feat: Multi-Monitor-Support — Wallpaper auf Sekundärmonitoren

- WallpaperWindow für Sekundärmonitore (nur Hintergrundbild)
- GreeterWindow bekommt bg_path als Parameter
- resolve_wallpaper_path() aus config.py extrahiert (wiederverwendbar)
- main.py: Monitor-Enumeration, Layer-Shell pro Monitor
- Keyboard-Exclusive nur auf dem primären Monitor
- CSS: ungültige max-width/max-height Properties entfernt

CLAUDE.md

@@ -42,8 +42,8 @@ uv run moongreet
 - `sessions.py` — Wayland/X11 Sessions aus .desktop Files
 - `power.py` — Reboot/Shutdown via loginctl
 - `i18n.py` — Locale-Erkennung (LANG / /etc/locale.conf) und String-Tabellen (DE/EN)
-- `greeter.py` — GTK4 UI (Overlay-Layout), Faillock-Warnung nach 2 Fehlversuchen
+- `greeter.py` — GTK4 UI (Overlay-Layout), Faillock-Warnung nach 2 Fehlversuchen, WallpaperWindow für Sekundärmonitore
-- `main.py` — Entry Point, GTK App, Layer Shell Setup
+- `main.py` — Entry Point, GTK App, Layer Shell Setup, Multi-Monitor-Orchestrierung
 
 ## Design Decisions
 

src/moongreet/config.py

@@ -1,8 +1,10 @@
 # ABOUTME: Configuration loading from moongreet.toml.
-# ABOUTME: Parses appearance and behavior settings for the greeter.
+# ABOUTME: Parses appearance and behavior settings with wallpaper path resolution.
 
 import tomllib
+from contextlib import AbstractContextManager
 from dataclasses import dataclass
+from importlib.resources import as_file, files
 from pathlib import Path
 
 DEFAULT_CONFIG_PATHS = [
@@ -50,3 +52,24 @@ def load_config(config_path: Path | None = None) -> Config:
         config.background = bg_path
 
     return config
+
+
+_PACKAGE_DATA = files("moongreet") / "data"
+_DEFAULT_WALLPAPER_PATH = _PACKAGE_DATA / "wallpaper.jpg"
+
+
+def resolve_wallpaper_path(
+    config: Config,
+) -> tuple[Path, AbstractContextManager | None]:
+    """Resolve the wallpaper path from config or fall back to the package default.
+
+    Returns (path, context_manager). The context_manager is non-None when a
+    package resource was extracted to a temporary file — the caller must keep
+    it alive and call __exit__ when done.
+    """
+    if config.background and config.background.exists():
+        return config.background, None
+
+    ctx = as_file(_DEFAULT_WALLPAPER_PATH)
+    path = ctx.__enter__()
+    return path, ctx

src/moongreet/greeter.py

@@ -10,7 +10,7 @@ import socket
 import stat
 import subprocess
 import threading
-from importlib.resources import as_file, files
+from importlib.resources import files
 from pathlib import Path
 
 import gi
@@ -18,7 +18,7 @@ gi.require_version("Gtk", "4.0")
 gi.require_version("Gdk", "4.0")
 from gi.repository import Gtk, Gdk, GLib, GdkPixbuf
 
-from moongreet.config import load_config
+from moongreet.config import load_config, resolve_wallpaper_path
 from moongreet.i18n import load_strings, Strings
 from moongreet.ipc import create_session, post_auth_response, start_session, cancel_session
 from moongreet.users import User, get_users, get_avatar_path, get_user_gtk_theme
@@ -33,7 +33,6 @@ VALID_USERNAME = re.compile(r"^[a-zA-Z0-9_.-]+$")
 MAX_USERNAME_LENGTH = 256
 PACKAGE_DATA = files("moongreet") / "data"
 DEFAULT_AVATAR_PATH = PACKAGE_DATA / "default-avatar.svg"
-DEFAULT_WALLPAPER_PATH = PACKAGE_DATA / "wallpaper.jpg"
 AVATAR_SIZE = 128
 
 
@@ -49,10 +48,35 @@ def faillock_warning(attempt_count: int, strings: Strings | None = None) -> str
     return None
 
 
+def _build_wallpaper_widget(bg_path: Path | None) -> Gtk.Widget:
+    """Create a wallpaper widget that fills the available space."""
+    if bg_path and bg_path.exists():
+        background = Gtk.Picture()
+        background.set_filename(str(bg_path))
+        background.set_content_fit(Gtk.ContentFit.COVER)
+        background.set_hexpand(True)
+        background.set_vexpand(True)
+        return background
+    background = Gtk.Box()
+    background.set_hexpand(True)
+    background.set_vexpand(True)
+    return background
+
+
+class WallpaperWindow(Gtk.ApplicationWindow):
+    """A window that shows only the wallpaper — used for secondary monitors."""
+
+    def __init__(self, bg_path: Path | None = None, **kwargs) -> None:
+        super().__init__(**kwargs)
+        self.add_css_class("greeter")
+        self.set_default_size(1920, 1080)
+        self.set_child(_build_wallpaper_widget(bg_path))
+
+
 class GreeterWindow(Gtk.ApplicationWindow):
     """The main greeter window with login UI."""
 
