gtk2/gtk/gtkrecentmanager.c

/* GTK - The GIMP Toolkit
 * gtkrecentmanager.c: a manager for the recently used resources
 *
 * Copyright (C) 2006 Emmanuele Bassi
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * GtkRecentManager:
 *
 * `GtkRecentManager` manages and looks up recently used files.
 *
 * Each recently used file is identified by its URI, and has meta-data
 * associated to it, like the names and command lines of the applications
 * that have registered it, the number of time each application has
 * registered the same file, the mime type of the file and whether
 * the file should be displayed only by the applications that have
 * registered it.
 *
 * The recently used files list is per user.
 *
 * `GtkRecentManager` acts like a database of all the recently
 * used files. You can create new `GtkRecentManager` objects, but
 * it is more efficient to use the default manager created by GTK.
 *
 * Adding a new recently used file is as simple as:
 *
 * ```c
 * GtkRecentManager *manager;
 *
 * manager = gtk_recent_manager_get_default ();
 * gtk_recent_manager_add_item (manager, file_uri);
 * ```
 *
 * The `GtkRecentManager` will try to gather all the needed information
 * from the file itself through GIO.
 *
 * Looking up the meta-data associated with a recently used file
 * given its URI requires calling [method@Gtk.RecentManager.lookup_item]:
 *
 * ```c
 * GtkRecentManager *manager;
 * GtkRecentInfo *info;
 * GError *error = NULL;
 *
 * manager = gtk_recent_manager_get_default ();
 * info = gtk_recent_manager_lookup_item (manager, file_uri, &error);
 * if (error)
 *   {
 *     g_warning ("Could not find the file: %s", error->message);
 *     g_error_free (error);
 *   }
 * else
 *  {
 *    // Use the info object
 *    gtk_recent_info_unref (info);
 *  }
 * ```
 *
 * In order to retrieve the list of recently used files, you can use
 * [method@Gtk.RecentManager.get_items], which returns a list of
 * [struct@Gtk.RecentInfo].
 *
 * Note that the maximum age of the recently used files list is
 * controllable through the [property@Gtk.Settings:gtk-recent-files-max-age]
 * property.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <glib.h>
#include <glib/gstdio.h>
#include <gio/gio.h>

#include "gtkrecentmanager.h"
#include "gtkintl.h"
#include "gtksettings.h"
#include "gtktypebuiltins.h"
#include "gtkprivate.h"
#include "gtkmarshalers.h"

/* the file where we store the recently used items */
#define GTK_RECENTLY_USED_FILE  "recently-used.xbel"

/* return all items by default */
#define DEFAULT_LIMIT   -1

/* limit the size of the list */
#define MAX_LIST_SIZE 1000

/* keep in sync with xdgmime */
#define GTK_RECENT_DEFAULT_MIME "application/octet-stream"

typedef struct
{
  char *name;
  char *exec;

  guint count;

  GDateTime *stamp;
} RecentAppInfo;

/**
 * GtkRecentInfo:
 *
 * `GtkRecentInfo` contains the metadata associated with an item in the
 * recently used files list.
 */
struct _GtkRecentInfo
{
  char *uri;

  char *display_name;
  char *description;

  GDateTime *added;
  GDateTime *modified;
  GDateTime *visited;

  char *mime_type;

  RecentAppInfo *applications;
  int n_applications;
  GHashTable *apps_lookup;

  char **groups;
  int n_groups;

  gboolean is_private;

  int ref_count;
};

struct _GtkRecentManagerPrivate
{
  char *filename;

  guint is_dirty : 1;

  int size;

  GBookmarkFile *recent_items;

  GFileMonitor *monitor;

  guint changed_timeout;
  guint changed_age;
};

enum
{
  PROP_0,

  PROP_FILENAME,
  PROP_LIMIT,
  PROP_SIZE
};

static void     gtk_recent_manager_dispose             (GObject           *object);
static void     gtk_recent_manager_finalize            (GObject           *object);
static void     gtk_recent_manager_set_property        (GObject           *object,
                                                        guint              prop_id,
                                                        const GValue      *value,
                                                        GParamSpec        *pspec);
static void     gtk_recent_manager_get_property        (GObject           *object,
                                                        guint              prop_id,
                                                        GValue            *value,
                                                        GParamSpec        *pspec);
static void     gtk_recent_manager_add_item_query_info (GObject           *source_object,
                                                        GAsyncResult      *res,
                                                        gpointer           user_data);
static void     gtk_recent_manager_monitor_changed     (GFileMonitor      *monitor,
                                                        GFile             *file,
                                                        GFile             *other_file,
                                                        GFileMonitorEvent  event_type,
                                                        gpointer           user_data);
static void     gtk_recent_manager_changed             (GtkRecentManager  *manager);
static void     gtk_recent_manager_real_changed        (GtkRecentManager  *manager);
static void     gtk_recent_manager_set_filename        (GtkRecentManager  *manager,
                                                        const char        *filename);
static void     gtk_recent_manager_clamp_to_age        (GtkRecentManager  *manager,
                                                        int                age);
static void     gtk_recent_manager_clamp_to_size       (GtkRecentManager  *manager,
                                                        const int          size);

static void     gtk_recent_manager_enabled_changed     (GtkRecentManager  *manager);


static void     build_recent_items_list                (GtkRecentManager  *manager);
static void     purge_recent_items_list                (GtkRecentManager  *manager,
                                                        GError           **error);

static GtkRecentInfo *gtk_recent_info_new  (const char    *uri);
static void           gtk_recent_info_free (GtkRecentInfo *recent_info);

static guint signal_changed = 0;

static GtkRecentManager *recent_manager_singleton = NULL;

G_DEFINE_TYPE_WITH_PRIVATE (GtkRecentManager, gtk_recent_manager, G_TYPE_OBJECT)

/* Test of haystack has the needle prefix, comparing case
 * insensitive. haystack may be UTF-8, but needle must
 * contain only lowercase ascii.
 */
static gboolean
has_case_prefix (const char *haystack,
                 const char *needle)
{
  const char *h, *n;

  /* Eat one character at a time. */
  h = haystack;
  n = needle;

  while (*n && *h && *n == g_ascii_tolower (*h))
    {
      n++;
      h++;
    }

  return *n == '\0';
}

GQuark
gtk_recent_manager_error_quark (void)
{
  return g_quark_from_static_string ("gtk-recent-manager-error-quark");
}

static void
gtk_recent_manager_class_init (GtkRecentManagerClass *klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->set_property = gtk_recent_manager_set_property;
  gobject_class->get_property = gtk_recent_manager_get_property;
  gobject_class->dispose = gtk_recent_manager_dispose;
  gobject_class->finalize = gtk_recent_manager_finalize;

  /**
   * GtkRecentManager:filename:
   *
   * The full path to the file to be used to store and read the
   * recently used resources list
   */
  g_object_class_install_property (gobject_class,
                                   PROP_FILENAME,
                                   g_param_spec_string ("filename",
                                                        P_("Filename"),
                                                        P_("The full path to the file to be used to store and read the list"),
                                                        NULL,
                                                        (G_PARAM_CONSTRUCT_ONLY | GTK_PARAM_READWRITE)));

  /**
   * GtkRecentManager:size:
   *
   * The size of the recently used resources list.
   */
  g_object_class_install_property (gobject_class,
                                   PROP_SIZE,
                                   g_param_spec_int ("size",
                                                     P_("Size"),
                                                     P_("The size of the recently used resources list"),
                                                     -1, G_MAXINT, 0,
                                                     GTK_PARAM_READABLE));

