DBusGProxy

DBusGProxy — DBus Proxy

Stability Level

Stable, unless otherwise indicated

Synopsis

struct              DBusGProxy;
DBusGProxy *        dbus_g_proxy_new_for_name           (DBusGConnection *connection,
                                                         const char *name,
                                                         const char *path,
                                                         const char *iface);
DBusGProxy *        dbus_g_proxy_new_for_name_owner     (DBusGConnection *connection,
                                                         const char *name,
                                                         const char *path,
                                                         const char *iface,
                                                         GError **error);
DBusGProxy *        dbus_g_proxy_new_from_proxy         (DBusGProxy *proxy,
                                                         const char *iface,
                                                         const char *path_name);
DBusGProxy *        dbus_g_proxy_new_for_peer           (DBusGConnection *connection,
                                                         const char *path_name,
                                                         const char *interface_name);
void                dbus_g_proxy_set_interface          (DBusGProxy *proxy,
                                                         const char *interface_name);
const char *        dbus_g_proxy_get_path               (DBusGProxy *proxy);
const char *        dbus_g_proxy_get_bus_name           (DBusGProxy *proxy);
const char *        dbus_g_proxy_get_interface          (DBusGProxy *proxy);
void                dbus_g_proxy_add_signal             (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GType first_type,
                                                         ...);
void                dbus_g_proxy_connect_signal         (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GCallback handler,
                                                         void *data,
                                                         GClosureNotify free_data_func);
void                dbus_g_proxy_disconnect_signal      (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GCallback handler,
                                                         void *data);
void                dbus_g_proxy_send                   (DBusGProxy *proxy,
                                                         DBusMessage *message,
                                                         dbus_uint32_t *client_serial);
gboolean            dbus_g_proxy_call                   (DBusGProxy *proxy,
                                                         const char *method,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);
gboolean            dbus_g_proxy_call_with_timeout      (DBusGProxy *proxy,
                                                         const char *method,
                                                         int timeout,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);
void                dbus_g_proxy_call_no_reply          (DBusGProxy *proxy,
                                                         const char *method,
                                                         GType first_arg_type,
                                                         ...);
DBusGProxyCall *    dbus_g_proxy_begin_call             (DBusGProxy *proxy,
                                                         const char *method,
                                                         DBusGProxyCallNotify notify,
                                                         gpointer data,
                                                         GDestroyNotify destroy,
                                                         GType first_arg_type,
                                                         ...);
DBusGProxyCall *    dbus_g_proxy_begin_call_with_timeout
                                                        (DBusGProxy *proxy,
                                                         const char *method,
                                                         DBusGProxyCallNotify notify,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy,
                                                         int timeout,
                                                         GType first_arg_type,
                                                         ...);
gboolean            dbus_g_proxy_end_call               (DBusGProxy *proxy,
                                                         DBusGProxyCall *call,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);
void                dbus_g_proxy_cancel_call            (DBusGProxy *proxy,
                                                         DBusGProxyCall *call);
void                dbus_g_proxy_set_default_timeout    (DBusGProxy *proxy,
                                                         int timeout);

Description

A DBusGProxy is a boxed type abstracting a DBusProxy.

Details

struct DBusGProxy

struct DBusGProxy {
  GObject parent;
};


dbus_g_proxy_new_for_name ()

DBusGProxy *        dbus_g_proxy_new_for_name           (DBusGConnection *connection,
                                                         const char *name,
                                                         const char *path,
                                                         const char *iface);

Creates a new proxy for a remote interface exported by a connection on a message bus. Method calls and signal connections over this proxy will go to the name owner; the name's owner is expected to support the given interface name. THE NAME OWNER MAY CHANGE OVER TIME, for example between two different method calls, unless the name is a unique name. If you need a fixed owner, you need to request the current owner and bind a proxy to its unique name rather than to the generic name; see dbus_g_proxy_new_for_name_owner().

A name-associated proxy only makes sense with a message bus, not for app-to-app direct dbus connections.

