diff --git a/cartridges/ui/closures.py b/cartridges/ui/closures.py
new file mode 100644
index 0000000..e39a1f2
--- /dev/null
+++ b/cartridges/ui/closures.py
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+# SPDX-FileCopyrightText: Copyright 2025 Jamie Gravendeel
+
+from collections.abc import Callable
+from typing import Any
+
+from gi.repository import Gtk
+
+
+def _closure[**P, R](func: Callable[P, R]) -> object:  # gi._gtktemplate.CallThing
+    @Gtk.Template.Callback()
+    @staticmethod
+    def wrapper(_obj, *args: P.args, **kwargs: P.kwargs) -> R:
+        return func(*args, **kwargs)
+
+    return wrapper
+
+
+@_closure
+def boolean(value: object) -> bool:
+    """Get a boolean for `value`."""
+    return bool(value)
+
+
+@_closure
+def concat(*strings: str) -> str:
+    """Join `strings`."""
+    return "".join(strings)
+
+
+@_closure
+def either[T](first: T, second: T) -> T:
+    """Return `first` or `second`."""
+    return first or second
+
+
+@_closure
+def format_string(string: str, *args: Any) -> str:
+    """Format `string` with `args`."""
+    return string.format(*args)
+
+
+@_closure
+def if_else[T](condition: object, first: T, second: T) -> T:
+    """Return `first` or `second` depending on `condition`."""
+    return first if condition else second
diff --git a/cartridges/ui/collection-details.blp b/cartridges/ui/collection-details.blp
index 4ec74f7..6d64ce5 100644
--- a/cartridges/ui/collection-details.blp
+++ b/cartridges/ui/collection-details.blp
@@ -2,7 +2,7 @@ using Gtk 4.0;
 using Adw 1;
 
 template $CollectionDetails: Adw.Dialog {
-  title: bind $_or(template.collection as <$Collection>.name, _("New Collection")) as <string>;
+  title: bind $either(template.collection as <$Collection>.name, _("New Collection")) as <string>;
   content-width: 360;
   default-widget: apply_button;
   focus-widget: name_entry;
@@ -31,7 +31,7 @@ template $CollectionDetails: Adw.Dialog {
       Button apply_button {
         action-name: "details.apply";
         icon-name: "apply-symbolic";
-        tooltip-text: bind $_if_else(template.collection as <$Collection>.in-model, _("Apply"), _("Add")) as <string>;
+        tooltip-text: bind $if_else(template.collection as <$Collection>.in-model, _("Apply"), _("Add")) as <string>;
 
         styles [
           "suggested-action",
diff --git a/cartridges/ui/collection_details.py b/cartridges/ui/collection_details.py
index 8f338ac..02b197b 100644
--- a/cartridges/ui/collection_details.py
+++ b/cartridges/ui/collection_details.py
@@ -9,6 +9,7 @@ from gi.repository import Adw, Gio, GObject, Gtk
 from cartridges import collections
 from cartridges.collections import Collection
 from cartridges.config import PREFIX
+from cartridges.ui import closures
 
 
 class _Icon(NamedTuple):
@@ -54,6 +55,9 @@ class CollectionDetails(Adw.Dialog):
 
     _selected_icon: str
 
+    either = closures.either
+    if_else = closures.if_else
+
     @GObject.Property(type=Collection)
     def collection(self) -> Collection:
         """The collection that `self` represents."""
@@ -128,11 +132,3 @@ class CollectionDetails(Adw.Dialog):
 
         collections.save()
         self.close()
-
-    @Gtk.Template.Callback()
-    def _or[T](self, _obj, first: T, second: T) -> T:
-        return first or second
-
-    @Gtk.Template.Callback()
-    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
-        return first if condition else second
diff --git a/cartridges/ui/cover.blp b/cartridges/ui/cover.blp
index c0e1045..3a4c300 100644
--- a/cartridges/ui/cover.blp
+++ b/cartridges/ui/cover.blp
@@ -15,7 +15,7 @@ template $Cover: Adw.Bin {
 
       child: Adw.ViewStack {
         name: "cover";
-        visible-child-name: bind $_if_else(template.paintable, "cover", "icon") as <string>;
+        visible-child-name: bind $if_else(template.paintable, "cover", "icon") as <string>;
         overflow: hidden;
         enable-transitions: true;
 
