Struct libpulse_binding::context::Context

pub struct Context { /* private fields */ }

An opaque connection context to a daemon.

Note: Saves a copy of active multi-use closure callbacks, which it frees on drop.

Implementations

impl Context

pub fn device_manager(&self) -> DeviceManager

Gets a device manager object linked to the current context, giving access to device manager routines.

See context::ext_device_manager.

impl Context

pub fn device_restore(&self) -> DeviceRestore

Gets a device restore object linked to the current context, giving access to device restore routines.

See context::ext_device_restore.

impl Context

pub fn stream_restore(&self) -> StreamRestore

Gets a stream restore object linked to the current context, giving access to stream restore routines.

See context::ext_stream_restore.

impl Context

pub fn introspect(&self) -> Introspector

Gets an introspection object linked to the current context, giving access to introspection routines.

See context::introspect.

impl Context

pub fn remove_sample<F>( &mut self, name: &str, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Removes a sample from the sample cache.

Returns an operation object which may be used to cancel the operation while it is running.

The callback must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn play_sample( &mut self, name: &str, dev: Option<&str>, volume: Option<Volume>, callback: Option<Box<dyn FnMut(bool) + 'static>> ) -> Operation<dyn FnMut(bool)>

Plays a sample from the sample cache to the specified device.

If the specified device is None use the default sink.

Params

• name: Name of the sample to play.
• dev: Sink to play this sample on, or None for default.
• volume: Volume to play this sample with, or None to leave the decision about the volume to the server side which is a good idea. Volume::INVALID has the same meaning as `None.
• callback: Optional success callback. It must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn play_sample_with_proplist( &mut self, name: &str, dev: Option<&str>, volume: Option<Volume>, proplist: &Proplist, callback: Option<Box<dyn FnMut(Result<u32, ()>) + 'static>> ) -> Operation<dyn FnMut(Result<u32, ()>)>

Plays a sample from the sample cache to the specified device, allowing specification of a property list for the playback stream.

If the device is None use the default sink.

Params

• name: Name of the sample to play.
• dev: Sink to play this sample on, or None for default.
• volume: Volume to play this sample with, or None to leave the decision about the volume to the server side which is a good idea. Volume::INVALID has the same meaning as `None.
• proplist: Property list for this sound. The property list of the cached entry will have this merged into it.
• callback: Optional success callback. It must accept an u32 index value wrapper in a Result. The index is the index of the sink input object. Err is given instead on failure.

Panics if the underlying C function returns a null pointer.

impl Context

pub fn subscribe<F>( &mut self, mask: InterestMaskSet, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Enables event notification.

The mask parameter is used to specify which facilities you are interested in being modified about. Use set_subscribe_callback() to set the actual callback that will be called when an event occurs.

The callback must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn set_subscribe_callback( &mut self, callback: Option<Box<dyn FnMut(Option<Facility>, Option<Operation>, u32) + 'static>> )

Sets the context specific call back function that is called whenever a subscribed-to event occurs.

Use subscribe() to set the facilities you are interested in receiving notifications for, and thus to start receiving notifications with the callback set here.

The callback must take three parameters. The first two are the facility and operation components of the event type respectively (the underlying C API provides this information combined into a single integer, here we extract the two component parts for you); these are wrapped in Option wrappers should the given values ever not map to the enum variants, but it’s probably safe to always just unwrap() them). The third parameter is an associated index value.

impl Context

pub fn new(mainloop: &impl Mainloop, name: &str) -> Option<Self>

Instantiates a new connection context with an abstract mainloop API and an application name.

It is recommended to use new_with_proplist() instead and specify some initial properties.

Note, this will fail either should the underlying C API call return a null pointer for some reason, or if the version of the PulseAudio client system library at runtime is found to be older than the minimum version set via this crate’s feature flags (as a means to help prevent “forward” compatibility problems, as discussed in the project COMPATIBILITY.md documentation).

pub fn new_with_proplist( mainloop: &impl Mainloop, name: &str, proplist: &Proplist ) -> Option<Self>

Instantiates a new connection context with an abstract mainloop API and an application name, and specify the initial client property list.

Note, this will fail either should the underlying C API call return a null pointer for some reason, or if the version of the PulseAudio client system library at runtime is found to be older than the minimum version set via this crate’s feature flags (as a means to help prevent “forward” compatibility problems, as discussed in the project COMPATIBILITY.md documentation).

pub fn set_state_callback( &mut self, callback: Option<Box<dyn FnMut() + 'static>> )

Sets a callback function that is called whenever the context status changes.

pub fn set_event_callback( &mut self, callback: Option<Box<dyn FnMut(String, Proplist) + 'static>> )

Sets a callback function that is called whenever a meta/policy control event is received.

The callback is given a name which represents what event occurred. The set of defined events can be extended at any time. Also, server modules may introduce additional message types so make sure that your callback function ignores messages it doesn’t know. It is also given an (owned) property list.

pub fn errno(&self) -> PAErr

Gets the error number of the last failed operation.

pub fn is_pending(&self) -> bool

Checks if some data is pending to be written to the connection (returns true if so).

pub fn get_state(&self) -> State

Gets the current context status.

pub fn connect( &mut self, server: Option<&str>, flags: FlagSet, api: Option<&SpawnApi> ) -> Result<(), PAErr>

Connects the context to the specified server.

