Changes for nullability of bindables

osu.Game.Rulesets.Taiko/Skinning/Legacy/LegacyTaikoScroller.cs

@@ -17,7 +17,7 @@ namespace osu.Game.Rulesets.Taiko.Skinning.Legacy
 {
     public partial class LegacyTaikoScroller : CompositeDrawable
     {
-        public Bindable<JudgementResult> LastResult = new Bindable<JudgementResult>();
+        public Bindable<JudgementResult?> LastResult = new Bindable<JudgementResult?>();
 
         public LegacyTaikoScroller()
         {

osu.Game/Graphics/UserInterface/DrawableStatefulMenuItem.cs

@@ -37,7 +37,7 @@ protected override bool OnMouseDown(MouseDownEvent e)
         private partial class ToggleTextContainer : TextContainer
         {
             private readonly StatefulMenuItem menuItem;
-            private readonly Bindable<object> state;
+            private readonly Bindable<object?> state;
             private readonly SpriteIcon stateIcon;
 
             public ToggleTextContainer(StatefulMenuItem menuItem)
@@ -61,7 +61,7 @@ protected override void LoadComplete()
                 state.BindValueChanged(updateState, true);
             }
 
-            private void updateState(ValueChangedEvent<object> state)
+            private void updateState(ValueChangedEvent<object?> state)
             {
                 var icon = menuItem.GetIconForState(state.NewValue);
 

osu.Game/Graphics/UserInterface/StatefulMenuItem.cs

@@ -2,7 +2,9 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Diagnostics;
 using osu.Framework.Bindables;
+using osu.Framework.Extensions.ObjectExtensions;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Localisation;
 
@@ -16,15 +18,15 @@ public abstract class StatefulMenuItem : OsuMenuItem
         /// <summary>
         /// The current state that should be displayed.
         /// </summary>
-        public readonly Bindable<object> State = new Bindable<object>();
+        public readonly Bindable<object?> State = new Bindable<object?>();
 
         /// <summary>
         /// Creates a new <see cref="StatefulMenuItem"/>.
         /// </summary>
         /// <param name="text">The text to display.</param>
         /// <param name="changeStateFunc">A function that mutates a state to another state after this <see cref="StatefulMenuItem"/> is pressed.</param>
         /// <param name="type">The type of action which this <see cref="StatefulMenuItem"/> performs.</param>
-        protected StatefulMenuItem(LocalisableString text, Func<object, object> changeStateFunc, MenuItemType type = MenuItemType.Standard)
+        protected StatefulMenuItem(LocalisableString text, Func<object?, object?> changeStateFunc, MenuItemType type = MenuItemType.Standard)
             : this(text, changeStateFunc, type, null)
         {
         }
@@ -36,7 +38,7 @@ protected StatefulMenuItem(LocalisableString text, Func<object, object> changeSt
         /// <param name="changeStateFunc">A function that mutates a state to another state after this <see cref="StatefulMenuItem"/> is pressed.</param>
         /// <param name="type">The type of action which this <see cref="StatefulMenuItem"/> performs.</param>
         /// <param name="action">A delegate to be invoked when this <see cref="StatefulMenuItem"/> is pressed.</param>
-        protected StatefulMenuItem(LocalisableString text, Func<object, object>? changeStateFunc, MenuItemType type, Action<object>? action)
+        protected StatefulMenuItem(LocalisableString text, Func<object?, object?>? changeStateFunc, MenuItemType type, Action<object?>? action)
             : base(text, type)
         {
             Action.Value = () =>
@@ -51,7 +53,7 @@ protected StatefulMenuItem(LocalisableString text, Func<object, object>? changeS
         /// </summary>
         /// <param name="state">The state to retrieve the relevant icon for.</param>
         /// <returns>The icon to be displayed for <paramref name="state"/>.</returns>
-        public abstract IconUsage? GetIconForState(object state);
+        public abstract IconUsage? GetIconForState(object? state);
     }
 
     public abstract class StatefulMenuItem<T> : StatefulMenuItem
@@ -81,20 +83,21 @@ protected StatefulMenuItem(LocalisableString text, Func<T, T>? changeStateFunc,
         /// <param name="type">The type of action which this <see cref="StatefulMenuItem"/> performs.</param>
         /// <param name="action">A delegate to be invoked when this <see cref="StatefulMenuItem"/> is pressed.</param>
         protected StatefulMenuItem(LocalisableString text, Func<T, T>? changeStateFunc, MenuItemType type, Action<T>? action)
-            : base(text, o => changeStateFunc?.Invoke((T)o) ?? o, type, o => action?.Invoke((T)o))
+            : base(text, o => changeStateFunc?.Invoke((T)o.AsNonNull()) ?? o, type, o => action?.Invoke((T)o.AsNonNull()))
         {
             base.State.BindValueChanged(state =>
             {
                 if (state.NewValue == null)
                     base.State.Value = default(T);
 
