ui: Use GObject.BindingGroup

cartridges/application.py

@@ -19,6 +19,11 @@ class Application(Adw.Application):
     def __init__(self):
         super().__init__(application_id=APP_ID)
 
+    @override
+    def do_startup(self):
+        Adw.Application.do_startup(self)
+        self.props.style_manager.props.color_scheme = Adw.ColorScheme.PREFER_DARK
+
         self.add_action_entries((
             ("quit", lambda *_: self.quit()),
             ("about", lambda *_: self._present_about_dialog()),
@@ -28,11 +33,6 @@ class Application(Adw.Application):
         sources.load()
         collections.load()
 
-    @override
-    def do_startup(self):
-        Adw.Application.do_startup(self)
-        Adw.StyleManager.get_default().props.color_scheme = Adw.ColorScheme.PREFER_DARK
-
     @override
     def do_activate(self):
         window = self.props.active_window or Window(application=self)

cartridges/gamepads.py

@@ -112,11 +112,6 @@ class Gamepad(GObject.Object):
             focus_widget.activate()
             return
 
-        if self.window.sidebar.get_focus_child():
-            selected_item = self.window.sidebar.get_selected_item()
-            self.window.navigate_sidebar(self.window.sidebar, item=selected_item)
-            return
-
         self.window.grid.activate_action(
             "list.activate-item",
             GLib.Variant.new_uint32(self._get_current_position()),
@@ -141,20 +136,7 @@ class Gamepad(GObject.Object):
             open_menu.grab_focus()
             return
 
-        grid_visible = self.window.view_stack.props.visible_child_name == "grid"
+        self.window.grid.grab_focus()
-        if self._is_focused_on_top_bar():
-            focus_widget = self.window.grid if grid_visible else self.window.sidebar
-
-        # If the grid is not visible (i.e no search results or imports)
-        # the searchbar is focused as a fallback.
-        fallback_child = (
-            self.window.grid
-            if self.window.sidebar.get_focus_child()
-            else self.window.sidebar
-        )
-        focus_widget = fallback_child if grid_visible else self.window.search_entry
-
-        focus_widget.grab_focus()
         self.window.props.focus_visible = True
 
     def _navigate_to_game_position(self, new_pos: int):
@@ -165,49 +147,16 @@ class Gamepad(GObject.Object):
 
     def _move_horizontally(self, direction: Gtk.DirectionType):
         if self._is_focused_on_top_bar():
-            if self.window.header_bar.child_focus(direction):
+            if not self.window.header_bar.child_focus(direction):
-                self.window.props.focus_visible = True
-                return
-
-            # The usual behaviour of child_focus() on the header bar on the
-            # left will result in the above child focus to fail, so
-            # we need to manually check the user is going left to then focus the
-            # sidebar.
-
-            if direction is not self._get_rtl_direction(
-                Gtk.DirectionType.RIGHT, Gtk.DirectionType.LEFT
-            ):
                 self.window.header_bar.keynav_failed(direction)
-                return
 
-            self.window.sidebar.grab_focus()
             self.window.props.focus_visible = True
             return
 
-        if self.window.sidebar.get_focus_child():
-            # The usual behaviour of child_focus() on the sidebar
-            # would result in the + button being focused, instead of the grid
-            # so we need to grab the focus of the grid if the user inputs the
-            # corresponding direction to the grid.
-
-            grid_direction = self._get_rtl_direction(
-                Gtk.DirectionType.LEFT, Gtk.DirectionType.RIGHT
-            )
-
-            # Focus the first game when re-entering from sidebar
-            if direction is grid_direction:
-                self.window.grid.scroll_to(0, Gtk.ListScrollFlags.FOCUS, None)
-                self.window.grid.grab_focus()
-                return
-
-            self.window.sidebar.keynav_failed(direction)
-            return
-
         if self._can_navigate_games_page():
-            if not self._get_focused_game():
+            self._navigate_to_game_position(
-                return
+                self._get_current_position()
-
+                + (
-            new_pos = self._get_current_position() + (
                     -1
                     if direction
                     == self._get_rtl_direction(
@@ -215,17 +164,7 @@ class Gamepad(GObject.Object):
                     )
                     else 1
                 )
-
+            )
-            # If the user is focused on the first game and tries to go
-            # back another game, instead of failing, the focus should
-            # change to the sidebar.
-
-            if new_pos < 0:
-                self.window.sidebar.grab_focus()
-                self.window.props.focus_visible = True
-                return
-
-            self._navigate_to_game_position(new_pos)
             return
 
         if self.window.navigation_view.props.visible_page_tag == "details":
@@ -245,14 +184,6 @@ class Gamepad(GObject.Object):
             self.window.grid.grab_focus()
             return
 
