Struct Timer 

pub struct Timer { /* private fields */ }

Tracks elapsed time. Enters the finished state once duration is reached.

Note that in order to advance the timer tick MUST be called.

Timer modes

There are two timer modes (TimerMode):

• Non repeating timers will stop tracking and stay in the finished state until reset.
• Repeating timers will only be in the finished state on each tick duration is reached or exceeded, and can still be reset at any given point.

Pausing timers

You can pause a timer using Timer::pause. Paused timers will not have elapsed time increased.

Elapsing multiple times a frame

Repeating timers might elapse multiple times per frame if the time is advanced by more than the timer duration. You can check how many times a timer elapsed each tick with Timer::times_finished_this_tick. For non-repeating timers, this will always be 0 or 1.

Implementations

impl Timer

pub fn new(duration: Duration, mode: TimerMode) -> Timer

Creates a new timer with a given duration.

See also Timer::from_seconds.

Examples found in repository

examples/2d/sprite_animation.rs (line 51)

    fn timer_from_fps(fps: u8) -> Timer {
        Timer::new(Duration::from_secs_f32(1.0 / (fps as f32)), TimerMode::Once)
    }

examples/window/custom_cursor_image.rs (line 108)

    fn timer_from_fps(fps: u8) -> Timer {
        Timer::new(Duration::from_secs_f32(1.0 / (fps as f32)), TimerMode::Once)
    }

examples/app/plugin.rs (line 35)

    fn build(&self, app: &mut App) {
        let state = PrintMessageState {
            message: self.message.clone(),
            timer: Timer::new(self.wait_duration, TimerMode::Repeating),
        };
        app.insert_resource(state)
            .add_systems(Update, print_message_system);
    }

examples/ui/ui_scaling.rs (line 14)

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .insert_resource(TargetScale {
            start_scale: 1.0,
            target_scale: 1.0,
            target_time: Timer::new(Duration::from_millis(SCALE_TIME), TimerMode::Once),
        })
        .add_systems(Startup, setup)
        .add_systems(
            Update,
            (change_scaling, apply_scaling.after(change_scaling)),
        )
        .run();
}

pub fn from_seconds(duration: f32, mode: TimerMode) -> Timer

Creates a new timer with a given duration in seconds.

Example

let mut timer = Timer::from_seconds(1.0, TimerMode::Once);

Examples found in repository

examples/stress_tests/many_cubes.rs (line 489)

    fn default() -> Self {
        Self(Timer::from_seconds(1.0, TimerMode::Repeating))
    }

examples/stress_tests/many_lights.rs (line 187)

    fn default() -> Self {
        Self(Timer::from_seconds(1.0, TimerMode::Repeating))
    }

examples/stress_tests/many_sprites.rs (line 114)

    fn default() -> Self {
        Self(Timer::from_seconds(1.0, TimerMode::Repeating))
    }

examples/stress_tests/many_text2d.rs (line 102)

    fn default() -> Self {
        Self(Timer::from_seconds(1.0, TimerMode::Repeating))
    }

examples/ecs/message.rs (line 29)

    fn default() -> Self {
        DamageTimer(Timer::from_seconds(1.0, TimerMode::Repeating))
    }

examples/games/contributors.rs (lines 38-41)

    fn default() -> Self {
        Self(Timer::from_seconds(
            SHOWCASE_TIMER_SECS,
            TimerMode::Repeating,
        ))
    }

Additional examples can be found in:

• examples/ui/font_atlas_debug.rs
• examples/time/timers.rs
• examples/ecs/generic_system.rs
• examples/ecs/state_scoped.rs
• examples/audio/soundtrack.rs
• examples/ui/directional_navigation.rs
• examples/games/alien_cake_addict.rs
• examples/2d/sprite_sheet.rs
• examples/games/game_menu.rs
• examples/2d/tilemap_chunk.rs
• examples/usage/cooldown.rs
• examples/animation/animated_mesh_events.rs
• examples/picking/sprite_picking.rs
• examples/input/text_input.rs
• examples/stress_tests/many_animated_sprites.rs
• examples/2d/sprite_scale.rs

pub fn is_finished(&self) -> bool

Returns true if the timer has reached its duration.

For repeating timers, this method behaves identically to Timer::just_finished.

