.c		\
 	$(srcdir)/clutter-color.c 		\
+	$(srcdir)/clutter-constraint.c		\
 	$(srcdir)/clutter-container.c		\
 	$(srcdir)/clutter-device-manager.c	\
 	$(srcdir)/clutter-drag-action.c		\

clutter/clutter-actor.c

@@ -229,6 +229,7 @@
 
 #include "clutter-action.h"
 #include "clutter-actor-meta-private.h"
+#include "clutter-constraint.h"
 #include "clutter-container.h"
 #include "clutter-debug.h"
 #include "clutter-enum-types.h"
@@ -397,6 +398,7 @@ struct _ClutterActorPrivate
   const ClutterActorBox *oob_queue_redraw_clip;
 
   ClutterMetaGroup *actions;
+  ClutterMetaGroup *constraints;
 };
 
 enum
@@ -479,7 +481,8 @@ enum
   PROP_TEXT_DIRECTION,
   PROP_HAS_POINTER,
 
-  PROP_ACTIONS
+  PROP_ACTIONS,
+  PROP_CONSTRAINTS
 };
 
 enum
@@ -2904,6 +2907,10 @@ clutter_actor_set_property (GObject      *object,
       clutter_actor_add_action (actor, g_value_get_object (value));
       break;
 
+    case PROP_CONSTRAINTS:
+      clutter_actor_add_constraint (actor, g_value_get_object (value));
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -4031,6 +4038,20 @@ clutter_actor_class_init (ClutterActorClass *klass)
                                CLUTTER_PARAM_WRITABLE);
   g_object_class_install_property (object_class, PROP_ACTIONS, pspec);
 
+  /**
+   * ClutterActor:constraints:
+   *
+   * Adds a #ClutterConstaint to the actor
+   *
+   * Since: 1.4
+   */
+  pspec = g_param_spec_object ("constraints",
+                               "Constraints",
+                               "Adds a constraint to the actor",
+                               CLUTTER_TYPE_CONSTRAINT,
+                               CLUTTER_PARAM_WRITABLE);
+  g_object_class_install_property (object_class, PROP_CONSTRAINTS, pspec);
+
   /**
    * ClutterActor::destroy:
    * @actor: the object which received the signal
@@ -10318,3 +10339,118 @@ clutter_actor_clear_actions (ClutterActor *self)
 
   _clutter_meta_group_clear_metas (self->priv->actions);
 }
+
+/**
+ * clutter_actor_add_constraint:
+ * @self: a #ClutterActor
+ * @constraint: a #ClutterConstraint
+ *
+ * Adds @constraint to the list of #ClutterConstraint<!-- -->s applied
+ * to @self
+ *
+ * The #ClutterActor will hold a reference on the @constraint until
+ * either clutter_actor_remove_constraint() or
+ * clutter_actor_clear_constraints() is called.
+ *
+ * Since: 1.4
+ */
+void
+clutter_actor_add_constraint (ClutterActor      *self,
+                              ClutterConstraint *constraint)
+{
+  ClutterActorPrivate *priv;
+
+  g_return_if_fail (CLUTTER_IS_ACTOR (self));
+  g_return_if_fail (CLUTTER_IS_ACTION (constraint));
+
+  priv = self->priv;
+
+  if (priv->constraints == NULL)
+    {
+      priv->constraints = g_object_new (CLUTTER_TYPE_META_GROUP, NULL);
+      priv->constraints->actor = self;
+    }
+
+  _clutter_meta_group_add_meta (priv->constraints,
+                                CLUTTER_ACTOR_META (constraint));
+
+  g_object_notify (G_OBJECT (self), "constraints");
+}
+
+/**
+ * clutter_actor_remove_constraint:
+ * @self: a #ClutterActor
+ * @constraint: a #ClutterConstraint
+ *
+ * Removes @constraint from the list of constraints applied to @self
+ *
+ * The reference held by @self on the #ClutterConstraint will be released
+ *
+ * Since: 1.4
+ */
+void
+clutter_actor_remove_constraint (ClutterActor      *self,
+                                 ClutterConstraint *constraint)
+{
+  ClutterActorPrivate *priv;
+
+  g_return_if_fail (CLUTTER_IS_ACTOR (self));
+  g_return_if_fail (CLUTTER_IS_ACTION (constraint));
+
+  priv = self->priv;
+
+  if (priv->constraints == NULL)
+    return;
+
+  _clutter_meta_group_remove_meta (priv->constraints,
+                                   CLUTTER_ACTOR_META (constraint));
+
+  g_object_notify (G_OBJECT (self), "constraints");
+}
+
+/**
+ * clutter_actor_get_constraints:
+ * @self: a #ClutterActor
+ *
+ * Retrieves the list of constraints applied to @self
+ *
+ * Return value: (transfer container) (element-type ClutterConstraint): a copy
+ *   of the list of #ClutterConstraint<!-- -->s. The contents of the list are
+ *   owned by the #ClutterActor. Use g_list_free() to free the resources
+ *   allocated by the returned #GList
+ *
+ * Since: 1.4
+ */
+GList *
+clutter_actor_get_constraints (ClutterActor *self)
+{
+  const GList *constraints;
+
+  g_return_val_if_fail (CLUTTER_IS_ACTOR (self), NULL);
+
+  if (self->priv->constraints == NULL)
+    return NULL;
+
+  constraints = _clutter_meta_group_peek_metas (self->priv->constraints);
+
+  return g_list_copy ((GList *) constraints);
+}
+
+/**
+ * clutter_actor_clear_constraints:
+ * @self: a #ClutterActor
+ *
+ * Clears the list of constraints applied to @self
+ *
+ * Since: 1.4
+ */
+void
+clutter_actor_clear_constraints (ClutterActor *self)
+{
+  g_return_if_fail (CLUTTER_IS_ACTOR (self));
+
+  if (self->priv->constraints == NULL)
+    return;
+
+  _clutter_meta_group_clear_metas (self->priv->constraints);
+}