-        if self.window.sidebar.get_focus_child():
-            if self.window.sidebar.child_focus(direction):
-                self.window.props.focus_visible = True
-                return
-
-            self.window.sidebar.keynav_failed(direction)
-            return
-
         if self._can_navigate_games_page():
             if not (game := self._get_focused_game()):
                 return

cartridges/sources/__init__.py

@@ -54,6 +54,8 @@ class _SourceModule(Protocol):
 class Source(GObject.Object, Gio.ListModel):  # pyright: ignore[reportIncompatibleMethodOverride]
     """A source of games to import."""
 
+    __gtype_name__ = __qualname__
+
     id = GObject.Property(type=str)
     name = GObject.Property(type=str)
     icon_name = GObject.Property(type=str)
@@ -65,11 +67,11 @@ class Source(GObject.Object, Gio.ListModel):  # pyright: ignore[reportIncompatib
 
         self.id, self.name, self._module = module.ID, module.NAME, module
         self.bind_property(
-            "name",
+            "id",
             self,
             "icon-name",
             GObject.BindingFlags.SYNC_CREATE,
-            lambda _, name: f"{name}-symbolic",
+            lambda _, ident: f"{ident}-symbolic",
         )
 
         try:

cartridges/ui/collection-details.blp

@@ -1,5 +1,11 @@
 using Gtk 4.0;
 using Adw 1;
+using GObject 2.0;
+
+GObject.SignalGroup collection_signals {
+  target: bind template.collection;
+  target-type: typeof<$Collection>;
+}
 
 template $CollectionDetails: Adw.Dialog {
   title: bind $_or(template.collection as <$Collection>.name, _("New Collection")) as <string>;

cartridges/ui/collection_details.py

@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: Copyright 2025 Jamie Gravendeel
 
 from itertools import product
-from typing import Any, NamedTuple, TypeVar, cast
+from typing import Any, NamedTuple
 
 from gi.repository import Adw, Gio, GObject, Gtk
 
@@ -40,8 +40,6 @@ _ICONS = (
     _Icon("fist", "✊"),
 )
 
-_T = TypeVar("_T")
-
 
 @Gtk.Template.from_resource(f"{PREFIX}/collection-details.ui")
 class CollectionDetails(Adw.Dialog):
@@ -52,6 +50,7 @@ class CollectionDetails(Adw.Dialog):
     name_entry: Adw.EntryRow = Gtk.Template.Child()
     icons_grid: Gtk.Grid = Gtk.Template.Child()
 
+    collection_signals: GObject.SignalGroup = Gtk.Template.Child()
     sort_changed = GObject.Signal()
 
     _selected_icon: str
@@ -65,10 +64,8 @@ class CollectionDetails(Adw.Dialog):
     def collection(self, collection: Collection):
         self._collection = collection
         self.insert_action_group("collection", collection)
-        remove_action = cast(Gio.SimpleAction, collection.lookup_action("remove"))
-        remove_action.connect("activate", lambda *_: self.force_close())
 
-    def __init__(self, **kwargs: Any):
+    def __init__(self, collection: Collection, **kwargs: Any):
         super().__init__(**kwargs)
 
         self.insert_action_group("details", group := Gio.SimpleActionGroup())
@@ -83,6 +80,13 @@ class CollectionDetails(Adw.Dialog):
             transform_to=lambda _, text: bool(text),
         )
 
+        self.collection_signals.connect_closure(
+            "notify::removed",
+            lambda *_: self.force_close(),
+            after=True,
+        )
+        self.collection = collection
+
         group_button = None
         for index, (row, col) in enumerate(product(range(3), range(7))):
             icon = _ICONS[index].name
@@ -132,9 +136,9 @@ class CollectionDetails(Adw.Dialog):
         self.close()
 