  /**
   * GtkRecentManager::changed:
   * @recent_manager: the recent manager
   *
   * Emitted when the current recently used resources manager changes
   * its contents.
   *
   * This can happen either by calling [method@Gtk.RecentManager.add_item]
   * or by another application.
   */
  signal_changed =
    g_signal_new (I_("changed"),
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (GtkRecentManagerClass, changed),
                  NULL, NULL,
                  NULL,
                  G_TYPE_NONE, 0);

  klass->changed = gtk_recent_manager_real_changed;
}

static void
gtk_recent_manager_init (GtkRecentManager *manager)
{
  GtkRecentManagerPrivate *priv;
  GtkSettings *settings;

  manager->priv = gtk_recent_manager_get_instance_private (manager);
  priv = manager->priv;

  priv->size = 0;
  priv->filename = NULL;

  settings = gtk_settings_get_default ();
  if (settings)
    g_signal_connect_swapped (settings, "notify::gtk-recent-files-enabled",
                              G_CALLBACK (gtk_recent_manager_enabled_changed), manager);
}

static void
gtk_recent_manager_set_property (GObject      *object,
                                 guint         prop_id,
                                 const GValue *value,
                                 GParamSpec   *pspec)
{
  GtkRecentManager *recent_manager = GTK_RECENT_MANAGER (object);

  switch (prop_id)
    {
    case PROP_FILENAME:
      gtk_recent_manager_set_filename (recent_manager, g_value_get_string (value));
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gtk_recent_manager_get_property (GObject    *object,
                                 guint       prop_id,
                                 GValue     *value,
                                 GParamSpec *pspec)
{
  GtkRecentManager *recent_manager = GTK_RECENT_MANAGER (object);

  switch (prop_id)
    {
    case PROP_FILENAME:
      g_value_set_string (value, recent_manager->priv->filename);
      break;
    case PROP_SIZE:
      g_value_set_int (value, recent_manager->priv->size);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
    }
}

static void
gtk_recent_manager_finalize (GObject *object)
{
  GtkRecentManager *manager = GTK_RECENT_MANAGER (object);
  GtkRecentManagerPrivate *priv = manager->priv;

  g_free (priv->filename);

  if (priv->recent_items != NULL)
    g_bookmark_file_free (priv->recent_items);

  G_OBJECT_CLASS (gtk_recent_manager_parent_class)->finalize (object);
}

static void
gtk_recent_manager_dispose (GObject *gobject)
{
  GtkRecentManager *manager = GTK_RECENT_MANAGER (gobject);
  GtkRecentManagerPrivate *priv = manager->priv;

  if (priv->monitor != NULL)
    {
      g_signal_handlers_disconnect_by_func (priv->monitor,
                                            G_CALLBACK (gtk_recent_manager_monitor_changed),
                                            manager);
      g_object_unref (priv->monitor);
      priv->monitor = NULL;
    }

  if (priv->changed_timeout != 0)
    {
      g_source_remove (priv->changed_timeout);
      priv->changed_timeout = 0;
      priv->changed_age = 0;
    }

  if (priv->is_dirty)
    {
      g_object_ref (manager);
      g_signal_emit (manager, signal_changed, 0);
      g_object_unref (manager);
    }

  G_OBJECT_CLASS (gtk_recent_manager_parent_class)->dispose (gobject);
}

static void
gtk_recent_manager_enabled_changed (GtkRecentManager *manager)
{
  manager->priv->is_dirty = TRUE;
  gtk_recent_manager_changed (manager);
}

static void
gtk_recent_manager_real_changed (GtkRecentManager *manager)
{
  GtkRecentManagerPrivate *priv = manager->priv;

  g_object_freeze_notify (G_OBJECT (manager));

  if (priv->is_dirty)
    {
      GError *write_error;

      /* we are marked as dirty, so we dump the content of our
       * recently used items list
       */
      if (!priv->recent_items)
        {
          /* if no container object has been defined, we create a new
           * empty container, and dump it
           */
          priv->recent_items = g_bookmark_file_new ();
          priv->size = 0;
        }
      else
        {
          GtkSettings *settings;
          int age;
          int max_size = MAX_LIST_SIZE;
          gboolean enabled;

          settings = gtk_settings_get_default ();
          if (settings)
            g_object_get (G_OBJECT (settings),
                          "gtk-recent-files-max-age", &age,
                          "gtk-recent-files-enabled", &enabled,
                          NULL);
          else
            {
              age = 30;
              enabled = TRUE;
            }

          if (age == 0 || max_size == 0 || !enabled)
            {
              g_bookmark_file_free (priv->recent_items);
              priv->recent_items = g_bookmark_file_new ();
              priv->size = 0;
            }
          else
            {
              if (age > 0)
                gtk_recent_manager_clamp_to_age (manager, age);
              if (max_size > 0)
                gtk_recent_manager_clamp_to_size (manager, max_size);
            }
        }

      if (priv->filename != NULL)
        {
          write_error = NULL;
          g_bookmark_file_to_file (priv->recent_items, priv->filename, &write_error);
          if (write_error)
            {
              char *utf8 = g_filename_to_utf8 (priv->filename, -1, NULL, NULL, NULL);
              g_warning ("Attempting to store changes into '%s', but failed: %s",
                         utf8 ? utf8 : "(invalid filename)",
                         write_error->message);
              g_free (utf8);
              g_error_free (write_error);
            }

          if (g_chmod (priv->filename, 0600) < 0)
            {
              char *utf8 = g_filename_to_utf8 (priv->filename, -1, NULL, NULL, NULL);
              g_warning ("Attempting to set the permissions of '%s', but failed: %s",
                         utf8 ? utf8 : "(invalid filename)",
                         g_strerror (errno));
              g_free (utf8);
            }
        }

      /* mark us as clean */
      priv->is_dirty = FALSE;
    }
  else
    {
      /* we are not marked as dirty, so we have been called
       * because the recently used resources file has been
       * changed (and not from us).
       */
      build_recent_items_list (manager);
    }

  g_object_thaw_notify (G_OBJECT (manager));
}

static void
gtk_recent_manager_monitor_changed (GFileMonitor      *monitor,
                                    GFile             *file,
                                    GFile             *other_file,
                                    GFileMonitorEvent  event_type,
                                    gpointer           user_data)
{
  GtkRecentManager *manager = user_data;

  switch (event_type)
    {
    case G_FILE_MONITOR_EVENT_CHANGED:
    case G_FILE_MONITOR_EVENT_CREATED:
    case G_FILE_MONITOR_EVENT_DELETED:
      gtk_recent_manager_changed (manager);
      break;

    case G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT:
    case G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED:
    case G_FILE_MONITOR_EVENT_PRE_UNMOUNT:
    case G_FILE_MONITOR_EVENT_UNMOUNTED:
    case G_FILE_MONITOR_EVENT_MOVED:
    case G_FILE_MONITOR_EVENT_RENAMED:
    case G_FILE_MONITOR_EVENT_MOVED_IN:
    case G_FILE_MONITOR_EVENT_MOVED_OUT:

    default:
      break;
    }
}

static char *
get_default_filename (void)
{
  if (g_mkdir_with_parents (g_get_user_data_dir (), 0755) == -1)
    {
      int saved_errno = errno;

      g_critical ("Unable to create user data directory '%s' for storing "
                  "the recently used files list: %s",
                  g_get_user_data_dir (),
                  g_strerror (saved_errno));

      return NULL;
    }

  return g_build_filename (g_get_user_data_dir (),
                           GTK_RECENTLY_USED_FILE,
                           NULL);
}

static void
gtk_recent_manager_set_filename (GtkRecentManager *manager,
                                 const char       *filename)
{
  GtkRecentManagerPrivate *priv;
  GFile *file;
  GError *error;

  g_assert (GTK_IS_RECENT_MANAGER (manager));

  priv = manager->priv;

