LADCCA Reference Manual
Audio application session management and configuration
Edition 0.4.0, October 2003
Covering LADCCA 0.4.0
Bob Ham (rah@bash.sh)
Table of Contents
LADCCA stands for Linux Audio Developer's Configuration and Connection API.
It is a session management system for audio applications on GNU/Linux. It
understands the JACK low latency audio API and the ALSA MIDI sequencer
interface. The system is comprised of a server program, @command{ladccad},
an application library, libladcca, and a command line control program,
@command{laddca_control}. The server and clients communicate over TCP
sockets. There are three kinds of clients: normal clients (audio
applications), user interfaces for the server, and connection patchbays.
In order to describe the system, we should introduce some terminology.
First of all, the server is the @command{ladccad} server program, an
omni-present marshaller and database for storing arbitrary application data.
The library is the `libladcca' shared library. It contains all
the functions that an application uses to communicate with the server and
take part in the system. Such an application is called a client.
The server deals with things in terms of collections of clients, called
projects. A project has a unique string name, a current directory
and a list of clients that are in that project. The server can have one
client that is a server interface that allows the user to control the
server. There is one server interface included with the system, the
@command{ladcca_control} program.
LADCCA is distributed under the GNU General Public License. A copy of the
license text is provided in the file `COPYING' along with the software
source code, or you can get a copy by writing to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
In plain english, the GPL basically restricts you from restricting other
people's use of the LADCCA source code (ie, all of LADCCA), and any additions you make to
the code, including linking with the LADCCA library. If you use code from this
software, your software must be relased under the GPL. If you modify this
software and release it, your modifications must be released under the GPL. If
you release software linked against the LADCCA library, your software must be
released under the GPL.
Note that this in no way restricts those people who want to release non-free
LADCCA clients. LADCCA operates using a well defined protocol over TCP
sockets. The high-level protocol is described within this document and
the lower-level bit-wise protocol can be garnered from the source itself.
This chapter describes how to get LADCCA installed on your system.
LADCCA depends on the ALSA library, the JACK library, a unique ID library
called libuuid and the XML library libxml2. You need these installed before attempting to install
LADCCA.
ALSA is available from http://www.alsa-project.org/.
JACK is available from http://jackit.sf.net/.
The libuuid library is included with the ubiquitous e2fsprogs package,
but if this is not installed on your system, it is available from
http://e2fsprogs.sf.net/.
The libxml2 library is available from http://www.xmlsoft.org/.
The LADCCA Control client depends on the GNU Readline library,
available from ftp://ftp.gnu.org/pub/gnu/readline/.
The LADCCA GTK Test Client and the LADCCA Save Button 2 client both depend
on the GTK+ 2 toolkit, available from ftp://ftp.gtk.org/pub/gtk/v2.0/.
The LADCCA Synth client has an optional GUI which also uses the GTK+ 2 toolkit.
The LADCCA Save Button client depends on the GTK+ 1.2 toolkit, also
available from ftp://ftp.gtk.org/pub/gtk/v1.2/.
First off, you need to download the package. It is available from the
LADCCA webpage, http://pkl.net/~node/ladcca.html. After you have
downloaded it, unpack the tarball into a directory using @command{tar xzf
/where/ever/you/put/ladcca-0.4.0.tar.gz} and change into the source directory
with @command{cd ladcca-0.4.0}.
The package uses the GNU autotools for configuration and makefile creation.
In order to install the package, you must complete three steps:
configuration; building; and installing.
To configure the package, there is a shell script named `configure' in the
top source directory. It is a standard GNU autoconf configure script, and
so accepts the standard GNU configuration options (such as
@option{--prefix}, @option{--datadir}, etc.) To run it type
@command{./configure} and add any options. The non-standard options that
the script recognises are described below.
Running the script with the @option{--help} option will also provide a
quick summary of the recognised options.
- @option{--disable-gtk2}
-
Prevents the configure script from checking for the presence of the
GTK+ 2 toolkit and disables the building of any code that relies on it. The
LADCCA Save Button 2 and LADCCA GTK Test Client both rely on GTK+ 2.
