Share ~/.config/hypr/monitors.json with the BOS Display panel

Read the file as the initial layout on start. After a successful
hyprctl apply (including applying a named profile), write pretty
JSON so Hyprland and bos-settings stay in sync. Profiles remain
named snapshots under ~/.config/breadmon/profiles/.

Pin bread-utils to bread-ecosystem v0.7.2.

Cargo.lock

@@ -33,8 +33,8 @@ dependencies = [
 
 [[package]]
 name = "bread-utils"
-version = "0.3.1"
+version = "0.7.2"
-source = "git+https://git.breadway.dev/Breadway/bread-ecosystem?tag=v0.7.1#db2fa3c4b4c1e6933bc5cf62a236d05972fdc886"
+source = "git+https://git.breadway.dev/Breadway/bread-ecosystem?tag=v0.7.2#30517f161724132cdeb658c04cf5e490be07ee73"
 dependencies = [
  "bread-shared",
  "dirs",

Cargo.toml

@@ -19,7 +19,7 @@ toml       = "0.8"
 anyhow     = "1"
 dirs       = "5"
 futures    = "0.3"
-bread-utils = { git = "https://git.breadway.dev/Breadway/bread-ecosystem", tag = "v0.7.1", features = ["bread-client"] }
+bread-utils = { git = "https://git.breadway.dev/Breadway/bread-ecosystem", tag = "v0.7.2", features = ["bread-client"] }
 
 [profile.release]
 lto = "thin"

EVENTS.md

@@ -14,9 +14,10 @@ connection (`BreadClient::emit` never blocks or errors the caller).
 
 This event is about breadmon's own live apply (`hyprctl eval
 'hl.monitor({...})'` on [BOS](https://git.breadway.dev/breadway/bos)-patched
-Hyprland). It is **not** fired by the `bos-settings` Display panel, which
+Hyprland). After that apply succeeds, breadmon also writes
-writes `~/.config/hypr/monitors.json` and is a separate store breadmon
+`~/.config/hypr/monitors.json` (the store shared with the `bos-settings`
-never reads or writes. Vanilla/upstream Hyprland has no `eval` request
+Display panel). The event is **not** fired by Display itself — that GUI
+only edits the JSON. Vanilla/upstream Hyprland has no `eval` request
 and no `hl.monitor()`, so apply fails there and this event is not
 published.
 

README.md

@@ -2,7 +2,7 @@
 
 A terminal UI monitor manager for Hyprland. Lets you position, configure, and mirror displays interactively, then apply a live layout on [BOS](https://git.breadway.dev/breadway/bos)-patched Hyprland.
 
-breadmon is **not** the Display panel in `bos-settings`. That panel edits `~/.config/hypr/monitors.json` (Hyprland's login/reload layout store). breadmon keeps its own named snapshots as TOML under `~/.config/breadmon/profiles/` and applies them live through BOS Hyprland. The two stores are independent — changing one does not update the other.
+The Display panel in `bos-settings` (GUI) and breadmon (TUI) share `~/.config/hypr/monitors.json` — the layout Hyprland reads at login/reload. Applying in breadmon writes that file so the settings app and the next session stay in sync. Named profiles remain optional snapshots under `~/.config/breadmon/profiles/`.
 
 ## Requirements
 
@@ -80,7 +80,7 @@ Finds the best common mode between two monitors and sets one to mirror the other
 
 ### Profiles
 
-Named snapshots of the current monitor configuration, stored as TOML files.
+Named snapshots of the current monitor configuration, stored as TOML files. Loading a profile updates the TUI; applying it (`a`) also writes `monitors.json`.
 
 | Key | Action |
 |-----|--------|
@@ -95,8 +95,8 @@ Profiles are saved to `~/.config/breadmon/profiles/`.
 
 | Key | Action |
 |-----|--------|
-| `a` | Apply current configuration via `hyprctl eval 'hl.monitor({...})'` (BOS-patched Hyprland only) |
+| `a` | Apply current configuration via `hyprctl eval 'hl.monitor({...})'` (BOS-patched Hyprland only) and write `~/.config/hypr/monitors.json` |
-| `s` | Save current configuration as a profile |
+| `s` | Write `~/.config/hypr/monitors.json` without a live apply |
 | `r` | Refresh monitor list from Hyprland |
 | `Ctrl+Z` | Undo last change (up to 20 steps) |
 | `q` / `Ctrl+C` | Quit (prompts once if there are unsaved changes) |
@@ -105,9 +105,19 @@ breadmon also listens on Hyprland's event socket and reloads the monitor list au
 
 ## Config
 
-Profiles are plain TOML files under `~/.config/breadmon/profiles/`. Each file records the monitor name, mode, position, scale, transform, VRR, DPMS, and mirror source. They are created and managed through the Profiles tab; there is no hand-written config file.
+**Shared store:** `~/.config/hypr/monitors.json` — the same file the bos-settings Display panel edits and Hyprland applies on login/reload. breadmon is the TUI; Display is the GUI. Schema:
 
-This is not `~/.config/hypr/monitors.json`. That file is the persistent Hyprland layout edited by the `bos-settings` Display panel and applied on login/reload. breadmon never reads or writes it.
+```json
+{
+  "monitors": [
+    { "output": "", "mode": "preferred", "position": "auto", "scale": "auto", "mirror": "<optional string>" }
+  ]
+}
+```
+
+Empty `output` is the wildcard default (any connector). breadmon loads this file on start (overlaid onto the live `hyprctl` list) and writes it — pretty JSON — after a successful apply, and when you press `s`.
+
+**Named snapshots:** plain TOML under `~/.config/breadmon/profiles/`. Each file records the monitor name, mode, position, scale, transform, VRR, DPMS, and mirror source. They are created and managed through the Profiles tab. Applying a profile writes `monitors.json` so Hyprland and Display stay in sync.
 
 ## bread event integration
 

src/layout.rs

@@ -196,7 +196,11 @@ mod tests {
         Monitor {
             name: name.into(),
             description: String::new(),
-            active_mode: Mode { width: w, height: h, refresh: 60.0 },
+            active_mode: Mode {
+                width: w,
+                height: h,
+                refresh: 60.0,
+            },
             x,
             y,
             scale: 1.0,

src/main.rs

@@ -3,6 +3,7 @@ mod layout;
 mod mirror;
 mod monitor;
 mod profile;
+mod store;
 mod ui;
 
 use std::io;
@@ -10,8 +11,7 @@ use std::io;
 use anyhow::Result;
 use crossterm::{
     event::{
-        DisableMouseCapture, EnableMouseCapture, Event, EventStream, KeyEventKind,
+        DisableMouseCapture, EnableMouseCapture, Event, EventStream, KeyEventKind, MouseEventKind,
-        MouseEventKind,
     },
     execute,
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
@@ -36,10 +36,15 @@ enum AppEvent {
 
 #[tokio::main]
 async fn main() -> Result<()> {
-    let monitors = monitor::load_monitors().await.unwrap_or_else(|e| {
+    let mut monitors = monitor::load_monitors().await.unwrap_or_else(|e| {
         eprintln!("Warning: could not load monitors: {}", e);
         vec![]
     });
+    match store::load() {
+        Ok(Some(file)) => store::apply_to_monitors(&file, &mut monitors),
+        Ok(None) => {}
+        Err(e) => eprintln!("Warning: could not load monitors.json: {}", e),
+    }
 