Examples

use std::time::Duration;

let mut timer_once = Timer::from_seconds(1.0, TimerMode::Once);
timer_once.tick(Duration::from_secs_f32(1.5));
assert!(timer_once.is_finished());
timer_once.tick(Duration::from_secs_f32(0.5));
assert!(timer_once.is_finished());

let mut timer_repeating = Timer::from_seconds(1.0, TimerMode::Repeating);
timer_repeating.tick(Duration::from_secs_f32(1.1));
assert!(timer_repeating.is_finished());
timer_repeating.tick(Duration::from_secs_f32(0.8));
assert!(!timer_repeating.is_finished());
timer_repeating.tick(Duration::from_secs_f32(0.6));
assert!(timer_repeating.is_finished());

Examples found in repository

examples/ui/ui_scaling.rs (line 118)

    fn already_completed(&self) -> bool {
        self.target_time.is_finished() && !self.target_time.just_finished()
    }

examples/app/plugin.rs (line 49)

fn print_message_system(mut state: ResMut<PrintMessageState>, time: Res<Time>) {
    if state.timer.tick(time.delta()).is_finished() {
        info!("{}", state.message);
    }
}

examples/games/game_menu.rs (line 103)

    fn countdown(
        mut game_state: ResMut<NextState<GameState>>,
        time: Res<Time>,
        mut timer: ResMut<SplashTimer>,
    ) {
        if timer.tick(time.delta()).is_finished() {
            game_state.set(GameState::Menu);
        }
    }
}

mod game {
    use bevy::{
        color::palettes::basic::{BLUE, LIME},
        prelude::*,
    };

    use super::{DisplayQuality, GameState, Volume, TEXT_COLOR};

    // This plugin will contain the game. In this case, it's just be a screen that will
    // display the current settings for 5 seconds before returning to the menu
    pub fn game_plugin(app: &mut App) {
        app.add_systems(OnEnter(GameState::Game), game_setup)
            .add_systems(Update, game.run_if(in_state(GameState::Game)));
    }

    // Tag component used to tag entities added on the game screen
    #[derive(Component)]
    struct OnGameScreen;

    #[derive(Resource, Deref, DerefMut)]
    struct GameTimer(Timer);

    fn game_setup(
        mut commands: Commands,
        display_quality: Res<DisplayQuality>,
        volume: Res<Volume>,
    ) {
        commands.spawn((
            DespawnOnExit(GameState::Game),
            Node {
                width: percent(100),
                height: percent(100),
                // center children
                align_items: AlignItems::Center,
                justify_content: JustifyContent::Center,
                ..default()
            },
            OnGameScreen,
            children![(
                Node {
                    // This will display its children in a column, from top to bottom
                    flex_direction: FlexDirection::Column,
                    // `align_items` will align children on the cross axis. Here the main axis is
                    // vertical (column), so the cross axis is horizontal. This will center the
                    // children
                    align_items: AlignItems::Center,
                    ..default()
                },
                BackgroundColor(Color::BLACK),
                children![
                    (
                        Text::new("Will be back to the menu shortly..."),
                        TextFont {
                            font_size: 67.0,
                            ..default()
                        },
                        TextColor(TEXT_COLOR),
                        Node {
                            margin: UiRect::all(px(50)),
                            ..default()
                        },
                    ),
                    (
                        Text::default(),
                        Node {
                            margin: UiRect::all(px(50)),
                            ..default()
                        },
                        children![
                            (
                                TextSpan(format!("quality: {:?}", *display_quality)),
                                TextFont {
                                    font_size: 50.0,
                                    ..default()
                                },
                                TextColor(BLUE.into()),
                            ),
                            (
                                TextSpan::new(" - "),
                                TextFont {
                                    font_size: 50.0,
                                    ..default()
                                },
                                TextColor(TEXT_COLOR),
                            ),
                            (
                                TextSpan(format!("volume: {:?}", *volume)),
                                TextFont {
                                    font_size: 50.0,
                                    ..default()
                                },
                                TextColor(LIME.into()),
                            ),
                        ]
                    ),
                ]
            )],
        ));
        // Spawn a 5 seconds timer to trigger going back to the menu
        commands.insert_resource(GameTimer(Timer::from_seconds(5.0, TimerMode::Once)));
    }

    // Tick the timer, and change state when finished
    fn game(
        time: Res<Time>,
        mut game_state: ResMut<NextState<GameState>>,
        mut timer: ResMut<GameTimer>,
    ) {
        if timer.tick(time.delta()).is_finished() {
            game_state.set(GameState::Menu);
        }
    }

examples/ecs/message.rs (line 45)

fn deal_damage_over_time(
    time: Res<Time>,
    mut state: ResMut<DamageTimer>,
    mut deal_damage_writer: MessageWriter<DealDamage>,
) {
    if state.tick(time.delta()).is_finished() {
        // Messages can be sent with 'write' and constructed just like any other object.
        deal_damage_writer.write(DealDamage { amount: 10 });
    }
}

examples/ecs/state_scoped.rs (line 119)

fn toggle(
    time: Res<Time>,
    mut timer: ResMut<TickTock>,
    state: Res<State<GameState>>,
    mut next_state: ResMut<NextState<GameState>>,
) {
    if !timer.0.tick(time.delta()).is_finished() {
        return;
    }
    *next_state = match state.get() {
        GameState::A => NextState::Pending(GameState::B),
        GameState::B => NextState::Pending(GameState::A),
    }
}

examples/window/custom_cursor_image.rs (line 120)

fn execute_animation(time: Res<Time>, mut query: Query<(&mut AnimationConfig, &mut CursorIcon)>) {
    for (mut config, mut cursor_icon) in &mut query {
        if let CursorIcon::Custom(CustomCursor::Image(ref mut image)) = *cursor_icon {
            config.frame_timer.tick(time.delta());

            if config.frame_timer.is_finished()
                && let Some(atlas) = image.texture_atlas.as_mut()
            {
                atlas.index += config.increment;

                if atlas.index > config.last_sprite_index {
                    atlas.index = config.first_sprite_index;
                }

                config.frame_timer = AnimationConfig::timer_from_fps(config.fps);
            }
        }
    }
}

