/*
 * Clutter.
 *
 * An OpenGL based 'interactive canvas' library.
 *
 * Copyright (C) 2009  Intel Corp.
 *
 * 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>
 */

/**
 * SECTION:clutter-device-manager
 * @short_description: Maintains the list of input devices
 *
 * #ClutterDeviceManager is a singleton object, owned by Clutter, which
 * maintains the list of #ClutterInputDevice<!-- -->s.
 *
 * Depending on the backend used by Clutter it is possible to use the
 * #ClutterDeviceManager::device-added and
 * #ClutterDeviceManager::device-removed to monitor addition and removal
 * of devices.
 *
 * #ClutterDeviceManager is available since Clutter 1.2
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "clutter-debug.h"
#include "clutter-device-manager.h"
#include "clutter-enum-types.h"
#include "clutter-marshal.h"
#include "clutter-private.h"

#define CLUTTER_DEVICE_MANAGER_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_DEVICE_MANAGER, ClutterDeviceManagerPrivate))

struct _ClutterDeviceManagerPrivate
{
  /* back-pointer to the backend */
  ClutterBackend *backend;
};

enum
{
  PROP_0,

  PROP_BACKEND
};

enum
{
  DEVICE_ADDED,
  DEVICE_REMOVED,

  LAST_SIGNAL
};

static guint manager_signals[LAST_SIGNAL] = { 0, };

G_DEFINE_ABSTRACT_TYPE (ClutterDeviceManager,
                        clutter_device_manager,
                        G_TYPE_OBJECT);

static void
clutter_device_manager_set_property (GObject      *gobject,
                                     guint         prop_id,
                                     const GValue *value,
                                     GParamSpec   *pspec)
{
  ClutterDeviceManagerPrivate *priv = CLUTTER_DEVICE_MANAGER (gobject)->priv;

  switch (prop_id)
    {
    case PROP_BACKEND:
      priv->backend = g_value_get_object (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
    }
}

static void
clutter_device_manager_get_property (GObject    *gobject,
                                     guint       prop_id,
                                     GValue     *value,
                                     GParamSpec *pspec)
{
  ClutterDeviceManagerPrivate *priv = CLUTTER_DEVICE_MANAGER (gobject)->priv;

  switch (prop_id)
    {
    case PROP_BACKEND:
      g_value_set_object (value, priv->backend);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
    }
}

static void
clutter_device_manager_class_init (ClutterDeviceManagerClass *klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  GParamSpec *pspec;

  g_type_class_add_private (klass, sizeof (ClutterDeviceManagerPrivate));

  gobject_class->set_property = clutter_device_manager_set_property;
  gobject_class->get_property = clutter_device_manager_get_property;

  pspec = g_param_spec_object ("backend",
                               "Backend",
                               "The ClutterBackend of the device manager",
                               CLUTTER_TYPE_BACKEND,
                               CLUTTER_PARAM_READWRITE |
                               G_PARAM_CONSTRUCT_ONLY);
  g_object_class_install_property (gobject_class, PROP_BACKEND, pspec);

  /**
   * ClutterDeviceManager::device-added:
   * @manager: the #ClutterDeviceManager that emitted the signal
   * @device: the newly added #ClutterInputDevice
   *
   * The ::device-added signal is emitted each time a device has been
   * added to the #ClutterDeviceManager
   *
   * Since: 1.2
   */
  manager_signals[DEVICE_ADDED] =
    g_signal_new (I_("device-added"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  0,
                  NULL, NULL,
                  clutter_marshal_VOID__OBJECT,
                  G_TYPE_NONE, 1,
                  CLUTTER_TYPE_INPUT_DEVICE);

  /**
   * ClutterDeviceManager::device-removed:
   * @manager: the #ClutterDeviceManager that emitted the signal
   * @device: the removed #ClutterInputDevice
   *
   * The ::device-removed signal is emitted each time a device has been
   * removed from the #ClutterDeviceManager
   *
   * Since: 1.2
   */
  manager_signals[DEVICE_REMOVED] =
    g_signal_new (I_("device-removed"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_LAST,
                  0,
                  NULL, NULL,
                  clutter_marshal_VOID__OBJECT,
                  G_TYPE_NONE, 1,
                  CLUTTER_TYPE_INPUT_DEVICE);
}

static void
clutter_device_manager_init (ClutterDeviceManager *self)
{
  self->priv = CLUTTER_DEVICE_MANAGER_GET_PRIVATE (self);
}

/**
 * clutter_device_manager_get_default:
 *
 * Retrieves the device manager singleton
 *
 * Return value: (transfer none): the #ClutterDeviceManager singleton.
 *   The returned instance is owned by Clutter and it should not be
 *   modified or freed
 *
 * Since: 1.2
 */
ClutterDeviceManager *
clutter_device_manager_get_default (void)
{
  ClutterBackendClass *klass;

  klass = CLUTTER_BACKEND_GET_CLASS (clutter_get_default_backend ());
  g_assert (klass->get_device_manager != NULL);

  return klass->get_device_manager (clutter_get_default_backend ());
}

/**
 * clutter_device_manager_list_devices:
 * @device_manager: a #ClutterDeviceManager
 *
 * Lists all currently registered input devices
 *
 * Return value: (transfer container) (element-type ClutterInputDevice):
 *   a newly allocated list of #ClutterInputDevice objects. Use
 *   g_slist_free() to deallocate it when done
 *
 * Since: 1.2
 */
GSList *
clutter_device_manager_list_devices (ClutterDeviceManager *device_manager)
{
  const GSList *devices;