This proxy will only emit the "destroy" signal if the DBusConnection is disconnected, the proxy has no remaining references, or the name is a unique name and its owner disappears. If a well-known name changes owner, the proxy will still be alive.

connection :

the connection to the remote bus

name :

any name on the message bus

Returns :

new proxy object

dbus_g_proxy_new_for_name_owner ()

DBusGProxy *        dbus_g_proxy_new_for_name_owner     (DBusGConnection *connection,
                                                         const char *name,
                                                         const char *path,
                                                         const char *iface,
                                                         GError **error);

Similar to dbus_g_proxy_new_for_name(), but makes a round-trip request to the message bus to get the current name owner, then binds the proxy to the unique name of the current owner, rather than to the well-known name. As a result, the name owner will not change over time, and the proxy will emit the "destroy" signal when the owner disappears from the message bus.

An example of the difference between dbus_g_proxy_new_for_name() and dbus_g_proxy_new_for_name_owner(): if you provide the well-known name "org.freedesktop.Database" dbus_g_proxy_new_for_name() remains bound to that name as it changes owner. dbus_g_proxy_new_for_name_owner() will fail if the name has no owner. If the name has an owner, dbus_g_proxy_new_for_name_owner() will bind to the unique name of that owner rather than the generic name.

connection :

the connection to the remote bus

name :

any name on the message bus

error :

return location for an error

Returns :

new proxy object, or NULL on error

dbus_g_proxy_new_from_proxy ()

DBusGProxy *        dbus_g_proxy_new_from_proxy         (DBusGProxy *proxy,
                                                         const char *iface,
                                                         const char *path_name);

Creates a proxy using an existing proxy as a template, substituting the specified interface and path. Either or both may be NULL.

proxy :

the proxy to use as a template

Returns :

new proxy object

dbus_g_proxy_new_for_peer ()

DBusGProxy *        dbus_g_proxy_new_for_peer           (DBusGConnection *connection,
                                                         const char *path_name,
                                                         const char *interface_name);

Creates a proxy for an object in peer application (one we're directly connected to). That is, this function is intended for use when there's no message bus involved, we're doing a simple 1-to-1 communication between two applications.

connection :

the connection to the peer

path_name :

name of the object inside the peer to call methods on

interface_name :

name of the interface to call methods on

Returns :

new proxy object

dbus_g_proxy_set_interface ()

void                dbus_g_proxy_set_interface          (DBusGProxy *proxy,
                                                         const char *interface_name);

Sets the object interface proxy is bound to

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

the proxy

interface_name :

an object interface

dbus_g_proxy_get_path ()

const char *        dbus_g_proxy_get_path               (DBusGProxy *proxy);

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

the proxy

Returns :

an object path

dbus_g_proxy_get_bus_name ()

const char *        dbus_g_proxy_get_bus_name           (DBusGProxy *proxy);

Gets the bus name a proxy is bound to (may be NULL in some cases). If you created the proxy with dbus_g_proxy_new_for_name(), then the name you passed to that will be returned. If you created it with dbus_g_proxy_new_for_name_owner(), then the unique connection name will be returned. If you created it with dbus_g_proxy_new_for_peer() then NULL will be returned.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

the proxy

Returns :

the bus name the proxy sends messages to

dbus_g_proxy_get_interface ()

const char *        dbus_g_proxy_get_interface          (DBusGProxy *proxy);

Gets the object interface proxy is bound to (may be NULL in some cases).

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

the proxy

Returns :

an object interface

dbus_g_proxy_add_signal ()

void                dbus_g_proxy_add_signal             (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GType first_type,
                                                         ...);

Specifies the argument signature of a D-Bus signal. When the signal is emitted by the remote object, if the GTypes corresponding to its arguments' types do not match the types given here, the signal will be ignored.

It is an error to add the same signal_name to the same proxy more than once, even if the argument types given are the same.