Additional examples can be found in:

• examples/time/timers.rs
• examples/games/alien_cake_addict.rs

pub fn finished(&self) -> bool

👎Deprecated since 0.17.0: Use is_finished instead

Returns true if the timer has reached its duration.

For repeating timers, this method behaves identically to Timer::just_finished.

Examples

use std::time::Duration;

let mut timer_once = Timer::from_seconds(1.0, TimerMode::Once);
timer_once.tick(Duration::from_secs_f32(1.5));
assert!(timer_once.finished());
timer_once.tick(Duration::from_secs_f32(0.5));
assert!(timer_once.finished());

let mut timer_repeating = Timer::from_seconds(1.0, TimerMode::Repeating);
timer_repeating.tick(Duration::from_secs_f32(1.1));
assert!(timer_repeating.finished());
timer_repeating.tick(Duration::from_secs_f32(0.8));
assert!(!timer_repeating.finished());
timer_repeating.tick(Duration::from_secs_f32(0.6));
assert!(timer_repeating.finished());

pub fn just_finished(&self) -> bool

Returns true only on the tick the timer reached its duration.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(1.5));
assert!(timer.just_finished());
timer.tick(Duration::from_secs_f32(0.5));
assert!(!timer.just_finished());

Examples found in repository

examples/ui/ui_scaling.rs (line 118)

    fn already_completed(&self) -> bool {
        self.target_time.is_finished() && !self.target_time.just_finished()
    }

examples/stress_tests/many_sprites.rs (line 122)

fn print_sprite_count(time: Res<Time>, mut timer: Local<PrintingTimer>, sprites: Query<&Sprite>) {
    timer.tick(time.delta());

    if timer.just_finished() {
        info!("Sprites: {}", sprites.iter().count());
    }
}

examples/stress_tests/many_lights.rs (line 145)

fn print_light_count(time: Res<Time>, mut timer: Local<PrintingTimer>, lights: Query<&PointLight>) {
    timer.0.tick(time.delta());

    if timer.0.just_finished() {
        info!("Lights: {}", lights.iter().len());
    }
}

struct LogVisibleLights;

impl Plugin for LogVisibleLights {
    fn build(&self, app: &mut App) {
        let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
            return;
        };

        render_app.add_systems(
            Render,
            print_visible_light_count.in_set(RenderSystems::Prepare),
        );
    }
}

// System for printing the number of meshes on every tick of the timer
fn print_visible_light_count(
    time: Res<Time>,
    mut timer: Local<PrintingTimer>,
    visible: Query<&ExtractedPointLight>,
    global_light_meta: Res<GlobalClusterableObjectMeta>,
) {
    timer.0.tick(time.delta());

    if timer.0.just_finished() {
        info!(
            "Visible Lights: {}, Rendered Lights: {}",
            visible.iter().len(),
            global_light_meta.entity_to_index.len()
        );
    }
}

examples/ecs/generic_system.rs (line 68)

fn print_text_system(time: Res<Time>, mut query: Query<(&mut PrinterTick, &TextToPrint)>) {
    for (mut timer, text) in &mut query {
        if timer.tick(time.delta()).just_finished() {
            info!("{}", text.0);
        }
    }
}

examples/time/timers.rs (line 50)

fn print_when_completed(time: Res<Time>, mut query: Query<&mut PrintOnCompletionTimer>) {
    for mut timer in &mut query {
        if timer.tick(time.delta()).just_finished() {
            info!("Entity timer just finished");
        }
    }
}

/// This system controls ticking the timer within the countdown resource and
/// handling its state.
fn countdown(time: Res<Time>, mut countdown: ResMut<Countdown>) {
    countdown.main_timer.tick(time.delta());

