feat: fade-in animation for panel and wallpaper windows

CSS opacity transition (350ms ease-in) triggered via adding
a 'visible' class after the window is mapped.

pkg/PKGBUILD

@@ -4,7 +4,7 @@
 # Maintainer: Dominik Kressler
 
 pkgname=moonlock-git
-pkgver=0.2.0.r0.g7cee4f4
+pkgver=0.3.0.r1.gfe6421c
 pkgrel=1
 pkgdesc="A secure Wayland lockscreen with GTK4, PAM and fingerprint support"
 arch=('any')

src/moonlock/lockscreen.py

@@ -53,6 +53,9 @@ class LockscreenWindow(Gtk.ApplicationWindow):
         self._setup_keyboard()
         self._password_entry.grab_focus()
 
+        # Fade-in after window is mapped
+        self.connect("map", self._on_map_fade_in)
+
         # Start fingerprint listener if available (only once across shared instances)
         if self._fp_available and not self._fp_listener._running:
             self._fp_listener.start(
@@ -61,6 +64,10 @@ class LockscreenWindow(Gtk.ApplicationWindow):
                 on_failure=self._on_fingerprint_failure,
             )
 
+    def _on_map_fade_in(self, widget: Gtk.Widget) -> None:
+        """Trigger fade-in once the window is visible."""
+        GLib.idle_add(lambda: self.add_css_class("visible") or GLib.SOURCE_REMOVE)
+
     def _build_ui(self) -> None:
         """Build the lockscreen layout."""
         # Main overlay for background + centered content

src/moonlock/style.css

@@ -6,6 +6,12 @@ window.lockscreen {
     background-color: #1a1a2e;
     background-size: cover;
     background-position: center;
+    opacity: 0;
+    transition: opacity 350ms ease-in;
+}
+
+window.lockscreen.visible {
+    opacity: 1;
 }
 
 /* Central login area */

uv.lock

@@ -4,7 +4,7 @@ requires-python = ">=3.11"
 
 [[package]]
 name = "moonlock"
-version = "0.2.0"
+version = "0.3.0"
 source = { editable = "." }
 dependencies = [
     { name = "pygobject" },