Actually include battery file

src/tiles/battery.rs

@@ -0,0 +1,47 @@
+use crate::tile::Block;
+use futures::{future::try_join3, stream, Stream};
+use futures_util::StreamExt;
+use std::error::Error;
+use tokio::fs::File;
+use tokio::prelude::*;
+
+pub fn battery_stream() -> impl Stream<Item = Result<Block, Box<dyn Error + Send + Sync>>> {
+    stream::repeat(()).then(|()| async {
+        let charge_now = async {
+            let mut raw = String::new();
+            File::open("/sys/class/power_supply/BAT0/charge_now")
+                .await?
+                .read_to_string(&mut raw)
+                .await?;
+            let charge: u32 = raw.trim_end().parse()?;
+            Result::<_, Box<dyn Error + Send + Sync>>::Ok(charge)
+        };
+        let charge_total = async {
+            let mut raw = String::new();
+            File::open("/sys/class/power_supply/BAT0/charge_full")
+                .await?
+                .read_to_string(&mut raw)
+                .await?;
+            let charge: u32 = raw.trim_end().parse()?;
+            Result::<_, Box<dyn Error + Send + Sync>>::Ok(charge)
+        };
+        let status = async {
+            let mut raw = String::new();
+            File::open("/sys/class/power_supply/BAT0/status")
+                .await?
+                .read_to_string(&mut raw)
+                .await?;
+            raw.truncate(raw.trim_end().len());
+            Result::<_, Box<dyn Error + Send + Sync>>::Ok(raw)
+        };
+        let (charge_now, charge_total, status) =
+            try_join3(charge_now, charge_total, status).await?;
+        let percentage = charge_now * 100 / charge_total;
+        Ok(Block {
+            full_text: format!("{}% {}", percentage, status).into(),
+            short_text: format!("{}%", percentage).into_boxed_str().into(),
+            name: "battery".into(),
+            ..Default::default()
+        })
+    })
+}