-    def __init__(self, **kwargs) -> None:
+    def __init__(self, bg_path: Path | None = None, **kwargs) -> None:
         super().__init__(**kwargs)
         self.add_css_class("greeter")
         self.set_default_size(1920, 1080)
@@ -67,14 +91,13 @@ class GreeterWindow(Gtk.ApplicationWindow):
         self._default_avatar_pixbuf: GdkPixbuf.Pixbuf | None = None
         self._avatar_cache: dict[str, GdkPixbuf.Pixbuf] = {}
         self._failed_attempts: dict[str, int] = {}
-        self._wallpaper_ctx = None
+        self._bg_path = bg_path
 
         self._build_ui()
         self._setup_keyboard_navigation()
         # Defer initial user selection until the window is realized,
         # so get_color() returns the actual theme foreground for SVG tinting
         self.connect("realize", self._on_realize)
-        self.connect("unrealize", self._on_unrealize)
 
     def _on_realize(self, widget: Gtk.Widget) -> None:
         """Called when the window is realized — select initial user.
@@ -85,35 +108,14 @@ class GreeterWindow(Gtk.ApplicationWindow):
         """
         GLib.idle_add(self._select_initial_user)
 
-    def _on_unrealize(self, widget: Gtk.Widget) -> None:
-        """Clean up resources when the window is unrealized."""
-        if self._wallpaper_ctx is not None:
-            self._wallpaper_ctx.__exit__(None, None, None)
-            self._wallpaper_ctx = None
-
     def _build_ui(self) -> None:
         """Build the complete greeter UI layout."""
         # Root overlay for layering
         overlay = Gtk.Overlay()
         self.set_child(overlay)
 
-        # Background wallpaper (blurred and darkened)
+        # Background wallpaper
-        bg_path = self._config.background
+        overlay.set_child(_build_wallpaper_widget(self._bg_path))
-        if not bg_path or not bg_path.exists():
-            # Extract package wallpaper to a real filesystem path (works in ZIP wheels too)
-            self._wallpaper_ctx = as_file(DEFAULT_WALLPAPER_PATH)
-            bg_path = self._wallpaper_ctx.__enter__()
-        if bg_path.exists():
-            background = Gtk.Picture()
-            background.set_filename(str(bg_path))
-            background.set_content_fit(Gtk.ContentFit.COVER)
-            background.set_hexpand(True)
-            background.set_vexpand(True)
-        else:
-            background = Gtk.Box()
-            background.set_hexpand(True)
-            background.set_vexpand(True)
-        overlay.set_child(background)
 
         # Main layout: 3 rows (top spacer, center login, bottom bar)
         main_box = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)

src/moongreet/main.py

@@ -1,6 +1,7 @@
 # ABOUTME: Entry point for Moongreet — sets up GTK Application and Layer Shell.
-# ABOUTME: Handles CLI invocation and initializes the greeter window.
+# ABOUTME: Handles multi-monitor setup: login UI on primary, wallpaper on secondary monitors.
 
+import logging
 import sys
 from importlib.resources import files
 
@@ -9,7 +10,8 @@ gi.require_version("Gtk", "4.0")
 gi.require_version("Gdk", "4.0")
 from gi.repository import Gtk, Gdk
 
-from moongreet.greeter import GreeterWindow
+from moongreet.config import load_config, resolve_wallpaper_path
+from moongreet.greeter import GreeterWindow, WallpaperWindow
 
 # gtk4-layer-shell is optional for development/testing
 try:
@@ -19,23 +21,65 @@ try:
 except (ValueError, ImportError):
     HAS_LAYER_SHELL = False
 
+logger = logging.getLogger(__name__)
+
 
 class MoongreetApp(Gtk.Application):
     """GTK Application for the Moongreet greeter."""
 
     def __init__(self) -> None:
         super().__init__(application_id="dev.moonarch.moongreet")
+        self._wallpaper_ctx = None
+        self._secondary_windows: list[WallpaperWindow] = []
 
     def do_activate(self) -> None:
-        """Create and present the greeter window."""
+        """Create and present greeter windows on all monitors."""
         self._register_icons()
         self._load_css()
-        window = GreeterWindow(application=self)
 