     // Terminal setup
     enable_raw_mode()?;
@@ -52,7 +57,11 @@ async fn main() -> Result<()> {
 
     // Restore terminal
     disable_raw_mode()?;
-    execute!(terminal.backend_mut(), LeaveAlternateScreen, DisableMouseCapture)?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
     terminal.show_cursor()?;
 
     result
@@ -162,23 +171,18 @@ async fn run(
                     crossterm::event::KeyCode::Char('s') => {
                         ui::layout_view::trigger_save(&mut state);
                     }
-                    crossterm::event::KeyCode::Char('r') => {
+                    crossterm::event::KeyCode::Char('r') => match monitor::load_monitors().await {
-                        match monitor::load_monitors().await {
+                        Ok(monitors) => {
-                            Ok(monitors) => {
+                            state.monitors = monitors;
-                                state.monitors = monitors;
+                            state.layout.clamp_selected(state.monitors.len());
-                                state.layout.clamp_selected(state.monitors.len());
+                            state.dirty = false;
-                                state.dirty = false;
+                            state.active_profile = None;
-                                state.active_profile = None;
+                            state.set_status("Monitors refreshed.", StatusLevel::Success);
-                                state.set_status("Monitors refreshed.", StatusLevel::Success);
-                            }
-                            Err(e) => {
-                                state.set_status(
-                                    format!("Refresh failed: {}", e),
-                                    StatusLevel::Error,
-                                );
-                            }
                         }
-                    }
+                        Err(e) => {
+                            state.set_status(format!("Refresh failed: {}", e), StatusLevel::Error);
+                        }
+                    },
                     _ => {
                         if !ui::handle_key(key, &mut state) {
                             break;
@@ -193,7 +197,18 @@ async fn run(
             match monitor::apply_monitors(&state.monitors).await {
                 Ok(()) => {
                     bread_events::emit_applied(state.active_profile.as_deref());
-                    state.set_status("Applied.", StatusLevel::Success);
+                    match store::save_from_monitors(&state.monitors) {
+                        Ok(()) => {
+                            state.dirty = false;
+                            state.set_status("Applied.", StatusLevel::Success);
+                        }
+                        Err(e) => {
+                            state.set_status(
+                                format!("Applied, but monitors.json write failed: {}", e),
+                                StatusLevel::Error,
+                            );
+                        }
+                    }
                 }
                 Err(e) => {
                     state.set_status(format!("Apply failed: {}", e), StatusLevel::Error);

src/mirror.rs

@@ -12,7 +12,11 @@ pub struct MirrorResult {
 }
 
 fn gcd(a: u32, b: u32) -> u32 {
-    if b == 0 { a } else { gcd(b, a % b) }
+    if b == 0 {
+        a
+    } else {
+        gcd(b, a % b)
+    }
 }
 
 fn reduced_ar(w: u32, h: u32) -> (u32, u32) {
@@ -35,7 +39,10 @@ pub fn find_mirror_modes(source: &Monitor, target: &Monitor) -> Option<MirrorRes
     // Group source modes by reduced AR
     let mut src_by_ar: HashMap<(u32, u32), Vec<&Mode>> = HashMap::new();
     for m in src_modes {
-        src_by_ar.entry(reduced_ar(m.width, m.height)).or_default().push(m);
+        src_by_ar
+            .entry(reduced_ar(m.width, m.height))
+            .or_default()
+            .push(m);
     }
 
     #[derive(Debug)]
@@ -53,8 +60,15 @@ pub fn find_mirror_modes(source: &Monitor, target: &Monitor) -> Option<MirrorRes
 
         if src_by_ar.contains_key(&tgt_ar) {
             // Check if we already have this exact pair
-            if !candidates.iter().any(|c| c.src_ar == tgt_ar && c.tgt_ar == tgt_ar && c.is_exact) {
+            if !candidates
-                candidates.push(Candidate { src_ar: tgt_ar, tgt_ar, is_exact: true });
+                .iter()
+                .any(|c| c.src_ar == tgt_ar && c.tgt_ar == tgt_ar && c.is_exact)
+            {
+                candidates.push(Candidate {
+                    src_ar: tgt_ar,
+                    tgt_ar,
+                    is_exact: true,
+                });
             }
             continue;
         }
@@ -63,9 +77,16 @@ pub fn find_mirror_modes(source: &Monitor, target: &Monitor) -> Option<MirrorRes
         for &s_ar in src_by_ar.keys() {
             let s_ratio = ratio_f64(s_ar);
             if (s_ratio - tgt_ratio).abs() / s_ratio < 0.05
-                && !candidates.iter().any(|c| c.src_ar == s_ar && c.tgt_ar == tgt_ar) {
+                && !candidates
-                    candidates.push(Candidate { src_ar: s_ar, tgt_ar, is_exact: false });
+                    .iter()
-                }
+                    .any(|c| c.src_ar == s_ar && c.tgt_ar == tgt_ar)
+            {
+                candidates.push(Candidate {
+                    src_ar: s_ar,
+                    tgt_ar,
+                    is_exact: false,
+                });
+            }
         }
     }
 
@@ -147,7 +168,10 @@ pub fn find_mirror_modes(source: &Monitor, target: &Monitor) -> Option<MirrorRes
         .collect();
 
     let chosen_refresh = if !exact_common.is_empty() {
-        exact_common.iter().copied().fold(f64::NEG_INFINITY, f64::max)
+        exact_common
+            .iter()
+            .copied()
+            .fold(f64::NEG_INFINITY, f64::max)
     } else {
         // Near-match within 1 Hz
         let near: Vec<f64> = src_refreshes
@@ -164,7 +188,10 @@ pub fn find_mirror_modes(source: &Monitor, target: &Monitor) -> Option<MirrorRes
             near.iter().copied().fold(f64::NEG_INFINITY, f64::max)
         } else {
             // Fallback: max source refresh
-            src_refreshes.iter().copied().fold(f64::NEG_INFINITY, f64::max)
+            src_refreshes
+                .iter()
+                .copied()
+                .fold(f64::NEG_INFINITY, f64::max)
         }
     };
 
@@ -217,7 +244,7 @@ pub fn refresh_match_label(result: &MirrorResult) -> &'static str {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::monitor::{Transform};
+    use crate::monitor::Transform;
 
     fn make_monitor_with_modes(name: &str, modes: Vec<Mode>) -> Monitor {
         let active = modes[0].clone();
@@ -240,7 +267,11 @@ mod tests {
     }
 
     fn m(w: u32, h: u32, r: f64) -> Mode {
-        Mode { width: w, height: h, refresh: r }
+        Mode {
+            width: w,
+            height: h,
+            refresh: r,
+        }
     }
 