If server is None, connect to the default server. This routine may but will not always return synchronously on error. Use set_state_callback() to be notified when the connection is established. If flags doesn’t have FlagSet::NOAUTOSPAWN set and no specific server is specified or accessible, a new daemon is spawned. If api is not None, the functions specified in the structure are used when forking a new child process.

pub fn disconnect(&mut self)

Terminates the context connection immediately.

pub fn drain<F>(&mut self, callback: F) -> Option<Operation<dyn FnMut()>>where F: FnMut() + 'static,

Drains the context.

If there is nothing to drain, the function returns None.

Note that it can also return None under other conditions. Many functions in the C API perform internal state validation checks and return a null pointer if they detect a problem, just as they return a null pointer on invalid input. Other functions panic on getting a null pointer return, however this function is unique in a null pointer also signalling something useful, and it is not possible to tell the difference. However, while I feel the need to be clear about the possibility, I believe that such invalid state conditions should only occur if there were a serious bug within PA, thus you are probably safe to just ignore this and always take a None return to indicate only that there is nothing to drain.

pub fn exit_daemon<F>(&mut self, callback: F) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Tells the daemon to exit.

The returned operation is unlikely to complete successfully, since the daemon probably died before returning a success notification.

The callback must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn set_default_sink<F>( &mut self, name: &str, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Sets the name of the default sink.

The callback must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn set_default_source<F>( &mut self, name: &str, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Sets the name of the default source.

The callback must accept a bool, which indicates success.

Panics if the underlying C function returns a null pointer.

pub fn is_local(&self) -> Option<bool>

Checks if this is a connection to a local daemon.

Returns true when the connection is to a local daemon. Returns None on error, for instance when no connection has been made yet.

pub fn set_name<F>( &mut self, name: &str, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Sets a different application name for context on the server.

Panics if the underlying C function returns a null pointer.

pub fn get_server(&self) -> Option<String>

Gets the server name this context is connected to.

pub fn get_protocol_version(&self) -> u32

Gets the protocol version of the library.

pub fn get_server_protocol_version(&self) -> Option<u32>

Gets the protocol version of the connected server.

Returns None on error.

pub fn proplist_update<F>( &mut self, mode: UpdateMode, pl: &Proplist, callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Updates the property list of the client, adding new entries.

Please note that it is highly recommended to set as many properties initially via new_with_proplist() as possible instead a posteriori with this function, since that information may then be used to route streams of the client to the right device.

Panics if the underlying C function returns a null pointer.

pub fn proplist_remove<F>( &mut self, keys: &[&str], callback: F ) -> Operation<dyn FnMut(bool)>where F: FnMut(bool) + 'static,

Updates the property list of the client, remove entries.

Panics if the underlying C function returns a null pointer.

pub fn get_index(&self) -> Option<u32>

Gets the client index this context is identified in the server with.

This is useful for usage with the introspection functions, such as Introspector::get_client_info().

Returns None on error.

pub fn rttime_new<T, F>( &self, mainloop: &dyn Mainloop<MI = T::MI>, time: MonotonicTs, callback: F ) -> Option<TimeEvent<T::MI>>where T: Mainloop + 'static, F: FnMut(TimeEventRef<T::MI>) + 'static,

Creates a new timer event source for the specified time.

This is an alternative to the mainloop new_timer_event_rt method.

A reference to the mainloop object is needed, in order to associate the event object with it. The association is done to ensure the event does not outlive the mainloop.

If pointer returned by underlying C function is NULL, None will be returned, otherwise a TimeEvent object will be returned.

Example event set to fire in five seconds time:

use libpulse_binding::time::{MonotonicTs, MicroSeconds};
let _t_event = context.rttime_new::<Mainloop, _>(&mainloop,
    MonotonicTs::now() + MicroSeconds::from_secs(5).unwrap(),
    |_| { println!("Timer event fired!"); });

Note: You must ensure that the returned event object lives for as long as you want its event(s) to fire, as its Drop implementation destroys the event source. I.e. if you create a new event, but then immediately drop the object returned here, no event will fire!

pub fn get_tile_size(&self, ss: Option<&Spec>) -> Option<usize>

Gets the optimal block size for passing around audio buffers.

It is recommended to allocate buffers of the size returned here when writing audio data to playback streams, if the latency constraints permit this. It is not recommended writing larger blocks than this because usually they will then be split up internally into chunks of this size. It is not recommended writing smaller blocks than this (unless required due to latency demands) because this increases CPU usage.

If ss is None you will be returned the byte-exact tile size.

If ss is invalid, returns None, else returns tile size rounded down to multiple of the frame size.

This is supposed to be used in a construct such as:

let ss = stream.get_sample_spec().unwrap();
let size = context.get_tile_size(Some(ss)).unwrap();

pub fn load_cookie_from_file( &mut self, cookie_file_path: &str ) -> Result<(), PAErr>

Loads the authentication cookie from a file.

This function is primarily meant for PulseAudio’s own tunnel modules, which need to load the cookie from a custom location. Applications don’t usually need to care about the cookie at all, but if it happens that you know what the authentication cookie is and your application needs to load it from a non-standard location, feel free to use this function.

Trait Implementations

impl Drop for Context

fn drop(&mut self)

Executes the destructor for this type.

impl Send for Context

impl Sync for Context