     @Gtk.Template.Callback()
-    def _or(self, _obj, first: _T, second: _T) -> _T:
+    def _or[T](self, _obj, first: T, second: T) -> T:
         return first or second
 
     @Gtk.Template.Callback()
-    def _if_else(self, _obj, condition: object, first: _T, second: _T) -> _T:
+    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
         return first if condition else second

cartridges/ui/collections.py

@@ -37,19 +37,9 @@ class CollectionFilter(Gtk.Filter):
 class CollectionSidebarItem(Adw.SidebarItem):  # pyright: ignore[reportAttributeAccessIssue]
     """A sidebar item representing a collection."""
 
-    @GObject.Property(type=Collection)
+    collection = GObject.Property(type=Collection)
-    def collection(self) -> Collection:
-        """The collection that `self` represents."""
-        return self._collection
 
-    @collection.setter
+    def __init__(self, collection: Collection, **kwargs: Any):
-    def collection(self, collection: Collection):
-        self._collection = collection
-        flags = GObject.BindingFlags.SYNC_CREATE
-        collection.bind_property("name", self, "title", flags)
-        collection.bind_property("icon-name", self, "icon-name", flags)
-
-    def __init__(self, **kwargs: Any):
         super().__init__(**kwargs)
 
         self.bind_property(
@@ -60,6 +50,13 @@ class CollectionSidebarItem(Adw.SidebarItem):  # pyright: ignore[reportAttribute
             lambda _, name: GLib.markup_escape_text(name),
         )
 
+        self._collection_bindings = GObject.BindingGroup()
+        flags = GObject.BindingFlags.DEFAULT
+        self._collection_bindings.bind("name", self, "title", flags)
+        self._collection_bindings.bind("icon-name", self, "icon-name", flags)
+        self.bind_property("collection", self._collection_bindings, "source")
+        self.collection = collection
+
 
 class CollectionButton(Gtk.ToggleButton):
     """A toggle button representing a collection."""

cartridges/ui/cover.blp

@@ -5,27 +5,27 @@ template $Cover: Adw.Bin {
   child: Adw.Clamp {
     orientation: vertical;
     unit: px;
-    maximum-size: bind _picture.height-request;
+    maximum-size: bind template.height;
-    tightening-threshold: bind _picture.height-request;
+    tightening-threshold: bind template.height;
 
     child: Adw.Clamp {
       unit: px;
-      maximum-size: bind _picture.width-request;
+      maximum-size: bind template.width;
-      tightening-threshold: bind _picture.width-request;
+      tightening-threshold: bind template.width;
 
       child: Adw.ViewStack {
         name: "cover";
-        visible-child-name: bind $_get_stack_child(template.paintable) as <string>;
+        visible-child-name: bind $_if_else(template.paintable, "cover", "icon") as <string>;
         overflow: hidden;
         enable-transitions: true;
 
         Adw.ViewStackPage {
           name: "cover";
 
-          child: Picture _picture {
+          child: Picture {
             paintable: bind template.paintable;
-            width-request: 200;
+            width-request: bind template.width;
-            height-request: 300;
+            height-request: bind template.height;
             content-fit: cover;
           };
         }
@@ -34,7 +34,10 @@ template $Cover: Adw.Bin {
           name: "icon";
 
           child: Image {
-            icon-name: bind template.app-icon-name;
+            icon-name: bind $_concat(
+              template.root as <Window>.application as <Application>.application-id,
+              "-symbolic"
+            ) as <string>;
             pixel-size: 80;
 
             styles [

cartridges/ui/cover.py

@@ -3,7 +3,7 @@
 
 from gi.repository import Adw, Gdk, GObject, Gtk
 
-from cartridges.config import APP_ID, PREFIX
+from cartridges.config import PREFIX
 
 
 @Gtk.Template.from_resource(f"{PREFIX}/cover.ui")
@@ -12,12 +12,14 @@ class Cover(Adw.Bin):
 