  /* if a filename is already set and filename is not NULL, then copy
   * it and reset the monitor; otherwise, if it's NULL we're being
   * called from the finalization sequence, so we simply disconnect
   * the monitoring and return.
   *
   * if no filename is set and filename is NULL, use the default.
   */
  if (priv->filename)
    {
      g_free (priv->filename);

      if (priv->monitor)
        {
          g_signal_handlers_disconnect_by_func (priv->monitor,
                                                G_CALLBACK (gtk_recent_manager_monitor_changed),
                                                manager);
          g_object_unref (priv->monitor);
          priv->monitor = NULL;
        }

      if (!filename || *filename == '\0')
        return;
      else
        priv->filename = g_strdup (filename);
    }
  else
    {
      if (!filename || *filename == '\0')
        priv->filename = get_default_filename ();
      else
        priv->filename = g_strdup (filename);
    }

  if (priv->filename != NULL)
    {
      file = g_file_new_for_path (priv->filename);

      error = NULL;
      priv->monitor = g_file_monitor_file (file, G_FILE_MONITOR_NONE, NULL, &error);
      if (error)
        {
          char *utf8 = g_filename_to_utf8 (priv->filename, -1, NULL, NULL, NULL);
          g_warning ("Unable to monitor '%s': %s\n"
                     "The GtkRecentManager will not update its contents "
                     "if the file is changed from other instances",
                     utf8 ? utf8 : "(invalid filename)",
                     error->message);
          g_free (utf8);
          g_error_free (error);
        }
      else
        g_signal_connect (priv->monitor, "changed",
                          G_CALLBACK (gtk_recent_manager_monitor_changed),
                          manager);

      g_object_unref (file);
    }

  build_recent_items_list (manager);
}

/* reads the recently used resources file and builds the items list.
 * we keep the items list inside the parser object, and build the
 * RecentInfo object only on user’s demand to avoid useless replication.
 * this function resets the dirty bit of the manager.
 */
static void
build_recent_items_list (GtkRecentManager *manager)
{
  GtkRecentManagerPrivate *priv = manager->priv;
  GError *read_error;
  int size;

  if (!priv->recent_items)
    {
      priv->recent_items = g_bookmark_file_new ();
      priv->size = 0;
    }

  if (priv->filename != NULL)
    {
      /* the file exists, and it's valid (we hope); if not, destroy the container
       * object and hope for a better result when the next "changed" signal is
       * fired.
       */
      read_error = NULL;
      g_bookmark_file_load_from_file (priv->recent_items, priv->filename, &read_error);
      if (read_error)
        {
          /* if the file does not exist we just wait for the first write
           * operation on this recent manager instance, to avoid creating
           * empty files and leading to spurious file system events (Sabayon
           * will not be happy about those)
           */
          if (read_error->domain == G_FILE_ERROR &&
              read_error->code != G_FILE_ERROR_NOENT)
            {
              char *utf8 = g_filename_to_utf8 (priv->filename, -1, NULL, NULL, NULL);
              g_warning ("Attempting to read the recently used resources "
                         "file at '%s', but the parser failed: %s.",
                         utf8 ? utf8 : "(invalid filename)",
                         read_error->message);
              g_free (utf8);
            }

          g_bookmark_file_free (priv->recent_items);
          priv->recent_items = NULL;

          g_error_free (read_error);
        }
      else
        {
          size = g_bookmark_file_get_size (priv->recent_items);
          if (priv->size != size)
            {
              priv->size = size;

              g_object_notify (G_OBJECT (manager), "size");
            }
        }
    }

  priv->is_dirty = FALSE;
}


/********************
 * GtkRecentManager *
 ********************/


/**
 * gtk_recent_manager_new:
 *
 * Creates a new recent manager object.
 *
 * Recent manager objects are used to handle the list of recently used
 * resources. A `GtkRecentManager` object monitors the recently used
 * resources list, and emits the [signal@Gtk.RecentManager::changed]
 * signal each time something inside the list changes.
 *
 * `GtkRecentManager` objects are expensive: be sure to create them
 * only when needed. You should use [type_func@Gtk.RecentManager.get_default]
 * instead.
 *
 * Returns: A newly created `GtkRecentManager` object
 */
GtkRecentManager *
gtk_recent_manager_new (void)
{
  return g_object_new (GTK_TYPE_RECENT_MANAGER, NULL);
}

/**
 * gtk_recent_manager_get_default:
 *
 * Gets a unique instance of `GtkRecentManager` that you can share
 * in your application without caring about memory management.
 *
 * Returns: (transfer none): A unique `GtkRecentManager`. Do not ref or
 *   unref it.
 */
GtkRecentManager *
gtk_recent_manager_get_default (void)
{
  if (G_UNLIKELY (!recent_manager_singleton))
    recent_manager_singleton = gtk_recent_manager_new ();

  return recent_manager_singleton;
}


static void
gtk_recent_manager_add_item_query_info (GObject      *source_object,
                                        GAsyncResult *res,
                                        gpointer      user_data)
{
  GFile *file = G_FILE (source_object);
  GtkRecentManager *manager = user_data;
  GtkRecentData recent_data;
  GFileInfo *file_info;
  char *uri, *basename, *content_type;

  uri = g_file_get_uri (file);

  file_info = g_file_query_info_finish (file, res, NULL); /* NULL-GError */

  recent_data.display_name = NULL;
  recent_data.description = NULL;

  if (file_info)
    {
      content_type = g_file_info_get_attribute_as_string (file_info, G_FILE_ATTRIBUTE_STANDARD_FAST_CONTENT_TYPE);

      if (G_LIKELY (content_type))
        recent_data.mime_type = g_content_type_get_mime_type (content_type);
      else
        recent_data.mime_type = g_strdup (GTK_RECENT_DEFAULT_MIME);

      g_free (content_type);
      g_object_unref (file_info);
    }
  else
    {
      basename = g_file_get_basename (file);
      content_type = g_content_type_guess (basename, NULL, 0, NULL);
      recent_data.mime_type = g_content_type_get_mime_type (content_type);
      g_free (basename);
      g_free (content_type);
    }

  recent_data.app_name = g_strdup (g_get_application_name ());
  recent_data.app_exec = g_strjoin (" ", g_get_prgname (), "%u", NULL);
  recent_data.groups = NULL;
  recent_data.is_private = FALSE;

  /* Ignore return value, this can't fail anyway since all required
   * fields are set
   */
  gtk_recent_manager_add_full (manager, uri, &recent_data);

  manager->priv->is_dirty = TRUE;
  gtk_recent_manager_changed (manager);

  g_free (recent_data.mime_type);
  g_free (recent_data.app_name);
  g_free (recent_data.app_exec);

  g_object_unref (manager);
  g_free (uri);
}

/**
 * gtk_recent_manager_add_item:
 * @manager: a `GtkRecentManager`
 * @uri: a valid URI
 *
 * Adds a new resource, pointed by @uri, into the recently used
 * resources list.
 *
 * This function automatically retrieves some of the needed
 * metadata and setting other metadata to common default values;
 * it then feeds the data to [method@Gtk.RecentManager.add_full].
 *
 * See [method@Gtk.RecentManager.add_full] if you want to explicitly
 * define the metadata for the resource pointed by @uri.
 *
 * Returns: %TRUE if the new item was successfully added
 *   to the recently used resources list
 */
gboolean
gtk_recent_manager_add_item (GtkRecentManager *manager,
                             const char       *uri)
{
  GFile* file;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), FALSE);
  g_return_val_if_fail (uri != NULL, FALSE);

  file = g_file_new_for_uri (uri);

  g_file_query_info_async (file,
                           G_FILE_ATTRIBUTE_STANDARD_FAST_CONTENT_TYPE,
                           G_PRIORITY_DEFAULT,
                           G_FILE_QUERY_INFO_NONE,
                           NULL,
                           gtk_recent_manager_add_item_query_info,
                           g_object_ref (manager));