- @option{--disable-gtk}
-
Prevents the configure script from checking for the presence of the
GTK+ 1.2 toolkit and disables the building of any code that relies on it.
The LADCCA Save Button client relies on GTK+ 1.2.
- @option{--enable-debug}
-
Causes the library, server and clients to be built with debugging output.
This is not very useful and only recommended for developers working on the
LADCCA code itself.
- @option{--with-default-dir=DIR}
-
Specifies the default directory, relative to \$HOME under which the server will create new project
directories. Without this option, the value defaults to `audio-projects'.
- @option{--disable-serv-inst}
-
The LADCCA server and library look up port addresses for the LADCCA service
using standard system calls that refer to the `/etc/services' database.
If `/etc/services' does not contain a valid entry, an error will result.
By default, the installation routine will install a service entry if one does not
exist. This flag disables that action.
To build the package, simply type @command{make} in the top source
directory. This will build the server, the library and the clients that are
compatible with the resources found by the configure script.
To install the package, type @command{make install} in the top source
directory. By default the package installation prefix is `/usr/local' but
the @option{--prefix} option to the configure script will change this. The
@command{ladccad} server and the clients that were built are installed in
`prefix/bin'. The libladcca client library is installed
in `prefix/lib'. The C header files for the client library are
installed under `prefix/include'. This manual is installed under
`prefix/info'.
With @command{make install}, the package is installed with debugging symbols in the object
files. To save space, you can install with @command{make install-strip} to
install the object files without debugging symbols.
The LADCCA server is called `ladccad'.
Run the @command{ladccad_control}. There is a @command{help} command.
This chapter provides a programming guide and library reference for
programmers of LADCCA clients.
In this section we give an overview of how the LADCCA system operates,
describing the server and client objects and operations that make it work. The
@command{ladccad} server must be running in order for clients to participate
in the system; clients cannot interoperate soley between themselves. The
server maintains a list of connected clients and a list of projects with
which these clients are associated.
The server and clients exchange events and configs over their connections. There
is one, and only one, bi-directional connection between a client and
the server. The transport for this connection is currently TCP.
An event is a very simple object having two relevant properties: a type and an
optional arbitrary character string. The type defines what the event means to the recipient,
and the string allows additional information to be included with it. For
example, if a client wishes the server to save the current project, it sends a
CCA_Save event to the server. While saving the project, the server
may wish to tell a client to save its data in a certain directory. To so,
it sends a CCA_Save_File event to the client with a string containing the
name of a directory into which the client should save its data files.
Clients can save data on the server if they wish. To do this, the
client declares that it wants to save data on the server when it initialises the server connection
and then later sends one or more configs to the server. A config is
also a very simple object. It has a client-unique character string key, and
a value of arbitrary size and type (well, almost arbitrary; its size must
be able to be described by a uint32_t integer due to byte-order conversions
done when sending data over the network.)
In this section we will examine a typical session in some detail, describing
the server and client operations that take place. In the session, the
server is started, a number of clients connect, the session is saved and
then restored.
Before all else, the user starts the server. It starts up and begins listening for
connections from clients. It doesn't do much else.
The user then starts a JACK client program. It opens a connection to the server
and provides it with all information that the server will need to run the
application again. This information includes: the current directory that
the user was in when they ran the program, the command line that started the
application and the class of the client (a character string that the
client application provides the initialisation routine that will never
change over all initialisations.)
With this information is included a set
of flags that describe the client to the server. This particular
client saves data to files and wants the server to tell it where to
save files when the project is saved, so it has the
CCA_Config_File flag set.
The client library starts two threads for communication with the server,
one for sending data and the other for recieving. It also sends, along with
the client supplied data, a number of parameters that were extracted from
the client's command line options before it checked them. This optionally includes the
name of the project that the client should initially be associated
with and a 128-bit, world-unique identifier for this particular client
instance (the LADCCCA ID.)
