libpurple/xfer.h

/* purple
 *
 * Purple is the legal property of its developers, whose names are too numerous
 * to list here.  Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
 */

#if !defined(PURPLE_GLOBAL_HEADER_INSIDE) && !defined(PURPLE_COMPILATION)
# error "only <purple.h> may be included directly"
#endif

#ifndef PURPLE_XFER_H
#define PURPLE_XFER_H
/**
 * SECTION:xfer
 * @section_id: libpurple-xfer
 * @short_description: <filename>xfer.h</filename>
 * @title: File Transfer API
 * @see_also: <link linkend="chapter-signals-xfer">File Transfer signals</link>
 */

#define PURPLE_TYPE_XFER_UI_OPS      (purple_xfer_ui_ops_get_type())

/**************************************************************************/
/* Data Structures                                                        */
/**************************************************************************/
typedef struct _PurpleXferUiOps PurpleXferUiOps;

#include <glib.h>
#include <stdio.h>

#include "account.h"
#include "connection.h"

/**
 * PurpleXferType:
 * @PURPLE_XFER_TYPE_UNKNOWN: Unknown file transfer type.
 * @PURPLE_XFER_TYPE_SEND:    File sending.
 * @PURPLE_XFER_TYPE_RECEIVE: File receiving.
 *
 * Types of file transfers.
 */
typedef enum
{
	PURPLE_XFER_TYPE_UNKNOWN = 0,
	PURPLE_XFER_TYPE_SEND,
	PURPLE_XFER_TYPE_RECEIVE
} PurpleXferType;

/**
 * PurpleXferStatus:
 * @PURPLE_XFER_STATUS_UNKNOWN:       Unknown, the xfer may be null.
 * @PURPLE_XFER_STATUS_NOT_STARTED:   It hasn't started yet.
 * @PURPLE_XFER_STATUS_ACCEPTED:      Receive accepted, but destination file
 *                                    not selected yet.
 * @PURPLE_XFER_STATUS_STARTED:       purple_xfer_start has been called.
 * @PURPLE_XFER_STATUS_DONE:          The xfer completed successfully.
 * @PURPLE_XFER_STATUS_CANCEL_LOCAL:  The xfer was cancelled by us.
 * @PURPLE_XFER_STATUS_CANCEL_REMOTE: The xfer was cancelled by the other end,
 *                                    or we couldn't connect.
 *
 * The different states of the xfer.
 */
typedef enum
{
	PURPLE_XFER_STATUS_UNKNOWN = 0,
	PURPLE_XFER_STATUS_NOT_STARTED,
	PURPLE_XFER_STATUS_ACCEPTED,
	PURPLE_XFER_STATUS_STARTED,
	PURPLE_XFER_STATUS_DONE,
	PURPLE_XFER_STATUS_CANCEL_LOCAL,
	PURPLE_XFER_STATUS_CANCEL_REMOTE
} PurpleXferStatus;

G_BEGIN_DECLS

#define PURPLE_TYPE_XFER             (purple_xfer_get_type())

G_DECLARE_DERIVABLE_TYPE(PurpleXfer, purple_xfer, PURPLE, XFER, GObject)

/**
 * PurpleXferUiOps:
 * @new_xfer: UI op that's called after a new transfer is created.
 *
 * File transfer UI operations.
 *
 * Any UI representing a file transfer must assign a filled-out
 * PurpleXferUiOps structure to the purple_xfer.
 */
struct _PurpleXferUiOps
{
	void (*new_xfer)(PurpleXfer *xfer);
};

