Remove MaskContainer dependency in MaskSelection

osu.Game/Rulesets/Edit/HitObjectComposer.cs

@@ -251,8 +251,7 @@ namespace osu.Game.Rulesets.Edit
         /// Creates a <see cref="MaskSelection"/> which outlines <see cref="DrawableHitObject"/>s
         /// and handles hitobject pattern adjustments.
         /// </summary>
-        /// <param name="maskContainer">The <see cref="HitObjectMask"/> container.</param>
+        public virtual MaskSelection CreateMaskSelection() => new MaskSelection();
-        public virtual MaskSelection CreateSelectionBox(MaskContainer maskContainer) => new MaskSelection(maskContainer);
 
         /// <summary>
         /// Creates a <see cref="ScalableContainer"/> which provides a layer above or below the <see cref="Playfield"/>.

osu.Game/Screens/Edit/Screens/Compose/Layers/HitObjectMaskLayer.cs

@@ -18,7 +18,6 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
         private readonly HitObjectComposer composer;
 
         private MaskContainer maskContainer;
-        private MaskSelection maskSelection;
 
         public HitObjectMaskLayer(Playfield playfield, HitObjectComposer composer)
         {
@@ -33,7 +32,12 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
         {
             maskContainer = new MaskContainer();
 
-            maskSelection = composer.CreateSelectionBox(maskContainer);
+            var maskSelection = composer.CreateMaskSelection();
+
+            maskContainer.MaskSelected += maskSelection.HandleSelected;
+            maskContainer.MaskDeselected += maskSelection.HandleDeselected;
+            maskContainer.MaskSelectionRequested += maskSelection.HandleSelectionRequested;
+            maskSelection.DeselectAll = maskContainer.DeselectAll;
 
             var dragLayer = new DragLayer(maskContainer.Select);
             dragLayer.DragEnd += () => maskSelection.UpdateVisibility();

osu.Game/Screens/Edit/Screens/Compose/Layers/MaskContainer.cs

@@ -87,7 +87,7 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
             return Compare(xMask, yMask);
         }
 
-        public int Compare(HitObjectMask x, HitObjectMask y)
+        public static int Compare(HitObjectMask x, HitObjectMask y)
         {
             // Put earlier hitobjects towards the end of the list, so they handle input first
             int i = y.HitObject.HitObject.StartTime.CompareTo(x.HitObject.HitObject.StartTime);

osu.Game/Screens/Edit/Screens/Compose/Layers/MaskSelection.cs

@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -22,26 +23,17 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
     {
         public const float BORDER_RADIUS = 2;
 
-        private readonly MaskContainer maskContainer;
-
         private readonly SortedList<HitObjectMask> selectedMasks;
 
         private Drawable outline;
 
-        public MaskSelection(MaskContainer maskContainer)
+        public MaskSelection()
         {
-            // todo: remove this
+            selectedMasks = new SortedList<HitObjectMask>(MaskContainer.Compare);
-            this.maskContainer = maskContainer;
-
-            selectedMasks = new SortedList<HitObjectMask>(maskContainer.Compare);
 
             RelativeSizeAxes = Axes.Both;
             AlwaysPresent = true;
             Alpha = 0;
-
-            maskContainer.MaskSelected += onSelected;
-            maskContainer.MaskDeselected += onDeselected;
-            maskContainer.MaskSelectionRequested += onSelectionRequested;
         }
 
         [BackgroundDependencyLoader]
@@ -99,9 +91,22 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
 
         #region Selection Handling
 
-        private void onSelected(HitObjectMask mask) => selectedMasks.Add(mask);
+        /// <summary>
+        /// Bind an action to deselect all selected masks.
+        /// </summary>
+        public Action DeselectAll { private get; set; }
 
-        private void onDeselected(HitObjectMask mask)
+        /// <summary>
+        /// Handle a mask becoming selected.
+        /// </summary>
+        /// <param name="mask">The mask.</param>
+        public void HandleSelected(HitObjectMask mask) => selectedMasks.Add(mask);
+
+        /// <summary>
+        /// Handle a mask becoming deselected.
+        /// </summary>
+        /// <param name="mask">The mask.</param>
+        public void HandleDeselected(HitObjectMask mask)
         {
             selectedMasks.Remove(mask);
 
@@ -110,7 +115,11 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
                 UpdateVisibility();
         }
 
-        private void onSelectionRequested(HitObjectMask mask)
+        /// <summary>
+        /// Handle a mask requesting selection.
+        /// </summary>
+        /// <param name="mask">The mask.</param>
+        public void HandleSelectionRequested(HitObjectMask mask)
         {
             if (GetContainingInputManager().CurrentState.Keyboard.ControlPressed)
             {
@@ -125,7 +134,8 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
                 if (mask.State == Visibility.Visible)
                     return;
 
-                maskContainer.DeselectAll();
+
+                DeselectAll?.Invoke();
                 mask.Select();
             }
 
@@ -170,14 +180,5 @@ namespace osu.Game.Screens.Edit.Screens.Compose.Layers
             outline.Size = bottomRight - topLeft;
             outline.Position = topLeft;
         }
-
-        protected override void Dispose(bool isDisposing)
-        {
-            base.Dispose(isDisposing);
-
-            maskContainer.MaskSelected -= onSelected;
-            maskContainer.MaskDeselected -= onDeselected;
-            maskContainer.MaskSelectionRequested -= onSelectionRequested;
-        }
     }
 }