     #[test]

src/monitor.rs

@@ -145,11 +145,15 @@ impl Monitor {
             .collect();
         // Sort descending by pixels then refresh for consistent ordering
         modes.sort_by(|a, b| {
-            b.pixels()
+            b.pixels().cmp(&a.pixels()).then(
-                .cmp(&a.pixels())
+                b.refresh
-                .then(b.refresh.partial_cmp(&a.refresh).unwrap_or(std::cmp::Ordering::Equal))
+                    .partial_cmp(&a.refresh)
+                    .unwrap_or(std::cmp::Ordering::Equal),
+            )
+        });
+        modes.dedup_by(|a, b| {
+            a.width == b.width && a.height == b.height && (a.refresh - b.refresh).abs() < 0.01
         });
-        modes.dedup_by(|a, b| a.width == b.width && a.height == b.height && (a.refresh - b.refresh).abs() < 0.01);
 
         let active_mode = Mode {
             width: raw.width,
@@ -214,8 +218,10 @@ impl Monitor {
         if self.physical_width_mm == 0 || self.physical_height_mm == 0 {
             return None;
         }
-        let diag_px = ((self.active_mode.width.pow(2) + self.active_mode.height.pow(2)) as f64).sqrt();
+        let diag_px =
-        let diag_mm = ((self.physical_width_mm.pow(2) + self.physical_height_mm.pow(2)) as f64).sqrt();
+            ((self.active_mode.width.pow(2) + self.active_mode.height.pow(2)) as f64).sqrt();
+        let diag_mm =
+            ((self.physical_width_mm.pow(2) + self.physical_height_mm.pow(2)) as f64).sqrt();
         Some(diag_px / (diag_mm / 25.4))
     }
 
@@ -268,8 +274,10 @@ pub async fn load_monitors() -> Result<Vec<Monitor>> {
 
     // Hyprland reports mirrorOf as a numeric ID string when using `monitors all`.
     // Resolve to monitor name so format_hypr_line emits the correct `mirror,<name>`.
-    let id_to_name: std::collections::HashMap<String, String> =
+    let id_to_name: std::collections::HashMap<String, String> = raw
-        raw.iter().map(|r| (r.id.to_string(), r.name.clone())).collect();
+        .iter()
+        .map(|r| (r.id.to_string(), r.name.clone()))
+        .collect();
 
     Ok(raw
         .into_iter()
@@ -284,6 +292,7 @@ pub async fn load_monitors() -> Result<Vec<Monitor>> {
         .collect())
 }
 
+#[cfg(test)]
 pub fn format_hypr_line(m: &Monitor) -> String {
     if let Some(src) = &m.mirror_of {
         format!(
@@ -444,7 +453,11 @@ mod tests {
 
     #[test]
     fn mode_compact_roundtrip() {
-        let m = Mode { width: 1920, height: 1080, refresh: 60.0 };
+        let m = Mode {
+            width: 1920,
+            height: 1080,
+            refresh: 60.0,
+        };
         let s = m.compact();
         let m2 = Mode::parse(&format!("{}Hz", s)).unwrap();
         assert_eq!(m.width, m2.width);
@@ -456,7 +469,11 @@ mod tests {
         let m = Monitor {
             name: "eDP-1".into(),
             description: String::new(),
-            active_mode: Mode { width: 1920, height: 1200, refresh: 60.0 },
+            active_mode: Mode {
+                width: 1920,
+                height: 1200,
+                refresh: 60.0,
+            },
             x: 0,
             y: 0,
             scale: 1.0,
@@ -480,7 +497,11 @@ mod tests {
         let m = Monitor {
             name: "HDMI-A-1".into(),
             description: String::new(),
-            active_mode: Mode { width: 1920, height: 1080, refresh: 60.0 },
+            active_mode: Mode {
+                width: 1920,
+                height: 1080,
+                refresh: 60.0,
+            },
             x: 1920,
             y: 0,
             scale: 1.0,

src/profile.rs

@@ -77,8 +77,7 @@ pub fn list() -> Result<Vec<String>> {
 
 pub fn delete(name: &str) -> Result<()> {
     let path = profiles_dir().join(format!("{}.toml", name));
-    std::fs::remove_file(&path)
+    std::fs::remove_file(&path).with_context(|| format!("failed to delete profile '{}'", name))
-        .with_context(|| format!("failed to delete profile '{}'", name))
 }
 
 pub fn from_monitors(name: &str, monitors: &[Monitor]) -> Profile {
@@ -150,7 +149,11 @@ mod tests {
         Monitor {
             name: name.into(),
             description: String::new(),
-            active_mode: Mode { width: w, height: h, refresh: 60.0 },
+            active_mode: Mode {
+                width: w,
+                height: h,
+                refresh: 60.0,
+            },
             x,
             y,
             scale: 1.0,

