glib2.0/gio/gpermission.c

479 lines
14 KiB
C

/*
* Copyright © 2010 Codethink Limited
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* 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/>.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "gpermission.h"
#include "gioerror.h"
#include "gioenums.h"
#include "gasyncresult.h"
#include "gtask.h"
#include "glibintl.h"
/**
* SECTION:gpermission
* @title: GPermission
* @short_description: An object representing the permission
* to perform a certain action
* @include: gio/gio.h
*
* A #GPermission represents the status of the caller's permission to
* perform a certain action.
*
* You can query if the action is currently allowed and if it is
* possible to acquire the permission so that the action will be allowed
* in the future.
*
* There is also an API to actually acquire the permission and one to
* release it.
*
* As an example, a #GPermission might represent the ability for the
* user to write to a #GSettings object. This #GPermission object could
* then be used to decide if it is appropriate to show a "Click here to
* unlock" button in a dialog and to provide the mechanism to invoke
* when that button is clicked.
**/
/**
* GPermission:
*
* #GPermission is an opaque data structure and can only be accessed
* using the following functions.
**/
struct _GPermissionPrivate
{
gboolean allowed;
gboolean can_acquire;
gboolean can_release;
};
enum {
PROP_NONE,
PROP_ALLOWED,
PROP_CAN_ACQUIRE,
PROP_CAN_RELEASE
};
G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GPermission, g_permission, G_TYPE_OBJECT)
/**
* g_permission_acquire:
* @permission: a #GPermission instance
* @cancellable: (nullable): a #GCancellable, or %NULL
* @error: a pointer to a %NULL #GError, or %NULL
*
* Attempts to acquire the permission represented by @permission.
*
* The precise method by which this happens depends on the permission
* and the underlying authentication mechanism. A simple example is
* that a dialog may appear asking the user to enter their password.
*
* You should check with g_permission_get_can_acquire() before calling
* this function.
*
* If the permission is acquired then %TRUE is returned. Otherwise,
* %FALSE is returned and @error is set appropriately.
*
* This call is blocking, likely for a very long time (in the case that
* user interaction is required). See g_permission_acquire_async() for
* the non-blocking version.
*
* Returns: %TRUE if the permission was successfully acquired
*
* Since: 2.26
*/
gboolean
g_permission_acquire (GPermission *permission,
GCancellable *cancellable,
GError **error)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return G_PERMISSION_GET_CLASS (permission)
->acquire (permission, cancellable, error);
}
/**
* g_permission_acquire_async:
* @permission: a #GPermission instance
* @cancellable: (nullable): a #GCancellable, or %NULL
* @callback: the #GAsyncReadyCallback to call when done
* @user_data: the user data to pass to @callback
*
* Attempts to acquire the permission represented by @permission.
*
* This is the first half of the asynchronous version of
* g_permission_acquire().
*
* Since: 2.26
**/
void
g_permission_acquire_async (GPermission *permission,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_return_if_fail (G_IS_PERMISSION (permission));
G_PERMISSION_GET_CLASS (permission)
->acquire_async (permission, cancellable, callback, user_data);
}
/**
* g_permission_acquire_finish:
* @permission: a #GPermission instance
* @result: the #GAsyncResult given to the #GAsyncReadyCallback
* @error: a pointer to a %NULL #GError, or %NULL
*
* Collects the result of attempting to acquire the permission
* represented by @permission.
*
* This is the second half of the asynchronous version of
* g_permission_acquire().
*
* Returns: %TRUE if the permission was successfully acquired
*
* Since: 2.26
**/
gboolean
g_permission_acquire_finish (GPermission *permission,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return G_PERMISSION_GET_CLASS (permission)
->acquire_finish (permission, result, error);
}
/**
* g_permission_release:
* @permission: a #GPermission instance
* @cancellable: (nullable): a #GCancellable, or %NULL
* @error: a pointer to a %NULL #GError, or %NULL
*
* Attempts to release the permission represented by @permission.
*
* The precise method by which this happens depends on the permission
* and the underlying authentication mechanism. In most cases the
* permission will be dropped immediately without further action.
*
* You should check with g_permission_get_can_release() before calling
* this function.
*
* If the permission is released then %TRUE is returned. Otherwise,
* %FALSE is returned and @error is set appropriately.
*
* This call is blocking, likely for a very long time (in the case that
* user interaction is required). See g_permission_release_async() for
* the non-blocking version.
*
* Returns: %TRUE if the permission was successfully released
*
* Since: 2.26
**/
gboolean
g_permission_release (GPermission *permission,
GCancellable *cancellable,
GError **error)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return G_PERMISSION_GET_CLASS (permission)
->release (permission, cancellable, error);
}
/**
* g_permission_release_async:
* @permission: a #GPermission instance
* @cancellable: (nullable): a #GCancellable, or %NULL
* @callback: the #GAsyncReadyCallback to call when done
* @user_data: the user data to pass to @callback
*
* Attempts to release the permission represented by @permission.
*
* This is the first half of the asynchronous version of
* g_permission_release().
*
* Since: 2.26
**/
void
g_permission_release_async (GPermission *permission,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_return_if_fail (G_IS_PERMISSION (permission));
G_PERMISSION_GET_CLASS (permission)
->release_async (permission, cancellable, callback, user_data);
}
/**
* g_permission_release_finish:
* @permission: a #GPermission instance
* @result: the #GAsyncResult given to the #GAsyncReadyCallback
* @error: a pointer to a %NULL #GError, or %NULL
*
* Collects the result of attempting to release the permission
* represented by @permission.
*
* This is the second half of the asynchronous version of
* g_permission_release().