  g_return_val_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager), NULL);

  devices = clutter_device_manager_peek_devices (device_manager);

  return g_slist_copy ((GSList *) devices);
}

/**
 * clutter_device_manager_peek_devices:
 * @device_manager: a #ClutterDeviceManager
 *
 * Lists all currently registered input devices
 *
 * Return value: (transfer none) (element-type ClutterInputDevice):
 *   a pointer to the internal list of #ClutterInputDevice objects. The
 *   returned list is owned by the #ClutterDeviceManager and should never
 *   be modified or freed
 *
 * Since: 1.2
 */
const GSList *
clutter_device_manager_peek_devices (ClutterDeviceManager *device_manager)
{
  ClutterDeviceManagerClass *manager_class;

  g_return_val_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager), NULL);

  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
  return manager_class->get_devices (device_manager);
}

/**
 * clutter_device_manager_get_device:
 * @device_manager: a #ClutterDeviceManager
 * @device_id: the integer id of a device
 *
 * Retrieves the #ClutterInputDevice with the given @device_id
 *
 * Return value: (transfer none): a #ClutterInputDevice or %NULL. The
 *   returned device is owned by the #ClutterDeviceManager and should
 *   never be modified or freed
 *
 * Since: 1.2
 */
ClutterInputDevice *
clutter_device_manager_get_device (ClutterDeviceManager *device_manager,
                                   gint                  device_id)
{
  ClutterDeviceManagerClass *manager_class;

  g_return_val_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager), NULL);

  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
  return manager_class->get_device (device_manager, device_id);
}

/**
 * clutter_device_manager_get_core_device:
 * @device_manager: a #ClutterDeviceManager
 * @device_type: the type of the core device
 *
 * Retrieves the core #ClutterInputDevice of type @device_type
 *
 * Core devices are devices created automatically by the default
 * Clutter backend
 *
 * Return value: (transfer none): a #ClutterInputDevice or %NULL. The
 *   returned device is owned by the #ClutterDeviceManager and should
 *   not be modified or freed
 *
 * Since: 1.2
 */
ClutterInputDevice *
clutter_device_manager_get_core_device (ClutterDeviceManager   *device_manager,
                                        ClutterInputDeviceType  device_type)
{
  ClutterDeviceManagerClass *manager_class;

  g_return_val_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager), NULL);

  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
  return manager_class->get_core_device (device_manager, device_type);
}

/*
 * _clutter_device_manager_add_device:
 * @device_manager: a #ClutterDeviceManager
 * @device: a #ClutterInputDevice
 *
 * Adds @device to the list of #ClutterInputDevice<!-- -->s maintained
 * by @device_manager
 *
 * The reference count of @device is not increased
 *
 * The #ClutterDeviceManager::device-added signal is emitted after
 * adding @device to the list
 */
void
_clutter_device_manager_add_device (ClutterDeviceManager *device_manager,
                                    ClutterInputDevice   *device)
{
  ClutterDeviceManagerClass *manager_class;

  g_return_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager));

  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
  g_assert (manager_class->add_device != NULL);

  manager_class->add_device (device_manager, device);

  g_signal_emit (device_manager, manager_signals[DEVICE_ADDED], 0, device);
}

/*
 * _clutter_device_manager_remove_device:
 * @device_manager: a #ClutterDeviceManager
 * @device: a #ClutterInputDevice
 *
 * Removes @device from the list of #ClutterInputDevice<!-- -->s
 * maintained by @device_manager
 *
 * The reference count of @device is not decreased
 *
 * The #ClutterDeviceManager::device-removed signal is emitted after
 * removing @device from the list
 */
void
_clutter_device_manager_remove_device (ClutterDeviceManager *device_manager,
                                       ClutterInputDevice   *device)
{
  ClutterDeviceManagerClass *manager_class;

  g_return_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager));

  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
  g_assert (manager_class->remove_device != NULL);

  manager_class->remove_device (device_manager, device);

  g_signal_emit (device_manager, manager_signals[DEVICE_REMOVED], 0, device);
}

/*
 * _clutter_device_manager_update_devices:
 * @device_manager: a #ClutterDeviceManager
 *
 * Updates every #ClutterInputDevice handled by @device_manager
 * by performing a pick paint at the coordinates of each pointer
 * device
 */
void
_clutter_device_manager_update_devices (ClutterDeviceManager *device_manager)
{
  const GSList *d;

  /* the user disabled motion events delivery on actors; we
   * don't perform any picking since the source of the events
   * will always be set to be the stage
   */
  if (!clutter_get_motion_events_enabled ())
    return;

  for (d = clutter_device_manager_peek_devices (device_manager);
       d != NULL;
       d = d->next)
    {
      ClutterInputDevice *device = d->data;
      ClutterInputDeviceType device_type;

      /* we only care about pointer devices */
      device_type = clutter_input_device_get_device_type (device);
      if (device_type != CLUTTER_POINTER_DEVICE)
        continue;

      /* out of stage */
      if (device->stage == NULL)
        continue;

      _clutter_input_device_update (device);
    }
}