Clock example (#997)

* Added clock example

* Formated and fixed clippy warnings

* Apply suggestions from code review

Co-authored-by: Marc Espin <[email protected]>

---------

Co-authored-by: Marc Espin <[email protected]>

examples/clock.rs

@@ -0,0 +1,106 @@
+use std::time::{
+    Duration,
+    SystemTime,
+    UNIX_EPOCH,
+};
+
+use freya::prelude::*;
+
+fn add_zero(time: i64) -> String {
+    if time.to_string().len() == 1 {
+        let mut zero = "0".to_owned();
+        zero.push_str(&time.to_string());
+        zero
+    } else {
+        time.to_string()
+    }
+}
+
+fn negative_add_zero(time: i64) -> String {
+    if time < 0 {
+        let number = add_zero(-time);
+        let mut minus = "-".to_owned();
+        minus.push_str(&number);
+        minus
+    } else {
+        add_zero(time)
+    }
+}
+
+fn format_time(time: &SystemTime, time_zone: i8) -> String {
+    let current_time =
+        time_zone as i64 * 3600 + time.duration_since(UNIX_EPOCH).unwrap().as_secs() as i64;
+    let seconds = add_zero(current_time.rem_euclid(60));
+    let minutes = add_zero(current_time.rem_euclid(3600) / 60);
+    let hours = add_zero(current_time.rem_euclid(86400) / 3600);
+    hours + ":" + &minutes + ":" + &seconds
+}
+
+fn app() -> Element {
+    let mut system_time = use_signal(SystemTime::now);
+    use_hook(move || {
+        spawn(async move {
+            let mut interval = tokio::time::interval(Duration::from_secs(1));
+
+            loop {
+                interval.tick().await;
+                system_time.set(SystemTime::now());
+            }
+        });
+    });
+
+    let mut time_zone = use_signal(|| 0);
+    let time = format_time(&system_time.read(), *time_zone.read());
+
+    rsx!(
+        rect {
+            height: "100%",
+            width: "100%",
+            main_align: "center",
+            cross_align: "center",
+            rect {
+                position: "absolute",
+                position_left: "0",
+                position_top: "0",
+                Dropdown {
+                    value: time_zone(),
+                    ScrollView {
+                        width: "200",
+                        height: "300",
+                        for i in -12..=14 {
+                            DropdownItem {
+                                value: i,
+                                onclick: move |_| time_zone.set(i),
+                                label {"UTC {negative_add_zero(i as i64)}:00"}
+                            }
+                        }
+                    }
+                }
+            }
+            rect {
+                corner_radius: "10",
+                main_align: "center",
+                background: "rgb(10, 90, 255)",
+                min_width: "500",
+                width: "90%",
+                height: "200",
+                label {
+                    font_family: "Consolas",
+                    text_align: "center",
+                    font_size: "100",
+                    "{time}"
+                }
+            }
+        }
+    )
+}
+
+fn main() {
+    launch_cfg(
+        app,
+        LaunchConfig::<()>::new()
+            .with_size(500.0, 400.0)
+            .with_min_size(500.0, 400.0)
+            .with_title("Clock"),
+    );
+}