/*

 * Copyright © 2013 Canonical Limited

 *

 * 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 2.1 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/>.

 *

 * Authors: Ryan Lortie <desrt@desrt.ca>

 */

#include "config.h"

#include "gpropertyaction.h"

#include "gsettings-mapping.h"

#include "gaction.h"

#include "glibintl.h"

/**

 * SECTION:gpropertyaction

 * @title: GPropertyAction

 * @short_description: A GAction reflecting a GObject property

 * @include: gio/gio.h

 *

 * A #GPropertyAction is a way to get a #GAction with a state value

 * reflecting and controlling the value of a #GObject property.

 *

 * The state of the action will correspond to the value of the property.

 * Changing it will change the property (assuming the requested value

 * matches the requirements as specified in the #GParamSpec).

 *

 * Only the most common types are presently supported.  Booleans are

 * mapped to booleans, strings to strings, signed/unsigned integers to

 * int32/uint32 and floats and doubles to doubles.

 *

 * If the property is an enum then the state will be string-typed and

 * conversion will automatically be performed between the enum value and

 * "nick" string as per the #GEnumValue table.

 *

 * Flags types are not currently supported.

 *

 * Properties of object types, boxed types and pointer types are not

 * supported and probably never will be.

 *

 * Properties of #GVariant types are not currently supported.

 *

 * If the property is boolean-valued then the action will have a NULL

 * parameter type, and activating the action (with no parameter) will

 * toggle the value of the property.

 *

 * In all other cases, the parameter type will correspond to the type of

 * the property.

 *

 * The general idea here is to reduce the number of locations where a

 * particular piece of state is kept (and therefore has to be synchronised

 * between). #GPropertyAction does not have a separate state that is kept

 * in sync with the property value -- its state is the property value.

 *

 * For example, it might be useful to create a #GAction corresponding to

 * the "visible-child-name" property of a #GtkStack so that the current

 * page can be switched from a menu.  The active radio indication in the

 * menu is then directly determined from the active page of the

 * #GtkStack.

 *

 * An anti-example would be binding the "active-id" property on a

 * #GtkComboBox.  This is because the state of the combobox itself is

 * probably uninteresting and is actually being used to control

 * something else.

 *

 * Another anti-example would be to bind to the "visible-child-name"

 * property of a #GtkStack if this value is actually stored in

 * #GSettings.  In that case, the real source of the value is

 * #GSettings.  If you want a #GAction to control a setting stored in

 * #GSettings, see g_settings_create_action() instead, and possibly

 * combine its use with g_settings_bind().

 *

 * Since: 2.38

 **/

struct _GPropertyAction

{

  GObject     parent_instance;

  gchar              *name;

  gpointer            object;

  GParamSpec         *pspec;

  const GVariantType *state_type;

  gboolean            invert_boolean;

};

/**

 * GPropertyAction:

 *

 * This type is opaque.

 *

 * Since: 2.38

 **/

typedef GObjectClass GPropertyActionClass;

static void g_property_action_iface_init (GActionInterface *iface);

G_DEFINE_TYPE_WITH_CODE (GPropertyAction, g_property_action, G_TYPE_OBJECT,

  G_IMPLEMENT_INTERFACE (G_TYPE_ACTION, g_property_action_iface_init))

enum

{

  PROP_NONE,

  PROP_NAME,

  PROP_PARAMETER_TYPE,

  PROP_ENABLED,

  PROP_STATE_TYPE,

  PROP_STATE,

  PROP_OBJECT,

  PROP_PROPERTY_NAME,

  PROP_INVERT_BOOLEAN

};

static gboolean

g_property_action_get_invert_boolean (GAction *action)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  return paction->invert_boolean;

}

static const gchar *

g_property_action_get_name (GAction *action)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  return paction->name;

}

static const GVariantType *

g_property_action_get_parameter_type (GAction *action)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  return paction->pspec->value_type == G_TYPE_BOOLEAN ? NULL : paction->state_type;