  g_object_unref (file);

  return TRUE;
}

/**
 * gtk_recent_manager_add_full:
 * @manager: a `GtkRecentManager`
 * @uri: a valid URI
 * @recent_data: metadata of the resource
 *
 * Adds a new resource, pointed by @uri, into the recently used
 * resources list, using the metadata specified inside the
 * `GtkRecentData` passed in @recent_data.
 *
 * The passed URI will be used to identify this resource inside the
 * list.
 *
 * In order to register the new recently used resource, metadata about
 * the resource must be passed as well as the URI; the metadata is
 * stored in a `GtkRecentData`, which must contain the MIME
 * type of the resource pointed by the URI; the name of the application
 * that is registering the item, and a command line to be used when
 * launching the item.
 *
 * Optionally, a `GtkRecentData` might contain a UTF-8 string
 * to be used when viewing the item instead of the last component of
 * the URI; a short description of the item; whether the item should
 * be considered private - that is, should be displayed only by the
 * applications that have registered it.
 *
 * Returns: %TRUE if the new item was successfully added to the
 *     recently used resources list, %FALSE otherwise
 */
gboolean
gtk_recent_manager_add_full (GtkRecentManager    *manager,
                             const char          *uri,
                             const GtkRecentData *data)
{
  GtkRecentManagerPrivate *priv;
  GtkSettings *settings;
  gboolean enabled;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), FALSE);
  g_return_val_if_fail (uri != NULL, FALSE);
  g_return_val_if_fail (data != NULL, FALSE);

  /* sanity checks */
  if ((data->display_name) &&
      (!g_utf8_validate (data->display_name, -1, NULL)))
    {
      g_warning ("Attempting to add '%s' to the list of recently used "
                 "resources, but the display name is not a valid UTF-8 "
                 "encoded string",
                 uri);
      return FALSE;
    }

  if ((data->description) &&
      (!g_utf8_validate (data->description, -1, NULL)))
    {
      g_warning ("Attempting to add '%s' to the list of recently used "
                 "resources, but the description is not a valid UTF-8 "
                 "encoded string",
                 uri);
      return FALSE;
    }


  if (!data->mime_type)
    {
      g_warning ("Attempting to add '%s' to the list of recently used "
                 "resources, but no MIME type was defined",
                 uri);
      return FALSE;
    }

  if (!data->app_name)
    {
      g_warning ("Attempting to add '%s' to the list of recently used "
                 "resources, but no name of the application that is "
                 "registering it was defined",
                 uri);
      return FALSE;
    }

  if (!data->app_exec)
    {
      g_warning ("Attempting to add '%s' to the list of recently used "
                 "resources, but no command line for the application "
                 "that is registering it was defined",
                 uri);
      return FALSE;
    }

  settings = gtk_settings_get_default ();
  g_object_get (G_OBJECT (settings), "gtk-recent-files-enabled", &enabled, NULL);
  if (!enabled)
    return TRUE;

  priv = manager->priv;

  if (!priv->recent_items)
    {
      priv->recent_items = g_bookmark_file_new ();
      priv->size = 0;
    }

  if (data->display_name)
    g_bookmark_file_set_title (priv->recent_items, uri, data->display_name);

  if (data->description)
    g_bookmark_file_set_description (priv->recent_items, uri, data->description);

  g_bookmark_file_set_mime_type (priv->recent_items, uri, data->mime_type);

  if (data->groups && ((char*)data->groups)[0] != '\0')
    {
      int j;

      for (j = 0; (data->groups)[j] != NULL; j++)
        g_bookmark_file_add_group (priv->recent_items, uri, (data->groups)[j]);
    }

  /* register the application; this will take care of updating the
   * registration count and time in case the application has
   * already registered the same document inside the list
   */
  g_bookmark_file_add_application (priv->recent_items, uri,
                                   data->app_name,
                                   data->app_exec);

  g_bookmark_file_set_is_private (priv->recent_items, uri,
                                  data->is_private);

  /* mark us as dirty, so that when emitting the "changed" signal we
   * will dump our changes
   */
  priv->is_dirty = TRUE;
  gtk_recent_manager_changed (manager);

  return TRUE;
}

/**
 * gtk_recent_manager_remove_item:
 * @manager: a `GtkRecentManager`
 * @uri: the URI of the item you wish to remove
 * @error: (allow-none): return location for a #GError, or %NULL
 *
 * Removes a resource pointed by @uri from the recently used resources
 * list handled by a recent manager.
 *
 * Returns: %TRUE if the item pointed by @uri has been successfully
 *   removed by the recently used resources list, and %FALSE otherwise
 */
gboolean
gtk_recent_manager_remove_item (GtkRecentManager  *manager,
                                const char        *uri,
                                GError           **error)
{
  GtkRecentManagerPrivate *priv;
  GError *remove_error = NULL;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), FALSE);
  g_return_val_if_fail (uri != NULL, FALSE);
  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  priv = manager->priv;

  if (!priv->recent_items)
    {
      priv->recent_items = g_bookmark_file_new ();
      priv->size = 0;

      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);

      return FALSE;
    }

  g_bookmark_file_remove_item (priv->recent_items, uri, &remove_error);
  if (remove_error)
    {
      g_error_free (remove_error);

      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);

      return FALSE;
    }

  priv->is_dirty = TRUE;
  gtk_recent_manager_changed (manager);

  return TRUE;
}

/**
 * gtk_recent_manager_has_item:
 * @manager: a `GtkRecentManager`
 * @uri: a URI
 *
 * Checks whether there is a recently used resource registered
 * with @uri inside the recent manager.
 *
 * Returns: %TRUE if the resource was found, %FALSE otherwise
 */
gboolean
gtk_recent_manager_has_item (GtkRecentManager *manager,
                             const char       *uri)
{
  GtkRecentManagerPrivate *priv;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), FALSE);
  g_return_val_if_fail (uri != NULL, FALSE);

  priv = manager->priv;
  g_return_val_if_fail (priv->recent_items != NULL, FALSE);

  return g_bookmark_file_has_item (priv->recent_items, uri);
}

static void
build_recent_info (GBookmarkFile *bookmarks,
                   GtkRecentInfo *info)
{
  char **apps, **groups;
  gsize apps_len, groups_len, i;
  int app_index;

  g_assert (bookmarks != NULL);
  g_assert (info != NULL);

  info->display_name = g_bookmark_file_get_title (bookmarks, info->uri, NULL);
  info->description = g_bookmark_file_get_description (bookmarks, info->uri, NULL);
  info->mime_type = g_bookmark_file_get_mime_type (bookmarks, info->uri, NULL);

  info->is_private = g_bookmark_file_get_is_private (bookmarks, info->uri, NULL);

  info->added = g_bookmark_file_get_added_date_time (bookmarks, info->uri, NULL);
  info->modified = g_bookmark_file_get_modified_date_time (bookmarks, info->uri, NULL);
  info->visited = g_bookmark_file_get_visited_date_time (bookmarks, info->uri, NULL);

  groups = g_bookmark_file_get_groups (bookmarks, info->uri, &groups_len, NULL);
  info->groups = g_malloc (sizeof (char *) * groups_len);
  info->n_groups = groups_len;
  for (i = 0; i < groups_len; i++)
    info->groups[i] = g_strdup (groups[i]);

  g_strfreev (groups);

  app_index = 0;
  apps = g_bookmark_file_get_applications (bookmarks, info->uri, &apps_len, NULL);
  info->applications = g_malloc (sizeof (RecentAppInfo ) * apps_len);
  info->n_applications = 0;
  for (i = 0; i < apps_len; i++)
    {
      char *app_name, *app_exec;
      guint count;
      GDateTime *stamp;
      RecentAppInfo *app_info;
      gboolean res;

