/*

 * Copyright © 2010 Codethink 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 "gaction.h"

#include "glibintl.h"

#include <string.h>

G_DEFINE_INTERFACE (GAction, g_action, G_TYPE_OBJECT)

/**

 * SECTION:gaction

 * @title: GAction

 * @short_description: An action interface

 * @include: gio/gio.h

 *

 * #GAction represents a single named action.

 *

 * The main interface to an action is that it can be activated with

 * g_action_activate().  This results in the 'activate' signal being

 * emitted.  An activation has a #GVariant parameter (which may be

 * %NULL).  The correct type for the parameter is determined by a static

 * parameter type (which is given at construction time).

 *

 * An action may optionally have a state, in which case the state may be

 * set with g_action_change_state().  This call takes a #GVariant.  The

 * correct type for the state is determined by a static state type

 * (which is given at construction time).

 *

 * The state may have a hint associated with it, specifying its valid

 * range.

 *

 * #GAction is merely the interface to the concept of an action, as

 * described above.  Various implementations of actions exist, including

 * #GSimpleAction.

 *

 * In all cases, the implementing class is responsible for storing the

 * name of the action, the parameter type, the enabled state, the

 * optional state type and the state and emitting the appropriate

 * signals when these change.  The implementor is responsible for filtering

 * calls to g_action_activate() and g_action_change_state() for type

 * safety and for the state being enabled.

 *

 * Probably the only useful thing to do with a #GAction is to put it

 * inside of a #GSimpleActionGroup.

 **/

/**

 * GAction:

 *

 * #GAction is an opaque data structure and can only be accessed

 * using the following functions.

 **/

/**

 * GActionInterface:

 * @get_name: the virtual function pointer for g_action_get_name()

 * @get_parameter_type: the virtual function pointer for g_action_get_parameter_type()

 * @get_state_type: the virtual function pointer for g_action_get_state_type()

 * @get_state_hint: the virtual function pointer for g_action_get_state_hint()

 * @get_enabled: the virtual function pointer for g_action_get_enabled()

 * @get_state: the virtual function pointer for g_action_get_state()

 * @change_state: the virtual function pointer for g_action_change_state()

 * @activate: the virtual function pointer for g_action_activate().  Note that #GAction does not have an

 *            'activate' signal but that implementations of it may have one.

 *

 * The virtual function table for #GAction.

 *

 * Since: 2.28

 */

void

g_action_default_init (GActionInterface *iface)

{

  /**

   * GAction:name:

   *

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

   * the action once it has been added to a #GActionGroup. It is immutable.

   *

   * Since: 2.28

   **/

  g_object_interface_install_property (iface,

                                       g_param_spec_string ("name",

                                                            P_("Action Name"),

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

                                                            NULL,

                                                            G_PARAM_READABLE |

                                                            G_PARAM_STATIC_STRINGS));

  /**

   * GAction:parameter-type:

   *

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

   * action. This is immutable, and may be %NULL if no parameter is needed when

   * activating the action.

   *

   * Since: 2.28

   **/

  g_object_interface_install_property (iface,

                                       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));

  /**

   * GAction: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: 2.28

   **/

  g_object_interface_install_property (iface,

                                       g_param_spec_boolean ("enabled",

                                                             P_("Enabled"),

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

                                                             TRUE,

                                                             G_PARAM_READABLE |

                                                             G_PARAM_STATIC_STRINGS));

  /**

   * GAction:state-type:

   *

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

   * action is stateless. This is immutable.

   *

   * Since: 2.28

   **/

  g_object_interface_install_property (iface,

                                       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));

  /**

   * GAction:state:

   *

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

   *

   * Since: 2.28

   **/

  g_object_interface_install_property (iface,

                                       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));

}

/**

 * g_action_change_state:

 * @action: a #GAction

 * @value: the new state

 *

 * Request for the state of @action to be changed to @value.

 *

 * The action must be stateful and @value must be of the correct type.

 * See g_action_get_state_type().

 *

 * This call merely requests a change.  The action may refuse to change

 * its state or may change its state to something other than @value.

 * See g_action_get_state_hint().

 *

 * If the @value GVariant is floating, it is consumed.

 *

 * Since: 2.30

 **/

void

g_action_change_state (GAction  *action,

                       GVariant *value)

{

  const GVariantType *state_type;

  g_return_if_fail (G_IS_ACTION (action));

  g_return_if_fail (value != NULL);

  state_type = g_action_get_state_type (action);

  g_return_if_fail (state_type != NULL);

  g_return_if_fail (g_variant_is_of_type (value, state_type));

  g_variant_ref_sink (value);

  G_ACTION_GET_IFACE (action)

    ->change_state (action, value);

  g_variant_unref (value);

}

/**

 * g_action_get_state:

 * @action: a #GAction

 *

 * Queries the current state of @action.