/**
 * PurpleXferClass:
 * @init: Called when the file transfer is accepted by the user.  Must call
 *   purple_xfer_start() and must be implemented.
 * @request_denied: Called when the file transfer is denied by the other side.
 * @start: Called to start the file transfer.
 * @end: Called when the file transfer should end.
 * @cancel_send: Handler for cancelling a sending file transfer.
 * @cancel_recv: Handler for cancelling a receiving file transfer.
 * @read: Called when reading data from the file transfer.
 * @write: Called when writing data to the file transfer.
 * @ack: Called when a file transfer is acknowledged.
 * @open_local: The vfunc for PurpleXfer::open-local. Since: 3.0.0
 * @query_local: The vfunc for PurpleXfer::query-local. Since: 3.0.0
 * @read_local: The vfunc for PurpleXfer::read-local. Since: 3.0.0
 * @write_local: The vfunc for PurpleXfer::write-local. Since: 3.0.0
 * @data_not_sent: The vfunc for PurpleXfer::data-not-sent. Since: 3.0.0
 *
 * Base class for all #PurpleXfer's
 */
struct _PurpleXferClass
{
	GObjectClass parent_class;

	void (*init)(PurpleXfer *xfer);
	void (*request_denied)(PurpleXfer *xfer);
	void (*start)(PurpleXfer *xfer);
	void (*end)(PurpleXfer *xfer);
	void (*cancel_send)(PurpleXfer *xfer);
	void (*cancel_recv)(PurpleXfer *xfer);
	gssize (*read)(PurpleXfer *xfer, guchar **buffer, gsize size);
	gssize (*write)(PurpleXfer *xfer, const guchar *buffer, gsize size);
	void (*ack)(PurpleXfer *xfer, const guchar *buffer, gsize size);

	gboolean (*open_local)(PurpleXfer *xfer);
	gboolean (*query_local)(PurpleXfer *xfer, const gchar *filename);
	gssize (*read_local)(PurpleXfer *xfer, guchar *buffer, gssize size);
	gssize (*write_local)(PurpleXfer *xfer, const guchar *buffer, gssize size);
	gboolean (*data_not_sent)(PurpleXfer *xfer, const guchar *buffer,
	                          gsize size);

	/*< private >*/
	gpointer reserved[4];
};

/**************************************************************************/
/* File Transfer API                                                      */
/**************************************************************************/

/**
 * purple_xfer_new:
 * @account: The account sending or receiving the file.
 * @type:    The type of file transfer.
 * @who:     The name of the remote user.
 *
 * Creates a new file transfer handle.
 * This is called by protocols.
 *
 * Returns: A file transfer handle.
 */
PurpleXfer *purple_xfer_new(PurpleAccount *account,
								PurpleXferType type, const char *who);

/**
 * purple_xfer_request:
 * @xfer: The file transfer to request confirmation on.
 *
 * Requests confirmation for a file transfer from the user. If receiving
 * a file which is known at this point, this requests user to accept and
 * save the file. If the filename is unknown (not set) this only requests user
 * to accept the file transfer. In this case protocol must call this function
 * again once the filename is available.
 */
void purple_xfer_request(PurpleXfer *xfer);

/**
 * purple_xfer_request_accepted:
 * @xfer:     The file transfer.
 * @filename: The filename.
 *
 * Called if the user accepts the file transfer request.
 */
void purple_xfer_request_accepted(PurpleXfer *xfer, const gchar *filename);

/**
 * purple_xfer_request_denied:
 * @xfer: The file transfer.
 *
 * Called if the user rejects the file transfer request.
 */
void purple_xfer_request_denied(PurpleXfer *xfer);

/**
 * purple_xfer_get_fd:
 * @xfer: The file transfer.
 *
 * Returns the socket file descriptor.
 *
 * Returns: The socket file descriptor.
 */
int purple_xfer_get_fd(PurpleXfer *xfer);

/**
 * purple_xfer_get_watcher:
 * @xfer: The file transfer.
 *
 * Returns the Watcher for the transfer.
 *
 * Returns: The watcher.
 */
int purple_xfer_get_watcher(PurpleXfer *xfer);

/**
 * purple_xfer_get_xfer_type:
 * @xfer: The file transfer.
 *
 * Returns the type of file transfer.
 *
 * Returns: The type of the file transfer.
 */
PurpleXferType purple_xfer_get_xfer_type(PurpleXfer *xfer);