      app_name = apps[i];

      res = g_bookmark_file_get_application_info (bookmarks, info->uri, app_name,
                                                  &app_exec,
                                                  &count,
                                                  &stamp,
                                                  NULL);
      if (!res)
        continue;

      app_info = &info->applications[app_index];
      app_info->name= g_strdup (app_name);
      app_info->exec = app_exec;
      app_info->count = count;
      app_info->stamp = g_date_time_ref (stamp);

      g_hash_table_replace (info->apps_lookup, app_info->name, app_info);

      app_index ++;
      info->n_applications ++;
    }

  g_strfreev (apps);
}

/**
 * gtk_recent_manager_lookup_item:
 * @manager: a `GtkRecentManager`
 * @uri: a URI
 * @error: (allow-none): a return location for a #GError, or %NULL
 *
 * Searches for a URI inside the recently used resources list, and
 * returns a `GtkRecentInfo` containing information about the resource
 * like its MIME type, or its display name.
 *
 * Returns: (nullable): a `GtkRecentInfo` containing information
 *   about the resource pointed by @uri, or %NULL if the URI was
 *   not registered in the recently used resources list. Free with
 *   [method@Gtk.RecentInfo.unref].
 */
GtkRecentInfo *
gtk_recent_manager_lookup_item (GtkRecentManager  *manager,
                                const char        *uri,
                                GError           **error)
{
  GtkRecentManagerPrivate *priv;
  GtkRecentInfo *info = NULL;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), NULL);
  g_return_val_if_fail (uri != NULL, NULL);
  g_return_val_if_fail (error == NULL || *error == NULL, NULL);

  priv = manager->priv;
  if (!priv->recent_items)
    {
      priv->recent_items = g_bookmark_file_new ();
      priv->size = 0;

      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);

      return NULL;
    }

  if (!g_bookmark_file_has_item (priv->recent_items, uri))
    {
      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);
      return NULL;
    }

  info = gtk_recent_info_new (uri);
  g_return_val_if_fail (info != NULL, NULL);

  /* fill the RecentInfo structure with the data retrieved by our
   * parser object from the storage file
   */
  build_recent_info (priv->recent_items, info);

  return info;
}

/**
 * gtk_recent_manager_move_item:
 * @manager: a `GtkRecentManager`
 * @uri: the URI of a recently used resource
 * @new_uri: (allow-none): the new URI of the recently used resource, or
 *    %NULL to remove the item pointed by @uri in the list
 * @error: (allow-none): a return location for a #GError, or %NULL
 *
 * Changes the location of a recently used resource from @uri to @new_uri.
 *
 * Please note that this function will not affect the resource pointed
 * by the URIs, but only the URI used in the recently used resources list.
 *
 * Returns: %TRUE on success
 */
gboolean
gtk_recent_manager_move_item (GtkRecentManager  *recent_manager,
                              const char        *uri,
                              const char        *new_uri,
                              GError           **error)
{
  GtkRecentManagerPrivate *priv;
  GError *move_error;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (recent_manager), FALSE);
  g_return_val_if_fail (uri != NULL, FALSE);
  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);

  priv = recent_manager->priv;

  if (!priv->recent_items)
    {
      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);
      return FALSE;
    }

  if (!g_bookmark_file_has_item (priv->recent_items, uri))
    {
      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_FOUND,
                   _("Unable to find an item with URI “%s”"),
                   uri);
      return FALSE;
    }

  move_error = NULL;
  if (!g_bookmark_file_move_item (priv->recent_items,
                                  uri,
                                  new_uri,
                                  &move_error))
    {
      g_error_free (move_error);

      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_UNKNOWN,
                   _("Unable to move the item with URI “%s” to “%s”"),
                   uri, new_uri);
      return FALSE;
    }

  priv->is_dirty = TRUE;
  gtk_recent_manager_changed (recent_manager);

  return TRUE;
}

/**
 * gtk_recent_manager_get_items:
 * @manager: a `GtkRecentManager`
 *
 * Gets the list of recently used resources.
 *
 * Returns: (element-type GtkRecentInfo) (transfer full): a list of
 *   newly allocated `GtkRecentInfo objects`. Use
 *   [method@Gtk.RecentInfo.unref] on each item inside the list, and then
 *   free the list itself using g_list_free().
 */
GList *
gtk_recent_manager_get_items (GtkRecentManager *manager)
{
  GtkRecentManagerPrivate *priv;
  GList *retval = NULL;
  char **uris;
  gsize uris_len, i;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), NULL);

  priv = manager->priv;
  if (!priv->recent_items)
    return NULL;

  uris = g_bookmark_file_get_uris (priv->recent_items, &uris_len);
  for (i = 0; i < uris_len; i++)
    {
      GtkRecentInfo *info;

      info = gtk_recent_info_new (uris[i]);
      build_recent_info (priv->recent_items, info);

      retval = g_list_prepend (retval, info);
    }

  g_strfreev (uris);

  return retval;
}

static void
purge_recent_items_list (GtkRecentManager  *manager,
                         GError           **error)
{
  GtkRecentManagerPrivate *priv = manager->priv;

  if (priv->recent_items == NULL)
    return;

  g_bookmark_file_free (priv->recent_items);
  priv->recent_items = g_bookmark_file_new ();
  priv->size = 0;

  /* emit the changed signal, to ensure that the purge is written */
  priv->is_dirty = TRUE;
  gtk_recent_manager_changed (manager);
}

/**
 * gtk_recent_manager_purge_items:
 * @manager: a `GtkRecentManager`
 * @error: (allow-none): a return location for a #GError, or %NULL
 *
 * Purges every item from the recently used resources list.
 *
 * Returns: the number of items that have been removed from the
 *   recently used resources list
 */
int
gtk_recent_manager_purge_items (GtkRecentManager  *manager,
                                GError           **error)
{
  GtkRecentManagerPrivate *priv;
  int count, purged;

  g_return_val_if_fail (GTK_IS_RECENT_MANAGER (manager), -1);

  priv = manager->priv;
  if (!priv->recent_items)
    return 0;

  count = g_bookmark_file_get_size (priv->recent_items);
  if (!count)
    return 0;

  purge_recent_items_list (manager, error);

  purged = count - g_bookmark_file_get_size (priv->recent_items);

  return purged;
}

static gboolean
emit_manager_changed (gpointer data)
{
  GtkRecentManager *manager = data;

  manager->priv->changed_age = 0;
  manager->priv->changed_timeout = 0;

  g_signal_emit (manager, signal_changed, 0);

  return FALSE;
}

static void
gtk_recent_manager_changed (GtkRecentManager *manager)
{
  /* coalesce consecutive changes
   *
   * we schedule a write in 250 msecs immediately; if we get more than one
   * request per millisecond before the timeout has a chance to run, we
   * schedule an emission immediately.
   */
  if (manager->priv->changed_timeout == 0)
    {
      manager->priv->changed_timeout = g_timeout_add (250, emit_manager_changed, manager);
      g_source_set_name_by_id (manager->priv->changed_timeout, "[gtk] emit_manager_changed");
    }
  else
    {
      manager->priv->changed_age += 1;

      if (manager->priv->changed_age > 250)
        {
          g_source_remove (manager->priv->changed_timeout);
          g_signal_emit (manager, signal_changed, 0);

          manager->priv->changed_age = 0;
          manager->priv->changed_timeout = 0;
        }
    }
}

static void
gtk_recent_manager_clamp_to_age (GtkRecentManager *manager,
                                 int               age)
{
  GtkRecentManagerPrivate *priv = manager->priv;
  char **uris;
  gsize n_uris, i;
  GDateTime *now;

