Add widget: Brightness

- Use `/sys/class/backlight/` values

src/widgets/brightnesswidget.rs

@@ -0,0 +1,84 @@
+use super::common::run_cmd;
+use crate::TopBar;
+use slint::{ComponentHandle, SharedString, Timer, TimerMode};
+use std::{fs, time::Duration};
+
+/// Read a file and trim whitespace
+fn read_file(path: &str) -> Option<String> {
+    fs::read_to_string(path).ok().map(|s| s.trim().to_string())
+}
+
+/// Return (`brightness`, `max_brightness`)
+/// Use the first device listed under /sys/class/backlight/
+fn read_brightness_raw() -> Option<(u32, u32)> {
+    let base = "/sys/class/backlight";
+    let mut entries = fs::read_dir(base).ok()?;
+
+    // First device (intel_backlight, amdgpu_bl0, acpi_video0, etc.)
+    let dev = entries.next()?.ok()?.path();
+
+    let b = read_file(dev.join("brightness").to_str()?)?.parse().ok()?;
+    let m = read_file(dev.join("max_brightness").to_str()?)?
+        .parse()
+        .ok()?;
+
+    Some((b, m))
+}
+
+/// Convert brightness raw values into a 0–100% percentage
+fn brightness_percent() -> u8 {
+    if let Some((b, m)) = read_brightness_raw()
+        && m > 0
+    {
+        return ((b as f32 / m as f32) * 100.0).round() as u8;
+    }
+    0
+}
+
+/// Pick an icon based on percentage
+fn brightness_icon(p: u8) -> SharedString {
+    let icon = match p {
+        0 => "󰃞",       // off
+        1..=20 => "󰃝",  // low
+        21..=60 => "󰃟", // medium
+        _ => "󰃠",       // high
+    };
+    SharedString::from(icon)
+}
+
+/// Tooltip text displayed when hovering the icon
+fn brightness_tooltip(p: u8) -> String {
+    format!("Brightness: {p}%")
+}
+
+/// Start timer to update brightness every second
+fn start_brightness_updater(ui: &TopBar) {
+    let weak = ui.as_weak();
+
+    let timer = Box::leak(Box::new(Timer::default()));
+    timer.start(TimerMode::Repeated, Duration::from_secs(1), move || {
+        if let Some(ui) = weak.upgrade() {
+            // Read brightness
+            let p = brightness_percent();
+
+            // Update properties on the root component
+            ui.set_brightness_icon(brightness_icon(p));
+            ui.set_brightness_tooltip(brightness_tooltip(p).into());
+        }
+    });
+}
+
+/// Public entry for this widget
+pub fn install(ui: &TopBar) {
+    let weak = ui.as_weak();
+
+    // Click callback (open brightness settings)
+    ui.on_show_brightness(move || {
+        if weak.upgrade().is_some() {
+            run_cmd("xclock"); // Fix later
+        }
+    });
+
+    // Start updating
+    start_brightness_updater(ui);
+}

src/widgets/mod.rs

@@ -1,4 +1,5 @@
 mod batterywidget;
+mod brightnesswidget;
 mod common;
 mod datewidget;
 mod timewidget;
@@ -11,6 +12,7 @@ pub fn install_callbacks(ui: &TopBar) {
     datewidget::install(ui);
     batterywidget::install(ui);
     volumewidget::install(ui);
+    brightnesswidget::install(ui);
 
     // In the future:
     // networkwidget::install(ui);

ui/topbar.slint

@@ -27,7 +27,6 @@ export component TopBar inherits Window {
     in property <color> battery_bg_clicked;*/
     callback show_battery();
 
-
     // Volume widget
     in property <string> volume_tooltip;      
     in property <string> volume_icon;  
@@ -37,6 +36,15 @@ export component TopBar inherits Window {
     in property <color> volume_bg_clicked;*/
     callback show_volume();
 
+    // brightness widget
+    in property <string> brightness_tooltip;      
+    in property <string> brightness_icon;  
+    /*in property <color> brightness_icon_color;
+    in property <color> brightness_bg_normal;
+    in property <color> brightness_bg_hover;
+    in property <color> brightness_bg_clicked;*/
+    callback show_brightness();
+
     title: "chocobar";
     width: bar_width *1px;
     height: bar_height *1px;
@@ -81,6 +89,18 @@ export component TopBar inherits Window {
                 HorizontalLayout {
                     alignment: end; // Right-align
                     
+                    // SquareIconWidget - brightness
+                    SquareIconWidget {
+                        bar_height: root.bar_height;
+                        icon_text: root.brightness_icon;
+                        tooltip_text: root.brightness_tooltip;
+                        /*icon_color: root.brightness_icon_color;
+                        bg_normal: root.brightness_bg_normal;
+                        bg_hover: root.brightness_bg_hover;
+                        bg_clicked: root.brightness_bg_clicked;*/
+                        square_btn_callback => root.show_brightness();
+                    }
+                    
                     // SquareIconWidget - Volume
                     SquareIconWidget {
                         bar_height: root.bar_height;