aligning public apis of Time,Timer and Stopwatch (#15962)

Fixes #15834

## Migration Guide

The APIs of `Time`, `Timer` and `Stopwatch` have been cleaned up for
consistency with each other and the standard library's `Duration` type.
The following methods have been renamed:

- `Stowatch::paused` -> `Stopwatch::is_paused`
- `Time::elapsed_seconds` -> `Time::elasped_secs` (including `_f64` and
`_wrapped` variants)

crates/bevy_animation/src/lib.rs

@@ -1005,7 +1005,7 @@ pub fn advance_animations(
     animation_graphs: Res<Assets<AnimationGraph>>,
     mut players: Query<(&mut AnimationPlayer, &AnimationGraphHandle)>,
 ) {
-    let delta_seconds = time.delta_seconds();
+    let delta_seconds = time.delta_secs();
     players
         .par_iter_mut()
         .for_each(|(mut player, graph_handle)| {

crates/bevy_animation/src/transition.rs

@@ -122,7 +122,7 @@ pub fn advance_transitions(
         for transition in &mut animation_transitions.transitions.iter_mut().rev() {
             // Decrease weight.
             transition.current_weight = (transition.current_weight
-                - transition.weight_decline_per_sec * time.delta_seconds())
+                - transition.weight_decline_per_sec * time.delta_secs())
             .max(0.0);
 
             // Update weight.

crates/bevy_diagnostic/src/frame_time_diagnostics_plugin.rs

@@ -33,7 +33,7 @@ impl FrameTimeDiagnosticsPlugin {
     ) {
         diagnostics.add_measurement(&Self::FRAME_COUNT, || frame_count.0 as f64);
 
-        let delta_seconds = time.delta_seconds_f64();
+        let delta_seconds = time.delta_secs_f64();
         if delta_seconds == 0.0 {
             return;
         }

crates/bevy_render/src/globals.rs

@@ -74,8 +74,8 @@ fn prepare_globals_buffer(
     frame_count: Res<FrameCount>,
 ) {
     let buffer = globals_buffer.buffer.get_mut();
-    buffer.time = time.elapsed_seconds_wrapped();
-    buffer.delta_time = time.delta_seconds();
+    buffer.time = time.elapsed_secs_wrapped();
+    buffer.delta_time = time.delta_secs();
     buffer.frame_count = frame_count.0;
 
     globals_buffer

crates/bevy_time/src/stopwatch.rs

@@ -21,15 +21,15 @@ use bevy_utils::Duration;
 /// assert_eq!(stopwatch.elapsed_secs(), 1.0);
 ///
 /// stopwatch.reset(); // reset the stopwatch
-/// assert!(stopwatch.paused());
+/// assert!(stopwatch.is_paused());
 /// assert_eq!(stopwatch.elapsed_secs(), 0.0);
 /// ```
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
 #[cfg_attr(feature = "serialize", derive(serde::Deserialize, serde::Serialize))]
 #[cfg_attr(feature = "bevy_reflect", derive(Reflect), reflect(Default))]
 pub struct Stopwatch {
     elapsed: Duration,
-    paused: bool,
+    is_paused: bool,
 }
 
 impl Stopwatch {
@@ -40,7 +40,7 @@ impl Stopwatch {
     /// # use bevy_time::*;
     /// let stopwatch = Stopwatch::new();
     /// assert_eq!(stopwatch.elapsed_secs(), 0.0);
-    /// assert_eq!(stopwatch.paused(), false);
+    /// assert_eq!(stopwatch.is_paused(), false);
     /// ```
     pub fn new() -> Self {
         Default::default()
@@ -128,7 +128,7 @@ impl Stopwatch {
     /// assert_eq!(stopwatch.elapsed_secs(), 1.5);
     /// ```
     pub fn tick(&mut self, delta: Duration) -> &Self {
-        if !self.paused() {
+        if !self.is_paused() {
             self.elapsed = self.elapsed.saturating_add(delta);
         }
         self
@@ -144,12 +144,12 @@ impl Stopwatch {
     /// let mut stopwatch = Stopwatch::new();
     /// stopwatch.pause();
     /// stopwatch.tick(Duration::from_secs_f32(1.5));
-    /// assert!(stopwatch.paused());
+    /// assert!(stopwatch.is_paused());
     /// assert_eq!(stopwatch.elapsed_secs(), 0.0);
     /// ```
     #[inline]
     pub fn pause(&mut self) {
-        self.paused = true;
+        self.is_paused = true;
     }
 
     /// Unpauses the stopwatch. Resume the effect of ticking on elapsed time.
@@ -163,12 +163,12 @@ impl Stopwatch {
     /// stopwatch.tick(Duration::from_secs_f32(1.0));
     /// stopwatch.unpause();
     /// stopwatch.tick(Duration::from_secs_f32(1.0));
-    /// assert!(!stopwatch.paused());
+    /// assert!(!stopwatch.is_paused());
     /// assert_eq!(stopwatch.elapsed_secs(), 1.0);
     /// ```
     #[inline]
     pub fn unpause(&mut self) {
-        self.paused = false;
+        self.is_paused = false;
     }
 
     /// Returns `true` if the stopwatch is paused.
@@ -177,15 +177,15 @@ impl Stopwatch {
     /// ```
     /// # use bevy_time::*;
     /// let mut stopwatch = Stopwatch::new();
-    /// assert!(!stopwatch.paused());
+    /// assert!(!stopwatch.is_paused());
     /// stopwatch.pause();
-    /// assert!(stopwatch.paused());
+    /// assert!(stopwatch.is_paused());
     /// stopwatch.unpause();
-    /// assert!(!stopwatch.paused());
+    /// assert!(!stopwatch.is_paused());
     /// ```
     #[inline]
-    pub fn paused(&self) -> bool {
-        self.paused
+    pub fn is_paused(&self) -> bool {
+        self.is_paused
     }
 
     /// Resets the stopwatch. The reset doesn't affect the paused state of the stopwatch.