Update timer example

Signed-off-by: Michael X. Grey <[email protected]>

Author: mxgrey

examples/rclrs_timer_demo/src/rclrs_timer_demo.rs

@@ -5,12 +5,14 @@
 use rclrs::{create_node, Context, Node, RclrsError, Timer};
 use std::{
     env,
-    sync::{Arc, Mutex},
+    sync::Arc,
+    time::Duration,
 };
 
 /// Contains both the node and timer.
 struct SimpleTimerNode {
     node: Arc<Node>,
+    #[allow(unused)]
     timer: Arc<Timer>,
 }
 
@@ -20,29 +22,25 @@ impl SimpleTimerNode {
     /// The callback will simply print to stdout:
     /// "Drinking 🧉 for the xth time every p nanoseconds."
     /// where x is the iteration callback counter and p is the period of the timer.
-    fn new(context: &Context, timer_period_ns: i64) -> Result<Self, RclrsError> {
+    fn new(context: &Context, timer_period: Duration) -> Result<Self, RclrsError> {
         let node = create_node(context, "simple_timer_node")?;
-        let count: Arc<Mutex<i32>> = Arc::new(Mutex::new(0));
-        let timer = node.create_timer(
-            timer_period_ns,
-            context,
-            Some(Box::new(move |_| {
-                let x = *count.lock().unwrap();
+        let mut x = 0;
+        let timer = node.create_timer_repeating(
+            timer_period,
+            move || {
+                x += 1;
                 println!(
-                    "Drinking 🧉 for the {}th time every {} nanoseconds.",
-                    x, timer_period_ns
+                    "Drinking 🧉 for the {x}th time every {:?}.",
+                    timer_period,
                 );
-                *count.lock().unwrap() = x + 1;
-            })),
-            None,
+            },
         )?;
         Ok(Self { node, timer })
     }
 }
 
 fn main() -> Result<(), RclrsError> {
-    let timer_period: i64 = 1e9 as i64; // 1 seconds.
     let context = Context::new(env::args()).unwrap();
-    let simple_timer_node = Arc::new(SimpleTimerNode::new(&context, timer_period).unwrap());
+    let simple_timer_node = Arc::new(SimpleTimerNode::new(&context, Duration::from_secs(1)).unwrap());
     rclrs::spin(simple_timer_node.node.clone())
 }