Server-side, the server wakes up to the fact that a new connection has
arrived and immediately adds it to a list of open connections and then
goes back to waiting. When the client sends the requisite information, the
server looks at it and decides what to do with the client. This client has
not requested a specific project to which it should be connected. However,
there are no existing projects so the server creates a new project with the
name `project-1' in the directory
`/home/user/audio-projects/project-1' (assuming the user
didn't specify a different default directory when running configure.) It
also generates a new LADCCA ID for the client. It then adds the
client to the new project and goes back to listening.
The client then connects up to the JACK server and, after having done this,
sends a CCA_Jack_Client_Name event to the server with the name that
it registered to JACK with as the string. This notifies the server that it
is a JACK client and needs its JACK port connections saved and restored.
The server will now pay attention to any activity regarding the client
(ie, port creation and destruction and port connection and disconnection.)
The user then starts a second client that uses the ALSA sequencer interface
and wishes to save data on the server. It connects to the server with a
different class to the JACK client and with the
CCA_Config_Data_Set flag set.
The server sees that this client also didn't specify a project, and so adds
it to the first available project; the same one as the previous project,
`project-1'. It also sees that the client wants to store data on the
server, and so it creates a directory within the project directory for this
data to be stored in and creates a database-style object to manage the
client's data.
The client then connects to the ALSA sequencer and sends its client ID to
the server in the first character of the string of a
CCA_Alsa_Client_Name event. The server regards this similarly to
the other client's JACK client name.
After the user has done some work in the two clients, they want to save
their work. They click a button on one of the clients (or something similar)
and the client sends a CCA_Save event to server. The server recieves
this and then iterates through each client in the project and checks its
flags. The JACK client saves data by itself (it has the
CCA_Config_File flag set,) so the server creates a
directory under the project directory for it to save in and then sends a
CCA_Save_File event to the client with a string containing the name
of the directory it made. The client recieves the event and saves its data into
the specified directory.
Next, the server examines the ALSA client. It wishes to save data on the
server, so the server sends a CCA_Save_Data_Set to the client. With
all of the clients iterated through, it now saves all the information it
needs to be able to restore them; their working directory, command line
options, etc. In order to do this, it asks the JACK server
to find the connections for the JACK client, and asks the ALSA sequencer to
find the connections for the ALSA client. It uses the client name and ID
that both clients sent to the server after opening their connections to the
respective systems. All of this information is stored
in a file under the project's directory. When this is done, the server goes
back to listening for events and configs.
The client, meanwhile,
has recieved the CCA_Save_Data_Set event and sends back a number of
configs to the server. When it has sent all the data it wishes to be saved,
it sends back a CCA_Save_Data_Set event. The server passes all of
the configs to the object managing the data store for the ALSA client.
When the server recieves the CCA_Save_Data_Set event
from the client, it tells the data store to write the data to
disk. The save is now complete.
Unfortunately for the user, the ALSA client crashes. The server detects
that the client has disconnected, and puts the client on a list of lost
clients for the project. The user then starts another copy of the client,
which connects to the server in the same way it did before. This time,
however, the server checks through the list of lost clients and finds that
the class of the new client matches the class of the lost client and so it
resumes the lost client using the new one. It gives it the 128-bit ID of
the lost client, adds it to the project, and then sends a
CCA_Restore_Data_Set event to the client. The client then cleans
itself up, ready to recieve the data set. The server sends the client the
configs, and then another CCA_Restore_Data_Set event. The client
recieves this data and its state has been restored that of the client that
crashed.
The user can stop this behaviour by specifying the
@option{--ladcca-no-autoresume} option on the client's command line.
The user has to go off and do other things, and so they close down
the clients and the server. Some time later, the user comes back and
wants to start working again so first, as always, they start up the server.
They then start the @command{ladcca_control} program. This is a text
interface command program for controlling the server. They get a command
prompt and into it type restore
/home/user/audio-projects/project-1. The ladcca_control client sends
a CCA_Restore event to the server with the specified directory as the
string. The server opens the file that it saved before, and reads in all
the information about the project and its clients. It creates a new project
with this information. The clients are created as lost clients, however.
The server then iterates through each client and starts a new copy of it
using the information provided when the original client connected. It also
adds some command line options that are extracted by the client library.