src/store.rs

@@ -0,0 +1,369 @@
+//! Shared Hyprland layout store: `~/.config/hypr/monitors.json`.
+//!
+//! Same schema as bos-settings `MonitorRule` and
+//! `iso/airootfs/etc/skel/.config/hypr/scripts/display/monitors.lua`.
+//! Empty `output` is the wildcard default (matches any connector).
+
+use anyhow::{Context, Result};
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+use crate::monitor::{Mode, Monitor};
+
+fn default_mode() -> String {
+    "preferred".to_string()
+}
+fn default_position() -> String {
+    "auto".to_string()
+}
+fn default_scale() -> String {
+    "auto".to_string()
+}
+
+/// One `hl.monitor()` rule. Field names and defaults must stay in sync with
+/// bos-settings `MonitorRule` and the ISO `monitors.lua` loader.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct MonitorRule {
+    pub output: String,
+    #[serde(default = "default_mode")]
+    pub mode: String,
+    #[serde(default = "default_position")]
+    pub position: String,
+    #[serde(default = "default_scale")]
+    pub scale: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub mirror: Option<String>,
+}
+
+impl Default for MonitorRule {
+    fn default() -> Self {
+        Self {
+            output: String::new(),
+            mode: default_mode(),
+            position: default_position(),
+            scale: default_scale(),
+            mirror: None,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct MonitorsFile {
+    #[serde(default)]
+    pub monitors: Vec<MonitorRule>,
+}
+
+impl Default for MonitorsFile {
+    fn default() -> Self {
+        Self {
+            monitors: vec![MonitorRule::default()],
+        }
+    }
+}
+
+/// `~/.config/hypr/monitors.json` — same path Hyprland and bos-settings use.
+pub fn config_path() -> PathBuf {
+    bread_utils::xdg::config_dir("hypr").join("monitors.json")
+}
+
+pub fn load() -> Result<Option<MonitorsFile>> {
+    load_from(&config_path())
+}
+
+pub fn load_from(path: &Path) -> Result<Option<MonitorsFile>> {
+    if !path.exists() {
+        return Ok(None);
+    }
+    let content = std::fs::read_to_string(path)
+        .with_context(|| format!("failed to read {}", path.display()))?;
+    let file: MonitorsFile = serde_json::from_str(&content)
+        .with_context(|| format!("failed to parse {}", path.display()))?;
+    // Empty file ≡ missing: Lua falls back to the wildcard default rather
+    // than applying zero rules (which can black-screen the session).
+    if file.monitors.is_empty() {
+        return Ok(None);
+    }
+    Ok(Some(file))
+}
+
+pub fn save(file: &MonitorsFile) -> Result<()> {
+    save_to(&config_path(), file)
+}
+
+pub fn save_to(path: &Path, file: &MonitorsFile) -> Result<()> {
+    let json = serde_json::to_string_pretty(file).context("failed to serialize monitors.json")?;
+    bread_utils::atomic::write_atomic_backed_up(path, &json)
+        .with_context(|| format!("failed to write {}", path.display()))
+}
+
+pub fn save_from_monitors(monitors: &[Monitor]) -> Result<()> {
+    save(&from_monitors(monitors))
+}
+
+/// Persist the TUI layout as named `hl.monitor()` rules. Mirror slaves are
+/// omitted (mirror is recorded on the source, matching `hl.monitor()`). If
+/// nothing is writable, emit the wildcard default so the file is never empty.
+pub fn from_monitors(monitors: &[Monitor]) -> MonitorsFile {
+    let mut source_to_slave: HashMap<&str, &str> = HashMap::new();
+    for m in monitors {
+        if let Some(src) = &m.mirror_of {
+            source_to_slave.insert(src.as_str(), m.name.as_str());
+        }
+    }
+
+    let mut rules = Vec::new();
+    for m in monitors {
+        if m.disabled || m.mirror_of.is_some() {
+            continue;
+        }
+        let refresh = (m.active_mode.refresh + 0.5) as u32;
+        rules.push(MonitorRule {
+            output: m.name.clone(),
+            mode: format!(
+                "{}x{}@{}",
+                m.active_mode.width, m.active_mode.height, refresh
+            ),
+            position: format!("{}x{}", m.x, m.y),
+            scale: format!("{:.2}", m.scale),
+            mirror: source_to_slave
+                .get(m.name.as_str())
+                .map(|s| (*s).to_owned()),
+        });
+    }
+
+    if rules.is_empty() {
+        MonitorsFile::default()
+    } else {
+        MonitorsFile { monitors: rules }
+    }
+}
+
+/// Overlay persisted rules onto live `hyprctl` monitors (matched by name;
+/// empty `output` is the wildcard fallback). `preferred` / `auto` leave the
+/// live value. A file with at least one named output is treated as a full
+/// layout and replaces live mirrors; a wildcard-only file does not.
+pub fn apply_to_monitors(file: &MonitorsFile, monitors: &mut [Monitor]) {
+    let has_specific = file.monitors.iter().any(|r| !r.output.is_empty());
+    if has_specific {
+        for m in monitors.iter_mut() {
+            m.mirror_of = None;
+        }
+        for rule in &file.monitors {
+            let Some(slave_name) = rule.mirror.as_deref().filter(|s| !s.is_empty()) else {
+                continue;
+            };
+            if rule.output.is_empty() {
+                continue;
+            }
+            if let Some(slave) = monitors.iter_mut().find(|m| m.name == slave_name) {
+                slave.mirror_of = Some(rule.output.clone());
+            }
+        }
+    }
+
+    for m in monitors.iter_mut() {
+        if let Some(rule) = find_rule(&file.monitors, &m.name) {
+            apply_rule_fields(m, rule);
+        }
+    }
+}
+
+fn find_rule<'a>(rules: &'a [MonitorRule], name: &str) -> Option<&'a MonitorRule> {
+    rules
+        .iter()
+        .find(|r| r.output == name)
+        .or_else(|| rules.iter().find(|r| r.output.is_empty()))
+}
+
+fn apply_rule_fields(m: &mut Monitor, rule: &MonitorRule) {
+    if rule.mode != "preferred" {
+        if let Some(mode) =
+            Mode::parse(&format!("{}Hz", rule.mode)).or_else(|| Mode::parse(&rule.mode))
+        {
+            m.active_mode = mode;
+        }
+    }
+    if rule.position != "auto" {
+        if let Some((x, y)) = parse_position(&rule.position) {
+            m.x = x;
+            m.y = y;
+        }
+    }
+    if rule.scale != "auto" {
+        if let Ok(scale) = rule.scale.parse::<f64>() {
+            if scale > 0.0 {
+                m.scale = scale;
+            }
+        }
+    }
+}
+
+fn parse_position(s: &str) -> Option<(i32, i32)> {
+    let (x, y) = s.split_once('x')?;
+    Some((x.parse().ok()?, y.parse().ok()?))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::monitor::Transform;
+
+    fn make_monitor(name: &str, w: u32, h: u32, x: i32, y: i32) -> Monitor {
+        Monitor {
+            name: name.into(),
+            description: String::new(),
+            active_mode: Mode {
+                width: w,
+                height: h,
+                refresh: 60.0,
+            },
+            x,
+            y,
+            scale: 1.0,
+            transform: Transform::Normal,
+            vrr: false,
+            dpms: true,
+            disabled: false,
+            mirror_of: None,
+            available_modes: vec![],
+            physical_width_mm: 0,
+            physical_height_mm: 0,
+        }
+    }
+
+    #[test]
+    fn iso_default_parses() {
+        let json = r#"{
+  "monitors": [
+    { "output": "", "mode": "preferred", "position": "auto", "scale": "auto" }
+  ]
+}"#;
+        let file: MonitorsFile = serde_json::from_str(json).unwrap();
+        assert_eq!(file.monitors.len(), 1);
+        assert_eq!(file.monitors[0], MonitorRule::default());
+    }
+
+    #[test]
+    fn pretty_roundtrip_omits_absent_mirror() {
+        let file = MonitorsFile::default();
+        let json = serde_json::to_string_pretty(&file).unwrap();
+        assert!(json.contains("\"output\": \"\""));
+        assert!(json.contains("\"mode\": \"preferred\""));
+        assert!(!json.contains("mirror"));
+        let back: MonitorsFile = serde_json::from_str(&json).unwrap();
+        assert_eq!(file, back);
+    }
+
+    #[test]
+    fn from_monitors_writes_named_rules_and_source_mirror() {
+        let mut hdmi = make_monitor("HDMI-A-1", 1920, 1080, 1920, 0);
+        hdmi.mirror_of = Some("eDP-1".into());
+        let file = from_monitors(&[make_monitor("eDP-1", 1920, 1200, 0, 0), hdmi]);
+        assert_eq!(file.monitors.len(), 1);
+        let rule = &file.monitors[0];
+        assert_eq!(rule.output, "eDP-1");
+        assert_eq!(rule.mode, "1920x1200@60");
+        assert_eq!(rule.position, "0x0");
+        assert_eq!(rule.scale, "1.00");
+        assert_eq!(rule.mirror.as_deref(), Some("HDMI-A-1"));
+    }
+
+    #[test]
+    fn from_monitors_empty_or_all_slaves_emits_wildcard() {
+        let mut only_slave = make_monitor("HDMI-A-1", 1920, 1080, 0, 0);
+        only_slave.mirror_of = Some("missing".into());
+        assert_eq!(from_monitors(&[]), MonitorsFile::default());
+        assert_eq!(from_monitors(&[only_slave]), MonitorsFile::default());
+    }
+
+    #[test]
+    fn wildcard_overlay_leaves_live_geometry_and_mirrors() {
+        let file = MonitorsFile::default();
+        let mut monitors = vec![make_monitor("eDP-1", 1920, 1200, 10, 20)];
+        monitors[0].scale = 1.5;
+        monitors[0].mirror_of = Some("HDMI-A-1".into());
+        apply_to_monitors(&file, &mut monitors);
+        assert_eq!(monitors[0].x, 10);
+        assert_eq!(monitors[0].y, 20);
+        assert!((monitors[0].scale - 1.5).abs() < f64::EPSILON);
+        assert_eq!(monitors[0].mirror_of.as_deref(), Some("HDMI-A-1"));
+    }
+
+    #[test]
+    fn specific_overlay_applies_fields_and_replaces_mirrors() {
+        let file = MonitorsFile {
+            monitors: vec![
+                MonitorRule {
+                    output: "eDP-1".into(),
+                    mode: "1920x1200@60".into(),
+                    position: "0x0".into(),
+                    scale: "1.25".into(),
+                    mirror: Some("HDMI-A-1".into()),
+                },
+                MonitorRule {
+                    output: "DP-1".into(),
+                    mode: "2560x1440@144".into(),
+                    position: "-2560x0".into(),
+                    scale: "1".into(),
+                    mirror: None,
+                },
+            ],
+        };
+        let mut monitors = vec![
+            make_monitor("eDP-1", 1600, 900, 100, 100),
+            make_monitor("HDMI-A-1", 1920, 1080, 200, 0),
+            make_monitor("DP-1", 1920, 1080, 300, 0),
+        ];
+        monitors[1].mirror_of = Some("DP-1".into());
+        apply_to_monitors(&file, &mut monitors);
+
+        assert_eq!(monitors[0].active_mode.width, 1920);
+        assert_eq!(monitors[0].active_mode.height, 1200);
+        assert!((monitors[0].active_mode.refresh - 60.0).abs() < 0.01);
+        assert_eq!(monitors[0].x, 0);
+        assert_eq!(monitors[0].y, 0);
+        assert!((monitors[0].scale - 1.25).abs() < f64::EPSILON);
+
+        assert_eq!(monitors[1].mirror_of.as_deref(), Some("eDP-1"));
+
+        assert_eq!(monitors[2].active_mode.width, 2560);
+        assert_eq!(monitors[2].x, -2560);
+        assert!(monitors[2].mirror_of.is_none());
+    }
+
+    #[test]
+    fn load_from_missing_or_empty_is_none() {
+        let dir = std::env::temp_dir().join(format!(
+            "breadmon-store-test-{}-{}",
+            std::process::id(),
+            "empty"
+        ));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let missing = dir.join("nope.json");
+        assert!(load_from(&missing).unwrap().is_none());
+
+        let empty = dir.join("empty.json");
+        std::fs::write(&empty, "{ \"monitors\": [] }\n").unwrap();
+        assert!(load_from(&empty).unwrap().is_none());
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn save_to_roundtrips() {
+        let dir = std::env::temp_dir().join(format!(
+            "breadmon-store-test-{}-{}",
+            std::process::id(),
+            "save"
+        ));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        let path = dir.join("monitors.json");
+        let file = from_monitors(&[make_monitor("eDP-1", 1920, 1200, 0, 0)]);
+        save_to(&path, &file).unwrap();
+        let loaded = load_from(&path).unwrap().unwrap();
+        assert_eq!(loaded, file);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+}

