timer with type param

crates/bevy_core/src/lib.rs

@@ -37,7 +37,7 @@ impl Plugin for CorePlugin {
             .init_resource::<FixedTimesteps>()
             .register_type::<Option<String>>()
             .register_type::<Range<f32>>()
-            .register_type::<Timer>()
+            .register_type::<Timer<()>>()
             .add_system_to_stage(stage::FIRST, time_system.system())
             .add_system_to_stage(stage::PRE_UPDATE, entity_labels_system.system());
     }

crates/bevy_core/src/time/timer.rs

@@ -7,19 +7,34 @@ use bevy_utils::Duration;
 /// 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.
 ///
 /// Paused timers will not have elapsed time increased.
-#[derive(Clone, Debug, Default, Reflect)]
+#[derive(Clone, Debug, Reflect)]
 #[reflect(Component)]
-pub struct Timer {
+pub struct Timer<T: Send + Sync + 'static = ()> {
     elapsed: f32,
     duration: f32,
     finished: bool,
     /// Will only be true on the tick `duration` is reached or exceeded.
     just_finished: bool,
     paused: bool,
     repeating: bool,
+    marker: std::marker::PhantomData<T>,
 }
 
-impl Timer {
+impl<T: Send + Sync + 'static> Default for Timer<T> {
+    fn default() -> Self {
+        Self {
+            elapsed: 0.,
+            duration: 0.,
+            finished: false,
+            just_finished: false,
+            paused: false,
+            repeating: false,
+            marker: std::marker::PhantomData::default(),
+        }
+    }
+}
+
+impl<T: Send + Sync + 'static> Timer<T> {
     pub fn new(duration: Duration, repeating: bool) -> Self {
         Timer {
             duration: duration.as_secs_f32(),
@@ -144,7 +159,7 @@ mod tests {
 
     #[test]
     fn test_non_repeating() {
-        let mut t = Timer::from_seconds(10.0, false);
+        let mut t = Timer::<()>::from_seconds(10.0, false);
         // Tick once, check all attributes
         t.tick(0.25);
         assert_eq!(t.elapsed(), 0.25);
@@ -183,7 +198,7 @@ mod tests {
 
     #[test]
     fn test_repeating() {
-        let mut t = Timer::from_seconds(2.0, true);
+        let mut t = Timer::<()>::from_seconds(2.0, true);
         // Tick once, check all attributes
         t.tick(0.75);
         assert_eq!(t.elapsed(), 0.75);

crates/bevy_diagnostic/src/print_diagnostics_plugin.rs

@@ -13,7 +13,7 @@ pub struct PrintDiagnosticsPlugin {
 
 /// State used by the [PrintDiagnosticsPlugin]
 pub struct PrintDiagnosticsState {
-    timer: Timer,
+    timer: Timer<PrintDiagnosticsPlugin>,
     filter: Option<Vec<DiagnosticId>>,
 }
 

crates/bevy_reflect/src/reflect.rs

@@ -75,3 +75,49 @@ impl dyn Reflect {
         self.any_mut().downcast_mut::<T>()
     }
 }
+
+impl<T: Send + Sync + 'static> Reflect for std::marker::PhantomData<T> {
+    fn type_name(&self) -> &str {
+        todo!()
+    }
+
+    fn any(&self) -> &dyn std::any::Any {
+        todo!()
+    }
+
+    fn any_mut(&mut self) -> &mut dyn std::any::Any {
+        todo!()
+    }
+
+    fn apply(&mut self, value: &dyn Reflect) {
+        todo!()
+    }
+
+    fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>> {
+        todo!()
+    }
+
+    fn reflect_ref(&self) -> ReflectRef {
+        todo!()
+    }
+
+    fn reflect_mut(&mut self) -> ReflectMut {
+        todo!()
+    }
+
+    fn clone_value(&self) -> Box<dyn Reflect> {
+        todo!()
+    }
+
+    fn reflect_hash(&self) -> Option<u64> {
+        todo!()
+    }
+
+    fn reflect_partial_eq(&self, _value: &dyn Reflect) -> Option<bool> {
+        todo!()
+    }
+
+    fn serializable(&self) -> Option<crate::serde::Serializable> {
+        todo!()
+    }
+}

examples/2d/contributors.rs

@@ -103,7 +103,10 @@ fn setup(
 
     sel.order.shuffle(&mut rnd);
 