     __gtype_name__ = __qualname__
 
-    picture = GObject.Property(lambda self: self._picture, type=Gtk.Picture)
     paintable = GObject.Property(type=Gdk.Paintable)
-    app_icon_name = GObject.Property(type=str, default=f"{APP_ID}-symbolic")
+    width = GObject.Property(type=int, default=200)
-
+    height = GObject.Property(type=int, default=300)
-    _picture = Gtk.Template.Child()
 
     @Gtk.Template.Callback()
-    def _get_stack_child(self, _obj, paintable: Gdk.Paintable | None) -> str:
+    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
-        return "cover" if paintable else "icon"
+        return first if condition else second
+
+    @Gtk.Template.Callback()
+    def _concat(self, _obj, *strings: str) -> str:
+        return "".join(strings)

cartridges/ui/game-details.blp

@@ -1,6 +1,12 @@
 using Gtk 4.0;
 using Gdk 4.0;
 using Adw 1;
+using GObject 2.0;
+
+GObject.SignalGroup game_signals {
+  target: bind template.game;
+  target-type: typeof<$Game>;
+}
 
 template $GameDetails: Adw.NavigationPage {
   name: "details";

cartridges/ui/game-item.blp

@@ -12,8 +12,8 @@ template $GameItem: Box {
 
   Adw.Clamp {
     unit: px;
-    maximum-size: bind cover.picture as <Picture>.width-request;
+    maximum-size: bind cover.width;
-    tightening-threshold: bind cover.picture as <Picture>.width-request;
+    tightening-threshold: bind cover.width;
 
     child: Overlay {
       child: $Cover cover {

cartridges/ui/game_details.py

@@ -7,7 +7,7 @@ import sys
 import time
 from datetime import UTC, datetime
 from gettext import gettext as _
-from typing import Any, TypeVar, cast
+from typing import Any, cast
 from urllib.parse import quote
 
 from gi.repository import Adw, Gdk, Gio, GLib, GObject, Gtk
@@ -20,14 +20,12 @@ from cartridges.sources import imported
 from .collections import CollectionsBox
 from .cover import Cover  # noqa: F401
 
-_POP_ON_ACTION = "hide", "unhide", "remove"
+_POP_ON_PROPERTY_NOTIFY = "hidden", "removed"
 _EDITABLE_PROPERTIES = {prop.name for prop in games.PROPERTIES if prop.editable}
 _REQUIRED_PROPERTIES = {
     prop.name for prop in games.PROPERTIES if prop.editable and prop.required
 }
 
-_T = TypeVar("_T")
-
 
 @Gtk.Template.from_resource(f"{PREFIX}/game-details.ui")
 class GameDetails(Adw.NavigationPage):
@@ -42,6 +40,7 @@ class GameDetails(Adw.NavigationPage):
     developer_entry: Adw.EntryRow = Gtk.Template.Child()
     executable_entry: Adw.EntryRow = Gtk.Template.Child()
 
+    game_signals: GObject.SignalGroup = Gtk.Template.Child()
     sort_changed = GObject.Signal()
 
     @GObject.Property(type=Game)
@@ -54,21 +53,9 @@ class GameDetails(Adw.NavigationPage):
         self._game = game
         self.insert_action_group("game", game)
 
-        for action, ident in self._signal_ids.copy().items():
-            action.disconnect(ident)
-            del self._signal_ids[action]
-
-        for name in _POP_ON_ACTION:
-            action = cast(Gio.SimpleAction, game.lookup_action(name))
-            self._signal_ids[action] = action.connect(
-                "activate", lambda *_: self.activate_action("navigation.pop")
-            )
-
     def __init__(self, **kwargs: Any):
         super().__init__(**kwargs)
 
-        self._signal_ids = dict[Gio.SimpleAction, int]()
-
         self.insert_action_group("details", group := Gio.SimpleActionGroup())
         group.add_action_entries((
             ("edit", lambda *_: self.edit()),
@@ -102,6 +89,13 @@ class GameDetails(Adw.NavigationPage):
         valid = Gtk.ClosureExpression.new(bool, lambda _, *values: all(values), entries)
         valid.bind(apply, "enabled")
 