    // The API encourages this kind of timer state checking (if you're only checking for one value)
    // Additionally, `is_finished()` would accomplish the same thing as `just_finished` due to the
    // timer being repeating, however this makes more sense visually.
    if countdown.percent_trigger.tick(time.delta()).just_finished() {
        if !countdown.main_timer.is_finished() {
            // Print the percent complete the main timer is.
            info!(
                "Timer is {:0.0}% complete!",
                countdown.main_timer.fraction() * 100.0
            );
        } else {
            // The timer has finished so we pause the percent output timer
            countdown.percent_trigger.pause();
            info!("Paused percent trigger timer");
        }
    }
}

examples/ui/directional_navigation.rs (line 95)

fn reset_button_after_interaction(
    time: Res<Time>,
    mut query: Query<(&mut ResetTimer, &mut BackgroundColor)>,
) {
    for (mut reset_timer, mut color) in query.iter_mut() {
        reset_timer.tick(time.delta());
        if reset_timer.just_finished() {
            color.0 = NORMAL_BUTTON.into();
        }
    }
}

Additional examples can be found in:

• examples/stress_tests/many_cubes.rs
• examples/audio/soundtrack.rs
• examples/input/text_input.rs
• examples/ui/font_atlas_debug.rs
• examples/2d/sprite_scale.rs
• examples/2d/sprite_sheet.rs
• examples/2d/tilemap_chunk.rs
• examples/picking/sprite_picking.rs
• examples/stress_tests/many_animated_sprites.rs
• examples/animation/animated_mesh_events.rs
• examples/stress_tests/many_text2d.rs
• examples/usage/cooldown.rs
• examples/2d/sprite_animation.rs
• examples/games/contributors.rs

pub fn elapsed(&self) -> Duration

Returns the time elapsed on the timer. Guaranteed to be between 0.0 and duration. Will only equal duration when the timer is finished and non repeating.

See also Stopwatch::elapsed.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.elapsed(), Duration::from_secs_f32(0.5));

pub fn elapsed_secs(&self) -> f32

Returns the time elapsed on the timer as an f32. See also Timer::elapsed.

pub fn elapsed_secs_f64(&self) -> f64

Returns the time elapsed on the timer as an f64. See also Timer::elapsed.

pub fn set_elapsed(&mut self, time: Duration)

Sets the elapsed time of the timer without any other considerations.

See also Stopwatch::set.

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.set_elapsed(Duration::from_secs(2));
assert_eq!(timer.elapsed(), Duration::from_secs(2));
// the timer is not finished even if the elapsed time is greater than the duration.
assert!(!timer.is_finished());

Examples found in repository

examples/stress_tests/many_animated_sprites.rs (line 78)

fn setup(
    mut commands: Commands,
    assets: Res<AssetServer>,
    mut texture_atlases: ResMut<Assets<TextureAtlasLayout>>,
) {
    warn!(include_str!("warning_string.txt"));

    let mut rng = rand::rng();

    let tile_size = Vec2::splat(64.0);
    let map_size = Vec2::splat(320.0);

    let half_x = (map_size.x / 2.0) as i32;
    let half_y = (map_size.y / 2.0) as i32;

    let texture_handle = assets.load("textures/rpg/chars/gabe/gabe-idle-run.png");
    let texture_atlas = TextureAtlasLayout::from_grid(UVec2::splat(24), 7, 1, None, None);
    let texture_atlas_handle = texture_atlases.add(texture_atlas);

    // Spawns the camera

    commands.spawn(Camera2d);

    // Builds and spawns the sprites
    for y in -half_y..half_y {
        for x in -half_x..half_x {
            let position = Vec2::new(x as f32, y as f32);
            let translation = (position * tile_size).extend(rng.random::<f32>());
            let rotation = Quat::from_rotation_z(rng.random::<f32>());
            let scale = Vec3::splat(rng.random::<f32>() * 2.0);
            let mut timer = Timer::from_seconds(0.1, TimerMode::Repeating);
            timer.set_elapsed(Duration::from_secs_f32(rng.random::<f32>()));

            commands.spawn((
                Sprite {
                    image: texture_handle.clone(),
                    texture_atlas: Some(TextureAtlas::from(texture_atlas_handle.clone())),
                    custom_size: Some(tile_size),
                    ..default()
                },
                Transform {
                    translation,
                    rotation,
                    scale,
                },
                AnimationTimer(timer),
            ));
        }
    }
}

pub fn duration(&self) -> Duration

Returns the duration of the timer.

Examples

use std::time::Duration;
let timer = Timer::new(Duration::from_secs(1), TimerMode::Once);
assert_eq!(timer.duration(), Duration::from_secs(1));

pub fn set_duration(&mut self, duration: Duration)

Sets the duration of the timer.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.5, TimerMode::Once);
timer.set_duration(Duration::from_secs(1));
assert_eq!(timer.duration(), Duration::from_secs(1));

pub fn finish(&mut self)

Finishes the timer.

Examples

let mut timer = Timer::from_seconds(1.5, TimerMode::Once);
timer.finish();
assert!(timer.finished());

pub fn mode(&self) -> TimerMode

Returns the mode of the timer.

Examples

let mut timer = Timer::from_seconds(1.0, TimerMode::Repeating);
assert_eq!(timer.mode(), TimerMode::Repeating);

pub fn set_mode(&mut self, mode: TimerMode)

Sets the mode of the timer.