/**
 * purple_xfer_get_account:
 * @xfer: The file transfer.
 *
 * Returns the account the file transfer is using.
 *
 * Returns: (transfer none): The account.
 */
PurpleAccount *purple_xfer_get_account(PurpleXfer *xfer);

/**
 * purple_xfer_set_remote_user:
 * @xfer: The file transfer.
 * @who:  The name of the remote user.
 *
 * Sets the name of the remote user.
 */
void purple_xfer_set_remote_user(PurpleXfer *xfer, const char *who);

/**
 * purple_xfer_get_remote_user:
 * @xfer: The file transfer.
 *
 * Returns the name of the remote user.
 *
 * Returns: The name of the remote user.
 */
const char *purple_xfer_get_remote_user(PurpleXfer *xfer);

/**
 * purple_xfer_get_status:
 * @xfer: The file transfer.
 *
 * Returns the status of the xfer.
 *
 * Returns: The status.
 */
PurpleXferStatus purple_xfer_get_status(PurpleXfer *xfer);

/**
 * purple_xfer_get_visible:
 * @xfer: The file transfer.
 *
 * Returns whether the UI should show the file transfer in its listing.
 *
 * Note, this is just a hint for UIs and has no effect internally.
 *
 * Returns: The visibility.
 *
 * Since: 3.0.0
 */
gboolean purple_xfer_get_visible(PurpleXfer *xfer);

/**
 * purple_xfer_is_cancelled:
 * @xfer: The file transfer.
 *
 * Returns true if the file transfer was cancelled.
 *
 * Returns: Whether or not the transfer was cancelled.
 */
gboolean purple_xfer_is_cancelled(PurpleXfer *xfer);

/**
 * purple_xfer_is_completed:
 * @xfer: The file transfer.
 *
 * Returns the completed state for a file transfer.
 *
 * Returns: The completed state.
 */
gboolean purple_xfer_is_completed(PurpleXfer *xfer);

/**
 * purple_xfer_get_filename:
 * @xfer: The file transfer.
 *
 * Returns the name of the file being sent or received.
 *
 * Returns: The filename.
 */
const char *purple_xfer_get_filename(PurpleXfer *xfer);

/**
 * purple_xfer_get_local_filename:
 * @xfer: The file transfer.
 *
 * Returns the file's destination filename,
 *
 * Returns: The destination filename.
 */
const char *purple_xfer_get_local_filename(PurpleXfer *xfer);

/**
 * purple_xfer_get_bytes_sent:
 * @xfer: The file transfer.
 *
 * Returns the number of bytes sent (or received) so far.
 *
 * Returns: The number of bytes sent.
 */
goffset purple_xfer_get_bytes_sent(PurpleXfer *xfer);

/**
 * purple_xfer_get_bytes_remaining:
 * @xfer: The file transfer.
 *
 * Returns the number of bytes remaining to send or receive.
 *
 * Returns: The number of bytes remaining.
 */
goffset purple_xfer_get_bytes_remaining(PurpleXfer *xfer);

/**
 * purple_xfer_get_size:
 * @xfer: The file transfer.
 *
 * Returns the size of the file being sent or received.
 *
 * Returns: The total size of the file.
 */
goffset purple_xfer_get_size(PurpleXfer *xfer);

/**
 * purple_xfer_get_progress:
 * @xfer: The file transfer.
 *
 * Returns the current percentage of progress of the transfer.
 *
 * This is a number between 0 (0%) and 1 (100%).
 *
 * Returns: The percentage complete.
 */
double purple_xfer_get_progress(PurpleXfer *xfer);

/**
 * purple_xfer_get_local_port:
 * @xfer: The file transfer.
 *
 * Returns the local port number in the file transfer.
 *
 * Returns: The port number on this end.
 */
guint16 purple_xfer_get_local_port(PurpleXfer *xfer);