}

static const GVariantType *

g_property_action_get_state_type (GAction *action)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  return paction->state_type;

}

static GVariant *

g_property_action_get_state_hint (GAction *action)

{

  return NULL;

}

static gboolean

g_property_action_get_enabled (GAction *action)

{

  return TRUE;

}

static void

g_property_action_set_state (GPropertyAction *paction,

                             GVariant        *variant)

{

  GValue value = G_VALUE_INIT;

  g_value_init (&value, paction->pspec->value_type);

  g_settings_get_mapping (&value, variant, NULL);

  if (paction->pspec->value_type == G_TYPE_BOOLEAN && paction->invert_boolean)

    g_value_set_boolean (&value, !g_value_get_boolean (&value));

  g_object_set_property (paction->object, paction->pspec->name, &value);

  g_value_unset (&value);

}

static void

g_property_action_change_state (GAction  *action,

                                GVariant *value)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  g_return_if_fail (g_variant_is_of_type (value, paction->state_type));

  g_property_action_set_state (paction, value);

}

static GVariant *

g_property_action_get_state (GAction *action)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  GValue value = G_VALUE_INIT;

  GVariant *result;

  g_value_init (&value, paction->pspec->value_type);

  g_object_get_property (paction->object, paction->pspec->name, &value);

  if (paction->pspec->value_type == G_TYPE_BOOLEAN && paction->invert_boolean)

    g_value_set_boolean (&value, !g_value_get_boolean (&value));

  result = g_settings_set_mapping (&value, paction->state_type, NULL);

  g_value_unset (&value);

  return g_variant_ref_sink (result);

}

static void

g_property_action_activate (GAction  *action,

                            GVariant *parameter)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (action);

  if (paction->pspec->value_type == G_TYPE_BOOLEAN)

    {

      gboolean value;

      g_return_if_fail (paction->pspec->value_type == G_TYPE_BOOLEAN && parameter == NULL);

      g_object_get (paction->object, paction->pspec->name, &value, NULL);

      value = !value;

      g_object_set (paction->object, paction->pspec->name, value, NULL);

    }

  else

    {

      g_return_if_fail (parameter != NULL && g_variant_is_of_type (parameter, paction->state_type));

      g_property_action_set_state (paction, parameter);

    }

}

static const GVariantType *

g_property_action_determine_type (GParamSpec *pspec)

{

  if (G_TYPE_IS_ENUM (pspec->value_type))

    return G_VARIANT_TYPE_STRING;

  switch (pspec->value_type)

    {

    case G_TYPE_BOOLEAN:

      return G_VARIANT_TYPE_BOOLEAN;

    case G_TYPE_INT:

      return G_VARIANT_TYPE_INT32;

    case G_TYPE_UINT:

      return G_VARIANT_TYPE_UINT32;

    case G_TYPE_DOUBLE:

    case G_TYPE_FLOAT:

      return G_VARIANT_TYPE_DOUBLE;

    case G_TYPE_STRING:

      return G_VARIANT_TYPE_STRING;

    default:

      g_critical ("Unable to use GPropertyAction with property '%s::%s' of type '%s'",

                  g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->value_type));

      return NULL;

    }

}

static void

g_property_action_notify (GObject    *object,

                          GParamSpec *pspec,

                          gpointer    user_data)

{

  GPropertyAction *paction = user_data;

  g_assert (object == paction->object);

  g_assert (pspec == paction->pspec);

  g_object_notify (G_OBJECT (paction), "state");

}

static void

g_property_action_set_property_name (GPropertyAction *paction,

                                     const gchar     *property_name)

{

  GParamSpec *pspec;

  gchar *detailed;

  pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (paction->object), property_name);

  if (pspec == NULL)

    {

      g_critical ("Attempted to use non-existent property '%s::%s' for GPropertyAction",

                  G_OBJECT_TYPE_NAME (paction->object), property_name);

      return;