It is also an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

the proxy for a remote interface

signal_name :

the name of the signal

first_type :

the first argument type, or G_TYPE_INVALID if none

dbus_g_proxy_connect_signal ()

void                dbus_g_proxy_connect_signal         (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GCallback handler,
                                                         void *data,
                                                         GClosureNotify free_data_func);

Connect a signal handler to a proxy for a remote interface. When the remote interface emits the specified signal, the proxy will emit a corresponding GLib signal.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

signal_name :

the DBus signal name to listen for

handler :

the handler to connect

data :

data to pass to handler

free_data_func :

callback function to destroy data

dbus_g_proxy_disconnect_signal ()

void                dbus_g_proxy_disconnect_signal      (DBusGProxy *proxy,
                                                         const char *signal_name,
                                                         GCallback handler,
                                                         void *data);

Disconnect all signal handlers from a proxy that match the given criteria.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

signal_name :

the DBus signal name to disconnect

handler :

the handler to disconnect

data :

the data that was registered with handler

dbus_g_proxy_send ()

void                dbus_g_proxy_send                   (DBusGProxy *proxy,
                                                         DBusMessage *message,
                                                         dbus_uint32_t *client_serial);

Sends a message to the interface we're proxying for. Does not block or wait for a reply. The message is only actually written out when you return to the main loop or block in dbus_g_connection_flush().

The message is modified to be addressed to the target interface. That is, a destination name field or whatever is needed will be added to the message. The basic point of this function is to add the necessary header fields, otherwise it's equivalent to dbus_connection_send().

This function adds a reference to the message, so the caller still owns its original reference.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

message :

the message to address and send

client_serial :

return location for message's serial, or NULL

dbus_g_proxy_call ()

gboolean            dbus_g_proxy_call                   (DBusGProxy *proxy,
                                                         const char *method,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);

Function for synchronously invoking a method and receiving reply values. This function is equivalent to dbus_g_proxy_begin_call followed by dbus_g_proxy_end_call. All of the input arguments are specified first, followed by G_TYPE_INVALID, followed by all of the output values, followed by a second G_TYPE_INVALID. Note that this means you must always specify G_TYPE_INVALID twice.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

method :

method to invoke

error :

return location for an error

first_arg_type :

type of first "in" argument

Returns :

FALSE if an error is set, TRUE otherwise.

dbus_g_proxy_call_with_timeout ()

gboolean            dbus_g_proxy_call_with_timeout      (DBusGProxy *proxy,
                                                         const char *method,
                                                         int timeout,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);

Function for synchronously invoking a method and receiving reply values. This function is equivalent to dbus_g_proxy_begin_call followed by dbus_g_proxy_end_call. All of the input arguments are specified first, followed by G_TYPE_INVALID, followed by all of the output values, followed by a second G_TYPE_INVALID. Note that this means you must always specify G_TYPE_INVALID twice.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

method :

method to invoke

timeout :

the timeout in milliseconds, or -1 to use a default

error :

return location for an error

first_arg_type :

type of first "in" argument

Returns :

FALSE if an error is set, TRUE otherwise.

dbus_g_proxy_call_no_reply ()

void                dbus_g_proxy_call_no_reply          (DBusGProxy *proxy,
                                                         const char *method,
                                                         GType first_arg_type,
                                                         ...);

Sends a method call message as with dbus_g_proxy_begin_call(), but does not ask for a reply or allow you to receive one.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

TODO: this particular function shouldn't die on out of memory, since you should be able to do a call with large arguments.

proxy :

a proxy for a remote interface

method :

the name of the method to invoke

first_arg_type :

type of the first argument

dbus_g_proxy_begin_call ()

DBusGProxyCall *    dbus_g_proxy_begin_call             (DBusGProxy *proxy,
                                                         const char *method,
                                                         DBusGProxyCallNotify notify,
                                                         gpointer data,
                                                         GDestroyNotify destroy,
                                                         GType first_arg_type,
                                                         ...);

Asynchronously invokes a method on a remote interface. The method call will not be sent over the wire until the application returns to the main loop, or blocks in dbus_g_connection_flush() to write out pending data. The call will be completed after a timeout, or when a reply is received. When the call returns, the callback specified will be invoked; you can then collect the results of the call (which may be an error, or a reply), use dbus_g_proxy_end_call().