src/ui/config_view.rs

@@ -125,7 +125,10 @@ impl ConfigState {
     }
 
     fn prev_field(&mut self) {
-        self.focused = self.focused.checked_sub(1).unwrap_or(ConfigField::ALL.len() - 1);
+        self.focused = self
+            .focused
+            .checked_sub(1)
+            .unwrap_or(ConfigField::ALL.len() - 1);
     }
 }
 
@@ -314,14 +317,22 @@ fn handle_field_key(event: KeyEvent, state: &mut AppState) {
             _ => {}
         },
         ConfigField::Vrr => match event.code {
-            KeyCode::Char('h') | KeyCode::Left | KeyCode::Char('l') | KeyCode::Right | KeyCode::Char(' ') => {
+            KeyCode::Char('h')
+            | KeyCode::Left
+            | KeyCode::Char('l')
+            | KeyCode::Right
+            | KeyCode::Char(' ') => {
                 state.monitors[idx].vrr = !state.monitors[idx].vrr;
                 state.mark_dirty();
             }
             _ => {}
         },
         ConfigField::Dpms => match event.code {
-            KeyCode::Char('h') | KeyCode::Left | KeyCode::Char('l') | KeyCode::Right | KeyCode::Char(' ') => {
+            KeyCode::Char('h')
+            | KeyCode::Left
+            | KeyCode::Char('l')
+            | KeyCode::Right
+            | KeyCode::Char(' ') => {
                 state.monitors[idx].dpms = !state.monitors[idx].dpms;
                 state.mark_dirty();
             }
@@ -358,7 +369,11 @@ fn sync_mode_to_monitor(state: &mut AppState, idx: usize) {
 }
 
 fn sync_mirror_to_monitor(state: &mut AppState, idx: usize) {
-    let chosen = state.config.mirror_options.get(state.config.mirror_idx).cloned();
+    let chosen = state
+        .config
+        .mirror_options
+        .get(state.config.mirror_idx)
+        .cloned();
     state.monitors[idx].mirror_of = match chosen.as_deref() {
         Some("(none)") | None => None,
         Some(s) => Some(s.to_owned()),
@@ -366,7 +381,10 @@ fn sync_mirror_to_monitor(state: &mut AppState, idx: usize) {
 }
 
 fn commit_scale(state: &mut AppState) {
-    let idx = state.config.monitor_idx.min(state.monitors.len().saturating_sub(1));
+    let idx = state
+        .config
+        .monitor_idx
+        .min(state.monitors.len().saturating_sub(1));
     if let Ok(v) = state.config.scale_str.parse::<f64>() {
         state.monitors[idx].scale = v.clamp(0.1, 10.0);
         state.config.scale_str = format!("{:.2}", state.monitors[idx].scale);
@@ -405,7 +423,11 @@ pub fn render(f: &mut Frame, area: Rect, state: &AppState) {
     };
     let header = format!(" {} — {}{}", m.name, m.description, ppi_hint);
     f.render_widget(
-        Paragraph::new(header).style(Style::default().fg(Color::White).add_modifier(Modifier::BOLD)),
+        Paragraph::new(header).style(
+            Style::default()
+                .fg(Color::White)
+                .add_modifier(Modifier::BOLD),
+        ),
         chunks[0],
     );
 
@@ -463,20 +485,31 @@ fn field_value(field: ConfigField, state: &AppState, m: &Monitor) -> String {
         }
         ConfigField::Scale => {
             if state.config.scale_editing {
-                format!("{}|  (Enter to commit, ,/. for ±0.1)", state.config.scale_str)
+                format!(
+                    "{}|  (Enter to commit, ,/. for ±0.1)",
+                    state.config.scale_str
+                )
             } else {
                 format!("{}  (,/. for ±0.1)", state.config.scale_str)
             }
         }
         ConfigField::Transform => Transform::all()
             [state.config.transform_idx.min(Transform::all().len() - 1)]
-            .label()
+        .label()
-            .to_owned(),
+        .to_owned(),
         ConfigField::Vrr => {
-            if m.vrr { "ON".to_owned() } else { "OFF".to_owned() }
+            if m.vrr {
+                "ON".to_owned()
+            } else {
+                "OFF".to_owned()
+            }
         }
         ConfigField::Dpms => {
-            if m.dpms { "ON".to_owned() } else { "OFF".to_owned() }
+            if m.dpms {
+                "ON".to_owned()
+            } else {
+                "OFF".to_owned()
+            }
         }
         ConfigField::MirrorOf => state
             .config

src/ui/layout_view.rs

@@ -8,7 +8,10 @@ use ratatui::{
 };
 
 use crate::{
-    layout::{auto_arrange, bounding_box, canvas_scale, canvas_to_world, move_selected, snap_position, world_to_canvas},
+    layout::{
+        auto_arrange, bounding_box, canvas_scale, canvas_to_world, move_selected, snap_position,
+        world_to_canvas,
+    },
     monitor::Monitor,
     ui::{AppState, DragState, StatusLevel, Tab},
 };
@@ -49,7 +52,9 @@ pub fn handle_key(event: KeyEvent, state: &mut AppState) {
             state.mark_dirty();
         }
         KeyCode::Enter => {
-            state.config.sync_from_monitor(state.layout.selected, &state.monitors);
+            state
+                .config
+                .sync_from_monitor(state.layout.selected, &state.monitors);
             state.tab = Tab::Config;
         }
         _ => {}
@@ -66,7 +71,8 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
             if let Some(idx) = monitor_at(col, row, canvas, state) {
                 let (min_x, min_y, _, _) = bounding_box(&state.monitors);
                 let scale = canvas_scale_for(canvas, state);
-                let (wx, wy) = canvas_to_world(col, row, scale, min_x, min_y, canvas.x + 1, canvas.y + 1);
+                let (wx, wy) =
+                    canvas_to_world(col, row, scale, min_x, min_y, canvas.x + 1, canvas.y + 1);
 