    }

  if (~pspec->flags & G_PARAM_READABLE || ~pspec->flags & G_PARAM_WRITABLE || pspec->flags & G_PARAM_CONSTRUCT_ONLY)

    {

      g_critical ("Property '%s::%s' used with GPropertyAction must be readable, writable, and not construct-only",

                  G_OBJECT_TYPE_NAME (paction->object), property_name);

      return;

    }

  paction->pspec = pspec;

  detailed = g_strconcat ("notify::", paction->pspec->name, NULL);

  paction->state_type = g_property_action_determine_type (paction->pspec);

  g_signal_connect (paction->object, detailed, G_CALLBACK (g_property_action_notify), paction);

  g_free (detailed);

}

static void

g_property_action_set_property (GObject      *object,

                                guint         prop_id,

                                const GValue *value,

                                GParamSpec   *pspec)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (object);

  switch (prop_id)

    {

    case PROP_NAME:

      paction->name = g_value_dup_string (value);

      break;

    case PROP_OBJECT:

      paction->object = g_value_dup_object (value);

      break;

    case PROP_PROPERTY_NAME:

      g_property_action_set_property_name (paction, g_value_get_string (value));

      break;

    case PROP_INVERT_BOOLEAN:

      paction->invert_boolean = g_value_get_boolean (value);

      break;

    default:

      g_assert_not_reached ();

    }

}

static void

g_property_action_get_property (GObject    *object,

                                guint       prop_id,

                                GValue     *value,

                                GParamSpec *pspec)

{

  GAction *action = G_ACTION (object);

  switch (prop_id)

    {

    case PROP_NAME:

      g_value_set_string (value, g_property_action_get_name (action));

      break;

    case PROP_PARAMETER_TYPE:

      g_value_set_boxed (value, g_property_action_get_parameter_type (action));

      break;

    case PROP_ENABLED:

      g_value_set_boolean (value, g_property_action_get_enabled (action));

      break;

    case PROP_STATE_TYPE:

      g_value_set_boxed (value, g_property_action_get_state_type (action));

      break;

    case PROP_STATE:

      g_value_take_variant (value, g_property_action_get_state (action));

      break;

    case PROP_INVERT_BOOLEAN:

      g_value_set_boolean (value, g_property_action_get_invert_boolean (action));

      break;

    default:

      g_assert_not_reached ();

    }

}

static void

g_property_action_finalize (GObject *object)

{

  GPropertyAction *paction = G_PROPERTY_ACTION (object);

  g_signal_handlers_disconnect_by_func (paction->object, g_property_action_notify, paction);

  g_object_unref (paction->object);

  g_free (paction->name);

  G_OBJECT_CLASS (g_property_action_parent_class)

    ->finalize (object);

}

void

g_property_action_init (GPropertyAction *property)

{

}

void

g_property_action_iface_init (GActionInterface *iface)

{

  iface->get_name = g_property_action_get_name;

  iface->get_parameter_type = g_property_action_get_parameter_type;

  iface->get_state_type = g_property_action_get_state_type;

  iface->get_state_hint = g_property_action_get_state_hint;

  iface->get_enabled = g_property_action_get_enabled;

  iface->get_state = g_property_action_get_state;

  iface->change_state = g_property_action_change_state;

  iface->activate = g_property_action_activate;

}

void

g_property_action_class_init (GPropertyActionClass *class)

{

  GObjectClass *object_class = G_OBJECT_CLASS (class);

  object_class->set_property = g_property_action_set_property;

  object_class->get_property = g_property_action_get_property;

  object_class->finalize = g_property_action_finalize;

  /**

   * GPropertyAction:name:

   *

   * The name of the action.  This is mostly meaningful for identifying

   * the action once it has been added to a #GActionMap.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_NAME,

                                   g_param_spec_string ("name",

                                                        P_("Action Name"),

                                                        P_("The name used to invoke the action"),

                                                        NULL,

                                                        G_PARAM_READWRITE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:parameter-type:

   *

   * The type of the parameter that must be given when activating the

   * action.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_PARAMETER_TYPE,

                                   g_param_spec_boxed ("parameter-type",

                                                       P_("Parameter Type"),

                                                       P_("The type of GVariant passed to activate()"),

                                                       G_TYPE_VARIANT_TYPE,

                                                       G_PARAM_READABLE |

                                                       G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:enabled:

   *

   * If @action is currently enabled.