  if (G_UNLIKELY (!priv->recent_items))
    return;

  now = g_date_time_new_now_utc ();

  uris = g_bookmark_file_get_uris (priv->recent_items, &n_uris);

  for (i = 0; i < n_uris; i++)
    {
      const char *uri = uris[i];
      GDateTime *modified;
      int item_age;

      modified = g_bookmark_file_get_modified_date_time (priv->recent_items, uri, NULL);

      item_age = (int) (g_date_time_difference (now, modified) / (double)G_TIME_SPAN_DAY);
      if (item_age > age)
        g_bookmark_file_remove_item (priv->recent_items, uri, NULL);
    }

  g_strfreev (uris);
}

static void
gtk_recent_manager_clamp_to_size (GtkRecentManager *manager,
                                  const int         size)
{
  GtkRecentManagerPrivate *priv = manager->priv;
  char **uris;
  gsize n_uris, i;

  if (G_UNLIKELY (!priv->recent_items) || G_UNLIKELY (size < 0))
    return;

  uris = g_bookmark_file_get_uris (priv->recent_items, &n_uris);

  if (n_uris < size)
  {
    g_strfreev (uris);
    return;
  }

  for (i = 0; i < n_uris - size; i++)
    {
      const char *uri = uris[i];
      g_bookmark_file_remove_item (priv->recent_items, uri, NULL);
    }

  g_strfreev (uris);
}

/*****************
 * GtkRecentInfo *
 *****************/

G_DEFINE_BOXED_TYPE (GtkRecentInfo, gtk_recent_info,
                     gtk_recent_info_ref,
                     gtk_recent_info_unref)

static GtkRecentInfo *
gtk_recent_info_new (const char *uri)
{
  GtkRecentInfo *info;

  g_assert (uri != NULL);

  info = g_new0 (GtkRecentInfo, 1);
  info->uri = g_strdup (uri);

  info->applications = NULL;
  info->apps_lookup = g_hash_table_new (g_str_hash, g_str_equal);

  info->groups = NULL;

  info->ref_count = 1;

  return info;
}

static void
gtk_recent_info_free (GtkRecentInfo *recent_info)
{
  int i;

  if (!recent_info)
    return;

  g_free (recent_info->uri);
  g_free (recent_info->display_name);
  g_free (recent_info->description);
  g_free (recent_info->mime_type);

  for (i = 0; i < recent_info->n_applications; i ++)
    {
      const RecentAppInfo *app_info = &recent_info->applications[i];

      g_free (app_info->name);
      g_free (app_info->exec);
      g_date_time_unref (app_info->stamp);
    }
  g_free (recent_info->applications);

  if (recent_info->apps_lookup)
    g_hash_table_destroy (recent_info->apps_lookup);

  for (i = 0; i < recent_info->n_groups; i ++)
    g_free (recent_info->groups[i]);

  g_free (recent_info->groups);

  g_free (recent_info);
}

/**
 * gtk_recent_info_ref:
 * @info: a `GtkRecentInfo`
 *
 * Increases the reference count of @recent_info by one.
 *
 * Returns: the recent info object with its reference count
 *     increased by one
 */
GtkRecentInfo *
gtk_recent_info_ref (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);
  g_return_val_if_fail (info->ref_count > 0, NULL);

  info->ref_count += 1;

  return info;
}

/**
 * gtk_recent_info_unref:
 * @info: a `GtkRecentInfo`
 *
 * Decreases the reference count of @info by one.
 *
 * If the reference count reaches zero, @info is
 * deallocated, and the memory freed.
 */
void
gtk_recent_info_unref (GtkRecentInfo *info)
{
  g_return_if_fail (info != NULL);
  g_return_if_fail (info->ref_count > 0);

  info->ref_count -= 1;

  if (info->ref_count == 0)
    gtk_recent_info_free (info);
}

/**
 * gtk_recent_info_get_uri:
 * @info: a `tkRecentInfo`
 *
 * Gets the URI of the resource.
 *
 * Returns: the URI of the resource. The returned string is
 *   owned by the recent manager, and should not be freed.
 */
const char *
gtk_recent_info_get_uri (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  return info->uri;
}

/**
 * gtk_recent_info_get_display_name:
 * @info: a `GtkRecentInfo`
 *
 * Gets the name of the resource.
 *
 * If none has been defined, the basename
 * of the resource is obtained.
 *
 * Returns: the display name of the resource. The returned string
 *   is owned by the recent manager, and should not be freed.
 */
const char *
gtk_recent_info_get_display_name (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  if (!info->display_name)
    info->display_name = gtk_recent_info_get_short_name (info);

  return info->display_name;
}

/**
 * gtk_recent_info_get_description:
 * @info: a `GtkRecentInfo`
 *
 * Gets the (short) description of the resource.
 *
 * Returns: the description of the resource. The returned string
 *   is owned by the recent manager, and should not be freed.
 **/
const char *
gtk_recent_info_get_description (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  return info->description;
}

/**
 * gtk_recent_info_get_mime_type:
 * @info: a `GtkRecentInfo`
 *
 * Gets the MIME type of the resource.
 *
 * Returns: the MIME type of the resource. The returned string
 *   is owned by the recent manager, and should not be freed.
 */
const char *
gtk_recent_info_get_mime_type (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  if (!info->mime_type)
    info->mime_type = g_strdup (GTK_RECENT_DEFAULT_MIME);

  return info->mime_type;
}

/**
 * gtk_recent_info_get_added:
 * @info: a `GtkRecentInfo`
 *
 * Gets the the time when the resource
 * was added to the recently used resources list.
 *
 * Returns: (transfer none): a #GDateTime for the time
 *    when the resource was added
 */
GDateTime *
gtk_recent_info_get_added (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  return info->added;
}

/**
 * gtk_recent_info_get_modified:
 * @info: a `GtkRecentInfo`
 *
 * Gets the time when the meta-data
 * for the resource was last modified.
 *
 * Returns: (transfer none): a #GDateTime for the time
 *    when the resource was last modified
 */
GDateTime *
gtk_recent_info_get_modified (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  return info->modified;
}

/**
 * gtk_recent_info_get_visited:
 * @info: a `GtkRecentInfo`
 *
 * Gets the time when the meta-data
 * for the resource was last visited.
 *
 * Returns: (transfer none): a #GDateTime for the time
 *    when the resource was last visited
 */
GDateTime *
gtk_recent_info_get_visited (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, NULL);

  return info->visited;
}

/**
 * gtk_recent_info_get_private_hint:
 * @info: a `GtkRecentInfo`
 *
 * Gets the value of the “private” flag.
 *
 * Resources in the recently used list that have this flag
 * set to %TRUE should only be displayed by the applications
 * that have registered them.
 *
 * Returns: %TRUE if the private flag was found, %FALSE otherwise
 */
gboolean
gtk_recent_info_get_private_hint (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, FALSE);

  return info->is_private;
}

/**
 * gtk_recent_info_get_application_info:
 * @info: a `GtkRecentInfo`
 * @app_name: the name of the application that has registered this item
 * @app_exec: (transfer none) (out): return location for the string containing
 *    the command line
 * @count: (out): return location for the number of times this item was registered
 * @stamp: (out) (transfer none): return location for the time this item was last
 *    registered for this application
 *
 * Gets the data regarding the application that has registered the resource
 * pointed by @info.
 *
 * If the command line contains any escape characters defined inside the
 * storage specification, they will be expanded.
 *
 * Returns: %TRUE if an application with @app_name has registered this
 *   resource inside the recently used list, or %FALSE otherwise. The
 *   @app_exec string is owned by the `GtkRecentInfo` and should not be
 *   modified or freed
 */
gboolean
gtk_recent_info_get_application_info (GtkRecentInfo  *info,
                                      const char     *app_name,
                                      const char    **app_exec,
                                      guint          *count,
                                      GDateTime     **stamp)
{
  RecentAppInfo *ai;