+                Debug.Assert(base.State.Value != null);
                 State.Value = (T)base.State.Value;
             }, true);
 
             State.BindValueChanged(state => base.State.Value = state.NewValue);
         }
 
-        public sealed override IconUsage? GetIconForState(object state) => GetIconForState((T)state);
+        public sealed override IconUsage? GetIconForState(object? state) => GetIconForState((T)state!);
 
         /// <summary>
         /// Retrieves the icon to be displayed for a state.

osu.Game/Overlays/Chat/ChatTextBar.cs

@@ -32,7 +32,7 @@ public partial class ChatTextBar : Container
         public void TextBoxKillFocus() => chatTextBox.KillFocus();
 
         [Resolved]
-        private Bindable<Channel> currentChannel { get; set; } = null!;
+        private Bindable<Channel?> currentChannel { get; set; } = null!;
 
         private Container chattingTextContainer = null!;
         private OsuSpriteText chattingText = null!;
@@ -138,7 +138,7 @@ protected override void LoadComplete()
 
             currentChannel.BindValueChanged(change =>
             {
-                Channel newChannel = change.NewValue;
+                Channel? newChannel = change.NewValue;
 
                 switch (newChannel?.Type)
                 {

osu.Game/Overlays/Settings/Sections/Graphics/LayoutSettings.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Drawing;
 using System.Linq;
 using osu.Framework;
@@ -200,11 +201,7 @@
 
             currentDisplay.BindValueChanged(display => Schedule(() =>
             {
-                if (display.NewValue == null)
-                {
-                    resolutions.Clear();
-                    return;
-                }
+                Debug.Assert(display.NewValue != null);
 
                 resolutions.ReplaceRange(1, resolutions.Count - 1, display.NewValue.DisplayModes
                                                                           .Where(m => m.Size.Width >= 800 && m.Size.Height >= 600)

osu.Game/Screens/Edit/Components/BottomBarContainer.cs

@@ -18,7 +18,7 @@ public partial class BottomBarContainer : Container
 
         protected readonly IBindable<WorkingBeatmap> Beatmap = new Bindable<WorkingBeatmap>();
 
-        protected readonly IBindable<Track> Track = new Bindable<Track>();
+        protected readonly IBindable<Track?> Track = new Bindable<Track?>();
 
         public readonly Drawable Background;
         private readonly Container content;

osu.Game/Screens/Edit/Setup/ColoursSection.cs

@@ -66,7 +66,7 @@ protected override void LoadComplete()
                 syncingColours = true;
 
                 comboColours.Colours.Clear();
-                comboColours.Colours.AddRange(Beatmap.BeatmapSkin?.ComboColours);
+                comboColours.Colours.AddRange(Beatmap.BeatmapSkin?.ComboColours ?? []);
 
                 syncingColours = false;
             });

osu.Game/Screens/Edit/Timing/EffectSection.cs

@@ -81,9 +81,9 @@ private void updateControlPointFromSlider(ValueChangedEvent<double> scrollSpeed)
             effectPoint.ScrollSpeedBindable.Value = scrollSpeed.NewValue;
         }
 
-        protected override EffectControlPoint CreatePoint()
+        protected override EffectControlPoint CreatePointFrom(double time)
         {
-            var reference = Beatmap.ControlPointInfo.EffectPointAt(SelectedGroup.Value.Time);
+            var reference = Beatmap.ControlPointInfo.EffectPointAt(time);
 
             return new EffectControlPoint
             {

osu.Game/Screens/Edit/Timing/GroupSection.cs

@@ -21,7 +21,7 @@ internal partial class GroupSection : CompositeDrawable
         private OsuButton button = null!;
 
         [Resolved]
-        protected Bindable<ControlPointGroup> SelectedGroup { get; private set; } = null!;
+        protected Bindable<ControlPointGroup?> SelectedGroup { get; private set; } = null!;
 
         [Resolved]
         protected EditorBeatmap Beatmap { get; private set; } = null!;

osu.Game/Screens/Edit/Timing/Section.cs

@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Diagnostics;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -30,7 +31,7 @@ internal abstract partial class Section<T> : CompositeDrawable
         protected EditorBeatmap Beatmap { get; private set; } = null!;
 
         [Resolved]
-        protected Bindable<ControlPointGroup> SelectedGroup { get; private set; } = null!;
+        protected Bindable<ControlPointGroup?> SelectedGroup { get; private set; } = null!;
 
         [Resolved]
         protected IEditorChangeHandler? ChangeHandler { get; private set; }
@@ -103,12 +104,13 @@ protected override void LoadComplete()
                     }
 
                     if (ControlPoint.Value == null)
-                        SelectedGroup.Value.Add(ControlPoint.Value = CreatePoint());
+                        SelectedGroup.Value.Add(ControlPoint.Value = CreatePointFrom(SelectedGroup.Value.Time));
                 }
                 else
                 {
                     if (ControlPoint.Value != null)
                     {
+                        Debug.Assert(SelectedGroup.Value != null);
                         SelectedGroup.Value.Remove(ControlPoint.Value);
                         ControlPoint.Value = null;
                     }
@@ -128,6 +130,6 @@ protected override void LoadComplete()
 
         protected abstract void OnControlPointChanged(ValueChangedEvent<T?> point);
 