Examples

let mut timer = Timer::from_seconds(1.0, TimerMode::Repeating);
timer.set_mode(TimerMode::Once);
assert_eq!(timer.mode(), TimerMode::Once);

pub fn tick(&mut self, delta: Duration) -> &Timer

Advance the timer by delta seconds. Non repeating timer will clamp at duration. Repeating timer will wrap around. Will not affect paused timers.

See also Stopwatch::tick.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
let mut repeating = Timer::from_seconds(1.0, TimerMode::Repeating);
timer.tick(Duration::from_secs_f32(1.5));
repeating.tick(Duration::from_secs_f32(1.5));
assert_eq!(timer.elapsed_secs(), 1.0);
assert_eq!(repeating.elapsed_secs(), 0.5);

Examples found in repository

examples/ui/ui_scaling.rs (line 113)

    fn tick(&mut self, delta: Duration) -> &Self {
        self.target_time.tick(delta);
        self
    }

examples/app/plugin.rs (line 49)

fn print_message_system(mut state: ResMut<PrintMessageState>, time: Res<Time>) {
    if state.timer.tick(time.delta()).is_finished() {
        info!("{}", state.message);
    }
}

examples/stress_tests/many_sprites.rs (line 120)

fn print_sprite_count(time: Res<Time>, mut timer: Local<PrintingTimer>, sprites: Query<&Sprite>) {
    timer.tick(time.delta());

    if timer.just_finished() {
        info!("Sprites: {}", sprites.iter().count());
    }
}

examples/stress_tests/many_lights.rs (line 143)

fn print_light_count(time: Res<Time>, mut timer: Local<PrintingTimer>, lights: Query<&PointLight>) {
    timer.0.tick(time.delta());

    if timer.0.just_finished() {
        info!("Lights: {}", lights.iter().len());
    }
}

struct LogVisibleLights;

impl Plugin for LogVisibleLights {
    fn build(&self, app: &mut App) {
        let Some(render_app) = app.get_sub_app_mut(RenderApp) else {
            return;
        };

        render_app.add_systems(
            Render,
            print_visible_light_count.in_set(RenderSystems::Prepare),
        );
    }
}

// System for printing the number of meshes on every tick of the timer
fn print_visible_light_count(
    time: Res<Time>,
    mut timer: Local<PrintingTimer>,
    visible: Query<&ExtractedPointLight>,
    global_light_meta: Res<GlobalClusterableObjectMeta>,
) {
    timer.0.tick(time.delta());

    if timer.0.just_finished() {
        info!(
            "Visible Lights: {}, Rendered Lights: {}",
            visible.iter().len(),
            global_light_meta.entity_to_index.len()
        );
    }
}

examples/ecs/generic_system.rs (line 68)

fn print_text_system(time: Res<Time>, mut query: Query<(&mut PrinterTick, &TextToPrint)>) {
    for (mut timer, text) in &mut query {
        if timer.tick(time.delta()).just_finished() {
            info!("{}", text.0);
        }
    }
}

examples/time/timers.rs (line 50)

fn print_when_completed(time: Res<Time>, mut query: Query<&mut PrintOnCompletionTimer>) {
    for mut timer in &mut query {
        if timer.tick(time.delta()).just_finished() {
            info!("Entity timer just finished");
        }
    }
}

/// This system controls ticking the timer within the countdown resource and
/// handling its state.
fn countdown(time: Res<Time>, mut countdown: ResMut<Countdown>) {
    countdown.main_timer.tick(time.delta());

    // The API encourages this kind of timer state checking (if you're only checking for one value)
    // Additionally, `is_finished()` would accomplish the same thing as `just_finished` due to the
    // timer being repeating, however this makes more sense visually.
    if countdown.percent_trigger.tick(time.delta()).just_finished() {
        if !countdown.main_timer.is_finished() {
            // Print the percent complete the main timer is.
            info!(
                "Timer is {:0.0}% complete!",
                countdown.main_timer.fraction() * 100.0
            );
        } else {
            // The timer has finished so we pause the percent output timer
            countdown.percent_trigger.pause();
            info!("Paused percent trigger timer");
        }
    }
}

Additional examples can be found in:

• examples/games/game_menu.rs
• examples/ui/directional_navigation.rs
• examples/ecs/message.rs
• examples/stress_tests/many_cubes.rs
• examples/audio/soundtrack.rs
• examples/ecs/state_scoped.rs
• examples/input/text_input.rs
• examples/ui/font_atlas_debug.rs
• examples/2d/sprite_scale.rs
• examples/2d/sprite_sheet.rs
• examples/2d/tilemap_chunk.rs
• examples/picking/sprite_picking.rs
• examples/stress_tests/many_animated_sprites.rs
• examples/animation/animated_mesh_events.rs
• examples/stress_tests/many_text2d.rs
• examples/usage/cooldown.rs
• examples/window/custom_cursor_image.rs
• examples/2d/sprite_animation.rs
• examples/games/contributors.rs
• examples/games/alien_cake_addict.rs

pub fn pause(&mut self)

Pauses the Timer. Disables the ticking of the timer.