These specify the LADCCA ID of the client, the project name that it should
be connecting to and the server's hostname and port. It then goes back to
waiting.
The new JACK client then connects to the server as normal. When the server
recieves it connection, it checks the client against the project's list of
lost clients. This time, however, it has its ID specified, so the server
will only resume a client with a matching ID. Lo and behold, such a client
exists. The server resumes the old JACK client, telling it to load its
state from the files in the project directory that the client previously
stored. It does so with a CCA_Restore_File event with the string as
the directory name. The ALSA client does exactly the same, except having
its data restored through CCA_Restore_Data_Set as described above.
Only one thing remains for the clients to be fully restored: the JACK and
ALSA sequencer connections. This happens when the clients send their
CCA_Jack_Client_Name and CCA_Alsa_Client_ID events. The
connections are stored with the LADCCA ID rather than the JACK
client name or ALSA client ID. When the client registers its name or ID,
the connections are converted from the LADCCA ID to the JACK client name or
ALSA client ID, and the connections are restored. It also pays attention to
connections to other clients within the same project, converting between JACK client
names, ALSA client IDs and LADCCA IDs as appropriate.
- Function: cca_client_t * cca_init (cca_args_t * args, const char * client_class, int client_flags, cca_protocol_t protocol)
-
Open a connection to the server. Returns
NULL on failure.
The args argument must be obtained using cca_extract_args.
The client_class argument must be a string that will never change over
invocations of the program. If using GNU automake, the best way to do this is to use
the PACKAGE_NAME macro that is automatically defined.
The client_flags
argument should be 0 or bitwise-OR'd values from this list:
CCA_Config_Data_Set
-
The client wishes to save its data use the LADCCA config system. See @xref{Configs} and
section 6.3 Event protocol.
CCA_Config_File
-
The client saves its data to a file. See section 6.3 Event protocol.
CCA_Server_Interface
-
The client is a server interface. See section 6.3.2 Server interfaces.
CCA_No_Autoresume
-
This flag is set by the @command{--ladcca-no-autoresume} command line option and
should not normally be set by clients themselves.
CCA_Terminal
-
The client is dependant on being run in a terminal.
The protocol argument should be the version of the high-level protocol that the client
implements See @xref{Protocol versioning} for information on how to contruct a cca_protocol_t
variable.
- Function: cca_args_t * cca_extract_args (int * argc, char *** argv)
-
Extract LADCCA-specific arguments from argc/argv for use in
cca_init. This should be done before the
client checks the arguments, obviously.
- Function: const char * cca_get_server_name (cca_client_t * client)
-
Get the hostname of the server.
- Function: unsigned int cca_get_pending_event_count (cca_client_t * client)
-
Get the number of pending events.
- Function: cca_event_t * cca_get_event (cca_client_t * client)
-
Retrieve an event. The event must be freed using
cca_event_destroy.
Returns NULL if there are no events pending.
- Function: unsigned int cca_get_pending_config_count (cca_client_t * client)
-
Get the number of pending configs.
- Function: cca_config_t * cca_get_config (cca_client_t * client)
-
Retrieve a config. The config must be freed using
cca_config_destroy.
Returns NULL if there are no configs pending.
- Function: void cca_send_event (cca_client_t * client, cca_event_t * event)
-
Send an event to the server. The event must be created using
cca_event_new or cca_event_new_with_type. The library takes over
ownership of the memory and it should not be freed by the client.
- Function: void cca_send_config (cca_client_t * client, cca_config_t * config)
-
Send some configuration data to the server. The config must be created using
cca_config_new, cca_config_new_with_key or
cca_config_dup. The library takes
over ownership of the memory and it should not be freed by the client.
- Macro: cca_enabled (client)
-
Check whether the cca_client_t pointer client is not
NULL, and if it
isn't, that the server is still connected.
- Function: int cca_server_connected (cca_client_t * client)
-
Check whether the server is connected. Returns 1 if the server is still
connected or 0 if it isn't
- Function: void cca_jack_client_name (cca_client_t * client, const char * name)
-
Tell the server the client's JACK client name. This is a convenience function
that just sends a CCA_Jack_Client_Name event to the server. @xref{Normal CCA_Jack_Client_Name}.