/**
 * purple_xfer_get_remote_ip:
 * @xfer: The file transfer.
 *
 * Returns the remote IP address in the file transfer.
 *
 * Returns: The IP address on the other end.
 */
const char *purple_xfer_get_remote_ip(PurpleXfer *xfer);

/**
 * purple_xfer_get_remote_port:
 * @xfer: The file transfer.
 *
 * Returns the remote port number in the file transfer.
 *
 * Returns: The port number on the other end.
 */
guint16 purple_xfer_get_remote_port(PurpleXfer *xfer);

/**
 * purple_xfer_get_start_time:
 * @xfer:  The file transfer.
 *
 * Returns the time the transfer of a file started.
 *
 * Returns: The monotonic time when the transfer started.
 */
gint64 purple_xfer_get_start_time(PurpleXfer *xfer);

/**
 * purple_xfer_get_end_time:
 * @xfer:  The file transfer.
 *
 * Returns the time the transfer of a file ended.
 *
 * Returns: The monotonic time when the transfer ended.
 */
gint64 purple_xfer_get_end_time(PurpleXfer *xfer);

/**
 * purple_xfer_set_fd:
 * @xfer:      The file transfer.
 * @fd:        The file descriptor.
 *
 * Sets the socket file descriptor.
 */
void purple_xfer_set_fd(PurpleXfer *xfer, int fd);

/**
 * purple_xfer_set_watcher:
 * @xfer:      The file transfer.
 * @watcher:   The watcher.
 *
 * Sets the watcher for the file transfer.
 */
void purple_xfer_set_watcher(PurpleXfer *xfer, int watcher);

/**
 * purple_xfer_set_completed:
 * @xfer:      The file transfer.
 * @completed: The completed state.
 *
 * Sets the completed state for the file transfer.
 */
void purple_xfer_set_completed(PurpleXfer *xfer, gboolean completed);

/**
 * purple_xfer_set_status:
 * @xfer:      The file transfer.
 * @status:    The current status.
 *
 * Sets the current status for the file transfer.
 */
void purple_xfer_set_status(PurpleXfer *xfer, PurpleXferStatus status);

/**
 * purple_xfer_set_visible:
 * @xfer: The file transfer.
 * @visible: The visibility.
 *
 * Sets whether the UI should show the file transfer in its listing.
 *
 * Note, this is just a hint for UIs and has no effect internally.
 *
 * Since: 3.0.0
 */
void purple_xfer_set_visible(PurpleXfer *xfer, gboolean visible);

/**
 * purple_xfer_set_message:
 * @xfer:     The file transfer.
 * @message: The message.
 *
 * Sets the message for the file transfer.
 */
void purple_xfer_set_message(PurpleXfer *xfer, const char *message);

/**
 * purple_xfer_get_message:
 * @xfer:     The file transfer.
 *
 * Returns the message for the file transfer.
 *
 * Returns: The message.
 */
const char *purple_xfer_get_message(PurpleXfer *xfer);

/**
 * purple_xfer_set_filename:
 * @xfer:     The file transfer.
 * @filename: The filename.
 *
 * Sets the filename for the file transfer.
 */
void purple_xfer_set_filename(PurpleXfer *xfer, const char *filename);

/**
 * purple_xfer_set_local_filename:
 * @xfer:     The file transfer.
 * @filename: The filename
 *
 * Sets the local filename for the file transfer.
 */
void purple_xfer_set_local_filename(PurpleXfer *xfer, const char *filename);

/**
 * purple_xfer_set_size:
 * @xfer: The file transfer.
 * @size: The size of the file.
 *
 * Sets the size of the file in a file transfer.
 */
void purple_xfer_set_size(PurpleXfer *xfer, goffset size);

/**
 * purple_xfer_set_local_port:
 * @xfer:          The file transfer.
 * @local_port:    The local port.
 *
 * Sets the local port of the file transfer.
 */
void purple_xfer_set_local_port(PurpleXfer *xfer, guint16 local_port);

