Add key binding to deselect all mods

Defaults to `Backspace`.

osu.Game.Tests/Visual/UserInterface/TestSceneModSelectOverlay.cs

@@ -1,4 +1,4 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// 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;
@@ -416,6 +416,22 @@ namespace osu.Game.Tests.Visual.UserInterface
             AddAssert("unimplemented mod panel is filtered", () => getPanelForMod(typeof(TestUnimplementedMod)).Filtered.Value);
         }
 
+        [Test]
+        public void TestDeselectAllViaKey()
+        {
+            createScreen();
+            changeRuleset(0);
+
+            AddStep("select DT + HD", () => SelectedMods.Value = new Mod[] { new OsuModDoubleTime(), new OsuModHidden() });
+            AddAssert("DT + HD selected", () => modSelectOverlay.ChildrenOfType<ModPanel>().Count(panel => panel.Active.Value) == 2);
+
+            AddStep("press bakcspace", () =>
+            {
+                InputManager.Key(Key.BackSpace);
+            });
+            AddUntilStep("all mods deselected", () => !SelectedMods.Value.Any());
+        }
+
         [Test]
         public void TestDeselectAllViaButton()
         {

osu.Game/Input/Bindings/GlobalActionContainer.cs

@@ -109,6 +109,7 @@ namespace osu.Game.Input.Bindings
             new KeyBinding(InputKey.F2, GlobalAction.SelectNextRandom),
             new KeyBinding(new[] { InputKey.Shift, InputKey.F2 }, GlobalAction.SelectPreviousRandom),
             new KeyBinding(InputKey.F3, GlobalAction.ToggleBeatmapOptions),
+            new KeyBinding(InputKey.BackSpace, GlobalAction.DeselectAllMods),
         };
 
         public IEnumerable<KeyBinding> AudioControlKeyBindings => new[]
@@ -318,5 +319,8 @@ namespace osu.Game.Input.Bindings
 
         [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.SelectNextGroup))]
         SelectNextGroup,
+
+        [LocalisableDescription(typeof(GlobalActionKeyBindingStrings), nameof(GlobalActionKeyBindingStrings.DeselectAllMods))]
+        DeselectAllMods,
     }
 }

osu.Game/Localisation/GlobalActionKeyBindingStrings.cs

@@ -209,6 +209,11 @@ namespace osu.Game.Localisation
         /// </summary>
         public static LocalisableString ToggleModSelection => new TranslatableString(getKey(@"toggle_mod_selection"), @"Toggle Mod Select");
 
+        /// <summary>
+        /// "Deselect all mods"
+        /// </summary>
+        public static LocalisableString DeselectAllMods => new TranslatableString(getKey(@"deselect_all_mods"), @"Deselect all mods");
+
         /// <summary>
         /// "Random"
         /// </summary>

osu.Game/Overlays/Mods/ModSelectOverlay.cs

@@ -508,6 +508,10 @@ namespace osu.Game.Overlays.Mods
                     hideOverlay(true);
                     return true;
                 }
+
+                case GlobalAction.DeselectAllMods:
+                    DeselectAll();
+                    return true;
             }
 
             return base.OnPressed(e);