-    commands.spawn((SelectTimer, Timer::from_seconds(SHOWCASE_TIMER_SECS, true)));
+    commands.spawn((Timer::<SelectTimer>::from_seconds(
+        SHOWCASE_TIMER_SECS,
+        true,
+    ),));
 
     commands
         .spawn((ContributorDisplay,))
@@ -132,7 +135,7 @@ fn select_system(
     mut materials: ResMut<Assets<ColorMaterial>>,
     mut sel: ResMut<ContributorSelection>,
     mut dq: Query<Mut<Text>, With<ContributorDisplay>>,
-    mut tq: Query<Mut<Timer>, With<SelectTimer>>,
+    mut tq: Query<Mut<Timer<SelectTimer>>>,
     mut q: Query<(&Contributor, &Handle<ColorMaterial>, &mut Transform)>,
     time: Res<Time>,
 ) {

examples/2d/sprite_sheet.rs

@@ -11,7 +11,11 @@ fn main() {
 fn animate_sprite_system(
     time: Res<Time>,
     texture_atlases: Res<Assets<TextureAtlas>>,
-    mut query: Query<(&mut Timer, &mut TextureAtlasSprite, &Handle<TextureAtlas>)>,
+    mut query: Query<(
+        &mut Timer<()>,
+        &mut TextureAtlasSprite,
+        &Handle<TextureAtlas>,
+    )>,
 ) {
     for (mut timer, mut sprite, texture_atlas_handle) in query.iter_mut() {
         timer.tick(time.delta_seconds());

examples/app/plugin.rs

@@ -35,7 +35,7 @@ impl Plugin for PrintMessagePlugin {
 
 struct PrintMessageState {
     message: String,
-    timer: Timer,
+    timer: Timer<()>,
 }
 
 fn print_message_system(mut state: ResMut<PrintMessageState>, time: Res<Time>) {

examples/ecs/event.rs

@@ -17,7 +17,7 @@ struct MyEvent {
 }
 
 struct EventTriggerState {
-    event_timer: Timer,
+    event_timer: Timer<()>,
 }
 
 impl Default for EventTriggerState {

examples/ecs/timers.rs

@@ -11,8 +11,8 @@ fn main() {
 }
 
 pub struct Countdown {
-    pub percent_trigger: Timer,
-    pub main_timer: Timer,
+    pub percent_trigger: Timer<()>,
+    pub main_timer: Timer<()>,
 }
 
 impl Countdown {
@@ -32,12 +32,12 @@ impl Default for Countdown {
 
 fn setup_system(commands: &mut Commands) {
     // Add an entity to the world with a timer
-    commands.spawn((Timer::from_seconds(5.0, false),));
+    commands.spawn((Timer::<()>::from_seconds(5.0, false),));
 }
 
 /// This system ticks all the `Timer` components on entities within the scene
 /// using bevy's `Time` resource to get the delta between each update.
-fn timer_system(time: Res<Time>, mut query: Query<&mut Timer>) {
+fn timer_system(time: Res<Time>, mut query: Query<&mut Timer<()>>) {
     for mut timer in query.iter_mut() {
         if timer.tick(time.delta_seconds()).just_finished() {
             info!("Entity timer just finished")

examples/ui/font_atlas_debug.rs

@@ -14,7 +14,7 @@ fn main() {
 struct State {
     atlas_count: u32,
     handle: Handle<Font>,
-    timer: Timer,
+    timer: Timer<()>,
 }
 
 impl Default for State {