  g_return_val_if_fail (info != NULL, FALSE);
  g_return_val_if_fail (app_name != NULL, FALSE);

  ai = (RecentAppInfo *) g_hash_table_lookup (info->apps_lookup,
                                              app_name);
  if (!ai)
    {
      g_warning ("No registered application with name '%s' "
                 "for item with URI '%s' found",
                 app_name,
                 info->uri);
      return FALSE;
    }

  if (app_exec)
    *app_exec = ai->exec;

  if (count)
    *count = ai->count;

  if (stamp)
    *stamp = ai->stamp;

  return TRUE;
}

/**
 * gtk_recent_info_get_applications:
 * @info: a `GtkRecentInfo`
 * @length: (out) (allow-none): return location for the length of the returned list
 *
 * Retrieves the list of applications that have registered this resource.
 *
 * Returns: (array length=length zero-terminated=1) (transfer full): a newly
 *   allocated %NULL-terminated array of strings. Use g_strfreev() to free it.
 */
char **
gtk_recent_info_get_applications (GtkRecentInfo *info,
                                  gsize         *length)
{
  char **retval;
  gsize n_apps, i;

  g_return_val_if_fail (info != NULL, NULL);

  if (!info->applications)
    {
      if (length)
        *length = 0;

      return NULL;
    }

  n_apps = info->n_applications;

  retval = g_new0 (char *, n_apps + 1);

  for (i = 0; i < info->n_applications; i ++)
    {
      const RecentAppInfo *ai = &info->applications[i];

      retval[i] = g_strdup (ai->name);
    }
  retval[i] = NULL;

  if (length)
    *length = info->n_applications;

  return retval;
}

/**
 * gtk_recent_info_has_application:
 * @info: a `GtkRecentInfo`
 * @app_name: a string containing an application name
 *
 * Checks whether an application registered this resource using @app_name.
 *
 * Returns: %TRUE if an application with name @app_name was found,
 *   %FALSE otherwise
 */
gboolean
gtk_recent_info_has_application (GtkRecentInfo *info,
                                 const char    *app_name)
{
  g_return_val_if_fail (info != NULL, FALSE);
  g_return_val_if_fail (app_name != NULL, FALSE);

  return (NULL != g_hash_table_lookup (info->apps_lookup, app_name));
}

/**
 * gtk_recent_info_last_application:
 * @info: a `GtkRecentInfo`
 *
 * Gets the name of the last application that have registered the
 * recently used resource represented by @info.
 *
 * Returns: an application name. Use g_free() to free it.
 */
char *
gtk_recent_info_last_application (GtkRecentInfo *info)
{
  int i;
  GDateTime *last_stamp = NULL;
  char *name = NULL;

  g_return_val_if_fail (info != NULL, NULL);

  for (i = 0; i < info->n_applications; i ++)
    {
      const RecentAppInfo *ai = &info->applications[i];

      if (last_stamp == NULL ||
          g_date_time_compare (ai->stamp, last_stamp) > 0)
        {
          name = ai->name;
          last_stamp = ai->stamp;
        }
    }

  return g_strdup (name);
}

/**
 * gtk_recent_info_get_gicon:
 * @info: a `GtkRecentInfo`
 *
 * Retrieves the icon associated to the resource MIME type.
 *
 * Returns: (nullable) (transfer full): a #GIcon containing the icon, or %NULL.
 *   Use g_object_unref() when finished using the icon
 */
GIcon *
gtk_recent_info_get_gicon (GtkRecentInfo *info)
{
  GIcon *icon = NULL;
  char *content_type;

  g_return_val_if_fail (info != NULL, NULL);

  if (info->mime_type != NULL &&
      (content_type = g_content_type_from_mime_type (info->mime_type)) != NULL)
    {
      icon = g_content_type_get_icon (content_type);
      g_free (content_type);
    }
  else
    {
      if (info->mime_type &&
          strcmp (info->mime_type, "x-directory/normal") == 0)
        icon = g_themed_icon_new ("folder");
      else
        icon = g_themed_icon_new ("text-x-generic");
    }

  return icon;
}

/**
 * gtk_recent_info_is_local:
 * @info: a `GtkRecentInfo`
 *
 * Checks whether the resource is local or not by looking at the
 * scheme of its URI.
 *
 * Returns: %TRUE if the resource is local
 */
gboolean
gtk_recent_info_is_local (GtkRecentInfo *info)
{
  g_return_val_if_fail (info != NULL, FALSE);

  return has_case_prefix (info->uri, "file:/");
}

/**
 * gtk_recent_info_exists:
 * @info: a `GtkRecentInfo`
 *
 * Checks whether the resource pointed by @info still exists.
 * At the moment this check is done only on resources pointing
 * to local files.
 *
 * Returns: %TRUE if the resource exists
 */
gboolean
gtk_recent_info_exists (GtkRecentInfo *info)
{
  char *filename;
  GStatBuf stat_buf;
  gboolean retval = FALSE;

  g_return_val_if_fail (info != NULL, FALSE);

  /* we guarantee only local resources */
  if (!gtk_recent_info_is_local (info))
    return FALSE;

  filename = g_filename_from_uri (info->uri, NULL, NULL);
  if (filename)
    {
      if (g_stat (filename, &stat_buf) == 0)
        retval = TRUE;

      g_free (filename);
    }

  return retval;
}

/**
 * gtk_recent_info_match:
 * @info_a: a `GtkRecentInfo`
 * @info_b: a `GtkRecentInfo`
 *
 * Checks whether two `GtkRecentInfo` point to the same resource.
 *
 * Returns: %TRUE if both `GtkRecentInfo` point to the same
 *   resource, %FALSE otherwise
 */
gboolean
gtk_recent_info_match (GtkRecentInfo *info_a,
                       GtkRecentInfo *info_b)
{
  g_return_val_if_fail (info_a != NULL, FALSE);
  g_return_val_if_fail (info_b != NULL, FALSE);

  return (0 == strcmp (info_a->uri, info_b->uri));
}

/* taken from gnome-vfs-uri.c */
static const char *
get_method_string (const char   *substring,
                   char        **method_string)
{
  const char *p;
  char *method;

  for (p = substring;
       g_ascii_isalnum (*p) || *p == '+' || *p == '-' || *p == '.';
       p++)
    ;

  if (*p == ':'
#ifdef G_OS_WIN32
                &&
      !(p == substring + 1 && g_ascii_isalpha (*substring))
#endif
                                                           )
    {
      /* Found toplevel method specification.  */
      method = g_strndup (substring, p - substring);
      *method_string = g_ascii_strdown (method, -1);
      g_free (method);
      p++;
    }
  else
    {
      *method_string = g_strdup ("file");
      p = substring;
    }

  return p;
}

/* Stolen from gnome_vfs_make_valid_utf8() */
static char *
make_valid_utf8 (const char *name)
{
  GString *string;
  const char *remainder, *invalid;
  int remaining_bytes, valid_bytes;

  string = NULL;
  remainder = name;
  remaining_bytes = name ? strlen (name) : 0;

  while (remaining_bytes != 0)
    {
      if (g_utf8_validate (remainder, remaining_bytes, &invalid))
        break;

      valid_bytes = invalid - remainder;

      if (string == NULL)
        string = g_string_sized_new (remaining_bytes);

      g_string_append_len (string, remainder, valid_bytes);
      g_string_append_c (string, '?');

      remaining_bytes -= valid_bytes + 1;
      remainder = invalid + 1;
    }

  if (string == NULL)
    return g_strdup (name);