   *

   * If the action is disabled then calls to g_action_activate() and

   * g_action_change_state() have no effect.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_ENABLED,

                                   g_param_spec_boolean ("enabled",

                                                         P_("Enabled"),

                                                         P_("If the action can be activated"),

                                                         TRUE,

                                                         G_PARAM_READABLE |

                                                         G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:state-type:

   *

   * The #GVariantType of the state that the action has, or %NULL if the

   * action is stateless.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_STATE_TYPE,

                                   g_param_spec_boxed ("state-type",

                                                       P_("State Type"),

                                                       P_("The type of the state kept by the action"),

                                                       G_TYPE_VARIANT_TYPE,

                                                       G_PARAM_READABLE |

                                                       G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:state:

   *

   * The state of the action, or %NULL if the action is stateless.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_STATE,

                                   g_param_spec_variant ("state",

                                                         P_("State"),

                                                         P_("The state the action is in"),

                                                         G_VARIANT_TYPE_ANY,

                                                         NULL,

                                                         G_PARAM_READABLE |

                                                         G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:object:

   *

   * The object to wrap a property on.

   *

   * The object must be a non-%NULL #GObject with properties.

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_OBJECT,

                                   g_param_spec_object ("object",

                                                        P_("Object"),

                                                        P_("The object with the property to wrap"),

                                                        G_TYPE_OBJECT,

                                                        G_PARAM_WRITABLE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:property-name:

   *

   * The name of the property to wrap on the object.

   *

   * The property must exist on the passed-in object and it must be

   * readable and writable (and not construct-only).

   *

   * Since: 2.38

   **/

  g_object_class_install_property (object_class, PROP_PROPERTY_NAME,

                                   g_param_spec_string ("property-name",

                                                        P_("Property name"),

                                                        P_("The name of the property to wrap"),

                                                        NULL,

                                                        G_PARAM_WRITABLE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

  /**

   * GPropertyAction:invert-boolean:

   *

   * If %TRUE, the state of the action will be the negation of the

   * property value, provided the property is boolean.

   *

   * Since: 2.46

   */

  g_object_class_install_property (object_class, PROP_INVERT_BOOLEAN,

                                   g_param_spec_boolean ("invert-boolean",

                                                         P_("Invert boolean"),

                                                         P_("Whether to invert the value of a boolean property"),

                                                         FALSE,

                                                         G_PARAM_READWRITE |

                                                         G_PARAM_CONSTRUCT_ONLY |

                                                         G_PARAM_STATIC_STRINGS));

}

/**

 * g_property_action_new:

 * @name: the name of the action to create

 * @object: (type GObject.Object): the object that has the property

 *   to wrap

 * @property_name: the name of the property

 *

 * Creates a #GAction corresponding to the value of property

 * @property_name on @object.

 *

 * The property must be existent and readable and writable (and not

 * construct-only).

 *

 * This function takes a reference on @object and doesn't release it

 * until the action is destroyed.

 *

 * Returns: a new #GPropertyAction

 *

 * Since: 2.38

 **/

GPropertyAction *

g_property_action_new (const gchar *name,

                       gpointer     object,

                       const gchar *property_name)

{

  g_return_val_if_fail (name != NULL, NULL);

  g_return_val_if_fail (G_IS_OBJECT (object), NULL);

  g_return_val_if_fail (property_name != NULL, NULL);

  return g_object_new (G_TYPE_PROPERTY_ACTION,

                       "name", name,

                       "object", object,

                       "property-name", property_name,

                       NULL);

}