feat: apply cursor theme via GtkSettings (v0.9.0)

GTK4 under greetd does not honour XCURSOR_THEME reliably, so the greeter
showed the wrong cursor over GTK widgets on some machines. Set
gtk-cursor-theme-name / -size on GtkSettings from new [appearance] config
fields (cursor-theme, cursor-size), mirroring the gtk-theme handling and
reusing is_valid_gtk_theme validation.

Salvaged from commit 29ce185 — tagged v0.9.0 on 2026-04-24 but never
pushed. The orphan branch's keyboard refactor (v0.10.0) is discarded,
superseded by the v0.8.7 single-window fix.

CLAUDE.md

@@ -43,7 +43,7 @@ cd pkg && makepkg -sf && sudo pacman -U moongreet-git-<version>-x86_64.pkg.tar.z
 - `power.rs` — Reboot/Shutdown via systemctl (`--no-ask-password`)
 - `i18n.rs` — Locale-Erkennung (LANG / /etc/locale.conf) und String-Tabellen (DE/EN), alle UI- und Login-Fehlermeldungen
 - `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)
+- `config.rs` — TOML-Config ([appearance] background, gtk-theme, cursor-theme, cursor-size, fingerprint-enabled) + Wallpaper-Fallback + Blur-Validierung (finite, clamp 0–200) + Cursor-Size-Validierung (range 1–256)
 - `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, ein Greeter-Fenster auf dem fokussierten Output (kein `set_monitor`), `KeyboardMode::Exclusive`, systemd-journal-logger
 - `resources/style.css` — Catppuccin-inspiriertes Theme
@@ -60,6 +60,7 @@ cd pkg && makepkg -sf && sudo pacman -U moongreet-git-<version>-x86_64.pkg.tar.z
 - **Symmetrie mit moonlock/moonset**: Gleiche Patterns (i18n, config, users, power, GResource, GPU-Blur)
 - **Session-Validierung**: Relative Pfade erlaubt (greetd löst PATH auf), nur `..`/Null-Bytes werden abgelehnt
 - **GTK-Theme-Validierung**: Nur alphanumerisch + `_-+.` erlaubt, verhindert Path-Traversal über Config
+- **Cursor-Theme via GtkSettings**: GTK4 unter greetd liest `XCURSOR_THEME` env nicht zuverlässig — Cursor wird via `gtk::Settings::set_gtk_cursor_theme_name()` gesetzt, analog zu `gtk-theme`. Gleiche Validierung (`is_valid_gtk_theme`) gegen Path-Traversal.
 - **Journal-Logging**: `systemd-journal-logger` statt File-Logging — `journalctl -t moongreet`, Debug-Level per `MOONGREET_DEBUG` Env-Var
 - **File Permissions**: Cache-Verzeichnisse 0o700 via `DirBuilder::mode()`, Cache-Dateien 0o600
 - **Testbare Persistence**: `save_*_to`/`load_*_from` Varianten mit konfigurierbarem Pfad für Unit-Tests

Cargo.lock

@@ -575,7 +575,7 @@ dependencies = [
 
 [[package]]
 name = "moongreet"
-version = "0.8.7"
+version = "0.9.0"
 dependencies = [
  "gdk-pixbuf",
  "gdk4",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "moongreet"
-version = "0.8.7"
+version = "0.9.0"
 edition = "2024"
 description = "A greetd greeter for Wayland with GTK4 and Layer Shell"
 license = "MIT"

DECISIONS.md

@@ -1,5 +1,12 @@
 # Decisions
 
+## 2026-06-02 – Cursor theme via GtkSettings, salvaged from unpushed work (v0.9.0)
+
+- **Who**: ClaudeCode, Dom
+- **Why**: On some machines the greeter showed the wrong (GTK-default) cursor. GTK4 under greetd does not honour `XCURSOR_THEME` reliably — niri renders its own pointer from the kdl `cursor` block, but GTK widgets (button hover, text-input I-beam) read `gtk-cursor-theme-name` on `GtkSettings`, which without a session settings.ini stays at the GTK default. This fix was written and tagged v0.9.0 on 2026-04-24 but never pushed — it sat in a local-only branch while the bug kept shipping. Salvaged onto main now (cherry-picked from commit 29ce185).
+- **Tradeoffs**: Adds two `[appearance]` config fields (`cursor-theme`, `cursor-size`), symmetric with the existing `gtk-theme` field. Alternative — a system-wide `/etc/gtk-4.0/settings.ini` with `gtk-cursor-theme-name=` — would couple moongreet to host GTK config and affect every GTK4 app; rejected for the same reason as `gtk-theme`.
+- **How**: `config.rs` gains `cursor_theme: Option<String>` and `cursor_size: Option<i32>` (range-validated 1–256). `greeter::create_greeter_window` applies them via `gtk::Settings::set_gtk_cursor_theme_name()` / `set_gtk_cursor_theme_size()` after the existing gtk-theme handling, reusing `is_valid_gtk_theme()`. Deployed `moongreet.toml` gains `cursor-theme = "Sweet-cursors"` + `cursor-size = 24`. The orphaned April branch (v0.9.0/v0.10.0) is otherwise discarded; its keyboard refactor is superseded by the v0.8.7 single-window fix.
+
 ## 2026-06-02 – Power buttons fixed (loginctl→systemctl) + single greeter window (v0.8.7)
 