  g_string_append (string, remainder);
  g_assert (g_utf8_validate (string->str, -1, NULL));

  return g_string_free (string, FALSE);
}

static char *
get_uri_shortname_for_display (const char *uri)
{
  char *name = NULL;
  gboolean validated = FALSE;

  if (has_case_prefix (uri, "file:/"))
    {
      char *local_file;

      local_file = g_filename_from_uri (uri, NULL, NULL);

      if (local_file)
        {
          name = g_filename_display_basename (local_file);
          validated = TRUE;
        }

      g_free (local_file);
    }

  if (!name)
    {
      char *method;
      char *local_file;
      const char *rest;

      rest = get_method_string (uri, &method);
      local_file = g_filename_display_basename (rest);

      name = g_strconcat (method, ": ", local_file, NULL);

      g_free (local_file);
      g_free (method);
    }

  g_assert (name != NULL);

  if (!validated && !g_utf8_validate (name, -1, NULL))
    {
      char *utf8_name;

      utf8_name = make_valid_utf8 (name);
      g_free (name);

      name = utf8_name;
    }

  return name;
}

/**
 * gtk_recent_info_get_short_name:
 * @info: an `GtkRecentInfo`
 *
 * Computes a valid UTF-8 string that can be used as the
 * name of the item in a menu or list.
 *
 * For example, calling this function on an item that refers
 * to “file:///foo/bar.txt” will yield “bar.txt”.
 *
 * Returns: A newly-allocated string in UTF-8 encoding
 *   free it with g_free()
 */
char *
gtk_recent_info_get_short_name (GtkRecentInfo *info)
{
  char *short_name;

  g_return_val_if_fail (info != NULL, NULL);

  if (info->uri == NULL)
    return NULL;

  short_name = get_uri_shortname_for_display (info->uri);

  return short_name;
}

/**
 * gtk_recent_info_get_uri_display:
 * @info: a `GtkRecentInfo`
 *
 * Gets a displayable version of the resource’s URI.
 *
 * If the resource is local, it returns a local path; if the
 * resource is not local, it returns the UTF-8 encoded content
 * of [method@Gtk.RecentInfo.get_uri].
 *
 * Returns: (nullable): a newly allocated UTF-8 string containing the
 *   resource’s URI or %NULL. Use g_free() when done using it.
 */
char *
gtk_recent_info_get_uri_display (GtkRecentInfo *info)
{
  char *retval;

  g_return_val_if_fail (info != NULL, NULL);

  retval = NULL;
  if (gtk_recent_info_is_local (info))
    {
      char *filename;

      filename = g_filename_from_uri (info->uri, NULL, NULL);
      if (!filename)
        return NULL;

      retval = g_filename_to_utf8 (filename, -1, NULL, NULL, NULL);
      g_free (filename);
    }
  else
    {
      retval = make_valid_utf8 (info->uri);
    }

  return retval;
}

/**
 * gtk_recent_info_get_age:
 * @info: a `GtkRecentInfo`
 *
 * Gets the number of days elapsed since the last update
 * of the resource pointed by @info.
 *
 * Returns: a positive integer containing the number of days
 *   elapsed since the time this resource was last modified
 */
int
gtk_recent_info_get_age (GtkRecentInfo *info)
{
  GDateTime *now;

  g_return_val_if_fail (info != NULL, -1);

  now = g_date_time_new_now_utc ();

  return (int) (g_date_time_difference (now, info->modified) / (double)G_TIME_SPAN_DAY);
}

/**
 * gtk_recent_info_get_groups:
 * @info: a `GtkRecentInfo`
 * @length: (out) (allow-none): return location for the number of groups returned
 *
 * Returns all groups registered for the recently used item @info.
 *
 * The array of returned group names will be %NULL terminated, so
 * length might optionally be %NULL.
 *
 * Returns: (array length=length zero-terminated=1) (transfer full):
 *   a newly allocated %NULL terminated array of strings.
 *   Use g_strfreev() to free it.
 */
char **
gtk_recent_info_get_groups (GtkRecentInfo *info,
                            gsize         *length)
{
  char **retval;
  gsize n_groups, i;

  g_return_val_if_fail (info != NULL, NULL);

  if (!info->groups || info->n_groups == 0)
    {
      if (length)
        *length = 0;

      return NULL;
    }

  n_groups = info->n_groups;

  retval = g_new0 (char *, n_groups + 1);

  for (i = 0; i < info->n_groups; i ++)
    retval[i] = g_strdup (info->groups[i]);

  retval[i] = NULL;

  if (length)
    *length = info->n_groups;

  return retval;
}

/**
 * gtk_recent_info_has_group:
 * @info: a `GtkRecentInfo`
 * @group_name: name of a group
 *
 * Checks whether @group_name appears inside the groups
 * registered for the recently used item @info.
 *
 * Returns: %TRUE if the group was found
 */
gboolean
gtk_recent_info_has_group (GtkRecentInfo *info,
                           const char    *group_name)
{
  int i;

  g_return_val_if_fail (info != NULL, FALSE);
  g_return_val_if_fail (group_name != NULL, FALSE);

  if (!info->groups)
    return FALSE;

  for (i = 0; i < info->n_groups; i ++)
    {
      const char *g = info->groups[i];

      if (strcmp (g, group_name) == 0)
        return TRUE;
    }

  return FALSE;
}

/**
 * gtk_recent_info_create_app_info:
 * @info: a `GtkRecentInfo`
 * @app_name: (allow-none): the name of the application that should
 *   be mapped to a `GAppInfo`; if %NULL is used then the default
 *   application for the MIME type is used
 * @error: (allow-none): return location for a #GError, or %NULL
 *
 * Creates a `GAppInfo` for the specified `GtkRecentInfo`
 *
 * Returns: (nullable) (transfer full): the newly created `GAppInfo`,
 *   or %NULL. In case of error, @error will be set either with a
 *   %GTK_RECENT_MANAGER_ERROR or a %G_IO_ERROR
 */
GAppInfo *
gtk_recent_info_create_app_info (GtkRecentInfo  *info,
                                 const char     *app_name,
                                 GError        **error)
{
  RecentAppInfo *ai;
  GAppInfo *app_info;
  GError *internal_error = NULL;

  g_return_val_if_fail (info != NULL, NULL);

  if (app_name == NULL || *app_name == '\0')
    {
      char *content_type;

      if (info->mime_type == NULL)
        return NULL;

      content_type = g_content_type_from_mime_type (info->mime_type);
      if (content_type == NULL)
        return NULL;

      app_info = g_app_info_get_default_for_type (content_type, TRUE);
      g_free (content_type);

      return app_info;
    }

  ai = g_hash_table_lookup (info->apps_lookup, app_name);
  if (ai == NULL)
    {
      g_set_error (error, GTK_RECENT_MANAGER_ERROR,
                   GTK_RECENT_MANAGER_ERROR_NOT_REGISTERED,
                   _("No registered application with name “%s” for item with URI “%s” found"),
                   app_name,
                   info->uri);
      return NULL;
    }

  internal_error = NULL;
  app_info = g_app_info_create_from_commandline (ai->exec, ai->name,
                                                 G_APP_INFO_CREATE_NONE,
                                                 &internal_error);
  if (internal_error != NULL)
    {
      g_propagate_error (error, internal_error);
      return NULL;
    }

  return app_info;
}

/*
 * _gtk_recent_manager_sync:
 *
 * Private function for synchronising the recent manager singleton.
 */
void
_gtk_recent_manager_sync (void)
{
  if (recent_manager_singleton)
    {
      /* force a dump of the contents of the recent manager singleton */
      recent_manager_singleton->priv->is_dirty = TRUE;
      gtk_recent_manager_real_changed (recent_manager_singleton);
    }
}