                 // Push undo at drag start, not on every move
                 state.push_undo();
@@ -85,12 +91,19 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
                 let canvas = canvas_area(state.terminal_size);
                 let (min_x, min_y, _, _) = bounding_box(&state.monitors);
                 let scale = canvas_scale_for(canvas, state);
-                let (wx, wy) = canvas_to_world(col, row, scale, min_x, min_y, canvas.x + 1, canvas.y + 1);
+                let (wx, wy) =
+                    canvas_to_world(col, row, scale, min_x, min_y, canvas.x + 1, canvas.y + 1);
 
                 let idx = drag.monitor_idx;
                 let new_x = drag.origin_x + (wx - drag.click_world_x);
                 let new_y = drag.origin_y + (wy - drag.click_world_y);
-                let (sx, sy) = snap_position(idx, new_x, new_y, &state.monitors, state.layout.snap_threshold);
+                let (sx, sy) = snap_position(
+                    idx,
+                    new_x,
+                    new_y,
+                    &state.monitors,
+                    state.layout.snap_threshold,
+                );
                 state.monitors[idx].x = sx;
                 state.monitors[idx].y = sy;
                 state.mark_dirty();
@@ -162,18 +175,31 @@ fn render_canvas(f: &mut Frame, area: Rect, state: &AppState) {
             continue;
         }
 
-        let rect = Rect { x: cx, y: cy, width: cw, height: ch };
+        let rect = Rect {
+            x: cx,
+            y: cy,
+            width: cw,
+            height: ch,
+        };
 
         let is_selected = i == selected;
-        let is_dragging = state.drag_state.as_ref().map(|d| d.monitor_idx == i).unwrap_or(false);
+        let is_dragging = state
+            .drag_state
+            .as_ref()
+            .map(|d| d.monitor_idx == i)
+            .unwrap_or(false);
         let is_overlapping = overlapping[i];
 
         let border_style = if is_dragging {
-            Style::default().fg(Color::Magenta).add_modifier(Modifier::BOLD)
+            Style::default()
+                .fg(Color::Magenta)
+                .add_modifier(Modifier::BOLD)
         } else if is_overlapping {
             Style::default().fg(Color::Red).add_modifier(Modifier::BOLD)
         } else if is_selected {
-            Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+            Style::default()
+                .fg(Color::Yellow)
+                .add_modifier(Modifier::BOLD)
         } else {
             Style::default().fg(Color::Blue)
         };
@@ -190,7 +216,10 @@ fn render_canvas(f: &mut Frame, area: Rect, state: &AppState) {
             })
             .border_style(border_style)
             .title(Span::styled(&label, border_style))
-            .title_bottom(Span::styled(&mode_str, Style::default().fg(Color::DarkGray)));
+            .title_bottom(Span::styled(
+                &mode_str,
+                Style::default().fg(Color::DarkGray),
+            ));
 
         f.render_widget(block, rect);
     }
@@ -203,7 +232,9 @@ fn render_readout(f: &mut Frame, area: Rect, state: &AppState) {
     let idx = state.layout.selected.min(state.monitors.len() - 1);
     let m = &state.monitors[idx];
 
-    let mirror_info = m.mirror_of.as_ref()
+    let mirror_info = m
+        .mirror_of
+        .as_ref()
         .map(|src| format!("  mirror:{}", src))
         .unwrap_or_default();
 
@@ -213,14 +244,24 @@ fn render_readout(f: &mut Frame, area: Rect, state: &AppState) {
         ""
     };
 
-    let drag_hint = if state.drag_state.is_some() { "  [dragging]" } else { "" };
+    let drag_hint = if state.drag_state.is_some() {
+        "  [dragging]"
+    } else {
+        ""
+    };
 
     let text = format!(
         " {}  x:{}  y:{}  {}x{}@{:.0}Hz  scale:{:.2}{}{}{}",
-        m.name, m.x, m.y,
+        m.name,
-        m.active_mode.width, m.active_mode.height, m.active_mode.refresh,
+        m.x,
+        m.y,
+        m.active_mode.width,
+        m.active_mode.height,
+        m.active_mode.refresh,
         m.scale,
-        mirror_info, overlap_warn, drag_hint,
+        mirror_info,
+        overlap_warn,
+        drag_hint,
     );
     f.render_widget(
         Paragraph::new(text).style(Style::default().fg(Color::Cyan)),
@@ -235,8 +276,10 @@ fn overlapping_monitors(monitors: &[Monitor]) -> Vec<bool> {
         for j in (i + 1)..monitors.len() {
             let a = &monitors[i];
             let b = &monitors[j];
-            if a.x < b.right_edge() && a.right_edge() > b.x
+            if a.x < b.right_edge()
-                && a.y < b.bottom_edge() && a.bottom_edge() > b.y
+                && a.right_edge() > b.x
+                && a.y < b.bottom_edge()
+                && a.bottom_edge() > b.y
             {
                 flags[i] = true;
                 flags[j] = true;
@@ -301,31 +344,13 @@ fn monitor_at(col: u16, row: u16, canvas: Rect, state: &AppState) -> Option<usiz
 }
 
 pub fn trigger_save(state: &mut AppState) {
-    use crate::monitor::format_hypr_line;
+    match crate::store::save_from_monitors(&state.monitors) {
-    use std::path::PathBuf;
-
-    let path: PathBuf = dirs::config_dir()
-        .unwrap_or_else(|| PathBuf::from(std::env::var("HOME").unwrap_or_default()))
-        .join("hypr/monitors.conf");
-
-    let is_new = !path.exists();
-    let mut lines = vec!["# Generated by breadmon — do not edit by hand".to_owned()];
-    for m in &state.monitors {
-        lines.push(format_hypr_line(m));
-    }
-    let content = lines.join("\n") + "\n";
-
-    match std::fs::write(&path, &content) {
         Ok(()) => {
-            if is_new {
-                state.set_status(
-                    format!("Saved. Add: source = {} to hyprland.conf", path.display()),
-                    StatusLevel::Success,
-                );
-            } else {
-                state.set_status(format!("Saved to {}", path.display()), StatusLevel::Success);
-            }
             state.dirty = false;
+            state.set_status(
+                format!("Saved to {}", crate::store::config_path().display()),
+                StatusLevel::Success,
+            );
         }
         Err(e) => state.set_status(format!("Save failed: {}", e), StatusLevel::Error),
     }