+        for name in _POP_ON_PROPERTY_NOTIFY:
+            self.game_signals.connect_closure(
+                f"notify::{name}",
+                lambda *_: self.activate_action("navigation.pop"),
+                after=True,
+            )
+
     def edit(self):
         """Enter edit mode."""
         for prop in _EDITABLE_PROPERTIES:
@@ -148,11 +142,11 @@ class GameDetails(Adw.NavigationPage):
             self.collections_box.finish()
 
     @Gtk.Template.Callback()
-    def _or(self, _obj, first: _T, second: _T) -> _T:
+    def _or[T](self, _obj, first: T, second: T) -> T:
         return first or second
 
     @Gtk.Template.Callback()
-    def _if_else(self, _obj, condition: object, first: _T, second: _T) -> _T:
+    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
         return first if condition else second
 
     @Gtk.Template.Callback()

cartridges/ui/games.py

@@ -19,7 +19,24 @@ _SORT_MODES = {
     "oldest": ("added", False),
 }
 
-model = Gtk.FlattenListModel.new(sources.model)
+filter_ = Gtk.EveryFilter()
+filter_.append(
+    Gtk.BoolFilter(
+        expression=Gtk.PropertyExpression.new(Game, None, "removed"),
+        invert=True,
+    )
+)
+filter_.append(
+    Gtk.BoolFilter(
+        expression=Gtk.PropertyExpression.new(Game, None, "blacklisted"),
+        invert=True,
+    )
+)
+model = Gtk.FilterListModel(
+    model=Gtk.FlattenListModel.new(sources.model),
+    filter=filter_,
+    watch_items=True,  # pyright: ignore[reportCallIssue]
+)
 
 
 class GameSorter(Gtk.Sorter):

cartridges/ui/meson.build

@@ -7,6 +7,7 @@ python.install_sources(
         'game_details.py',
         'game_item.py',
         'games.py',
+        'sources.py',
         'window.py',
     ),
     subdir: 'cartridges' / 'ui',

cartridges/ui/sources.py

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+# SPDX-FileCopyrightText: Copyright 2025 Jamie Gravendeel
+
+from typing import Any
+
+from gi.repository import Adw, Gio, GObject, Gtk
+
+from cartridges import sources
+from cartridges.sources import Source
+from cartridges.ui import games
+
+
+class SourceSidebarItem(Adw.SidebarItem):  # pyright: ignore[reportAttributeAccessIssue]
+    """A sidebar item representing a source."""
+
+    source = GObject.Property(type=Source)
+    model = GObject.Property(type=Gio.ListModel)
+
+    def __init__(self, source: Source, **kwargs: Any):
+        super().__init__(**kwargs)
+
+        # https://gitlab.gnome.org/GNOME/gtk/-/issues/7959
+        self._model_signals = GObject.SignalGroup.new(Gio.ListModel)
+        self._model_signals.connect_closure(
+            "items-changed",
+            lambda model, *_: model.notify("n-items"),
+            after=True,
+        )
+
+        self._source_bindings = GObject.BindingGroup()
+        flags = GObject.BindingFlags.DEFAULT
+        self._source_bindings.bind("name", self, "title", flags)
+        self._source_bindings.bind("icon-name", self, "icon-name", flags)
+        self.bind_property("source", self._source_bindings, "source")
+
+        self.model = Gtk.FilterListModel(filter=games.filter_, watch_items=True)  # pyright: ignore[reportCallIssue]
+        self.model.bind_property(
+            "n-items",
+            self,
+            "visible",
+            GObject.BindingFlags.SYNC_CREATE,
+        )
+        self.bind_property("source", self.model, "model")
+        self.source = source
+
+
+model = Gtk.SortListModel.new(
+    sources.model,
+    Gtk.StringSorter.new(Gtk.PropertyExpression.new(Source, None, "name")),
+)

cartridges/ui/window.blp

@@ -1,5 +1,17 @@
 using Gtk 4.0;
 using Adw 1;
+using GObject 2.0;
+using Gio 2.0;
+
+GObject.SignalGroup collection_signals {
+  target: bind template.collection;
+  target-type: typeof<$Collection>;
+}
+
+GObject.SignalGroup model_signals {
+  target: bind template.model;
+  target-type: typeof<Gio.ListModel>;
+}
 
 template $Window: Adw.ApplicationWindow {
   realize => $_setup_gamepad_monitor();
@@ -94,6 +106,10 @@ template $Window: Adw.ApplicationWindow {
                 }
               }
 
