fix: keyboard focus on built-in display to avoid evdi phantom grab (v0.8.4)

DisplayLink/evdi virtual displays enumerate as DVI-I-* before eDP-1 and
were stealing the KeyboardMode::Exclusive grab on the first enumerated
monitor, leaving the visible greeter surfaces without keyboard input.

Introduce pick_primary_monitor_index() that prefers eDP/LVDS/DSI
connectors for the keyboard grab and falls back to index 0 when no
built-in panel is present. Pure, unit-tested; hotplug path unchanged.

CLAUDE.md

@@ -45,7 +45,7 @@ cd pkg && makepkg -sf && sudo pacman -U moongreet-git-<version>-x86_64.pkg.tar.z
 - `fingerprint.rs` — fprintd D-Bus Probe (gio::DBusProxy) — Geräteerkennung und Enrollment-Check für UI-Feedback
 - `config.rs` — TOML-Config ([appearance] background, gtk-theme, fingerprint-enabled) + Wallpaper-Fallback + Blur-Validierung (finite, clamp 0–200)
 - `greeter.rs` — GTK4 UI (Overlay-Layout), Login-Flow via greetd IPC (Multi-Stage-Auth für fprintd), Faillock-Warnung, Avatar-Cache, Last-User/Last-Session Persistence (0o700 Dirs, 0o600 Files)
-- `main.rs` — Entry Point, GTK App, Layer Shell Setup, Multi-Monitor mit Hotplug via `items-changed` auf Monitor-ListModel (one greeter window per monitor, first gets keyboard), systemd-journal-logger
+- `main.rs` — Entry Point, GTK App, Layer Shell Setup, Multi-Monitor mit Hotplug via `items-changed` auf Monitor-ListModel (one greeter window per monitor; keyboard goes to the built-in display via `pick_primary_monitor_index`, falls back to first), systemd-journal-logger
 - `resources/style.css` — Catppuccin-inspiriertes Theme
 
 ## Design Decisions

Cargo.lock

@@ -575,7 +575,7 @@ dependencies = [
 
 [[package]]
 name = "moongreet"
-version = "0.8.3"
+version = "0.8.4"
 dependencies = [
  "gdk-pixbuf",
  "gdk4",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "moongreet"
-version = "0.8.3"
+version = "0.8.4"
 edition = "2024"
 description = "A greetd greeter for Wayland with GTK4 and Layer Shell"
 license = "MIT"

DECISIONS.md

@@ -1,5 +1,12 @@
 # Decisions
 
+## 2026-04-23 – Keyboard focus on built-in display, not first enumerated monitor (v0.8.4)
+
+- **Who**: ClaudeCode, Dom
+- **Why**: With a DisplayLink dock attached, the greeter showed its UI on all monitors but the password entry accepted no input. `display.monitors()` enumerated evdi phantom connectors (`DVI-I-*`) before the laptop panel (`eDP-1`); the v0.8.0 logic gave `KeyboardMode::Exclusive` to index 0, so the keyboard grab landed on an invisible surface. Symptom showed up on 2026-04-23 after kernel 6.19.11 → 6.19.12 + moongreet 0.8.0 → 0.8.2 changed evdi enumeration timing — previous Thursdays with the same dock worked.
+- **Tradeoffs**: Prefers built-in displays by connector-name pattern (`eDP*`/`LVDS*`/`DSI*`) rather than a generic "primary monitor" concept — Wayland has no portable primary signal, and gdk4's `primary_monitor()` was removed. Pattern-matching covers every current Linux laptop, at the cost of a tiny list to maintain if a new form factor ships a new connector type. Fallback is still index 0, so behavior on desktops without a built-in panel is unchanged.
+- **How**: New pure function `pick_primary_monitor_index()` in `main.rs` scans connector names and returns the built-in index (or 0). Used during initial enumeration to decide which window gets `KeyboardMode::Exclusive`. Hotplug branch unchanged — new monitors still get keyboard=false so focus never migrates off the panel. Unit-tested against evdi/eDP/LVDS/DSI/HDMI/DP mixes.
+
 ## 2026-04-21 – Ship polkit rule in moongreet instead of moonarch (v0.8.3)
 
 - **Who**: ClaudeCode, Dom

src/main.rs

@@ -40,6 +40,26 @@ fn setup_layer_shell(window: &gtk::ApplicationWindow, keyboard: bool, layer: gtk
     window.set_anchor(gtk4_layer_shell::Edge::Right, true);
 }
 