 *

 * If the action is not stateful then %NULL will be returned.  If the

 * action is stateful then the type of the return value is the type

 * given by g_action_get_state_type().

 *

 * The return value (if non-%NULL) should be freed with

 * g_variant_unref() when it is no longer required.

 *

 * Returns: (nullable) (transfer full): the current state of the action

 *

 * Since: 2.28

 **/

GVariant *

g_action_get_state (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), NULL);

  return G_ACTION_GET_IFACE (action)

    ->get_state (action);

}

/**

 * g_action_get_name:

 * @action: a #GAction

 *

 * Queries the name of @action.

 *

 * Returns: the name of the action

 *

 * Since: 2.28

 **/

const gchar *

g_action_get_name (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), NULL);

  return G_ACTION_GET_IFACE (action)

    ->get_name (action);

}

/**

 * g_action_get_parameter_type:

 * @action: a #GAction

 *

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

 * @action.

 *

 * When activating the action using g_action_activate(), the #GVariant

 * given to that function must be of the type returned by this function.

 *

 * In the case that this function returns %NULL, you must not give any

 * #GVariant, but %NULL instead.

 *

 * Returns: (nullable): the parameter type

 *

 * Since: 2.28

 **/

const GVariantType *

g_action_get_parameter_type (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), NULL);

  return G_ACTION_GET_IFACE (action)

    ->get_parameter_type (action);

}

/**

 * g_action_get_state_type:

 * @action: a #GAction

 *

 * Queries the type of the state of @action.

 *

 * If the action is stateful (e.g. created with

 * g_simple_action_new_stateful()) then this function returns the

 * #GVariantType of the state.  This is the type of the initial value

 * given as the state. All calls to g_action_change_state() must give a

 * #GVariant of this type and g_action_get_state() will return a

 * #GVariant of the same type.

 *

 * If the action is not stateful (e.g. created with g_simple_action_new())

 * then this function will return %NULL. In that case, g_action_get_state()

 * will return %NULL and you must not call g_action_change_state().

 *

 * Returns: (nullable): the state type, if the action is stateful

 *

 * Since: 2.28

 **/

const GVariantType *

g_action_get_state_type (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), NULL);

  return G_ACTION_GET_IFACE (action)

    ->get_state_type (action);

}

/**

 * g_action_get_state_hint:

 * @action: a #GAction

 *

 * Requests a hint about the valid range of values for the state of

 * @action.

 *

 * If %NULL is returned it either means that the action is not stateful

 * or that there is no hint about the valid range of values for the

 * state of the action.

 *

 * If a #GVariant array is returned then each item in the array is a

 * possible value for the state.  If a #GVariant pair (ie: two-tuple) is

 * returned then the tuple specifies the inclusive lower and upper bound

 * of valid values for the state.

 *

 * In any case, the information is merely a hint.  It may be possible to

 * have a state value outside of the hinted range and setting a value

 * within the range may fail.

 *

 * The return value (if non-%NULL) should be freed with

 * g_variant_unref() when it is no longer required.

 *

 * Returns: (nullable) (transfer full): the state range hint

 *

 * Since: 2.28

 **/

GVariant *

g_action_get_state_hint (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), NULL);

  return G_ACTION_GET_IFACE (action)

    ->get_state_hint (action);

}

/**

 * g_action_get_enabled:

 * @action: a #GAction

 *

 * Checks if @action is currently enabled.

 *

 * An action must be enabled in order to be activated or in order to

 * have its state changed from outside callers.

 *

 * Returns: whether the action is enabled

 *

 * Since: 2.28

 **/

gboolean

g_action_get_enabled (GAction *action)

{

  g_return_val_if_fail (G_IS_ACTION (action), FALSE);

  return G_ACTION_GET_IFACE (action)

    ->get_enabled (action);

}

/**

 * g_action_activate:

 * @action: a #GAction

 * @parameter: (nullable): the parameter to the activation

 *

 * Activates the action.

 *

 * @parameter must be the correct type of parameter for the action (ie:

 * the parameter type given at construction time).  If the parameter

 * type was %NULL then @parameter must also be %NULL.

 *

 * If the @parameter GVariant is floating, it is consumed.

 *

 * Since: 2.28

 **/

void

g_action_activate (GAction  *action,

                   GVariant *parameter)

{

  g_return_if_fail (G_IS_ACTION (action));

  if (parameter != NULL)

    g_variant_ref_sink (parameter);

  G_ACTION_GET_IFACE (action)

    ->activate (action, parameter);

  if (parameter != NULL)

    g_variant_unref (parameter);

}

/**

 * g_action_name_is_valid:

 * @action_name: a potential action name

 *

 * Checks if @action_name is valid.

 *

 * @action_name is valid if it consists only of alphanumeric characters,

 * plus '-' and '.'.  The empty string is not a valid action name.

 *

 * It is an error to call this function with a non-utf8 @action_name.

 * @action_name must not be %NULL.