@anchor{cca_alsa_client_id}
- Function: void cca_alsa_client_id (cca_client_t * client, unsigned char id);
-
Tell the server the client's ALSA client ID. This just is a convenience function that
just sends a CCA_Alsa_Client_ID event to the server. @xref{Normal CCA_Alsa_Client_ID}.
@anchor{Protocol versioning}
The event protocol (See section 6.3 Event protocol,) is versioned with a major and minor component.
The cca_protocol_t type represents a version number
in a 32-bit unsigned integer split 16:16. A protocol is comptible with the server's
protocol if the major numbers are the same and the minor number is less than,
or equal to, the server's minor number (ie, 1.0 is compatible with a server
using 1.0, 1.1 is compatible with a server using 1.3, but neither 2.0 or 1.6 are
compatible with a server using 1.4. The minor component may be dropped in
the future.
- Macro: CCA_PROTOCOL (major, minor)
-
Contruct a protocol version with a major component major and a minor
component minor.
- Macro: CCA_PROTOCOL_GET_MAJOR (protocol)
-
Obtain the major component of a
cca_protocol_t protocol version.
- Macro: CCA_PROTOCOL_GET_MINOR (protocol)
-
Obtain the minor component of a
cca_protocol_t protocol version.
- Function: const char * cca_protocol_string (cca_protocol_t protocol)
-
Obtain a string representation of the protocol version protocol.
String representations are of the form "major.minor".
@anchor{Events}
- Function: cca_event_t * cca_event_new (void)
-
- Function: cca_event_t * cca_event_new_with_type (enum CCA_Event_Type type)
-
- Function: void cca_event_destroy (cca_event_t * event)
-
- Function: enum CCA_Event_Type cca_event_get_type (const cca_event_t * event)
-
- Function: const char * cca_event_get_string (const cca_event_t * event)
-
- Function: void cca_event_set_type (cca_event_t * event, enum CCA_Event_Type type)
-
- Function: void cca_event_set_string (cca_event_t * event, const char * string);
-
@anchor{Server interface events}
All events have a LADCCA ID and project name property. They are only relevant to server
interfaces, however, which need to refer to clients other than themselves and to projects
(server interfaces are never assigned to a project.)
- Function: void cca_event_get_client_id (const cca_event_t * event, uuid_t id)
-
The event's client ID property will be copied into id.
- Function: const char * cca_event_get_string (const cca_event_t * event)
-
- Function: void cca_event_set_client_id (cca_event_t * event, enum uuid_t id)
-
- Function: void cca_event_set_project (cca_event_t * event, const char * project_name);
-
@anchor{Configs}
- Function: cca_config_t * cca_config_new (void)
-
- Function: cca_config_t * cca_config_dup (const cca_config_t * config)
-
- Function: cca_config_t * cca_config_new_with_key (const char * key)
-
- Function: void cca_config_destroy (cca_config_t * config)
-
- Function: const char * cca_config_get_key (const cca_config_t * config)
-
- Function: const void * cca_config_get_value (const cca_config_t * config)
-
- Function: size_t cca_config_get_value_size (const cca_config_t * config)
-
- Function: void cca_config_set_key (cca_config_t * config, const char * key)
-
- Function: void cca_config_set_value (cca_config_t * config, const void * value, size_t value_size)
-
With these functions, no type checking is done; you can do
cca_config_get_value_int on a config that was set with
cca_config_set_value_float. The integer values are converted
to and from network byte order as appropriate.
- Function: uint32_t cca_config_get_value_int (const cca_config_t * config)
-
- Function: float cca_config_get_value_float (const cca_config_t * config)
-
- Function: double cca_config_get_value_double (const cca_config_t * config)
-
- Function: const char * cca_config_get_value_string (const cca_config_t * config)
-
- Function: void cca_config_set_value_int (cca_config_t * config, uint32_t value)
-
- Function: void cca_config_set_value_float (cca_config_t * config, float value)
-
- Function: void cca_config_set_value_double (cca_config_t * config, double value)
-
- Function: void cca_config_set_value_string (cca_config_t * config, const char * value)
-
This section describes version 2.0 of the event protocol.