+        # Resolve wallpaper once, share across all windows
+        config = load_config()
+        bg_path, self._wallpaper_ctx = resolve_wallpaper_path(config)
+
+        display = Gdk.Display.get_default()
+        monitors = display.get_monitors()
+        primary_monitor = None
+
+        # Find primary monitor — fall back to first available
+        for i in range(monitors.get_n_items()):
+            monitor = monitors.get_item(i)
+            if hasattr(monitor, 'is_primary') and monitor.is_primary():
+                primary_monitor = monitor
+                break
+        if primary_monitor is None and monitors.get_n_items() > 0:
+            primary_monitor = monitors.get_item(0)
+
+        # Main greeter window (login UI) on primary monitor
+        greeter = GreeterWindow(bg_path=bg_path, application=self)
         if HAS_LAYER_SHELL:
-            self._setup_layer_shell(window)
+            self._setup_layer_shell(greeter, keyboard=True)
+            if primary_monitor is not None:
+                Gtk4LayerShell.set_monitor(greeter, primary_monitor)
+        greeter.present()
 
-        window.present()
+        # Wallpaper-only windows on secondary monitors
+        for i in range(monitors.get_n_items()):
+            monitor = monitors.get_item(i)
+            if monitor == primary_monitor:
+                continue
+            wallpaper_win = WallpaperWindow(bg_path=bg_path, application=self)
+            if HAS_LAYER_SHELL:
+                self._setup_layer_shell(wallpaper_win, keyboard=False)
+                Gtk4LayerShell.set_monitor(wallpaper_win, monitor)
+            wallpaper_win.present()
+            self._secondary_windows.append(wallpaper_win)
+
+    def do_shutdown(self) -> None:
+        """Clean up wallpaper context manager on exit."""
+        if self._wallpaper_ctx is not None:
+            self._wallpaper_ctx.__exit__(None, None, None)
+            self._wallpaper_ctx = None
+        Gtk.Application.do_shutdown(self)
 
     def _register_icons(self) -> None:
         """Register custom icons from the package data/icons directory."""
@@ -54,13 +98,14 @@ class MoongreetApp(Gtk.Application):
             Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION,
         )
 
-    def _setup_layer_shell(self, window: Gtk.Window) -> None:
+    def _setup_layer_shell(self, window: Gtk.Window, keyboard: bool = False) -> None:
-        """Configure gtk4-layer-shell for fullscreen greeter display."""
+        """Configure gtk4-layer-shell for fullscreen display."""
         Gtk4LayerShell.init_for_window(window)
         Gtk4LayerShell.set_layer(window, Gtk4LayerShell.Layer.TOP)
-        Gtk4LayerShell.set_keyboard_mode(
+        if keyboard:
-            window, Gtk4LayerShell.KeyboardMode.EXCLUSIVE
+            Gtk4LayerShell.set_keyboard_mode(
-        )
+                window, Gtk4LayerShell.KeyboardMode.EXCLUSIVE
+            )
         # Anchor to all edges for fullscreen
         for edge in [
             Gtk4LayerShell.Edge.TOP,

src/moongreet/style.css

@@ -15,13 +15,11 @@ window.greeter {
     background-color: alpha(@theme_bg_color, 0.7);
 }
 
-/* Round avatar image */
+/* Round avatar image — size is set via set_size_request() in code */
 .avatar {
     border-radius: 50%;
     min-width: 128px;
     min-height: 128px;
-    max-width: 128px;
-    max-height: 128px;
     background-color: @theme_selected_bg_color;
     border: 3px solid alpha(white, 0.3);
 }

tests/test_config.py

@@ -5,7 +5,7 @@ from pathlib import Path
 
 import pytest
 
-from moongreet.config import load_config, Config
+from moongreet.config import load_config, resolve_wallpaper_path, Config
 
 
 class TestLoadConfig:
@@ -53,3 +53,38 @@ class TestLoadConfig:
         config = load_config(toml_file)
 
         assert config.background == tmp_path / "wallpaper.jpg"
+
+
+class TestResolveWallpaperPath:
+    """Tests for resolving the wallpaper path from config or package default."""
+
+    def test_uses_configured_path_when_exists(self, tmp_path: Path) -> None:
+        wallpaper = tmp_path / "custom.jpg"
+        wallpaper.write_bytes(b"fake-image")
+        config = Config(background=wallpaper)
+
+        path, ctx = resolve_wallpaper_path(config)
+
+        assert path == wallpaper
+        assert ctx is None
+
+    def test_falls_back_to_package_default(self) -> None:
+        config = Config(background=None)
+
+        path, ctx = resolve_wallpaper_path(config)
+
+        assert path is not None
+        assert path.exists()
+        assert ctx is not None
+        # Clean up context manager
+        ctx.__exit__(None, None, None)
+
+    def test_falls_back_when_configured_path_missing(self, tmp_path: Path) -> None:
+        config = Config(background=tmp_path / "nonexistent.jpg")
+
+        path, ctx = resolve_wallpaper_path(config)
+
+        assert path is not None
+        assert path.exists()
+        assert ctx is not None
+        ctx.__exit__(None, None, None)