 *

 * Returns: %TRUE if @action_name is valid

 *

 * Since: 2.38

 **/

gboolean

g_action_name_is_valid (const gchar *action_name)

{

  gchar c;

  gint i;

  g_return_val_if_fail (action_name != NULL, FALSE);

  for (i = 0; (c = action_name[i]); i++)

    if (!g_ascii_isalnum (c) && c != '.' && c != '-')

      return FALSE;

  return i > 0;

}

/**

 * g_action_parse_detailed_name:

 * @detailed_name: a detailed action name

 * @action_name: (out): the action name

 * @target_value: (out): the target value, or %NULL for no target

 * @error: a pointer to a %NULL #GError, or %NULL

 *

 * Parses a detailed action name into its separate name and target

 * components.

 *

 * Detailed action names can have three formats.

 *

 * The first format is used to represent an action name with no target

 * value and consists of just an action name containing no whitespace

 * nor the characters ':', '(' or ')'.  For example: "app.action".

 *

 * The second format is used to represent an action with a target value

 * that is a non-empty string consisting only of alphanumerics, plus '-'

 * and '.'.  In that case, the action name and target value are

 * separated by a double colon ("::").  For example:

 * "app.action::target".

 *

 * The third format is used to represent an action with any type of

 * target value, including strings.  The target value follows the action

 * name, surrounded in parens.  For example: "app.action(42)".  The

 * target value is parsed using g_variant_parse().  If a tuple-typed

 * value is desired, it must be specified in the same way, resulting in

 * two sets of parens, for example: "app.action((1,2,3))".  A string

 * target can be specified this way as well: "app.action('target')".

 * For strings, this third format must be used if * target value is

 * empty or contains characters other than alphanumerics, '-' and '.'.

 *

 * Returns: %TRUE if successful, else %FALSE with @error set

 *

 * Since: 2.38

 **/

gboolean

g_action_parse_detailed_name (const gchar  *detailed_name,

                              gchar       **action_name,

                              GVariant    **target_value,

                              GError      **error)

{

  const gchar *target;

  gsize target_len;

  gsize base_len;

  /* For historical (compatibility) reasons, this function accepts some

   * cases of invalid action names as long as they don't interfere with

   * the separation of the action from the target value.

   *

   * We decide which format we have based on which we see first between

   * '::' '(' and '\0'.

   */

  if (*detailed_name == '\0' || *detailed_name == ' ')

    goto bad_fmt;

  base_len = strcspn (detailed_name, ": ()");

  target = detailed_name + base_len;

  target_len = strlen (target);

  switch (target[0])

    {

    case ' ':

    case ')':

      goto bad_fmt;

    case ':':

      if (target[1] != ':')

        goto bad_fmt;

      *target_value = g_variant_ref_sink (g_variant_new_string (target + 2));

      break;

    case '(':

      {

        if (target[target_len - 1] != ')')

          goto bad_fmt;

        *target_value = g_variant_parse (NULL, target + 1, target + target_len - 1, NULL, error);

        if (*target_value == NULL)

          goto bad_fmt;

      }

      break;

    case '\0':

      *target_value = NULL;

      break;

    }

  *action_name = g_strndup (detailed_name, base_len);

  return TRUE;

bad_fmt:

  if (error)

    {

      if (*error == NULL)

        g_set_error (error, G_VARIANT_PARSE_ERROR, G_VARIANT_PARSE_ERROR_FAILED,

                     "Detailed action name '%s' has invalid format", detailed_name);

      else

        g_prefix_error (error, "Detailed action name '%s' has invalid format: ", detailed_name);

    }

  return FALSE;

}

/**

 * g_action_print_detailed_name:

 * @action_name: a valid action name

 * @target_value: (nullable): a #GVariant target value, or %NULL

 *

 * Formats a detailed action name from @action_name and @target_value.

 *

 * It is an error to call this function with an invalid action name.

 *

 * This function is the opposite of g_action_parse_detailed_name().

 * It will produce a string that can be parsed back to the @action_name

 * and @target_value by that function.

 *

 * See that function for the types of strings that will be printed by

 * this function.

 *

 * Returns: a detailed format string

 *

 * Since: 2.38

 **/

gchar *

g_action_print_detailed_name (const gchar *action_name,

                              GVariant    *target_value)

{

  g_return_val_if_fail (g_action_name_is_valid (action_name), NULL);

  if (target_value == NULL)

    return g_strdup (action_name);

  if (g_variant_is_of_type (target_value, G_VARIANT_TYPE_STRING))

    {

      const gchar *str = g_variant_get_string (target_value, NULL);

      if (g_action_name_is_valid (str))

        return g_strconcat (action_name, "::", str, NULL);

    }

  {

    GString *result = g_string_new (action_name);

    g_string_append_c (result, '(');

    g_variant_print_string (target_value, result, TRUE);

    g_string_append_c (result, ')');

    return g_string_free (result, FALSE);

  }

}