clutter/clutter-constraint.c

@@ -0,0 +1,21 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "clutter-constraint.h"
+
+#include "clutter-actor-meta-private.h"
+
+G_DEFINE_ABSTRACT_TYPE (ClutterConstraint,
+                        clutter_constraint,
+                        CLUTTER_TYPE_ACTOR_META);
+
+static void
+clutter_constraint_class_init (ClutterConstraintClass *klass)
+{
+}
+
+static void
+clutter_constraint_init (ClutterConstraint *self)
+{
+}

clutter/clutter-constraint.h

@@ -0,0 +1,100 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Copyright (C) 2010  Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author:
+ *   Emmanuele Bassi <ebassi@linux.intel.com>
+ */
+
+#if !defined(__CLUTTER_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <clutter/clutter.h> can be included directly."
+#endif
+
+#ifndef __CLUTTER_CONSTRAINT_H__
+#define __CLUTTER_CONSTRAINT_H__
+
+#include <clutter/clutter-actor-meta.h>
+
+G_BEGIN_DECLS
+
+#define CLUTTER_TYPE_CONSTRAINT                 (clutter_constraint_get_type ())
+#define CLUTTER_CONSTRAINT(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), CLUTTER_TYPE_CONSTRAINT, ClutterConstraint))
+#define CLUTTER_IS_CONSTRAINT(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), CLUTTER_TYPE_CONSTRAINT))
+#define CLUTTER_CONSTRAINT_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_CONSTRAINT, ClutterConstraintClass))
+#define CLUTTER_IS_CONSTRAINT_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_CONSTRAINT))
+#define CLUTTER_CONSTRAINT_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_CONSTRAINT, ClutterConstraintClass))
+
+typedef struct _ClutterConstraintPrivate        ClutterConstraintPrivate;
+typedef struct _ClutterConstraintClass          ClutterConstraintClass;
+
+/**
+ * ClutterConstraint:
+ *
+ * The <structname>ClutterConstraint</structname> structure contains only
+ * private data and should be accessed using the provided API
+ *
+ * Since: 1.4
+ */
+struct _ClutterConstraint
+{
+  /*< private >*/
+  ClutterActorMeta parent_instance;
+
+  ClutterConstraintPrivate *priv;
+};
+
+/**
+ * ClutterConstraintClass:
+ * @set_actor: virtual function, called when a constraint is applied to
+ *   a #ClutterActor
+ *
+ * The <structname>ClutterConstraintClass</structname> structure contains
+ * only private data
+ *
+ * Since: 1.4
+ */
+struct _ClutterConstraintClass
+{
+  /*< private >*/
+  ClutterActorMetaClass parent_class;
+
+  /*< private >*/
+  void (* _clutter_constraint1) (void);
+  void (* _clutter_constraint2) (void);
+  void (* _clutter_constraint3) (void);
+  void (* _clutter_constraint4) (void);
+  void (* _clutter_constraint5) (void);
+  void (* _clutter_constraint6) (void);
+  void (* _clutter_constraint7) (void);
+  void (* _clutter_constraint8) (void);
+};
+
+GType clutter_constraint_get_type (void) G_GNUC_CONST;
+
+/* ClutterActor API */
+void   clutter_actor_add_constraint    (ClutterActor      *actor,
+                                        ClutterConstraint *constraint);
+void   clutter_actor_remove_constraint (ClutterActor      *actor,
+                                        ClutterConstraint *constraint);
+GList *clutter_actor_get_constraints   (ClutterActor      *actor);
+void   clutter_actor_clear_constraints (ClutterActor      *actor);
+
+G_END_DECLS
+
+#endif /* __CLUTTER_CONSTRAINT_H__ */

clutter/clutter-types.h

@@ -45,11 +45,12 @@ typedef struct _ClutterStage            ClutterStage;
 typedef struct _ClutterContainer        ClutterContainer; /* dummy */
 typedef struct _ClutterChildMeta        ClutterChildMeta;
 typedef struct _ClutterLayoutMeta       ClutterLayoutMeta;
+typedef struct _ClutterActorMeta        ClutterActorMeta;
 
 typedef struct _ClutterAnimator         ClutterAnimator;
-typedef struct _ClutterAction           ClutterAction;
 
-typedef struct _ClutterActorMeta        ClutterActorMeta;
+typedef struct _ClutterAction           ClutterAction;
+typedef struct _ClutterConstraint       ClutterConstraint;
 
 typedef union _ClutterEvent             ClutterEvent;
 

clutter/clutter.h

@@ -53,6 +53,7 @@
 #include "clutter-child-meta.h"
 #include "clutter-clone.h"
 #include "clutter-color.h"
+#include "clutter-constraint.h"
 #include "clutter-container.h"
 #include "clutter-device-manager.h"
 #include "clutter-drag-action.h"