See also Stopwatch::pause.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.pause();
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.elapsed_secs(), 0.0);

Examples found in repository

examples/time/timers.rs (line 73)

fn countdown(time: Res<Time>, mut countdown: ResMut<Countdown>) {
    countdown.main_timer.tick(time.delta());

    // The API encourages this kind of timer state checking (if you're only checking for one value)
    // Additionally, `is_finished()` would accomplish the same thing as `just_finished` due to the
    // timer being repeating, however this makes more sense visually.
    if countdown.percent_trigger.tick(time.delta()).just_finished() {
        if !countdown.main_timer.is_finished() {
            // Print the percent complete the main timer is.
            info!(
                "Timer is {:0.0}% complete!",
                countdown.main_timer.fraction() * 100.0
            );
        } else {
            // The timer has finished so we pause the percent output timer
            countdown.percent_trigger.pause();
            info!("Paused percent trigger timer");
        }
    }
}

pub fn unpause(&mut self)

Unpauses the Timer. Resumes the ticking of the timer.

See also Stopwatch::unpause().

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.pause();
timer.tick(Duration::from_secs_f32(0.5));
timer.unpause();
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.elapsed_secs(), 0.5);

pub fn is_paused(&self) -> bool

Returns true if the timer is paused.

See also Stopwatch::is_paused.

Examples

let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
assert!(!timer.is_paused());
timer.pause();
assert!(timer.is_paused());
timer.unpause();
assert!(!timer.is_paused());

pub fn paused(&self) -> bool

👎Deprecated since 0.17.0: Use is_paused instead

Returns true if the timer is paused.

See also Stopwatch::is_paused.

Examples

let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
assert!(!timer.paused());
timer.pause();
assert!(timer.paused());
timer.unpause();
assert!(!timer.paused());

pub fn reset(&mut self)

Resets the timer. The reset doesn’t affect the paused state of the timer.

See also Stopwatch::reset.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(1.5));
timer.reset();
assert!(!timer.is_finished());
assert!(!timer.just_finished());
assert_eq!(timer.elapsed_secs(), 0.0);

Examples found in repository

examples/ui/ui_scaling.rs (line 103)

    fn set_scale(&mut self, scale: f32) {
        self.start_scale = self.current_scale();
        self.target_scale = scale;
        self.target_time.reset();
    }

examples/usage/cooldown.rs (line 146)

fn activate_ability(
    mut commands: Commands,
    mut interaction_query: Query<
        (
            Entity,
            &Interaction,
            &mut Cooldown,
            &Name,
            Option<&ActiveCooldown>,
        ),
        (Changed<Interaction>, With<Button>),
    >,
    mut text: Query<&mut Text>,
) -> Result {
    for (entity, interaction, mut cooldown, name, on_cooldown) in &mut interaction_query {
        if *interaction == Interaction::Pressed {
            if on_cooldown.is_none() {
                cooldown.0.reset();
                commands.entity(entity).insert(ActiveCooldown);
                **text.single_mut()? = format!("You ate {name}");
            } else {
                **text.single_mut()? = format!(
                    "You can eat {name} again in {} seconds.",
                    cooldown.0.remaining_secs().ceil()
                );
            }
        }
    }

    Ok(())
}

examples/games/alien_cake_addict.rs (line 241)

fn move_player(
    mut commands: Commands,
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut game: ResMut<Game>,
    mut transforms: Query<&mut Transform>,
    time: Res<Time>,
) {
    if game.player.move_cooldown.tick(time.delta()).is_finished() {
        let mut moved = false;
        let mut rotation = 0.0;

        if keyboard_input.pressed(KeyCode::ArrowUp) {
            if game.player.i < BOARD_SIZE_I - 1 {
                game.player.i += 1;
            }
            rotation = -PI / 2.;
            moved = true;
        }
        if keyboard_input.pressed(KeyCode::ArrowDown) {
            if game.player.i > 0 {
                game.player.i -= 1;
            }
            rotation = PI / 2.;
            moved = true;
        }
        if keyboard_input.pressed(KeyCode::ArrowRight) {
            if game.player.j < BOARD_SIZE_J - 1 {
                game.player.j += 1;
            }
            rotation = PI;
            moved = true;
        }
        if keyboard_input.pressed(KeyCode::ArrowLeft) {
            if game.player.j > 0 {
                game.player.j -= 1;
            }
            rotation = 0.0;
            moved = true;
        }

        // move on the board
        if moved {
            game.player.move_cooldown.reset();
            *transforms.get_mut(game.player.entity.unwrap()).unwrap() = Transform {
                translation: Vec3::new(
                    game.player.i as f32,
                    game.board[game.player.j][game.player.i].height,
                    game.player.j as f32,
                ),
                rotation: Quat::from_rotation_y(rotation),
                ..default()
            };
        }
    }

    // eat the cake!
    if let Some(entity) = game.bonus.entity
        && game.player.i == game.bonus.i
        && game.player.j == game.bonus.j
    {
        game.score += 2;
        game.cake_eaten += 1;
        commands.entity(entity).despawn();
        game.bonus.entity = None;
    }
}

pub fn fraction(&self) -> f32

Returns the fraction of the timer elapsed time (goes from 0.0 to 1.0).

