ei_seat

Set Of Input Devices That Logically Belong Together

An ei_seat represents a set of input devices that logically belong together. In most cases only one seat is present and all input devices on that seat share the same pointer and keyboard focus.

A seat has potential capabilities, a client is expected to bind to those capabilities. The EIS implementation then creates logical input devices based on the capabilities the client is interested in.

Immediately after creation of the ei_seat object, the EIS implementation sends a burst of events with information about this seat. This burst of events is terminated by the ei_seat.done event.

Requests

ei_seat.release

Since Version1 Request Opcode0

ei_seat.release()

Informs the EIS implementation that the client is no longer interested in this seat. The EIS implementation should release any resources associated with this seat and send the ei_seat.destroyed event once finished.

Note that releasing a seat does not guarantee that another seat becomes available. In other words, in most single-seat cases, releasing the seat means that the connection becomes effectively inert.

ei_seat.bind

Since Version1 Request Opcode1

ei_seat.bind(capabilities)

Binds to the given bitmask of capabilities. Each one of the bit values in the given bitmask must originate from one of the ei_seat.capability events. See its documentation for more examples.

The EIS implementation should return compatible devices with ei_seat.device events.

Binding masks that are not supported in the ei_device’s interface version is a client bug and may result in disconnection.

A client may send this request multiple times to adjust the capabilities it is interested in. If previously-bound capabilities are dropped by the client, the EIS implementation may ei_device.remove devices that have these capabilities.

Events

ei_seat.destroyed

Since Version1 Event Opcode0

ei_seat.destroyed(serial)

Informs the client that this seat has been removed, and that it should release all associated resources.

This ei_seat object will be destroyed by the EIS implementation immediately after after this event is sent and as such the client must not attempt to use it after that point.

ei_seat.name

Since Version1 Event Opcode1

ei_seat.name(name)

The name of this seat, if any. This event is optional and sent once immediately after object creation.

It is a protocol violation to send this event after the ei_seat.done event.

ei_seat.capability

Since Version1 Event Opcode2

ei_seat.capability(mask, interface)

Informs the client that this seat supports devices with the given interface. The interface must be mapped to a bitmask by the EIS implementation. The client may apply the binary OR operation onto these bitmasks in ei_seat.bind. In response, the EIS implementation may then create devices based on those bound capabilities.

For example, an EIS implementation may advertise support for ei_pointer devices at bitmask 0x1, ei_keyboard devices at 0x4 and ei_touchscreen devices at 0x8. A client may then execute the request ``ei_seat.bind(0xC) to bind to keyboard and touchscreen devices but not pointing devices.

The EIS implementation must not advertise capabilities for interfaces that have not been negotiated in the ei_handshake object.

The EIS implementation may decide which capabilities a given seat has. After ei_seat.done, the capabilities are constant for the lifetime of the seat but may differ between seats. The masks may be sparse bitwise.

This event is sent multiple time for each supported interface, finishing with ei_seat.done.

ei_seat.done

Since Version1 Event Opcode3

ei_seat.done()

Notification that the initial burst of events is complete and the client can set up this seat now.

It is a protocol violation to send this event more than once.

ei_seat.device

Since Version1 Event Opcode4

ei_seat.device(device, version)

Informs the client that a new device has been added to the seat.

The EIS implementation must never announce devices that have not been bound to with ei_seat.bind.

This event is only sent if the client announced support for the ei_device interface in ei_handshake.interface_version. The interface version is less than or equal to the client-supported version in ei_handshake.interface_version for the ei_device interface.