+/// Pick the index of the built-in display among the given connector names.
+///
+/// Prefers `eDP*` / `LVDS*` / `DSI*` over anything else — otherwise keyboard
+/// focus can land on DisplayLink/evdi phantom displays (connector `DVI-I-*`)
+/// that are enumerated before the laptop panel. Falls back to index 0 when
+/// no built-in connector is present.
+fn pick_primary_monitor_index<'a, I>(connectors: I) -> usize
+where
+    I: IntoIterator<Item = Option<&'a str>>,
+{
+    for (i, conn) in connectors.into_iter().enumerate() {
+        if let Some(c) = conn
+            && (c.starts_with("eDP") || c.starts_with("LVDS") || c.starts_with("DSI"))
+        {
+            return i;
+        }
+    }
+    0
+}
+
 fn activate(app: &gtk::Application) {
     let display = match gdk::Display::default() {
         Some(d) => d,
@@ -66,20 +86,37 @@ fn activate(app: &gtk::Application) {
     log::debug!("Layer shell: {use_layer_shell}");
 
     if use_layer_shell {
-        // One greeter window per monitor — only the first gets keyboard input
+        // One greeter window per monitor — keyboard focus goes to the
+        // built-in display so DisplayLink/evdi phantoms don't steal it.
         let monitors = display.monitors();
-        log::debug!("Monitor count: {}", monitors.n_items());
-        let mut first = true;
-        for i in 0..monitors.n_items() {
+        let count = monitors.n_items();
+        log::debug!("Monitor count: {count}");
+
+        let connectors: Vec<Option<String>> = (0..count)
+            .map(|i| {
+                monitors
+                    .item(i)
+                    .and_then(|obj| obj.downcast::<gdk::Monitor>().ok())
+                    .and_then(|m| m.connector())
+                    .map(|gs| gs.to_string())
+            })
+            .collect();
+
+        let primary_idx = pick_primary_monitor_index(connectors.iter().map(|o| o.as_deref()));
+        log::debug!(
+            "Primary monitor: idx={primary_idx} connector={:?}",
+            connectors.get(primary_idx).and_then(|o| o.as_deref())
+        );
+
+        for i in 0..count {
             if let Some(monitor) = monitors
                 .item(i)
                 .and_then(|obj| obj.downcast::<gdk::Monitor>().ok())
             {
                 let window = greeter::create_greeter_window(bg_texture.as_ref(), &config, &blur_cache, app);
-                setup_layer_shell(&window, first, gtk4_layer_shell::Layer::Top);
+                setup_layer_shell(&window, i as usize == primary_idx, gtk4_layer_shell::Layer::Top);
                 window.set_monitor(Some(&monitor));
                 window.present();
-                first = false;
             }
         }
 
@@ -135,6 +172,47 @@ fn setup_logging() {
     log::set_max_level(level);
 }
 
+#[cfg(test)]
+mod tests {
+    use super::pick_primary_monitor_index;
+
+    #[test]
+    fn prefers_edp_over_phantom_dvi() {
+        assert_eq!(
+            pick_primary_monitor_index([Some("DVI-I-1"), Some("eDP-1"), Some("DVI-I-2")]),
+            1,
+        );
+    }
+
+    #[test]
+    fn prefers_lvds() {
+        assert_eq!(pick_primary_monitor_index([Some("HDMI-A-1"), Some("LVDS-1")]), 1);
+    }
+
+    #[test]
+    fn prefers_dsi() {
+        assert_eq!(pick_primary_monitor_index([Some("DP-1"), Some("DSI-1")]), 1);
+    }
+
+    #[test]
+    fn falls_back_to_first_without_builtin() {
+        assert_eq!(
+            pick_primary_monitor_index([Some("DVI-I-1"), Some("HDMI-A-1")]),
+            0,
+        );
+    }
+
+    #[test]
+    fn skips_missing_connector() {
+        assert_eq!(pick_primary_monitor_index([None, Some("eDP-1")]), 1);
+    }
+
+    #[test]
+    fn empty_returns_zero() {
+        assert_eq!(pick_primary_monitor_index(std::iter::empty::<Option<&str>>()), 0);
+    }
+}
+
 fn main() {
     setup_logging();
     log::info!("Moongreet starting");