This section deals with normal clients (as opposed to section 6.3.2 Server interfaces.)
CCA_Client_Name
-
- To server, non-
NULL string
-
Set the client's user-visible name.
- To server,
NULL string
-
Request the client's user-visible name.
- From server
-
This will only be sent in response to a
CCA_Client_Name with a
NULL string. The string will be NULL if the client has not
set a user-visible name, and the name itself if it has.
CCA_Jack_Client_Name
-
@anchor{Normal CCA_Jack_Client_Name}
- To server, non-
NULL string
-
Tell the server what name the client is connected to JACK with.
Clients should only ever send one non-
NULL CCA_Jack_Client_Name
event. Note that you must send this event after calling
jack_activate(); otherwise, the server will not be able to connect
the client's ports.
- To server,
NULL string
-
Request the client name that the server thinks the client is connected to
JACK with.
- From server
-
This will only be sent in response to a
CCA_Jack_Client_Name with a
NULL string. The string will be NULL if the client has not
set a JACK client name, and the client name itself if it has.
CCA_Alsa_Client_ID
-
@anchor{Normal CCA_Alsa_Client_ID}
To communicate ALSA client IDs within events, use the first character
of a two character string of the form
{ id, '\0' } as the
event string. A
convenience function, cca_alsa_client_id, exists to do this for you
(see @xref{cca_alsa_client_id}.)
- To server, non-
NULL string
-
Tell the server what ID the client is connected to ALSA with.
Clients should only ever send one non-
NULL CCA_Alsa_Client_ID
event.
- To server,
NULL string
-
Request the client ID that the server thinks the client is connected to
ALSA with.
- From server
-
This will only be sent in response to a
CCA_Alsa_Client_ID with a
NULL string. The string will be NULL if the client has not
set an ALSA client ID, and a string containing the ALSA client ID as described
above if it has.
CCA_Save_File
-
- From server
-
Tell the client to save all its data to files within a specific directory.
The event string will never be
NULL and will contain the name of the
directory in which the client should save its data. Clients must always
send a CCA_Save_File event back to the server when they have finished
saving their data. The client should not
rely on the directory existing after it has sent its CCA_Save_File
event back. It is valid behaviour for a client to save no files within the
directory. Files should always be overwritten (ie, using the "w" flag
with fopen(),) preferably without user confirmation if you care
for their sanity.
- From client
-
Tell the server that the client has finished saving its data within the
directory it was told to. The string is ignored.
CCA_Restore_File
-
- From server
-
Tell the client to load all its data from files within a specific directory.
The event string will never be
NULL and will contain the name of the
directory from which the client should load its data. Clients must always
send a CCA_Restore_File event back to the server when they have finished
restoring their data. The client should not
rely on the directory existing after it has sent its CCA_Restore_File
event back.
- From client
-
Tell the server that the client has finished restoring its data from within the
directory it was told to. The string is ignored.
CCA_Save_Data_Set
-
- From server
-
Tell the client to send all its configuration data to the server with a
number of configs. The client must always send a
CCA_Save_Data_Set
event back to the server when it has finished sending its configs. The
event string will always be NULL.
- From client
-
Tell the server that the client has finished sending its configs to the
server. The event string is ignored.
CCA_Restore_Data_Set
-
- From server
-
Tell the client to immediately expect a stream of configs from the server.
This event will only be sent if there are one or more configs to be sent.
The event string will always be
NULL. The client must always send
a CCA_Restore_Data_Set back to the server when it has recieved
all of its configs.
- From client
-
Tell the server that the client has finished recieving its configs from the
server. The event string is ignored.
CCA_Save
-
- From client
-
Tell the server to save the project that the client is attached to.
- From server
-
Never occurs.
CCA_Quit
-
- From client
-
Tell the server to close all clients in the project that the client is attached to.