/**
 * purple_xfer_set_bytes_sent:
 * @xfer:       The file transfer.
 * @bytes_sent: The new current position in the file.  If we're
 *                   sending a file then this is the next byte that we
 *                   will send.  If we're receiving a file, this is the
 *                   next byte that we expect to receive.
 *
 * Sets the current working position in the active file transfer.  This
 * can be used to jump backward in the file if the protocol detects
 * that some bit of data needs to be resent or has been sent twice.
 *
 * It's used for pausing and resuming an oscar file transfer.
 */
void purple_xfer_set_bytes_sent(PurpleXfer *xfer, goffset bytes_sent);

/**
 * purple_xfer_get_ui_ops:
 * @xfer: The file transfer.
 *
 * Returns the UI operations structure for a file transfer.
 *
 * Returns: The UI operations structure.
 */
PurpleXferUiOps *purple_xfer_get_ui_ops(PurpleXfer *xfer);

/**
 * purple_xfer_read:
 * @xfer:   The file transfer.
 * @buffer: The buffer that will be created to contain the data.
 *
 * Reads in data from a file transfer stream.
 *
 * Returns: The number of bytes read, or -1.
 */
gssize purple_xfer_read(PurpleXfer *xfer, guchar **buffer);

/**
 * purple_xfer_write:
 * @xfer:   The file transfer.
 * @buffer: The buffer to read the data from.
 * @size:   The number of bytes to write.
 *
 * Writes data to a file transfer stream.
 *
 * Returns: The number of bytes written, or -1.
 */
gssize purple_xfer_write(PurpleXfer *xfer, const guchar *buffer, gsize size);

/**
 * purple_xfer_write_file:
 * @xfer:   The file transfer.
 * @buffer: The buffer to read the data from.
 * @size:   The number of bytes to write.
 *
 * Writes chunk of received file.
 *
 * Returns: TRUE on success, FALSE otherwise.
 *
 * Since: 2.11.0
 */
gboolean
purple_xfer_write_file(PurpleXfer *xfer, const guchar *buffer, gsize size);

/**
 * purple_xfer_read_file:
 * @xfer:   The file transfer.
 * @buffer: The buffer to write the data to.
 * @size:   The size of buffer.
 *
 * Writes chunk of file being sent.
 *
 * Returns: Number of bytes written (0 means, the device is busy), or -1 on
 *         failure.
 *
 * Since: 2.11.0
 */
gssize
purple_xfer_read_file(PurpleXfer *xfer, guchar *buffer, gsize size);

/**
 * purple_xfer_start:
 * @xfer: The file transfer.
 * @fd:   The file descriptor for the socket.
 * @ip:   The IP address to connect to.
 * @port: The port to connect to.
 *
 * Starts a file transfer.
 *
 * Either @fd must be specified <emphasis>or</emphasis> @ip and @port on a
 * file receive transfer. On send, @fd must be specified, and
 * @ip and @port are ignored.
 *
 * Passing @fd as '-1' is a special-case and indicates to the
 * protocol to facilitate the file transfer itself.
 */
void purple_xfer_start(PurpleXfer *xfer, int fd, const char *ip, guint16 port);

/**
 * purple_xfer_end:
 * @xfer: The file transfer.
 *
 * Ends a file transfer.
 */
void purple_xfer_end(PurpleXfer *xfer);

/**
 * purple_xfer_cancel_local:
 * @xfer: The file transfer.
 *
 * Cancels a file transfer on the local end.
 */
void purple_xfer_cancel_local(PurpleXfer *xfer);

/**
 * purple_xfer_cancel_remote:
 * @xfer: The file transfer.
 *
 * Cancels a file transfer from the remote end.
 */
void purple_xfer_cancel_remote(PurpleXfer *xfer);