src/ui/mirror_view.rs

@@ -45,7 +45,9 @@ impl MirrorState {
     fn next_field(&mut self) {
         // Skip Apply/Cancel if no result yet
         let mut next = (self.focused + 1) % FIELDS.len();
-        if self.result.is_none() && (FIELDS[next] == MirrorField::Apply || FIELDS[next] == MirrorField::Cancel) {
+        if self.result.is_none()
+            && (FIELDS[next] == MirrorField::Apply || FIELDS[next] == MirrorField::Cancel)
+        {
             next = 0;
         }
         self.focused = next;
@@ -54,8 +56,13 @@ impl MirrorState {
     fn prev_field(&mut self) {
         let len = FIELDS.len();
         let mut prev = self.focused.checked_sub(1).unwrap_or(len - 1);
-        if self.result.is_none() && (FIELDS[prev] == MirrorField::Apply || FIELDS[prev] == MirrorField::Cancel) {
+        if self.result.is_none()
-            prev = FIELDS.iter().position(|&f| f == MirrorField::Compute).unwrap_or(2);
+            && (FIELDS[prev] == MirrorField::Apply || FIELDS[prev] == MirrorField::Cancel)
+        {
+            prev = FIELDS
+                .iter()
+                .position(|&f| f == MirrorField::Compute)
+                .unwrap_or(2);
         }
         self.focused = prev;
     }
@@ -86,12 +93,14 @@ pub fn handle_key(event: KeyEvent, state: &mut AppState) {
         }
         KeyCode::Char('h') | KeyCode::Left => match state.mirror.current_field() {
             MirrorField::Source => {
-                state.mirror.source_idx = state.mirror.source_idx.checked_sub(1).unwrap_or(count - 1);
+                state.mirror.source_idx =
+                    state.mirror.source_idx.checked_sub(1).unwrap_or(count - 1);
                 state.mirror.fix_indices(count);
                 state.mirror.result = None;
             }
             MirrorField::Target => {
-                state.mirror.target_idx = state.mirror.target_idx.checked_sub(1).unwrap_or(count - 1);
+                state.mirror.target_idx =
+                    state.mirror.target_idx.checked_sub(1).unwrap_or(count - 1);
                 state.mirror.fix_indices(count);
                 state.mirror.result = None;
             }
@@ -118,7 +127,10 @@ pub fn handle_key(event: KeyEvent, state: &mut AppState) {
                     Some(result) => {
                         state.mirror.result = Some(result);
                         // Move focus to Apply
-                        state.mirror.focused = FIELDS.iter().position(|&f| f == MirrorField::Apply).unwrap_or(3);
+                        state.mirror.focused = FIELDS
+                            .iter()
+                            .position(|&f| f == MirrorField::Apply)
+                            .unwrap_or(3);
                     }
                     None => {
                         state.set_status(
@@ -143,9 +155,7 @@ pub fn handle_key(event: KeyEvent, state: &mut AppState) {
                     state.set_status(
                         format!(
                             "Mirror set: {} → {} at {}",
-                            src_name,
+                            src_name, state.monitors[tgt_idx].name, result.mirror_mode
-                            state.monitors[tgt_idx].name,
-                            result.mirror_mode
                         ),
                         StatusLevel::Success,
                     );
@@ -182,17 +192,26 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
             match row {
                 2 | 3 => {
                     // Source picker area
-                    let f_idx = FIELDS.iter().position(|&f| f == MirrorField::Source).unwrap_or(0);
+                    let f_idx = FIELDS
+                        .iter()
+                        .position(|&f| f == MirrorField::Source)
+                        .unwrap_or(0);
                     state.mirror.focused = f_idx;
                 }
                 4 | 5 => {
                     // Target picker area
-                    let f_idx = FIELDS.iter().position(|&f| f == MirrorField::Target).unwrap_or(1);
+                    let f_idx = FIELDS
+                        .iter()
+                        .position(|&f| f == MirrorField::Target)
+                        .unwrap_or(1);
                     state.mirror.focused = f_idx;
                 }
                 6 => {
                     // Compute button
-                    let f_idx = FIELDS.iter().position(|&f| f == MirrorField::Compute).unwrap_or(2);
+                    let f_idx = FIELDS
+                        .iter()
+                        .position(|&f| f == MirrorField::Compute)
+                        .unwrap_or(2);
                     state.mirror.focused = f_idx;
                     // Also activate it
                     let src = &state.monitors[state.mirror.source_idx];
@@ -200,7 +219,10 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
                     match crate::mirror::find_mirror_modes(src, tgt) {
                         Some(result) => {
                             state.mirror.result = Some(result);
-                            state.mirror.focused = FIELDS.iter().position(|&f| f == MirrorField::Apply).unwrap_or(3);
+                            state.mirror.focused = FIELDS
+                                .iter()
+                                .position(|&f| f == MirrorField::Apply)
+                                .unwrap_or(3);
                         }
                         None => {
                             state.set_status(
@@ -218,7 +240,10 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
                     let col = event.column;
                     if col < 20 {
                         // Activate Apply
-                        state.mirror.focused = FIELDS.iter().position(|&f| f == MirrorField::Apply).unwrap_or(3);
+                        state.mirror.focused = FIELDS
+                            .iter()
+                            .position(|&f| f == MirrorField::Apply)
+                            .unwrap_or(3);
                         if let Some(result) = state.mirror.result.clone() {
                             state.push_undo();
                             let src_name = state.monitors[state.mirror.source_idx].name.clone();
@@ -229,7 +254,10 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
                             state.mirror.result = None;
                             state.mirror.focused = 0;
                             state.set_status(
-                                format!("Mirror set: {} → {} at {}", src_name, state.monitors[tgt_idx].name, result.mirror_mode),
+                                format!(
+                                    "Mirror set: {} → {} at {}",
+                                    src_name, state.monitors[tgt_idx].name, result.mirror_mode
+                                ),
                                 crate::ui::StatusLevel::Success,
                             );
                         }
@@ -246,33 +274,33 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
             // Scroll in source/target pickers to cycle monitors
             match state.mirror.current_field() {
                 MirrorField::Source => {
-                    state.mirror.source_idx = state.mirror.source_idx.checked_sub(1).unwrap_or(count - 1);
+                    state.mirror.source_idx =
+                        state.mirror.source_idx.checked_sub(1).unwrap_or(count - 1);
                     state.mirror.fix_indices(count);
                     state.mirror.result = None;
                 }
                 MirrorField::Target => {
-                    state.mirror.target_idx = state.mirror.target_idx.checked_sub(1).unwrap_or(count - 1);
+                    state.mirror.target_idx =
+                        state.mirror.target_idx.checked_sub(1).unwrap_or(count - 1);
                     state.mirror.fix_indices(count);
                     state.mirror.result = None;
                 }
                 _ => {}
             }
         }
-        MouseEventKind::ScrollDown => {
+        MouseEventKind::ScrollDown => match state.mirror.current_field() {
-            match state.mirror.current_field() {
+            MirrorField::Source => {
-                MirrorField::Source => {
+                state.mirror.source_idx = (state.mirror.source_idx + 1) % count;
-                    state.mirror.source_idx = (state.mirror.source_idx + 1) % count;
+                state.mirror.fix_indices(count);
-                    state.mirror.fix_indices(count);
+                state.mirror.result = None;
-                    state.mirror.result = None;
-                }
-                MirrorField::Target => {
-                    state.mirror.target_idx = (state.mirror.target_idx + 1) % count;
-                    state.mirror.fix_indices(count);
-                    state.mirror.result = None;
-                }
-                _ => {}
             }
-        }
+            MirrorField::Target => {
+                state.mirror.target_idx = (state.mirror.target_idx + 1) % count;
+                state.mirror.fix_indices(count);
+                state.mirror.result = None;
+            }
+            _ => {}
+        },
         _ => {}
     }
 }
@@ -324,12 +352,16 @@ fn render_pickers(f: &mut Frame, area: Rect, state: &AppState, count: usize) {
     let focused = state.mirror.current_field();
 
