Struct TouchInteractionId

#[repr(C)]
pub struct TouchInteractionId {
    pub device_id: u32,
    pub pointer_id: u32,
    pub interaction_id: u32,
}

A unique identifier for a “interaction” of touch events in an event stream. Touch events are observed as a succession of interactions, as fingers engage and disengage with the display.

A finite sequence of pointer events that follows the EventPhase state machine, starting from the initial state ADD, is called an interaction. A closed (or past) interaction is one where it has reached the terminal state (REMOVE or CANCEL); an open (or current) interaction is one where it has not.

For a given device pointer, a stream of events is observed as a succession of zero or more closed interactions (the past history of user engagement), followed by at most one open interaction (the current user engagement).

Because we need to group pointer events by their interaction, touch event carries an interaction id that is unique in that pointer stream. This common reference makes it possible to operate on a closed interaction, as well as an open interaction.

Also see EventPhase for a discussion on event streams by mice.

Fields

device_id: u32

An identifier for the pointer device that issues touch event streams. A device may own multiple pointers, each with its own |pointer_id|.

pointer_id: u32

An identifier of the pointer that issued this event. It is unique only to a specific |device_id|. Each (device_id, pointer_id) pair issues at most one open interaction at a time.

interaction_id: u32

An identifier of the interaction. It is unique only to a specific (device_id, pointer_id) pair.

Trait Implementations

impl Clone for TouchInteractionId

fn clone(&self) -> TouchInteractionId

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TouchInteractionId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<D: ResourceDialect> Decode<TouchInteractionId, D> for TouchInteractionId

fn new_empty() -> Self

Creates a valid instance of Self. The specific value does not matter, since it will be overwritten by decode.

unsafe fn decode( &mut self, decoder: &mut Decoder<'_, D>, offset: usize, _depth: Depth, ) -> Result<()>

Decodes an object of type T from the decoder’s buffers into self.

impl<D: ResourceDialect> Encode<TouchInteractionId, D> for &TouchInteractionId

unsafe fn encode( self, encoder: &mut Encoder<'_, D>, offset: usize, _depth: Depth, ) -> Result<()>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID.

impl<D: ResourceDialect, T0: Encode<u32, D>, T1: Encode<u32, D>, T2: Encode<u32, D>> Encode<TouchInteractionId, D> for (T0, T1, T2)

unsafe fn encode( self, encoder: &mut Encoder<'_, D>, offset: usize, depth: Depth, ) -> Result<()>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID.

impl Hash for TouchInteractionId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for TouchInteractionId

fn cmp(&self, other: &TouchInteractionId) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for TouchInteractionId

fn eq(&self, other: &TouchInteractionId) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for TouchInteractionId

fn partial_cmp(&self, other: &TouchInteractionId) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TypeMarker for TouchInteractionId

type Owned = TouchInteractionId

The owned Rust type which this FIDL type decodes into.

fn inline_align(_context: Context) -> usize

Returns the minimum required alignment of the inline portion of the encoded object. It must be a (nonzero) power of two.

fn inline_size(_context: Context) -> usize

Returns the size of the inline portion of the encoded object, including padding for alignment. Must be a multiple of inline_align.

fn encode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and encoding requires no validation. When true, we can optimize encoding arrays and vectors of Self::Owned to a single memcpy.

fn decode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and decoding requires no validation. When true, we can optimize decoding arrays and vectors of Self::Owned to a single memcpy.

impl ValueTypeMarker for TouchInteractionId

type Borrowed<'a> = &'a TouchInteractionId

The Rust type to use for encoding. This is a particular Encode<Self> type cheaply obtainable from &Self::Owned. There are three cases:

fn borrow(value: &<Self as TypeMarker>::Owned) -> Self::Borrowed<'_>

Cheaply converts from &Self::Owned to Self::Borrowed.

impl Copy for TouchInteractionId

impl Eq for TouchInteractionId

impl Persistable for TouchInteractionId

impl StructuralPartialEq for TouchInteractionId