/**
 * purple_xfer_error:
 * @type:    The type of file transfer.
 * @account: The account sending or receiving the file.
 * @who:     The user on the other end of the transfer.
 * @msg:     The message to display.
 *
 * Displays a file transfer-related error message.
 *
 * This is a wrapper around purple_notify_error(), which automatically
 * specifies a title ("File transfer to <literal>user</literal> failed" or
 * "File Transfer from <literal>user</literal> failed").
 */
void purple_xfer_error(PurpleXferType type, PurpleAccount *account, const char *who, const char *msg);

/**
 * purple_xfer_conversation_write:
 * @xfer: The file transfer to which this message relates.
 * @message: The message to display.
 * @is_error: Is this an error message?.
 *
 * Displays a file transfer-related message in the conversation window
 *
 * This is a wrapper around purple_conversation_write_system_message
 */
void purple_xfer_conversation_write(PurpleXfer *xfer, const gchar *message, gboolean is_error);

/**
 * purple_xfer_ui_ready:
 * @xfer: The file transfer which is ready.
 *
 * Allows the UI to signal it's ready to send/receive data (depending on
 * the direction of the file transfer. Used when the UI is providing
 * read/write/data_not_sent UI ops.
 */
void purple_xfer_ui_ready(PurpleXfer *xfer);

/**
 * purple_xfer_protocol_ready:
 * @xfer: The file transfer which is ready.
 *
 * Allows the protocol to signal it's ready to send/receive data (depending on
 * the direction of the file transfer. Used when the protocol provides read/write
 * ops and cannot/does not provide a raw fd to the core.
 */
void purple_xfer_protocol_ready(PurpleXfer *xfer);

/**
 * purple_xfer_get_thumbnail:
 * @xfer: The file transfer to get the thumbnail for
 * @len:  If not %NULL, the length of the thumbnail data returned
 *             will be set in the location pointed to by this.
 *
 * Gets the thumbnail data for a transfer
 *
 * Returns: The thumbnail data, or NULL if there is no thumbnail
 */
gconstpointer purple_xfer_get_thumbnail(PurpleXfer *xfer, gsize *len);

/**
 * purple_xfer_get_thumbnail_mimetype:
 * @xfer: The file transfer to get the mimetype for
 *
 * Gets the mimetype of the thumbnail preview for a transfer
 *
 * Returns: The mimetype of the thumbnail, or %NULL if not thumbnail is set
 */
const gchar *purple_xfer_get_thumbnail_mimetype(PurpleXfer *xfer);


/**
 * purple_xfer_set_thumbnail:
 * @xfer: The file transfer to set the data for
 * @thumbnail: A pointer to the thumbnail data, this will be copied
 * @size: The size in bytes of the passed in thumbnail data
 * @mimetype: The mimetype of the generated thumbnail
 *
 * Sets the thumbnail data for a transfer
 */
void purple_xfer_set_thumbnail(PurpleXfer *xfer, gconstpointer thumbnail,
	gsize size, const gchar *mimetype);

/**
 * purple_xfer_prepare_thumbnail:
 * @xfer: The file transfer to create a thumbnail for
 * @formats: A comma-separated list of mimetypes for image formats
 *	 	  the protocols can use for thumbnails.
 *
 * Prepare a thumbnail for a transfer (if the UI supports it)
 * will be no-op in case the UI doesn't implement thumbnail creation
 */
void purple_xfer_prepare_thumbnail(PurpleXfer *xfer, const gchar *formats);

/**************************************************************************/
/* File Transfer Subsystem API                                            */
/**************************************************************************/

/**
 * purple_xfer_ui_ops_get_type:
 *
 * Returns: The #GType for the #PurpleXferUiOps boxed structure.
 */
GType purple_xfer_ui_ops_get_type(void);

/**
 * purple_xfers_get_all:
 *
 * Returns all xfers
 *
 * Returns: (element-type Purple.Xfer) (transfer none): all current xfers
 *          with refs
 */
GList *purple_xfers_get_all(void);