It is an error to call this method on a proxy that has emitted the "destroy" signal.

TODO this particular function shouldn't die on out of memory, since you should be able to do a call with large arguments.

proxy :

a proxy for a remote interface

method :

the name of the method to invoke

notify :

callback to be invoked when method returns

destroy :

function called to destroy user_data

first_arg_type :

type of the first argument

Returns :

call identifier.

dbus_g_proxy_begin_call_with_timeout ()

DBusGProxyCall *    dbus_g_proxy_begin_call_with_timeout
                                                        (DBusGProxy *proxy,
                                                         const char *method,
                                                         DBusGProxyCallNotify notify,
                                                         gpointer user_data,
                                                         GDestroyNotify destroy,
                                                         int timeout,
                                                         GType first_arg_type,
                                                         ...);

Asynchronously invokes a method on a remote interface. The method call will not be sent over the wire until the application returns to the main loop, or blocks in dbus_g_connection_flush() to write out pending data. The call will be completed after a timeout, or when a reply is received. When the call returns, the callback specified will be invoked; you can then collect the results of the call (which may be an error, or a reply), use dbus_g_proxy_end_call().

It is an error to call this method on a proxy that has emitted the "destroy" signal.

TODO this particular function shouldn't die on out of memory, since you should be able to do a call with large arguments.

proxy :

a proxy for a remote interface

method :

the name of the method to invoke

notify :

callback to be invoked when method returns

user_data :

user data passed to callback

destroy :

function called to destroy user_data

timeout :

the timeout in milliseconds, or -1 to use a default

first_arg_type :

type of the first argument

Returns :

call identifier.

dbus_g_proxy_end_call ()

gboolean            dbus_g_proxy_end_call               (DBusGProxy *proxy,
                                                         DBusGProxyCall *call,
                                                         GError **error,
                                                         GType first_arg_type,
                                                         ...);

Collects the results of a method call. The method call was normally initiated with dbus_g_proxy_end_call(). You may use this function outside of the callback given to dbus_g_proxy_begin_call; in that case this function will block if the results haven't yet been received.

If the call results in an error, the error is set as normal for GError and the function returns FALSE.

Otherwise, the "out" parameters and return value of the method are stored in the provided varargs list. The list should be terminated with G_TYPE_INVALID.

proxy :

a proxy for a remote interface

call :

the pending call ID from dbus_g_proxy_begin_call()

error :

return location for an error

first_arg_type :

type of first "out" argument

Returns :

FALSE if an error is set.

dbus_g_proxy_cancel_call ()

void                dbus_g_proxy_cancel_call            (DBusGProxy *proxy,
                                                         DBusGProxyCall *call);

Cancels a pending method call. The method call was normally initiated with dbus_g_proxy_begin_call(). This function may not be used on pending calls that have already been ended with dbus_g_proxy_end_call.

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

call :

the pending call ID from dbus_g_proxy_begin_call()

dbus_g_proxy_set_default_timeout ()

void                dbus_g_proxy_set_default_timeout    (DBusGProxy *proxy,
                                                         int timeout);

Sets the default timeout to use for a proxy. This timeout will be used in calls where the timeout is not specified, or is specified to be -1. If this timeout is also set to -1, libdbus will use a reasonable default value.

This is useful for long-running operations that takes longer than the default timeout (which is a on the order of magnitude of tens of seconds). For some applications, consider using a pattern where the method returns once the operation is underway (e.g. immediately) and emits a signal when the operation terminates (though beware of leaking information with/in the signal return value).

It is an error to call this method on a proxy that has emitted the "destroy" signal.

proxy :

a proxy for a remote interface

timeout :

the timeout in milliseconds, or -1 to reset to the libdbus default

Since 0.75

See Also

DBusProxy