     let src_style = if focused == MirrorField::Source {
-        Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Yellow)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::White)
     };
     let tgt_style = if focused == MirrorField::Target {
-        Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Yellow)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::White)
     };
@@ -354,7 +386,9 @@ fn render_pickers(f: &mut Frame, area: Rect, state: &AppState, count: usize) {
 fn render_compute_btn(f: &mut Frame, area: Rect, state: &AppState) {
     let focused = state.mirror.current_field() == MirrorField::Compute;
     let style = if focused {
-        Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Yellow)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::DarkGray)
     };
@@ -376,12 +410,16 @@ fn render_result(f: &mut Frame, area: Rect, state: &AppState, result: &MirrorRes
 
     let focused = state.mirror.current_field();
     let apply_style = if focused == MirrorField::Apply {
-        Style::default().fg(Color::Green).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Green)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::White)
     };
     let cancel_style = if focused == MirrorField::Cancel {
-        Style::default().fg(Color::Yellow).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Yellow)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::DarkGray)
     };
@@ -397,7 +435,10 @@ fn render_result(f: &mut Frame, area: Rect, state: &AppState, result: &MirrorRes
             Style::default().fg(Color::White),
         )),
         Line::from(Span::styled(
-            format!("  Refresh:      {:.2} Hz  ({})", result.refresh, refresh_label),
+            format!(
+                "  Refresh:      {:.2} Hz  ({})",
+                result.refresh, refresh_label
+            ),
             Style::default().fg(Color::White),
         )),
         Line::raw(""),

src/ui/mod.rs

@@ -14,10 +14,7 @@ use ratatui::{
     Frame,
 };
 
-use crate::{
+use crate::{layout::LayoutState, monitor::Monitor};
-    layout::LayoutState,
-    monitor::Monitor,
-};
 
 use config_view::ConfigState;
 use mirror_view::MirrorState;
@@ -141,7 +138,11 @@ impl AppState {
     }
 
     pub fn set_status(&mut self, text: impl Into<String>, level: StatusLevel) {
-        self.status = Some(StatusMsg { text: text.into(), level, born: Instant::now() });
+        self.status = Some(StatusMsg {
+            text: text.into(),
+            level,
+            born: Instant::now(),
+        });
     }
 
     /// Mark the in-memory layout as edited. Also forgets `active_profile`
@@ -163,7 +164,8 @@ impl AppState {
     pub fn switch_tab(&mut self, tab: Tab) {
         self.tab = tab;
         if tab == Tab::Config {
-            self.config.sync_from_monitor(self.layout.selected, &self.monitors);
+            self.config
+                .sync_from_monitor(self.layout.selected, &self.monitors);
         }
     }
 
@@ -214,10 +216,22 @@ pub fn handle_key(event: KeyEvent, state: &mut AppState) -> bool {
 
     // Global tab switching
     match event.code {
-        KeyCode::Char('1') | KeyCode::F(1) => { state.switch_tab(Tab::Layout); return true; }
+        KeyCode::Char('1') | KeyCode::F(1) => {
-        KeyCode::Char('2') | KeyCode::F(2) => { state.switch_tab(Tab::Config); return true; }
+            state.switch_tab(Tab::Layout);
-        KeyCode::Char('3') | KeyCode::F(3) => { state.switch_tab(Tab::Mirror); return true; }
+            return true;
-        KeyCode::Char('4') | KeyCode::F(4) => { state.switch_tab(Tab::Profiles); return true; }
+        }
+        KeyCode::Char('2') | KeyCode::F(2) => {
+            state.switch_tab(Tab::Config);
+            return true;
+        }
+        KeyCode::Char('3') | KeyCode::F(3) => {
+            state.switch_tab(Tab::Mirror);
+            return true;
+        }
+        KeyCode::Char('4') | KeyCode::F(4) => {
+            state.switch_tab(Tab::Profiles);
+            return true;
+        }
         _ => {}
     }
 

src/ui/profiles_view.rs

@@ -126,7 +126,10 @@ fn handle_list_key(event: KeyEvent, state: &mut AppState) {
                     match profile::delete(&name) {
                         Ok(()) => {
                             state.profiles.refresh();
-                            state.set_status(format!("Deleted profile '{}'", name), StatusLevel::Success);
+                            state.set_status(
+                                format!("Deleted profile '{}'", name),
+                                StatusLevel::Success,
+                            );
                         }
                         Err(e) => {
                             state.set_status(format!("Delete failed: {}", e), StatusLevel::Error);
@@ -195,8 +198,11 @@ pub fn handle_mouse(event: MouseEvent, state: &mut AppState) {
         MouseEventKind::ScrollUp => {
             let count = state.profiles.profiles.len();
             if count > 0 {
-                state.profiles.selected_idx =
+                state.profiles.selected_idx = state
-                    state.profiles.selected_idx.checked_sub(1).unwrap_or(count - 1);
+                    .profiles
+                    .selected_idx
+                    .checked_sub(1)
+                    .unwrap_or(count - 1);
                 state.profiles.focused = ProfileField::List;
             }
         }
@@ -308,7 +314,9 @@ fn render_list(f: &mut Frame, area: Rect, state: &AppState) {
                         .add_modifier(Modifier::BOLD)
                         .bg(Color::DarkGray)
                 } else if is_selected {
-                    Style::default().fg(Color::White).add_modifier(Modifier::BOLD)
+                    Style::default()
+                        .fg(Color::White)
+                        .add_modifier(Modifier::BOLD)
                 } else {
                     Style::default().fg(Color::White)
                 };
@@ -362,22 +370,28 @@ fn render_save_row(f: &mut Frame, area: Rect, state: &AppState) {
         Style::default().fg(Color::DarkGray)
     };
     f.render_widget(
-        Paragraph::new(input_display)
+        Paragraph::new(input_display).style(input_style).block(
-            .style(input_style)
+            Block::default()
-            .block(Block::default().borders(Borders::ALL).border_style(input_style)),
+                .borders(Borders::ALL)
+                .border_style(input_style),
+        ),
         chunks[0],
     );
 
     // Save button
     let save_style = if save_focused {
-        Style::default().fg(Color::Green).add_modifier(Modifier::BOLD)
+        Style::default()
+            .fg(Color::Green)
+            .add_modifier(Modifier::BOLD)
     } else {
         Style::default().fg(Color::DarkGray)
     };
     f.render_widget(
-        Paragraph::new(" [ Save ] ")
+        Paragraph::new(" [ Save ] ").style(save_style).block(
-            .style(save_style)
+            Block::default()
-            .block(Block::default().borders(Borders::ALL).border_style(save_style)),
+                .borders(Borders::ALL)
+                .border_style(save_style),
+        ),
         chunks[1],
     );
 }