- From server
-
The client should immediately quit without saving. No more events will be
sent by the server and the client's connection will be terminated.
Server interfaces are treated very differently to normal interfaces. Events from and
to server interfaces are, for the most part, in order to describe and manipulate existing
projects and clients. For this reason, the cca_event_t type has
project and client_id properties which facilitate this. @xref{Server interface events}. The project property contains the name of the project.
A server interface should start up with the default assumption that there are no projects. Upon
connection, the server will send appropriate events (CCA_Project_Add,
CCA_Client_Add, CCA_Client_Name, etc) that describe the current state of the
system. From then on, events will be sent to keep the interface up to date with the
server's state.
CCA_Project_Add
-
- From interface
-
Restore a project from an existing directory. The event string should contain the
directory's name.
project
-
Ignored.
client_id
-
Ignored.
- From server
-
A new project has been added. The event string will contain the project's name.
project
-
NULL
client_id
-
Undefined.
CCA_Project_Remove
-
- From interface
-
Close an open project. All of the project's clients will be told to quit and the
project will be removed from the server's project list.
project
-
The project to remove.
client_id
-
Ignored.
- From server
-
A project has been removed.
project
-
The project that has been removed.
client_id
-
Undefined.
CCA_Project_Dir
-
- From interface, non-
NULL string
-
Move a project to a different directory. The directory name should be contained in
the event's string.
project
-
The project to move.
client_id
-
Undefined.
- From interface,
NULL string
-
Request a project's directory.
project
-
The project whose directory is being requested.
client_id
-
Undefined.
- From server
-
A declaration of the project's directory; either because it has been requested
or because the project has been moved. The directory name is contained in
the event's string.
project
-
The project whose directory is being declared.
client ID
-
Undefined.
CCA_Project_Name
-
- From interface
-
Change a project's name. The new project name should be contained in the
event's string.
project
-
The project name to change.
client_id
-
Undefined.
- From server
-
A project's name has changed. The new project name is contained in the event's
string.
project
-
The project name that has changed.
client ID
-
Undefined.
CCA_Client_Add
-
- From interface
-
Should not occur
- From server
-
A new client has been added.
project
-
The project that the new client has been added to.
client ID
-
The new client's ID.
CCA_Client_Name
-
- From interface, non-
NULL string
-
Should not occur.
- From interface,
NULL string
-
Request a client's name.
project
-
The client's project.
client ID
-
The client's ID.
- From server
-
A declaration of a client's name; either because it has been requested
or because the client set the name. The name is contained in
the event's string.
project
-
The client's project.
client ID
-
The client's ID.
CCA_Jack_Client_Name
-
- From interface, non-
NULL string
-
Should not occur.
- From interface,
NULL string
-
Request a client's JACK client name.
project
-
The client's project.
client ID
-
The client's ID.
- From server
-
A declaration of a client's JACK client name; either because it has been requested
or because the client set the name. The client name is contained in
the event's string.
project
-
The client's project.
client ID
-
The client's ID.
CCA_Alsa_Client_ID
-
- From interface, non-
NULL string
-
Should not occur.
- From interface,
NULL string
-
Request a client's ALSA client ID.
project
-
The client's project.
client ID
-
The client's LADCCA ID.
- From server
-
A declaration of a client's ALSA client ID; either because it has been requested
or because the client set the ID. The ALSA client ID is contained in
the event's string, as desribed in @xref{Normal CCA_Alsa_Client_ID}.
project
-
The client's project.
client ID
-
The client's LADCCA ID.
CCA_Percentage
-
This event exists to provide user feedback on the status of save
operations and perhaps other operations in future. The server will
first send a percentage of 0, then successive percentages up to and
including 100. When the operation is complete, the server will send
a percentage of 0 again.
- From interface
-
Should not occur.
- From server
-
The percentage of completion of the current operation. The percentage
is sent as a string, derived from
sprintfing an int.
project
-
The project whose operation is being described.
client ID
-
Undefined.
Version 1.2, November 2002
Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
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PREAMBLE
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MODIFICATIONS
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Add an appropriate copyright notice for your modifications
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