@@ -34,7 +34,7 @@ template $Cover: Adw.Bin {
           name: "icon";
 
           child: Image {
-            icon-name: bind $_concat(
+            icon-name: bind $concat(
               template.root as <Window>.application as <Application>.application-id,
               "-symbolic"
             ) as <string>;
diff --git a/cartridges/ui/cover.py b/cartridges/ui/cover.py
index 0178ebc..57c171e 100644
--- a/cartridges/ui/cover.py
+++ b/cartridges/ui/cover.py
@@ -4,6 +4,7 @@
 from gi.repository import Adw, Gdk, GObject, Gtk
 
 from cartridges.config import PREFIX
+from cartridges.ui import closures
 
 
 @Gtk.Template.from_resource(f"{PREFIX}/cover.ui")
@@ -16,10 +17,5 @@ class Cover(Adw.Bin):
     width = GObject.Property(type=int, default=200)
     height = GObject.Property(type=int, default=300)
 
-    @Gtk.Template.Callback()
-    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
-        return first if condition else second
-
-    @Gtk.Template.Callback()
-    def _concat(self, _obj, *strings: str) -> str:
-        return "".join(strings)
+    concat = closures.concat
+    if_else = closures.if_else
diff --git a/cartridges/ui/game-details.blp b/cartridges/ui/game-details.blp
index b56800b..2da6eba 100644
--- a/cartridges/ui/game-details.blp
+++ b/cartridges/ui/game-details.blp
@@ -5,7 +5,7 @@ using Adw 1;
 template $GameDetails: Adw.NavigationPage {
   name: "details";
   tag: "details";
-  title: bind $_or(template.game as <$Game>.name, _("Add Game")) as <string>;
+  title: bind $either(template.game as <$Game>.name, _("Add Game")) as <string>;
   hidden => $_cancel();
 
   ShortcutController {
@@ -101,7 +101,7 @@ template $GameDetails: Adw.NavigationPage {
 
                   Label developer_label {
                     label: bind template.game as <$Game>.developer;
-                    visible: bind $_bool(template.game as <$Game>.developer) as <bool>;
+                    visible: bind $boolean(template.game as <$Game>.developer) as <bool>;
                     halign: start;
                     max-width-chars: 36;
                     wrap: true;
@@ -119,14 +119,20 @@ template $GameDetails: Adw.NavigationPage {
                     spacing: 9;
 
                     Label last_played_label {
-                      label: bind $_date_label(_("Last played: {}"), template.game as <$Game>.last_played) as <string>;
+                      label: bind $format_string(
+                        _("Last played: {}"),
+                        $_pretty_date(template.game as <$Game>.last_played) as <string>
+                      ) as <string>;
                       halign: start;
                       wrap: true;
                       wrap-mode: word_char;
                     }
 
                     Label added_label {
-                      label: bind $_date_label(_("Added: {}"), template.game as <$Game>.added) as <string>;
+                      label: bind $format_string(
+                        _("Added: {}"),
+                        $_pretty_date(template.game as <$Game>.added) as <string>
+                      ) as <string>;
                       halign: start;
                       wrap: true;
                       wrap-mode: word_char;
@@ -376,7 +382,7 @@ template $GameDetails: Adw.NavigationPage {
 
                     Button apply_button {
                       action-name: "details.apply";
-                      label: bind $_if_else(template.game as <$Game>.added, _("Apply"), _("Add")) as <string>;
+                      label: bind $if_else(template.game as <$Game>.added, _("Apply"), _("Add")) as <string>;
 
                       styles [
                         "pill",
diff --git a/cartridges/ui/game_details.py b/cartridges/ui/game_details.py
index 314ee2e..e1c01c4 100644
--- a/cartridges/ui/game_details.py
+++ b/cartridges/ui/game_details.py
@@ -16,6 +16,7 @@ from cartridges import games, sources
 from cartridges.config import PREFIX
 from cartridges.games import Game
 from cartridges.sources import imported
+from cartridges.ui import closures
 
 from .collections import CollectionsBox
 from .cover import Cover  # noqa: F401
@@ -42,6 +43,11 @@ class GameDetails(Adw.NavigationPage):
 
     sort_changed = GObject.Signal()
 
+    boolean = closures.boolean
+    either = closures.either
+    format_string = closures.format_string
+    if_else = closures.if_else
+
     @GObject.Property(type=Game)
     def game(self) -> Game:
         """The game whose details to show."""
@@ -145,14 +151,6 @@ class GameDetails(Adw.NavigationPage):
         else:
             self.collections_box.finish()
 
-    @Gtk.Template.Callback()
-    def _or[T](self, _obj, first: T, second: T) -> T:
-        return first or second
-
-    @Gtk.Template.Callback()
-    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
-        return first if condition else second
-
     @Gtk.Template.Callback()
     def _downscale_image(self, _obj, cover: Gdk.Texture | None) -> Gdk.Texture | None:
         if cover and (renderer := cast(Gtk.Native, self.props.root).get_renderer()):
@@ -163,10 +161,10 @@ class GameDetails(Adw.NavigationPage):
         return None
 