 - **Who**: ClaudeCode, Dom

config/moongreet.toml

@@ -8,3 +8,8 @@ background = "/usr/share/backgrounds/wallpaper.jpg"
 # GTK theme name — must match a directory in /usr/share/themes/
 # Required because GTK4 under greetd does not reliably read settings.ini
 gtk-theme = "Colloid-Grey-Dark-Catppuccin"
+
+# Cursor theme name — must match a directory in /usr/share/icons/
+# GTK4 under greetd does not honour XCURSOR_THEME, so set it here.
+cursor-theme = "Sweet-cursors"
+cursor-size = 24

src/config.rs

@@ -25,6 +25,10 @@ struct Appearance {
     background_blur: Option<f32>,
     #[serde(rename = "gtk-theme")]
     gtk_theme: Option<String>,
+    #[serde(rename = "cursor-theme")]
+    cursor_theme: Option<String>,
+    #[serde(rename = "cursor-size")]
+    cursor_size: Option<i32>,
     #[serde(rename = "fingerprint-enabled")]
     fingerprint_enabled: Option<bool>,
 }
@@ -35,6 +39,8 @@ pub struct Config {
     pub background_path: Option<String>,
     pub background_blur: Option<f32>,
     pub gtk_theme: Option<String>,
+    pub cursor_theme: Option<String>,
+    pub cursor_size: Option<i32>,
     pub fingerprint_enabled: bool,
 }
 
@@ -44,6 +50,8 @@ impl Default for Config {
             background_path: None,
             background_blur: None,
             gtk_theme: None,
+            cursor_theme: None,
+            cursor_size: None,
             fingerprint_enabled: true,
         }
     }
@@ -88,6 +96,16 @@ pub fn load_config(config_paths: Option<&[PathBuf]>) -> Config {
                             if appearance.gtk_theme.is_some() {
                                 merged.gtk_theme = appearance.gtk_theme;
                             }
+                            if appearance.cursor_theme.is_some() {
+                                merged.cursor_theme = appearance.cursor_theme;
+                            }
+                            if let Some(size) = appearance.cursor_size {
+                                if (1..=256).contains(&size) {
+                                    merged.cursor_size = Some(size);
+                                } else {
+                                    log::warn!("Ignoring cursor-size out of range (1–256): {size}");
+                                }
+                            }
                             if let Some(fp) = appearance.fingerprint_enabled {
                                 merged.fingerprint_enabled = fp;
                             }
@@ -104,7 +122,15 @@ pub fn load_config(config_paths: Option<&[PathBuf]>) -> Config {
         }
     }
 
-    log::debug!("Config result: background={:?}, blur={:?}, gtk_theme={:?}, fingerprint={}", merged.background_path, merged.background_blur, merged.gtk_theme, merged.fingerprint_enabled);
+    log::debug!(
+        "Config result: background={:?}, blur={:?}, gtk_theme={:?}, cursor_theme={:?}, cursor_size={:?}, fingerprint={}",
+        merged.background_path,
+        merged.background_blur,
+        merged.gtk_theme,
+        merged.cursor_theme,
+        merged.cursor_size,
+        merged.fingerprint_enabled
+    );
     merged
 }
 
@@ -331,6 +357,40 @@ mod tests {
         assert!(config.background_blur.is_none());
     }
 
+    // -- Cursor theme tests --
+
+    #[test]
+    fn load_config_cursor_theme_and_size() {
+        let dir = tempfile::tempdir().unwrap();
+        let conf = dir.path().join("moongreet.toml");
+        fs::write(
+            &conf,
+            "[appearance]\ncursor-theme = \"Sweet-cursors\"\ncursor-size = 32\n",
+        )
+        .unwrap();
+        let config = load_config(Some(&[conf]));
+        assert_eq!(config.cursor_theme.as_deref(), Some("Sweet-cursors"));
+        assert_eq!(config.cursor_size, Some(32));
+    }
+
+    #[test]
+    fn load_config_cursor_size_out_of_range_rejected() {
+        let dir = tempfile::tempdir().unwrap();
+        let conf = dir.path().join("moongreet.toml");
+        fs::write(&conf, "[appearance]\ncursor-size = 9999\n").unwrap();
+        let config = load_config(Some(&[conf]));
+        assert!(config.cursor_size.is_none());
+    }
+
+    #[test]
+    fn load_config_cursor_size_zero_rejected() {
+        let dir = tempfile::tempdir().unwrap();
+        let conf = dir.path().join("moongreet.toml");
+        fs::write(&conf, "[appearance]\ncursor-size = 0\n").unwrap();
+        let config = load_config(Some(&[conf]));
+        assert!(config.cursor_size.is_none());
+    }
+
     #[test]
     fn load_config_blur_inf_rejected() {
         let dir = tempfile::tempdir().unwrap();

src/greeter.rs

@@ -262,6 +262,23 @@ pub fn create_greeter_window(
         }
     }
 
+    // Apply cursor theme from config — GTK4 under greetd does not read XCURSOR_THEME
+    // reliably, so set the gtk-cursor-theme-name property directly.
+    if let Some(ref cursor) = config.cursor_theme {
+        if is_valid_gtk_theme(cursor) {
+            if let Some(settings) = gtk::Settings::default() {
+                settings.set_gtk_cursor_theme_name(Some(cursor));
+            }
+        } else {
+            log::warn!("Ignoring invalid cursor theme name: {cursor}");
+        }
+    }
+    if let Some(size) = config.cursor_size {
+        if let Some(settings) = gtk::Settings::default() {
+            settings.set_gtk_cursor_theme_size(size);
+        }
+    }
+
     let strings = load_strings(None);
     let fingerprint_enabled = config.fingerprint_enabled;
     let all_users = users::get_users(None);