power: set color when battery power low.

src/colors.rs

@@ -0,0 +1,15 @@
+use i3monkit::ColorRGB;
+
+pub const WHITE: ColorRGB = ColorRGB(255, 255, 255);
+
+pub fn lerp(c1: ColorRGB, c2: ColorRGB, alpha: f32) -> ColorRGB {
+    ColorRGB(
+        (c1.0 as f32 * (1. - alpha) + c2.0 as f32 * alpha) as u8,
+        (c1.1 as f32 * (1. - alpha) + c2.1 as f32 * alpha) as u8,
+        (c1.2 as f32 * (1. - alpha) + c2.2 as f32 * alpha) as u8,
+    )
+}
+
+pub fn to_string(c: ColorRGB) -> String {
+    format!("#{:02x}{:02x}{:02x}", c.0, c.1, c.2)
+}

src/lib.rs

@@ -1,2 +1,3 @@
+pub mod colors;
 pub mod spark;
 pub mod widgets;

src/widgets/cpu.rs

@@ -4,7 +4,7 @@ use std::io::{BufRead, BufReader, Result};
 
 use i3monkit::{Block, ColorRGB, Widget, WidgetUpdate};
 
-use crate::spark;
+use crate::{colors, spark};
 
 #[derive(Debug)]
 struct Stat {
@@ -20,18 +20,6 @@ pub struct CpuWidget {
     history: Vec<VecDeque<f32>>,
 }
 
-fn color_lerp(c1: ColorRGB, c2: ColorRGB, alpha: f32) -> ColorRGB {
-    ColorRGB(
-        (c1.0 as f32 * (1. - alpha) + c2.0 as f32 * alpha) as u8,
-        (c1.1 as f32 * (1. - alpha) + c2.1 as f32 * alpha) as u8,
-        (c1.2 as f32 * (1. - alpha) + c2.2 as f32 * alpha) as u8,
-    )
-}
-
-fn color_to_string(c: ColorRGB) -> String {
-    format!("#{:02x}{:02x}{:02x}", c.0, c.1, c.2)
-}
-
 impl CpuWidget {
     fn read_status() -> Result<Vec<Stat>> {
         let file = File::open("/proc/stat")?;
@@ -92,10 +80,10 @@ impl CpuWidget {
                     .iter()
                     .zip(sg.chars())
                     .map(|(v, g)| {
-                        let c = color_lerp(ColorRGB::green(), ColorRGB::red(), *v);
+                        let c = colors::lerp(ColorRGB::green(), ColorRGB::red(), *v);
                         format!(
                             r##"<span foreground="{}">{}</span>"##,
-                            color_to_string(c),
+                            colors::to_string(c),
                             g
                         )
                     })

src/widgets/power.rs

@@ -13,9 +13,11 @@
 use std::collections::HashMap;
 
 use glob::glob;
-use i3monkit::{Block, Widget, WidgetUpdate};
+use i3monkit::{Block, ColorRGB, Widget, WidgetUpdate};
 use thiserror::Error;
 
+use crate::colors;
+
 #[derive(Debug, Default)]
 pub struct PowerSupply {}
 
@@ -71,14 +73,24 @@ impl PowerSupply {
             } else {
                 BATT_0
             };
+
+            let color = if cap >= 50 {
+                colors::WHITE
+            } else if cap >= 25 {
+                ColorRGB::yellow()
+            } else {
+                ColorRGB::red()
+            };
             res.push(format!(
-                "{} {}: <span face=\"pango:Font Awesome 5 Free\">{}</span>",
+                r##"{} {}: {}% <span color="{}" face="pango:Font Awesome 5 Free">{}</span>"##,
                 values
                     .get("POWER_SUPPLY_MANUFACTURER")
                     .unwrap_or(&"Unknown mfg"),
                 values
                     .get("POWER_SUPPLY_MODEL_NAME")
                     .unwrap_or(&"Unknown model"),
+                cap,
+                colors::to_string(color),
                 power,
             ));
         }