     @Gtk.Template.Callback()
-    def _date_label(self, _obj, label: str, timestamp: int) -> str:
+    def _pretty_date(self, _obj, timestamp: int) -> str:
         date = datetime.fromtimestamp(timestamp, UTC)
         now = datetime.now(UTC)
-        return label.format(
+        return (
             _("Never")
             if not timestamp
             else _("Today")
@@ -188,10 +186,6 @@ class GameDetails(Adw.NavigationPage):
             else date.strftime("%Y")
         )
 
-    @Gtk.Template.Callback()
-    def _bool(self, _obj, o: object) -> bool:
-        return bool(o)
-
     @Gtk.Template.Callback()
     def _format_more_info(self, _obj, label: str) -> str:
         executable = _("program")
diff --git a/cartridges/ui/meson.build b/cartridges/ui/meson.build
index b9eb6de..24ebe06 100644
--- a/cartridges/ui/meson.build
+++ b/cartridges/ui/meson.build
@@ -1,6 +1,7 @@
 python.install_sources(
     files(
         '__init__.py',
+        'closures.py',
         'collection_details.py',
         'collections.py',
         'cover.py',
diff --git a/cartridges/ui/window.blp b/cartridges/ui/window.blp
index a872c7b..ddc06cc 100644
--- a/cartridges/ui/window.blp
+++ b/cartridges/ui/window.blp
@@ -213,16 +213,16 @@ template $Window: Adw.ApplicationWindow {
 
             content: Adw.ToastOverlay toast_overlay {
               child: Adw.ViewStack {
-                visible-child-name: bind $_if_else(
+                visible-child-name: bind $if_else(
                   grid.model as <NoSelection>.n-items,
                   "grid",
-                  $_if_else(
+                  $if_else(
                     template.search-text,
                     "empty-search",
-                    $_if_else(
+                    $if_else(
                       template.collection,
                       "empty-collection",
-                      $_if_else(template.show-hidden, "empty-hidden", "empty") as <string>
+                      $if_else(template.show-hidden, "empty-hidden", "empty") as <string>
                     ) as <string>
                   ) as <string>
                 ) as <string>;
@@ -310,7 +310,10 @@ template $Window: Adw.ApplicationWindow {
 
                   child: Adw.StatusPage {
                     icon-name: bind template.collection as <$Collection>.icon-name;
-                    title: bind $_format(_("No Games in {}"), template.collection as <$Collection>.name) as <string>;
+                    title: bind $format_string(
+                      _("No Games in {}"),
+                      template.collection as <$Collection>.name,
+                    ) as <string>;
                   };
                 }
 
diff --git a/cartridges/ui/window.py b/cartridges/ui/window.py
index 3df39ed..9b6eccd 100644
--- a/cartridges/ui/window.py
+++ b/cartridges/ui/window.py
@@ -14,7 +14,7 @@ from cartridges import STATE_SETTINGS
 from cartridges.collections import Collection
 from cartridges.config import PREFIX, PROFILE
 from cartridges.sources import Source, imported
-from cartridges.ui import collections, games, sources
+from cartridges.ui import closures, collections, games, sources
 
 from .collection_details import CollectionDetails
 from .collections import CollectionFilter, CollectionSidebarItem
@@ -73,6 +73,9 @@ class Window(Adw.ApplicationWindow):
     _collection_removed_signal: int | None = None
     _selected_sidebar_item = 0
 
+    format_string = closures.format_string
+    if_else = closures.if_else
+
     @GObject.Property(type=Collection)
     def collection(self) -> Collection | None:
         """The currently selected collection."""
@@ -232,14 +235,6 @@ class Window(Adw.ApplicationWindow):
             Gamepad.window = self  # pyright: ignore[reportPossiblyUnboundVariable]
             gamepads.setup_monitor()  # pyright: ignore[reportPossiblyUnboundVariable]
 
-    @Gtk.Template.Callback()
-    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
-        return first if condition else second
-
-    @Gtk.Template.Callback()
-    def _format(self, _obj, string: str, *args: Any) -> str:
-        return string.format(*args)
-
     @Gtk.Template.Callback()
     def _show_details(self, grid: Gtk.GridView, position: int):
         self.details.game = cast(Gio.ListModel, grid.props.model).get_item(position)
diff --git a/po/POTFILES.in b/po/POTFILES.in
index 661a261..cea44a7 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -6,6 +6,7 @@ cartridges/sources/__init__.py
 cartridges/sources/heroic.py
 cartridges/sources/imported.py
 cartridges/sources/steam.py
+cartridges/ui/closures.py
 cartridges/ui/collection-details.blp
 cartridges/ui/collection_details.py
 cartridges/ui/collections.py