Expose selected objects from SelectionLayer

osu.Game/Rulesets/Edit/Layers/Selection/DragSelector.cs

@@ -12,6 +12,7 @@ using osu.Game.Graphics;
 using osu.Game.Rulesets.Objects.Drawables;
 using OpenTK;
 using OpenTK.Graphics;
+using osu.Framework.Configuration;
 
 namespace osu.Game.Rulesets.Edit.Layers.Selection
 {
@@ -20,6 +21,8 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
     /// </summary>
     public class DragSelector : CompositeDrawable
     {
+        public readonly Bindable<SelectionInfo> Selection = new Bindable<SelectionInfo>();
+
         /// <summary>
         /// The <see cref="DrawableHitObject"/>s that can be selected through a drag-selection.
         /// </summary>
@@ -103,7 +106,6 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
         }
 
         private readonly List<DrawableHitObject> capturedHitObjects = new List<DrawableHitObject>();
-        public IReadOnlyList<DrawableHitObject> CapturedHitObjects => capturedHitObjects;
 
         /// <summary>
         /// Processes hitobjects to determine which ones are captured by the drag selection.
@@ -128,7 +130,7 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
         /// </summary>
         public void FinishCapture()
         {
-            if (CapturedHitObjects.Count == 0)
+            if (capturedHitObjects.Count == 0)
             {
                 Hide();
                 return;
@@ -158,6 +160,12 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
             // Transform into markers to let the user modify the drag selection further.
             background.Delay(50).FadeOut(200);
             markers.FadeIn(200);
+
+            Selection.Value = new SelectionInfo
+            {
+                Objects = capturedHitObjects,
+                SelectionQuad = Parent.ToScreenSpace(dragRectangle)
+            };
         }
 
         private bool isActive = true;
@@ -167,6 +175,8 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
         {
             isActive = false;
             this.FadeOut(400, Easing.OutQuint).Expire();
+
+            Selection.Value = null;
         }
     }
 }

osu.Game/Rulesets/Edit/Layers/Selection/SelectionInfo.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+using osu.Framework.Graphics.Primitives;
+using osu.Game.Rulesets.Objects.Drawables;
+
+namespace osu.Game.Rulesets.Edit.Layers.Selection
+{
+    public class SelectionInfo
+    {
+        /// <summary>
+        /// The objects that are captured by the selection.
+        /// </summary>
+        public IEnumerable<DrawableHitObject> Objects;
+
+        /// <summary>
+        /// The screen space quad of the selection box surrounding <see cref="Objects"/>.
+        /// </summary>
+        public Quad SelectionQuad;
+    }
+}

osu.Game/Rulesets/Edit/Layers/Selection/SelectionLayer.cs

@@ -1,15 +1,21 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
+using System.Collections.Generic;
+using osu.Framework.Configuration;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Input;
+using osu.Game.Rulesets.Objects.Drawables;
 using osu.Game.Rulesets.UI;
 
 namespace osu.Game.Rulesets.Edit.Layers.Selection
 {
     public class SelectionLayer : CompositeDrawable
     {
+        public readonly Bindable<SelectionInfo> Selection = new Bindable<SelectionInfo>();
+
         private readonly Playfield playfield;
 
         public SelectionLayer(Playfield playfield)
@@ -25,11 +31,14 @@ namespace osu.Game.Rulesets.Edit.Layers.Selection
         {
             // Hide the previous drag box - we won't be working with it any longer
             selector?.Hide();
+
             AddInternal(selector = new DragSelector(ToLocalSpace(state.Mouse.NativeState.Position))
             {
-                CapturableObjects = playfield.HitObjects.Objects
+                CapturableObjects = playfield.HitObjects.Objects,
             });
 
+            Selection.BindTo(selector.Selection);
+
             return true;
         }
 

osu.Game/osu.Game.csproj

@@ -314,6 +314,7 @@
     <Compile Include="Rulesets\Edit\Layers\Selection\DragSelector.cs" />
     <Compile Include="Rulesets\Edit\Layers\Selection\Marker.cs" />
     <Compile Include="Rulesets\Edit\Layers\Selection\MarkerContainer.cs" />
+    <Compile Include="Rulesets\Edit\Layers\Selection\SelectionInfo.cs" />
     <Compile Include="Rulesets\Edit\Layers\Selection\SelectionLayer.cs" />
     <Compile Include="Screens\Edit\Components\BottomBarContainer.cs" />
     <Compile Include="Screens\Edit\Components\PlaybackControl.cs" />