Class

ALSACtlCard

Description [src]

class ALSACtl.Card : GObject.Object {
  parent_instance: GObject
}

An GObject-derived object to express sound card. A ALSACtlCard is a GObject-derived object to express sound card. Applications use the instance of object to manipulate functionalities on sound card. After the call of alsactl_card_open() for the numeric ID of sound card, the object maintains file descriptor till object destruction.

Ancestors

GObject

Constructors

alsactl_card_new

Allocate and return an instance of ALSACtlCard.

Instance methods

alsactl_card_add_elems

Add the user-defined elements and return the list of their identifier.

alsactl_card_command_elem_tlv

Command the given array of bytes as Type/Length/Value data for element pointed by the identifier.

alsactl_card_create_source

Allocate GSource structure to handle events from ALSA control character device. In each iteration of GMainContext, the read(2) system call is executed to dispatch control event for ALSACtlCard::handle-elem-event signal, according to the result of poll(2) system call.

alsactl_card_get_elem_id_list

Generate a list of ALSACtlElemId for ALSA control character device associated to the sound card.

alsactl_card_get_elem_info

Get information of element corresponding to given id.

alsactl_card_get_info

Get the information of sound card.

alsactl_card_get_protocol_version

Get the version of control protocol currently used. The version is expressed as the array with three elements; major, minor, and micro version in the order. The length of major version is 16 bit, the length of minor and micro version is 8 bit each.

alsactl_card_lock_elem

Lock/Unlock indicated element not to be written by the other processes.

alsactl_card_open

Open ALSA control character device for the sound card.

alsactl_card_read_elem_tlv

Read Type/Length/Value data from element pointed by the identifier and fulfil the given array of bytes with the data.

alsactl_card_read_elem_value

Read given value from element indicated by the given identifier.

alsactl_card_remove_elems

Remove user-defined elements pointed by the identifier.

alsactl_card_replace_elems

Add user-defined elements to replace the existent ones.

alsactl_card_write_elem_tlv

Write the given array of bytes as Type/Length/Value data for element pointed by the identifier.

alsactl_card_write_elem_value

Write given value to element indicated by the given identifier.

Methods inherited from GObject (43)

Please see GObject for a full list of methods.

Properties

ALSACtl.Card:devnode

The full path to special file of control character device.

ALSACtl.Card:subscribed

Whether to be subscribed for event.

Signals

ALSACtl.Card::handle-disconnection

Emitted when the sound card is not available anymore due to unbinding driver or hot unplugging. The owner of this object should call g_object_unref() as quickly as possible to be going to release ALSA control character device.

ALSACtl.Card::handle-elem-event

Emitted when event occurs for any element.

Signals inherited from GObject (1)

GObject.Object::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Class structure

struct ALSACtlCardClass {
  GObjectClass parent_class;
  void (* handle_elem_event) (
    ALSACtlCard* self,
    const ALSACtlElemId* elem_id,
    ALSACtlElemEventMask events
  );
  void (* handle_disconnection) (
    ALSACtlCard* self
  );
  
}

Class members

`parent_class`	`GObjectClass`
	No description available.
`handle_elem_event`	`void (* handle_elem_event) ( ALSACtlCard* self, const ALSACtlElemId* elem_id, ALSACtlElemEventMask events )`
	No description available.
`handle_disconnection`	`void (* handle_disconnection) ( ALSACtlCard* self )`
	No description available.

Virtual methods

ALSACtl.CardClass.handle_disconnection

Class closure for the ALSACtlCard::handle-disconnection signal.

ALSACtl.CardClass.handle_elem_event

Class closure for the ALSACtlCard::handle-elem-event signal.