+              Adw.SidebarSection sources {
+                title: _("Sources");
+              }
+
               Adw.SidebarSection collections {
                 title: _("Collections");
 
@@ -208,7 +224,7 @@ template $Window: Adw.ApplicationWindow {
             }
 
             content: Adw.ToastOverlay toast_overlay {
-              child: Adw.ViewStack view_stack {
+              child: Adw.ViewStack {
                 visible-child-name: bind $_if_else(
                   grid.model as <NoSelection>.n-items,
                   "grid",
@@ -262,16 +278,6 @@ template $Window: Adw.ApplicationWindow {
                                 expression: expr item as <$Game>.hidden;
                                 invert: bind template.show-hidden inverted;
                               }
-
-                              BoolFilter {
-                                expression: expr item as <$Game>.removed;
-                                invert: true;
-                              }
-
-                              BoolFilter {
-                                expression: expr item as <$Game>.blacklisted;
-                                invert: true;
-                              }
                             };
 
                             model: bind template.model;

cartridges/ui/window.py

@@ -6,7 +6,7 @@
 import sys
 from collections.abc import Callable
 from gettext import gettext as _
-from typing import Any, TypeVar, cast
+from typing import Any, cast
 
 from gi.repository import Adw, Gio, GLib, GObject, Gtk
 
@@ -14,13 +14,14 @@ from cartridges import STATE_SETTINGS
 from cartridges.collections import Collection
 from cartridges.config import PREFIX, PROFILE
 from cartridges.sources import imported
-from cartridges.ui import collections, games
+from cartridges.ui import collections, games, sources
 
 from .collection_details import CollectionDetails
 from .collections import CollectionFilter, CollectionSidebarItem
 from .game_details import GameDetails
 from .game_item import GameItem  # noqa: F401
 from .games import GameSorter
+from .sources import SourceSidebarItem
 
 if sys.platform.startswith("linux"):
     from cartridges import gamepads
@@ -34,7 +35,6 @@ SORT_MODES = {
     "oldest": ("added", True),
 }
 
-_T = TypeVar("_T")
 type _UndoFunc = Callable[[], Any]
 
 
@@ -46,6 +46,7 @@ class Window(Adw.ApplicationWindow):
 
     split_view: Adw.OverlaySplitView = Gtk.Template.Child()
     sidebar: Adw.Sidebar = Gtk.Template.Child()  # pyright: ignore[reportAttributeAccessIssue]
+    sources: Adw.SidebarSection = Gtk.Template.Child()  # pyright: ignore[reportAttributeAccessIssue]
     collections: Adw.SidebarSection = Gtk.Template.Child()  # pyright: ignore[reportAttributeAccessIssue]
     new_collection_item: Adw.SidebarItem = Gtk.Template.Child()  # pyright: ignore[reportAttributeAccessIssue]
     collection_menu: Gio.Menu = Gtk.Template.Child()
@@ -56,44 +57,23 @@ class Window(Adw.ApplicationWindow):
     sort_button: Gtk.MenuButton = Gtk.Template.Child()
     main_menu_button: Gtk.MenuButton = Gtk.Template.Child()
     toast_overlay: Adw.ToastOverlay = Gtk.Template.Child()
-    view_stack: Adw.ViewStack = Gtk.Template.Child()
     grid: Gtk.GridView = Gtk.Template.Child()
     sorter: GameSorter = Gtk.Template.Child()
     collection_filter: CollectionFilter = Gtk.Template.Child()
     details: GameDetails = Gtk.Template.Child()
 
-    model = GObject.Property(type=Gio.ListModel, default=games.model)
+    collection = GObject.Property(type=Collection)
+    collection_signals: GObject.SignalGroup = Gtk.Template.Child()
+    model = GObject.Property(type=Gio.ListModel)
+    model_signals: GObject.SignalGroup = Gtk.Template.Child()
 
     search_text = GObject.Property(type=str)
     show_hidden = GObject.Property(type=bool, default=False)
 
     settings = GObject.Property(type=Gtk.Settings)
 
-    _collection: Collection | None = None
-    _collection_removed_signal: int | None = None
     _selected_sidebar_item = 0
 