*
* Returns: %TRUE if the permission was successfully released
*
* Since: 2.26
**/
gboolean
g_permission_release_finish (GPermission *permission,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return G_PERMISSION_GET_CLASS (permission)
->release_finish (permission, result, error);
}
/**
* g_permission_get_allowed:
* @permission: a #GPermission instance
*
* Gets the value of the 'allowed' property. This property is %TRUE if
* the caller currently has permission to perform the action that
* @permission represents the permission to perform.
*
* Returns: the value of the 'allowed' property
*
* Since: 2.26
**/
gboolean
g_permission_get_allowed (GPermission *permission)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return permission->priv->allowed;
}
/**
* g_permission_get_can_acquire:
* @permission: a #GPermission instance
*
* Gets the value of the 'can-acquire' property. This property is %TRUE
* if it is generally possible to acquire the permission by calling
* g_permission_acquire().
*
* Returns: the value of the 'can-acquire' property
*
* Since: 2.26
**/
gboolean
g_permission_get_can_acquire (GPermission *permission)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return permission->priv->can_acquire;
}
/**
* g_permission_get_can_release:
* @permission: a #GPermission instance
*
* Gets the value of the 'can-release' property. This property is %TRUE
* if it is generally possible to release the permission by calling
* g_permission_release().
*
* Returns: the value of the 'can-release' property
*
* Since: 2.26
**/
gboolean
g_permission_get_can_release (GPermission *permission)
{
g_return_val_if_fail (G_IS_PERMISSION (permission), FALSE);
return permission->priv->can_release;
}
/**
* g_permission_impl_update:
* @permission: a #GPermission instance
* @allowed: the new value for the 'allowed' property
* @can_acquire: the new value for the 'can-acquire' property
* @can_release: the new value for the 'can-release' property
*
* This function is called by the #GPermission implementation to update
* the properties of the permission. You should never call this
* function except from a #GPermission implementation.
*
* GObject notify signals are generated, as appropriate.
*
* Since: 2.26
**/
void
g_permission_impl_update (GPermission *permission,
gboolean allowed,
gboolean can_acquire,
gboolean can_release)
{
GObject *object;
g_return_if_fail (G_IS_PERMISSION (permission));
object = G_OBJECT (permission);
g_object_freeze_notify (object);
allowed = allowed != FALSE;
if (allowed != permission->priv->allowed)
{
permission->priv->allowed = allowed;
g_object_notify (object, "allowed");
}
can_acquire = can_acquire != FALSE;
if (can_acquire != permission->priv->can_acquire)
{
permission->priv->can_acquire = can_acquire;
g_object_notify (object, "can-acquire");
}
can_release = can_release != FALSE;
if (can_release != permission->priv->can_release)
{
permission->priv->can_release = can_release;
g_object_notify (object, "can-release");
}
g_object_thaw_notify (object);
}
static void
g_permission_get_property (GObject *object, guint prop_id,
GValue *value, GParamSpec *pspec)
{
GPermission *permission = G_PERMISSION (object);
switch (prop_id)
{
case PROP_ALLOWED:
g_value_set_boolean (value, permission->priv->allowed);
break;
case PROP_CAN_ACQUIRE:
g_value_set_boolean (value, permission->priv->can_acquire);
break;
case PROP_CAN_RELEASE:
g_value_set_boolean (value, permission->priv->can_release);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
static void
g_permission_init (GPermission *permission)
{
permission->priv = g_permission_get_instance_private (permission);
}
static gboolean
acquire_or_release (GPermission *permission,
GCancellable *cancellable,
GError **error)
{
g_set_error_literal (error,
G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
"Can't acquire or release permission");
return FALSE;
}
static void
acquire_or_release_async (GPermission *permission,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_task_report_new_error (permission,
callback, user_data,
NULL,
G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
"Can't acquire or release permission");
}
static gboolean
acquire_or_release_finish (GPermission *permission,
GAsyncResult *result,
GError **error)
{
return g_task_propagate_boolean (G_TASK (result), error);
}
static void
g_permission_class_init (GPermissionClass *class)
{
GObjectClass *object_class = G_OBJECT_CLASS (class);
object_class->get_property = g_permission_get_property;
class->acquire = acquire_or_release;
class->release = acquire_or_release;
class->acquire_async = acquire_or_release_async;
class->release_async = acquire_or_release_async;
class->acquire_finish = acquire_or_release_finish;
class->release_finish = acquire_or_release_finish;
/**
* GPermission:allowed:
*
* %TRUE if the caller currently has permission to perform the action that
* @permission represents the permission to perform.
*/
g_object_class_install_property (object_class, PROP_ALLOWED,
g_param_spec_boolean ("allowed",
P_("Is allowed"),
P_("If the caller is allowed to perform the action"),
FALSE,
G_PARAM_STATIC_STRINGS | G_PARAM_READABLE));
/**
* GPermission:can-acquire:
*
* %TRUE if it is generally possible to acquire the permission by calling
* g_permission_acquire().
*/
g_object_class_install_property (object_class, PROP_CAN_ACQUIRE,
g_param_spec_boolean ("can-acquire",
P_("Can acquire"),
P_("If calling g_permission_acquire() makes sense"),
FALSE,
G_PARAM_STATIC_STRINGS | G_PARAM_READABLE));
/**
* GPermission:can-release:
*
* %TRUE if it is generally possible to release the permission by calling
* g_permission_release().
*/
g_object_class_install_property (object_class, PROP_CAN_RELEASE,
g_param_spec_boolean ("can-release",
P_("Can release"),
P_("If calling g_permission_release() makes sense"),
FALSE,
G_PARAM_STATIC_STRINGS | G_PARAM_READABLE));
}