-        protected abstract T CreatePoint();
+        protected abstract T CreatePointFrom(double time);
     }
 }

osu.Game/Screens/Edit/Timing/TapTimingControl.cs

@@ -31,7 +31,7 @@ public partial class TapTimingControl : CompositeDrawable
         private OsuConfigManager configManager { get; set; } = null!;
 
         [Resolved]
-        private Bindable<ControlPointGroup> selectedGroup { get; set; } = null!;
+        private Bindable<ControlPointGroup?> selectedGroup { get; set; } = null!;
 
         private readonly BindableBool isHandlingTapping = new BindableBool();
 

osu.Game/Screens/Edit/Timing/TimingSection.cs

@@ -83,9 +83,9 @@ protected override void OnControlPointChanged(ValueChangedEvent<TimingControlPoi
             }
         }
 
-        protected override TimingControlPoint CreatePoint()
+        protected override TimingControlPoint CreatePointFrom(double time)
         {
-            var reference = Beatmap.ControlPointInfo.TimingPointAt(SelectedGroup.Value.Time);
+            var reference = Beatmap.ControlPointInfo.TimingPointAt(time);
 
             return new TimingControlPoint
             {

osu.Game/Screens/OnlinePlay/Match/DrawableMatchRoom.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Diagnostics;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -38,6 +39,10 @@ public DrawableMatchRoom(Room room, bool allowEdit = true)
         {
             this.allowEdit = allowEdit;
 
+            // Roslyn sees required non-nullable property as nullable in constructor,
+            // as it can't see the implementation provides a fallback.
+            Debug.Assert(SelectedItem != null);
+
             base.SelectedItem.BindTo(SelectedItem);
         }
 

osu.Game/Screens/Select/Leaderboards/BeatmapLeaderboard.cs

@@ -68,7 +68,7 @@ public bool FilterMods
         }
 
         [Resolved]
-        private IBindable<RulesetInfo> ruleset { get; set; } = null!;
+        private IBindable<RulesetInfo?> ruleset { get; set; } = null!;
 
         [Resolved]
         private IBindable<IReadOnlyList<Mod>> mods { get; set; } = null!;
@@ -186,6 +186,7 @@ private void subscribeToLocalScores(BeatmapInfo beatmapInfo, CancellationToken c
             scoreSubscription?.Dispose();
             scoreSubscription = null;
 
+            Debug.Assert(ruleset.Value != null);
             scoreSubscription = realm.RegisterForNotifications(r =>
                 r.All<ScoreInfo>().Filter($"{nameof(ScoreInfo.BeatmapInfo)}.{nameof(BeatmapInfo.ID)} == $0"
                                           + $" AND {nameof(ScoreInfo.BeatmapInfo)}.{nameof(BeatmapInfo.Hash)} == {nameof(ScoreInfo.BeatmapHash)}"

osu.Game/Screens/Select/SongSelect.cs

@@ -135,7 +135,7 @@ public abstract partial class SongSelect : ScreenWithBeatmapBackground, IKeyBind
 
         private FooterButtonOptions beatmapOptionsButton = null!;
 
-        private readonly Bindable<RulesetInfo> decoupledRuleset = new Bindable<RulesetInfo>();
+        private readonly Bindable<RulesetInfo?> decoupledRuleset = new Bindable<RulesetInfo?>();
 
         private double audioFeedbackLastPlaybackTime;
 
@@ -426,7 +426,7 @@ protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnl
 
             dependencies.CacheAs(this);
             dependencies.CacheAs(decoupledRuleset);
-            dependencies.CacheAs<IBindable<RulesetInfo>>(decoupledRuleset);
+            dependencies.CacheAs<IBindable<RulesetInfo?>>(decoupledRuleset);
 
             return dependencies;
         }
@@ -994,7 +994,7 @@ private void bindBindables()
 
             selectedMods.BindValueChanged(_ =>
             {
-                if (decoupledRuleset.Value.Equals(rulesetNoDebounce))
+                if (decoupledRuleset.Value?.Equals(rulesetNoDebounce) ?? false)
                     advancedStats.Mods.Value = selectedMods.Value;
             }, true);
 

osu.Game/Skinning/SkinnableSprite.cs

@@ -48,7 +48,7 @@ public SkinnableSprite()
 
             SpriteName.BindValueChanged(name =>
             {
-                ((SpriteComponentLookup)ComponentLookup).LookupName = name.NewValue ?? string.Empty;
+                ((SpriteComponentLookup)ComponentLookup).LookupName = name.NewValue;
                 if (IsLoaded)
                     SkinChanged(CurrentSkin);
             });