/**
 * purple_xfers_get_handle:
 *
 * Returns the handle to the file transfer subsystem
 *
 * Returns: The handle
 */
void *purple_xfers_get_handle(void);

/**
 * purple_xfers_init:
 *
 * Initializes the file transfer subsystem
 */
void purple_xfers_init(void);

/**
 * purple_xfers_uninit:
 *
 * Uninitializes the file transfer subsystem
 */
void purple_xfers_uninit(void);

/**
 * purple_xfers_set_ui_ops:
 * @ops: The UI operations structure.
 *
 * Sets the UI operations structure to be used in all purple file transfers.
 */
void purple_xfers_set_ui_ops(PurpleXferUiOps *ops);

/**
 * purple_xfers_get_ui_ops:
 *
 * Returns the UI operations structure to be used in all purple file transfers.
 *
 * Returns: The UI operations structure.
 */
PurpleXferUiOps *purple_xfers_get_ui_ops(void);

/******************************************************************************
 * Protocol Interface
 *****************************************************************************/
#define PURPLE_TYPE_PROTOCOL_XFER (purple_protocol_xfer_get_type())

/**
 * purple_protocol_xfer_get_type:
 *
 * Returns: The #GType for the protocol xfer interface.
 */
G_DECLARE_INTERFACE(PurpleProtocolXfer, purple_protocol_xfer, PURPLE,
                    PROTOCOL_XFER, GObject)

/**
 * PurpleProtocolXferInterface:
 * @can_receive: A method to determine if we can receive a file.
 * @send_file: A method to determine if we can send a file.
 * @new_xfer: A method to create a new file transfer.
 *
 * The protocol file transfer interface.
 *
 * This interface provides file transfer callbacks for the protocol.
 */
struct _PurpleProtocolXferInterface {
	/*< private >*/
	GTypeInterface parent_iface;

	/*< public >*/
	gboolean (*can_receive)(PurpleProtocolXfer *prplxfer,
	                        PurpleConnection *connection, const gchar *who);

	void (*send_file)(PurpleProtocolXfer *prplxfer,
	                  PurpleConnection *connection, const gchar *who,
	                  const gchar *filename);

	PurpleXfer *(*new_xfer)(PurpleProtocolXfer *prplxfer,
	                        PurpleConnection *connection, const gchar *who);
};

/**
 * purple_protocol_xfer_can_receive:
 * @prplxfer: The #PurpleProtocolXfer implementer instance
 * @connection: The #PurpleConnection that we're checking
 * @who: The user that we want to send a file transfer to.
 *
 * Checks whether or not we can transfer a file to @who.
 *
 * Returns: TRUE on success, FALSE otherwise.
 */
gboolean purple_protocol_xfer_can_receive(PurpleProtocolXfer *prplxfer, PurpleConnection *connection, const gchar *who);

/**
 * purple_protocol_xfer_send_file:
 * @prplxfer: The #PurpleProtocolXfer implementer instance
 * @connection: The #PurpleConnection that we're checking
 * @who: The user that we want to set a file transfer to.
 * @filename: The name of the file to send.
 *
 * Sends @filename to @who.
 */
void purple_protocol_xfer_send_file(PurpleProtocolXfer *prplxfer, PurpleConnection *connection, const gchar *who, const gchar *filename);

/**
 * purple_protocol_xfer_new_xfer:
 * @prplxfer: The #PurpleProtocolXfer implementer instance
 * @connection: The #PurpleConnection that we're checking
 * @who: The user that we want to send a file transfer to.
 *
 * Creates a new #PurpleXfer to @who.
 *
 * Returns: (transfer full): A new #PurpleXfer instance.
 */
PurpleXfer *purple_protocol_xfer_new_xfer(PurpleProtocolXfer *prplxfer, PurpleConnection *connection, const gchar *who);

G_END_DECLS

#endif /* PURPLE_XFER_H */