Module event

Input event types and enumerations.

All device event iterators will yield InputEvent, the base event type.

Events carry the following information:

• Timestamp (InputEvent::time): The time at which the event has been inserted into the kernel buffer. The default time source is the system’s real-time clock, which is also used by SystemTime::now. It can be changed by calling Evdev::set_clockid.
• Event Type (InputEvent::event_type): The broad category of event. The EventType determines which of the event wrappers listed below is responsible.
• Event Code (InputEvent::raw_code): A u16 identifying the button, axis, or other object affected by the event. This is typically wrapped in a type like Syn, Key, Abs or Rel and accessed from a specific event wrapper.
• Event Value (InputEvent::raw_value): An i32 describing what happened to the object identified by the code. This can be the new state of an Abs axis, an incremental movement of a Rel axis, the new state (pressed/released/repeated) of a Key or Switch, or some other value.

InputEvent::kind can be used to obtain an EventKind, which can be conveniently matched on to handle the different types of events.

Devices may emit a variety of different types of events, which are all wrapped by the following Rust types in this module:

• SynEvent
• KeyEvent
• RelEvent
• AbsEvent
• SwitchEvent
• MiscEvent
• LedEvent
• RepeatEvent
• SoundEvent
• UinputEvent
• ForceFeedbackEvent

All of these event types can be converted to EventKind and InputEvent via From and Into, and can be Dereferenced to obtain the InputEvent they wrap.

Serde support

If the serde feature is enabled, implementations of Serialize and Deserialize will be provided for the following types:

• Abs
• Key
• Rel
• Misc
• Led
• Switch
• Sound

For human-readable formats, the serde representation will use the evdev constant name if the value has one (eg. KEY_F1, ABS_Y, …), and the raw u16 code if it does not. Deserialization from a human-readable format will accept either.

Note that this means that when a new key or axis name is added in a later version of this crate, older versions will not be able to deserialize it. evdevil guarantees only old->new compatibility between non-breaking versions, not new->old.

Note also that some values have multiple names. For example, Key::BTN_TRIGGER_HAPPY is the same value as Key::BTN_TRIGGER_HAPPY1. Deserialization will accept either name, but serialization has to pick a single name, which is typically the first one with a given value, but is not generally guaranteed to be any specific constant name.

For non-human-readable formats, the raw numeric code is always used, and formats that aren’t self-describing (like postcard) are supported. There is also no compatibility concern in case new key or axis names are added in later versions.

Structs

Abs

An absolute axis identifier.

AbsEvent

An absolute axis change.

EventType

Types of InputEvents

ForceFeedbackEvent

Starts or stops previously uploaded force-feedback effects.

InputEvent

An input event received from or sent to an evdev.

Key

An evdev key or button identifier.

KeyEvent

A key press/release/repeat event.

KeyState

State of a Key, stored as the value of a KeyEvent.

Led

A device LED or other indicator.

LedEvent

Reports or changes the state of device LEDs.

Misc

A miscellaneous event type (MSC_*).

MiscEvent

Miscellaneous management events.

MtToolType

Multi-touch contact tool.

Rel

A relative axis identifier.

RelEvent

A relative axis change.

Repeat

Autorepeat setting.

RepeatEvent

The key repeat settings have been changed.

Sound

A sound effect.

SoundEvent

Plays simple sounds on the device.

Switch

A binary switch (SW_*).

SwitchEvent

A switch state change.

Syn

Synchronization event types.

SynEvent

A synchronization event.

UinputCode

Event codes for UinputEvent.

UinputEvent

Internal events sent to UinputDevices.

Enums

EventKind

Enumeration of event types.

ForceFeedbackCode

Code of a ForceFeedbackEvent.