[mutter] compositor: Add MetaDnDActor

[Jasper St. Pierre <jstpierre src gnome org>]

commit 28e59c5a8f70e2d6e9a10da1e0063be945de936e
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Oct 6 16:53:04 2014 +0200

    compositor: Add MetaDnDActor
    
    This actor is a subclass of MetaFeedbackActor that additionally
    implements the "drag failed" animation, snapping back to the drag
    origin position in a surface.

 src/Makefile.am                         |    2 +
 src/compositor/meta-dnd-actor-private.h |   64 +++++++++
 src/compositor/meta-dnd-actor.c         |  231 +++++++++++++++++++++++++++++++
 3 files changed, 297 insertions(+), 0 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index 7f3418d..3a92f5f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -109,6 +109,8 @@ libmutter_la_SOURCES =                              \
        compositor/meta-background-group.c      \
        compositor/meta-cullable.c              \
        compositor/meta-cullable.h              \
+       compositor/meta-dnd-actor.c             \
+       compositor/meta-dnd-actor-private.h     \
        compositor/meta-feedback-actor.c        \
        compositor/meta-feedback-actor-private.h        \
        compositor/meta-module.c                \
diff --git a/src/compositor/meta-dnd-actor-private.h b/src/compositor/meta-dnd-actor-private.h
new file mode 100644
index 0000000..63a05f9
--- /dev/null
+++ b/src/compositor/meta-dnd-actor-private.h
@@ -0,0 +1,64 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * meta-dnd-actor-private.h: Actor for painting the DnD surface
+ *
+ * Copyright 2014 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Carlos Garnacho <carlosg gnome org>
+ */
+
+#ifndef META_DND_ACTOR_PRIVATE_H
+#define META_DND_ACTOR_PRIVATE_H
+
+#include "meta-feedback-actor-private.h"
+
+/**
+ * MetaDnDActor:
+ *
+ * This class handles the rendering of the DnD surface
+ */
+
+#define META_TYPE_DND_ACTOR            (meta_dnd_actor_get_type ())
+#define META_DND_ACTOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_DND_ACTOR, 
MetaDnDActor))
+#define META_DND_ACTOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), META_TYPE_DND_ACTOR, 
MetaDnDActorClass))
+#define META_IS_DND_ACTOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_TYPE_DND_ACTOR))
+#define META_IS_DND_ACTOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), META_TYPE_DND_ACTOR))
+#define META_DND_ACTOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), META_TYPE_DND_ACTOR, 
MetaDnDActorClass))
+
+typedef struct _MetaDnDActor        MetaDnDActor;
+typedef struct _MetaDnDActorClass   MetaDnDActorClass;
+
+struct _MetaDnDActorClass
+{
+  /*< private >*/
+  MetaFeedbackActorClass parent_class;
+};
+
+struct _MetaDnDActor
+{
+  MetaFeedbackActor parent;
+};
+
+GType         meta_dnd_actor_get_type (void);
+
+ClutterActor *meta_dnd_actor_new (ClutterActor *drag_origin,
+                                  int           start_x,
+                                  int           start_y);
+
+void          meta_dnd_actor_drag_finish (MetaDnDActor *self,
+                                          gboolean      success);
+
+#endif /* META_DND_ACTOR_PRIVATE_H */
diff --git a/src/compositor/meta-dnd-actor.c b/src/compositor/meta-dnd-actor.c
new file mode 100644
index 0000000..de58060
--- /dev/null
+++ b/src/compositor/meta-dnd-actor.c
@@ -0,0 +1,231 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * Copyright 2014 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Carlos Garnacho <carlosg gnome org>
+ */
+
+/**
+ * SECTION:meta-dnd-actor
+ * @title: MetaDnDActor
+ * @short_description: Actor for painting the drag and drop surface
+ *
+ */
+
+#include <config.h>
+
+#include <clutter/clutter.h>
+
+#include "meta-dnd-actor-private.h"
+
+#define DRAG_FAILED_DURATION 500
+
+enum {
+  PROP_DRAG_ORIGIN = 1,
+  PROP_DRAG_START_X,
+  PROP_DRAG_START_Y
+};
+
+typedef struct _MetaDnDActorPrivate MetaDnDActorPrivate;
+
+struct _MetaDnDActorPrivate
+{
+  ClutterActor *drag_origin;
+  int drag_start_x;
+  int drag_start_y;
+};
+
+G_DEFINE_TYPE_WITH_PRIVATE (MetaDnDActor, meta_dnd_actor, META_TYPE_FEEDBACK_ACTOR)
+
+static void
+meta_dnd_actor_set_property (GObject      *object,
+                             guint         prop_id,
+                             const GValue *value,
+                             GParamSpec   *pspec)
+{
+  MetaDnDActor *self = META_DND_ACTOR (object);
+  MetaDnDActorPrivate *priv = meta_dnd_actor_get_instance_private (self);
+
+  switch (prop_id)
+    {
+    case PROP_DRAG_ORIGIN:
+      priv->drag_origin = g_value_get_object (value);
+      break;
+    case PROP_DRAG_START_X:
+      priv->drag_start_x = g_value_get_int (value);
+      break;
+    case PROP_DRAG_START_Y:
+      priv->drag_start_y = g_value_get_int (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+meta_dnd_actor_get_property (GObject      *object,
+                             guint         prop_id,
+                             GValue       *value,
+                             GParamSpec   *pspec)
+{
+  MetaDnDActor *self = META_DND_ACTOR (object);
+  MetaDnDActorPrivate *priv = meta_dnd_actor_get_instance_private (self);
+
+  switch (prop_id)
+    {
+    case PROP_DRAG_ORIGIN:
+      g_value_set_object (value, priv->drag_origin);
+      break;
+    case PROP_DRAG_START_X:
+      g_value_set_int (value, priv->drag_start_x);
+      break;
+    case PROP_DRAG_START_Y:
+      g_value_set_int (value, priv->drag_start_y);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+meta_dnd_actor_class_init (MetaDnDActorClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GParamSpec *pspec;
+
+  object_class->set_property = meta_dnd_actor_set_property;
+  object_class->get_property = meta_dnd_actor_get_property;
+
+  pspec = g_param_spec_object ("drag-origin",
+                               "Drag origin",
+                               "The origin of the DnD operation",
+                               CLUTTER_TYPE_ACTOR,
+                               G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_property (object_class,
+                                   PROP_DRAG_ORIGIN,
+                                   pspec);
+
+  pspec = g_param_spec_int ("drag-start-x",
+                            "Drag start X",
+                            "The X axis of the drag start point",
+                            0, G_MAXINT, 0,
+                            G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_property (object_class,
+                                   PROP_DRAG_START_X,
+                                   pspec);
+
+  pspec = g_param_spec_int ("drag-start-y",
+                            "Drag start Y",
+                            "The Y axis of the drag start point",
+                            0, G_MAXINT, 0,
+                            G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY);
+
+  g_object_class_install_property (object_class,
+                                   PROP_DRAG_START_Y,
+                                   pspec);
+}
+
+static void
+meta_dnd_actor_init (MetaDnDActor *self)
+{
+}
+
+/**
+ * meta_dnd_actor_new:
+ *
+ * Creates a new actor to draw the current drag and drop surface.
+ *
+ * Return value: the newly created background actor
+ */
+ClutterActor *
+meta_dnd_actor_new (ClutterActor *drag_origin,
+                    int           drag_start_x,
+                    int           drag_start_y)
+{
+  MetaDnDActor *self;
+
+  self = g_object_new (META_TYPE_DND_ACTOR,
+                       "drag-origin", drag_origin,
+                       "drag-start-x", drag_start_x,
+                       "drag-start-y", drag_start_y,
+                       NULL);
+
+  return CLUTTER_ACTOR (self);
+}
+
+static void
+drag_failed_complete (ClutterTimeline *timeline,
+                      gboolean         is_finished,
+                      gpointer         user_data)
+{
+  ClutterActor *self = user_data;
+
+  clutter_actor_remove_all_children (self);
+  clutter_actor_destroy (self);
+}
+
+void
+meta_dnd_actor_drag_finish (MetaDnDActor *self,
+                            gboolean      success)
+{
+  MetaDnDActorPrivate *priv;
+  ClutterActor *actor;
+
+  g_return_if_fail (META_IS_DND_ACTOR (self));
+
+  actor = CLUTTER_ACTOR (self);
+  priv = meta_dnd_actor_get_instance_private (self);
+
+  if (success)
+    {
+      clutter_actor_remove_all_children (CLUTTER_ACTOR (self));
+      clutter_actor_destroy (CLUTTER_ACTOR (self));
+    }
+  else
+    {
+      ClutterTransition *transition;
+
+      clutter_actor_save_easing_state (actor);
+      clutter_actor_set_easing_mode (actor, CLUTTER_EASE_OUT_CUBIC);
+      clutter_actor_set_easing_duration (actor, DRAG_FAILED_DURATION);
+      clutter_actor_set_opacity (actor, 0);
+
+      if (CLUTTER_ACTOR_IS_VISIBLE (priv->drag_origin))
+        {
+          int anchor_x, anchor_y;
+          ClutterPoint dest;
+
+          clutter_actor_get_transformed_position (priv->drag_origin,
+                                                  &dest.x, &dest.y);
+          meta_feedback_actor_get_anchor (META_FEEDBACK_ACTOR (self),
+                                          &anchor_x, &anchor_y);
+
+          dest.x += priv->drag_start_x - anchor_x;
+          dest.y += priv->drag_start_y - anchor_y;
+          clutter_actor_set_position (actor, dest.x, dest.y);
+        }
+
+      transition = clutter_actor_get_transition (actor, "opacity");
+      g_signal_connect (transition, "stopped",
+                        G_CALLBACK (drag_failed_complete), self);
+
+      clutter_actor_restore_easing_state (actor);
+    }
+}