SelectionMask -> SelectionBlueprint

osu.Game/Rulesets/Edit/SelectionBlueprint.cs

@@ -0,0 +1,147 @@
+// 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 osu.Framework;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Primitives;
+using osu.Framework.Input.Events;
+using osu.Framework.Input.States;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Rulesets.Objects.Drawables;
+using OpenTK;
+
+namespace osu.Game.Rulesets.Edit
+{
+    /// <summary>
+    /// A mask placed above a <see cref="DrawableHitObject"/> adding editing functionality.
+    /// </summary>
+    public class SelectionBlueprint : CompositeDrawable, IStateful<SelectionState>
+    {
+        /// <summary>
+        /// Invoked when this <see cref="SelectionBlueprint"/> has been selected.
+        /// </summary>
+        public event Action<SelectionBlueprint> Selected;
+
+        /// <summary>
+        /// Invoked when this <see cref="SelectionBlueprint"/> has been deselected.
+        /// </summary>
+        public event Action<SelectionBlueprint> Deselected;
+
+        /// <summary>
+        /// Invoked when this <see cref="SelectionBlueprint"/> has requested selection.
+        /// Will fire even if already selected. Does not actually perform selection.
+        /// </summary>
+        public event Action<SelectionBlueprint, InputState> SelectionRequested;
+
+        /// <summary>
+        /// Invoked when this <see cref="SelectionBlueprint"/> has requested drag.
+        /// </summary>
+        public event Action<SelectionBlueprint, Vector2, InputState> DragRequested;
+
+        /// <summary>
+        /// The <see cref="DrawableHitObject"/> which this <see cref="SelectionBlueprint"/> applies to.
+        /// </summary>
+        public readonly DrawableHitObject HitObject;
+
+        protected override bool ShouldBeAlive => HitObject.IsAlive && HitObject.IsPresent || State == SelectionState.Selected;
+        public override bool HandlePositionalInput => ShouldBeAlive;
+        public override bool RemoveWhenNotAlive => false;
+
+        public SelectionBlueprint(DrawableHitObject hitObject)
+        {
+            HitObject = hitObject;
+
+            RelativeSizeAxes = Axes.Both;
+
+            AlwaysPresent = true;
+            Alpha = 0;
+        }
+
+        private SelectionState state;
+
+        public event Action<SelectionState> StateChanged;
+
+        public SelectionState State
+        {
+            get => state;
+            set
+            {
+                if (state == value) return;
+
+                state = value;
+                switch (state)
+                {
+                    case SelectionState.Selected:
+                        Show();
+                        Selected?.Invoke(this);
+                        break;
+                    case SelectionState.NotSelected:
+                        Hide();
+                        Deselected?.Invoke(this);
+                        break;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Selects this <see cref="SelectionBlueprint"/>, causing it to become visible.
+        /// </summary>
+        public void Select() => State = SelectionState.Selected;
+
+        /// <summary>
+        /// Deselects this <see cref="SelectionBlueprint"/>, causing it to become invisible.
+        /// </summary>
+        public void Deselect() => State = SelectionState.NotSelected;
+
+        public bool IsSelected => State == SelectionState.Selected;
+
+        public override bool ReceivePositionalInputAt(Vector2 screenSpacePos) => HitObject.ReceivePositionalInputAt(screenSpacePos);
+
+        private bool selectionRequested;
+
+        protected override bool OnMouseDown(MouseDownEvent e)
+        {
+            selectionRequested = false;
+
+            if (State == SelectionState.NotSelected)
+            {
+                SelectionRequested?.Invoke(this, e.CurrentState);
+                selectionRequested = true;
+            }
+
+            return IsSelected;
+        }
+
+        protected override bool OnClick(ClickEvent e)
+        {
+            if (State == SelectionState.Selected && !selectionRequested)
+            {
+                selectionRequested = true;
+                SelectionRequested?.Invoke(this, e.CurrentState);
+                return true;
+            }
+
+            return base.OnClick(e);
+        }
+
+        protected override bool OnDragStart(DragStartEvent e) => true;
+
+        protected override bool OnDrag(DragEvent e)
+        {
+            DragRequested?.Invoke(this, e.Delta, e.CurrentState);
+            return true;
+        }
+
+        /// <summary>
+        /// The screen-space point that causes this <see cref="SelectionBlueprint"/> to be selected.
+        /// </summary>
+        public virtual Vector2 SelectionPoint => HitObject.ScreenSpaceDrawQuad.Centre;
+
+        /// <summary>
+        /// The screen-space quad that outlines this <see cref="SelectionBlueprint"/> for selections.
+        /// </summary>
+        public virtual Quad SelectionQuad => HitObject.ScreenSpaceDrawQuad;
+    }
+}