Struct Timer

pub struct Timer {
    pub created: Instant,
    pub last_run: Option<Instant>,
    pub delay: Option<Duration>,
    pub interval: Option<Duration>,
    pub timeout: Option<Duration>,
    pub callback: TimerCallback,
}

A Timer is a function that is run on every frame.

There are often a lot of visual tasks such as animations or fetching the next frame for a GIF or video, etc. - that need to run every frame or every X milliseconds, but they aren’t heavy enough to warrant creating a thread - otherwise the framework would create too many threads, which leads to a lot of context switching and bad performance.

The callback of a Timer should be fast enough to run under 16ms, otherwise running timers will block the main UI thread.

Fields

created: Instant

Stores when the timer was created (usually acquired by Instant::now())

last_run: Option<Instant>

When the timer was last called (None only when the timer hasn’t been called yet).

delay: Option<Duration>

If the timer shouldn’t start instantly, but rather be delayed by a certain timeframe

interval: Option<Duration>

How frequently the timer should run, i.e. set this to Some(Duration::from_millis(16)) to run the timer every 16ms. If this value is set to None, (the default), the timer will execute the timer as-fast-as-possible (i.e. at a faster framerate than the framework itself) - which might be performance intensive.

timeout: Option<Duration>

When to stop the timer (for example, you can stop the execution after 5s using Some(Duration::from_secs(5))).

callback: TimerCallback

Callback to be called for this timer

Implementations

impl Timer

pub fn new(callback: TimerCallbackType) -> Self

Create a new timer

pub fn with_delay(self, delay: Duration) -> Self

Delays the timer to not start immediately but rather start after a certain time frame has elapsed.

pub fn with_interval(self, interval: Duration) -> Self

Converts the timer into a timer, running the function only if the given Duration has elapsed since the last run

pub fn with_timeout(self, timeout: Duration) -> Self

Converts the timer into a countdown, by giving it a maximum duration (counted from the creation of the Timer, not the first use).

pub fn invoke<'a>(&mut self, info: TimerCallbackInfo<'a>) -> TimerCallbackReturn

Crate-internal: Invokes the timer if the timer and the self.timeout allow it to

Trait Implementations

impl Clone for Timer

fn clone(&self) -> Timer

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Timer

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

Formats the value using the given formatter.

impl Hash for Timer

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 PartialEq for Timer

fn eq(&self, other: &Timer) -> 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 Copy for Timer

impl Eq for Timer

impl StructuralPartialEq for Timer