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(2.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.fraction(), 0.25);

Examples found in repository

examples/ui/ui_scaling.rs (line 107)

    fn current_scale(&self) -> f32 {
        let completion = self.target_time.fraction();
        let t = ease_in_expo(completion);
        self.start_scale.lerp(self.target_scale, t)
    }

examples/animation/animated_mesh_events.rs (line 208)

fn simulate_particles(
    mut commands: Commands,
    mut query: Query<(Entity, &mut Transform, &mut Particle)>,
    time: Res<Time>,
) {
    for (entity, mut transform, mut particle) in &mut query {
        if particle.lifetime_timer.tick(time.delta()).just_finished() {
            commands.entity(entity).despawn();
            return;
        }

        transform.translation += particle.velocity * time.delta_secs();
        transform.scale = Vec3::splat(particle.size.lerp(0.0, particle.lifetime_timer.fraction()));
        particle
            .velocity
            .smooth_nudge(&Vec3::ZERO, 4.0, time.delta_secs());
    }
}

examples/usage/cooldown.rs (line 174)

fn animate_cooldowns(
    time: Res<Time>,
    mut commands: Commands,
    buttons: Query<(Entity, &mut Cooldown, &Children), With<ActiveCooldown>>,
    mut nodes: Query<&mut Node>,
) -> Result {
    for (entity, mut timer, children) in buttons {
        timer.0.tick(time.delta());
        let cooldown = children.first().ok_or("No child")?;
        if timer.0.just_finished() {
            commands.entity(entity).remove::<ActiveCooldown>();
            nodes.get_mut(*cooldown)?.height = percent(0);
        } else {
            nodes.get_mut(*cooldown)?.height = percent((1. - timer.0.fraction()) * 100.);
        }
    }

    Ok(())
}

examples/time/timers.rs (line 69)

fn countdown(time: Res<Time>, mut countdown: ResMut<Countdown>) {
    countdown.main_timer.tick(time.delta());

    // The API encourages this kind of timer state checking (if you're only checking for one value)
    // Additionally, `is_finished()` would accomplish the same thing as `just_finished` due to the
    // timer being repeating, however this makes more sense visually.
    if countdown.percent_trigger.tick(time.delta()).just_finished() {
        if !countdown.main_timer.is_finished() {
            // Print the percent complete the main timer is.
            info!(
                "Timer is {:0.0}% complete!",
                countdown.main_timer.fraction() * 100.0
            );
        } else {
            // The timer has finished so we pause the percent output timer
            countdown.percent_trigger.pause();
            info!("Paused percent trigger timer");
        }
    }
}

pub fn fraction_remaining(&self) -> f32

Returns the fraction of the timer remaining time (goes from 1.0 to 0.0).

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(2.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.fraction_remaining(), 0.75);

pub fn remaining_secs(&self) -> f32

Returns the remaining time in seconds

Examples

use std::cmp::Ordering;
use std::time::Duration;
let mut timer = Timer::from_seconds(2.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(0.5));
let result = timer.remaining_secs().total_cmp(&1.5);
assert_eq!(Ordering::Equal, result);

Examples found in repository

examples/usage/cooldown.rs (line 152)

fn activate_ability(
    mut commands: Commands,
    mut interaction_query: Query<
        (
            Entity,
            &Interaction,
            &mut Cooldown,
            &Name,
            Option<&ActiveCooldown>,
        ),
        (Changed<Interaction>, With<Button>),
    >,
    mut text: Query<&mut Text>,
) -> Result {
    for (entity, interaction, mut cooldown, name, on_cooldown) in &mut interaction_query {
        if *interaction == Interaction::Pressed {
            if on_cooldown.is_none() {
                cooldown.0.reset();
                commands.entity(entity).insert(ActiveCooldown);
                **text.single_mut()? = format!("You ate {name}");
            } else {
                **text.single_mut()? = format!(
                    "You can eat {name} again in {} seconds.",
                    cooldown.0.remaining_secs().ceil()
                );
            }
        }
    }

    Ok(())
}

pub fn remaining(&self) -> Duration

Returns the remaining time using Duration

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(2.0, TimerMode::Once);
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.remaining(), Duration::from_secs_f32(1.5));

pub fn times_finished_this_tick(&self) -> u32

Returns the number of times a repeating timer finished during the last tick call.

