SharedItemComponent (#3513)

* StorableComponent refactor

* ItemComponent refactor

* conflict fixes

* removes redundant null check

* removes redundant item throwing code

* fix conflicts

* ExplosionLaunchedComponent

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Shared/GameObjects/Components/Storage/SharedItemComponent.cs

@@ -0,0 +1,184 @@
+#nullable enable
+using Content.Shared.GameObjects.EntitySystems;
+using Content.Shared.GameObjects.EntitySystems.ActionBlocker;
+using Content.Shared.Interfaces.GameObjects.Components;
+using Content.Shared.Utility;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Maths;
+using Robust.Shared.Physics;
+using Robust.Shared.Players;
+using Robust.Shared.Serialization;
+using Robust.Shared.Serialization.Manager.Attributes;
+using Robust.Shared.ViewVariables;
+using System;
+
+namespace Content.Shared.GameObjects.Components.Storage
+{
+    /// <summary>
+    ///    Players can pick up, drop, and put items in bags, and they can be seen in player's hands.
+    /// </summary>
+    public abstract class SharedItemComponent : Component, IEquipped, IUnequipped, IInteractHand
+    {
+        public override string Name => "Item";
+
+        public override uint? NetID => ContentNetIDs.ITEM;
+
+        /// <summary>
+        ///     How much big this item is.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        public int Size
+        {
+            get => _size;
+            set
+            {
+                _size = value;
+                Dirty();
+            }
+        }
+        [DataField("size")]
+        private int _size;
+
+        /// <summary>
+        ///     Part of the state of the sprite shown on the player when this item is in their hands.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        public string? EquippedPrefix
+        {
+            get => _equippedPrefix;
+            set
+            {
+                _equippedPrefix = value;
+                OnEquippedPrefixChange();
+                Dirty();
+            }
+        }
+        [DataField("HeldPrefix")]
+        private string? _equippedPrefix;
+
+        /// <summary>
+        ///     Color of the sprite shown on the player when this item is in their hands.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        public Color Color
+        {
+            get => _color;
+            protected set
+            {
+                _color = value;
+                Dirty();
+            }
+        }
+        [DataField("color")]
+        private Color _color = Color.White;
+
+        /// <summary>
+        ///     Rsi of the sprite shown on the player when this item is in their hands.
+        /// </summary>
+        [ViewVariables(VVAccess.ReadWrite)]
+        public string? RsiPath
+        {
+            get => _rsiPath;
+            set
+            {
+                _rsiPath = value;
+                Dirty();
+            }
+        }
+        [DataField("sprite")]
+        private string? _rsiPath;
+
+        public override ComponentState GetComponentState(ICommonSession player)
+        {
+            return new ItemComponentState(Size, EquippedPrefix, Color, RsiPath);
+        }
+
+        public override void HandleComponentState(ComponentState? curState, ComponentState? nextState)
+        {
+            base.HandleComponentState(curState, nextState);
+
+            if (curState is not ItemComponentState state)
+                return;
+
+            Size = state.Size;
+            EquippedPrefix = state.EquippedPrefix;
+            Color = state.Color;
+            RsiPath = state.RsiPath;
+        }
+
+        /// <summary>
+        ///     If a player can pick up this item.
+        /// </summary>
+        public bool CanPickup(IEntity user)
+        {
+            if (!ActionBlockerSystem.CanPickup(user))
+                return false;
+
+            if (user.Transform.MapID != Owner.Transform.MapID)
+                return false;
+
+            if (!Owner.TryGetComponent(out IPhysBody? physics) || physics.BodyType == BodyType.Static)
+                return false;
+
+            return user.InRangeUnobstructed(Owner, ignoreInsideBlocker: true, popup: true);
+        }
+
+        void IEquipped.Equipped(EquippedEventArgs eventArgs)
+        {
+            EquippedToSlot();
+        }
+
+        void IUnequipped.Unequipped(UnequippedEventArgs eventArgs)
+        {
+            RemovedFromSlot();
+        }
+
+        bool IInteractHand.InteractHand(InteractHandEventArgs eventArgs)
+        {
+            return TryPutInHand(eventArgs.User);
+        }
+
+        /// <summary>
+        ///     Tries to put this item in a player's hands.
+        ///     TODO: Move server implementation here once hands are in shared.
+        /// </summary>
+        public abstract bool TryPutInHand(IEntity user);
+
+        protected virtual void OnEquippedPrefixChange() { }
+
+        public virtual void RemovedFromSlot() { }
+
+        public virtual void EquippedToSlot() { }
+    }
+
+    [Serializable, NetSerializable]
+    public class ItemComponentState : ComponentState
+    {
+        public int Size { get; }
+        public string? EquippedPrefix { get; }
+        public Color Color { get; }
+        public string? RsiPath { get; }
+
+        public ItemComponentState(int size, string? equippedPrefix, Color color, string? rsiPath) : base(ContentNetIDs.ITEM)
+        {
+            Size = size;
+            EquippedPrefix = equippedPrefix;
+            Color = color;
+            RsiPath = rsiPath;
+        }
+    }
+
+    /// <summary>
+    ///     Reference sizes for common containers and items.
+    /// </summary>
+    public enum ReferenceSizes
+    {
+        Wallet = 4,
+        Pocket = 12,
+        Box = 24,
+        Belt = 30,
+        Toolbox = 60,
+        Backpack = 100,
+        NoStoring = 9999
+    }
+}