-    @GObject.Property(type=Collection)
-    def collection(self) -> Collection | None:
-        """The currently selected collection."""
-        return self._collection
-
-    @collection.setter
-    def collection(self, collection: Collection | None):
-        if self._collection and self._collection_removed_signal:
-            self._collection.disconnect(self._collection_removed_signal)
-
-        self._collection = collection
-        self._collection_removed_signal = (
-            collection.connect("notify::removed", lambda *_: self._collection_removed())
-            if collection
-            else None
-        )
-
-    def _collection_removed(self):
-        self.collection = None
-        self.sidebar.props.selected = 0
-
     def __init__(self, **kwargs: Any):
         super().__init__(**kwargs)
 
@@ -110,9 +90,13 @@ class Window(Adw.ApplicationWindow):
 
         # https://gitlab.gnome.org/GNOME/gtk/-/issues/7901
         self.search_entry.set_key_capture_widget(self)
+        self.sources.bind_model(
+            sources.model,
+            lambda source: SourceSidebarItem(source),
+        )
         self.collections.bind_model(
             collections.model,
-            lambda collection: CollectionSidebarItem(collection=collection),
+            lambda collection: CollectionSidebarItem(collection),
         )
 
         self.add_action(STATE_SETTINGS.create_action("show-sidebar"))
@@ -148,6 +132,18 @@ class Window(Adw.ApplicationWindow):
             ("undo", lambda *_: self._undo()),
         ))
 
+        self.collection_signals.connect_closure(
+            "notify::removed",
+            lambda *_: self._collection_removed(),
+            after=True,
+        )
+        self.model_signals.connect_closure(
+            "items-changed",
+            lambda model, *_: None if model else self._model_emptied(),
+            after=True,
+        )
+        self.model = games.model
+
         self._history: dict[Adw.Toast, _UndoFunc] = {}
 
     def send_toast(self, title: str, *, undo: _UndoFunc | None = None):
@@ -164,26 +160,13 @@ class Window(Adw.ApplicationWindow):
 
         self.toast_overlay.add_toast(toast)
 
-    def navigate_sidebar(self, sidebar: Adw.Sidebar, item: Adw.SidebarItem):  # pyright: ignore[reportAttributeAccessIssue]
+    def _collection_removed(self):
-        """Select given item in the sidebar.
-
-        Item should correspond to a collection, or the all game category/
-        new collection buttons.
-        """
-        match item:
-            case self.new_collection_item:
-                self._add_collection()
-                sidebar.props.selected = self._selected_sidebar_item
-            case CollectionSidebarItem():
-                self.collection = item.collection
-            case _:
         self.collection = None
+        self.sidebar.props.selected = 0
 
-        if item is not self.new_collection_item:
+    def _model_emptied(self):
-            self._selected_sidebar_item = sidebar.props.selected
+        self.model = games.model
-
+        self.sidebar.props.selected = 0
-        if self.split_view.props.collapsed:
-            self.split_view.props.show_sidebar = False
 
     @Gtk.Template.Callback()
     def _show_sidebar_title(self, _obj, layout: str) -> bool:
@@ -192,7 +175,27 @@ class Window(Adw.ApplicationWindow):
 
     @Gtk.Template.Callback()
     def _navigate(self, sidebar: Adw.Sidebar, index: int):  # pyright: ignore[reportAttributeAccessIssue]
-        self.navigate_sidebar(sidebar, sidebar.get_item(index))
+        item = sidebar.get_item(index)
+
+        match item:
+            case self.new_collection_item:
+                self._add_collection()
+                sidebar.props.selected = self._selected_sidebar_item
+            case SourceSidebarItem():
+                self.collection = None
+                self.model = item.model
+            case CollectionSidebarItem():
+                self.collection = item.collection
+                self.model = games.model
+            case _:
+                self.collection = None
+                self.model = games.model
+
+        if item is not self.new_collection_item:
+            self._selected_sidebar_item = index
+
+        if self.split_view.props.collapsed:
+            self.split_view.props.show_sidebar = False
 