For non repeating-timers, this method will only ever return 0 or 1.

Examples

use std::time::Duration;
let mut timer = Timer::from_seconds(1.0, TimerMode::Repeating);
timer.tick(Duration::from_secs_f32(6.0));
assert_eq!(timer.times_finished_this_tick(), 6);
timer.tick(Duration::from_secs_f32(2.0));
assert_eq!(timer.times_finished_this_tick(), 2);
timer.tick(Duration::from_secs_f32(0.5));
assert_eq!(timer.times_finished_this_tick(), 0);

Trait Implementations

impl Clone for Timer

fn clone(&self) -> Timer

Returns a duplicate 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<(), Error>

Formats the value using the given formatter.

impl Default for Timer

fn default() -> Timer

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Timer

fn deserialize<__D>( __deserializer: __D, ) -> Result<Timer, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl FromArg for Timer

type This<'from_arg> = Timer

The type to convert into.

fn from_arg(arg: Arg<'_>) -> Result<<Timer as FromArg>::This<'_>, ArgError>

Creates an item from an argument.

impl FromReflect for Timer

fn from_reflect(reflect: &(dyn PartialReflect + 'static)) -> Option<Timer>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn PartialReflect>, ) -> Result<Self, Box<dyn PartialReflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl GetOwnership for Timer

fn ownership() -> Ownership

Returns the ownership of Self.

impl GetTypeRegistration for Timer

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl IntoReturn for Timer

fn into_return<'into_return>(self) -> Return<'into_return>

where Timer: 'into_return,

Converts Self into a Return value.

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 PartialReflect for Timer

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

fn try_apply( &mut self, value: &(dyn PartialReflect + 'static), ) -> Result<(), ApplyError>

Tries to apply a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<Timer>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn try_into_reflect( self: Box<Timer>, ) -> Result<Box<dyn Reflect>, Box<dyn PartialReflect>>

Attempts to cast this type to a boxed, fully-reflected value.

fn try_as_reflect(&self) -> Option<&(dyn Reflect + 'static)>

Attempts to cast this type to a fully-reflected value.

fn try_as_reflect_mut(&mut self) -> Option<&mut (dyn Reflect + 'static)>

Attempts to cast this type to a mutable, fully-reflected value.

fn into_partial_reflect(self: Box<Timer>) -> Box<dyn PartialReflect>

Casts this type to a boxed, reflected value.

fn as_partial_reflect(&self) -> &(dyn PartialReflect + 'static)

Casts this type to a reflected value.

fn as_partial_reflect_mut(&mut self) -> &mut (dyn PartialReflect + 'static)

Casts this type to a mutable, reflected value.

fn reflect_partial_eq( &self, value: &(dyn PartialReflect + 'static), ) -> Option<bool>

Returns a “partial equality” comparison result.

fn reflect_clone(&self) -> Result<Box<dyn Reflect>, ReflectCloneError>

Attempts to clone Self using reflection.

fn apply(&mut self, value: &(dyn PartialReflect + 'static))

Applies a reflected value to this value.

fn to_dynamic(&self) -> Box<dyn PartialReflect>

Converts this reflected value into its dynamic representation based on its kind.

fn reflect_clone_and_take<T>(&self) -> Result<T, ReflectCloneError>

where T: 'static, Self: Sized + TypePath,

For a type implementing PartialReflect, combines reflect_clone and take in a useful fashion, automatically constructing an appropriate ReflectCloneError if the downcast fails.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

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

Debug formatter for the value.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl Reflect for Timer

fn into_any(self: Box<Timer>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<Timer>) -> Box<dyn Reflect>

Casts this type to a boxed, fully-reflected value.

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a fully-reflected value.

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable, fully-reflected value.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

impl Serialize for Timer

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Struct for Timer

fn field(&self, name: &str) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field named name as a &dyn PartialReflect.

fn field_mut( &mut self, name: &str, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field named name as a &mut dyn PartialReflect.

fn field_at(&self, index: usize) -> Option<&(dyn PartialReflect + 'static)>

Returns a reference to the value of the field with index index as a &dyn PartialReflect.

fn field_at_mut( &mut self, index: usize, ) -> Option<&mut (dyn PartialReflect + 'static)>

Returns a mutable reference to the value of the field with index index as a &mut dyn PartialReflect.

fn name_at(&self, index: usize) -> Option<&str>

Returns the name of the field with index index.

fn field_len(&self) -> usize

Returns the number of fields in the struct.

fn iter_fields(&self) -> FieldIter<'_>

Returns an iterator over the values of the reflectable fields for this struct.

fn to_dynamic_struct(&self) -> DynamicStruct

Creates a new DynamicStruct from this struct.

fn get_represented_struct_info(&self) -> Option<&'static StructInfo>

Will return None if TypeInfo is not available.

impl TypePath for Timer

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl Typed for Timer

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl Eq for Timer

impl StructuralPartialEq for Timer