     @Gtk.Template.Callback()
     def _update_selection(self, sidebar: Adw.Sidebar, *_args):  # pyright: ignore[reportAttributeAccessIssue]
@@ -221,7 +224,7 @@ class Window(Adw.ApplicationWindow):
             gamepads.setup_monitor()  # pyright: ignore[reportPossiblyUnboundVariable]
 
     @Gtk.Template.Callback()
-    def _if_else(self, _obj, condition: object, first: _T, second: _T) -> _T:
+    def _if_else[T](self, _obj, condition: object, first: T, second: T) -> T:
         return first if condition else second
 
     @Gtk.Template.Callback()
@@ -273,12 +276,12 @@ class Window(Adw.ApplicationWindow):
         if game_id:
             collection.game_ids.add(game_id)
 
-        details = CollectionDetails(collection=collection)
+        details = CollectionDetails(collection)
         details.present(self)
 
     def _edit_collection(self, pos: int):
         collection = self.collections.get_item(pos).collection
-        details = CollectionDetails(collection=collection)
+        details = CollectionDetails(collection)
         details.connect(
             "sort-changed",
             lambda *_: collections.sorter.changed(Gtk.SorterChange.DIFFERENT),

data/icons/heroic-symbolic.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="none"><path fill="#000" fill-rule="evenodd" d="m7.872 16-3.817-3.083L2 2.79 7.872 0l5.871 2.789-2.055 10.128zm0-4.257-.294-.293-.88-7.927 1.1-1.908 1.174 1.908-.807 7.927zm-.294.367-.147.367-1.761.294-.294-.66.294-.662 1.761.294zm-.073.734-.22 1.541.587.294.587-.294-.22-1.541-.367-.22zm.807-.367-.147-.367.147-.367 1.761-.293.294.66-.294.66z" clip-rule="evenodd"/></svg>

data/icons/icons.gresource.xml.in

@@ -4,6 +4,10 @@
     <file>apply-symbolic.svg</file>
     <file>cancel-symbolic.svg</file>
     <file>filter-symbolic.svg</file>
+    <!-- Sources -->
+    <file>heroic-symbolic.svg</file>
+    <file>imported-symbolic.svg</file>
+    <file>steam-symbolic.svg</file>
     <!-- Categories -->
     <file>collection-symbolic.svg</file>
     <file>ball-symbolic.svg</file>

data/icons/imported-symbolic.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"><path fill="#222" d="M7 1v6H1v2h6v6h2V9h6V7H9V1zm0 0"/></svg>

data/icons/steam-symbolic.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="none"><g clip-path="url(#a)"><path fill="#000" fill-rule="evenodd" d="M9.352 5.1a1.509 1.509 0 1 0 2.51 1.675A1.509 1.509 0 0 0 9.352 5.1m2.923-.277a2.009 2.009 0 1 1-3.34 2.231 2.009 2.009 0 0 1 3.34-2.23ZM5.01 12.131l-.983-.407a1.7 1.7 0 0 0 3.108-.103 1.696 1.696 0 0 0-1.213-2.29 1.7 1.7 0 0 0-.966.07l1.015.421a1.249 1.249 0 0 1-.96 2.307zM2.546 2.121A8 8 0 0 1 7.966 0l.003.013a7.99 7.99 0 0 1 7.159 4.432 7.996 7.996 0 0 1-4.277 11.018 7.99 7.99 0 0 1-8.274-1.558A8 8 0 0 1 .279 10.18l3.064 1.267A2.264 2.264 0 0 0 7.823 11v-.107l2.718-1.938h.063A3.016 3.016 0 1 0 7.589 5.94v.031l-1.906 2.76h-.126c-.454 0-.898.138-1.273.395L0 7.354A8 8 0 0 1 2.546 2.12Z" clip-rule="evenodd"/></g><defs><clipPath id="a"><path fill="#fff" d="M0 0h16v16H0z"/></clipPath></defs></svg>

po/POTFILES.in

@@ -17,6 +17,7 @@ cartridges/ui/game_details.py
 cartridges/ui/game_item.py
 cartridges/ui/games.py
 cartridges/ui/shortcuts-dialog.blp
+cartridges/ui/sources.py
 cartridges/ui/window.blp
 cartridges/ui/window.py
 data/page.kramo.Cartridges.desktop.in