Add Item Transfer System (#476)

# Description

This PR adds the ability to transfer objects from one player's hand to
another player's hand, as in SS13.

I have little coding experience, so my solutions may not be ideal.

---

# TODO

- [x] Make the code work
- [x] Add popup
- [x] Write a summary of the code
- [x] Сorrect inaccuracies

<details><summary><h1>Media</h1></summary>
<p>

https://youtu.be/zTQWTsYm1gw

</p>
</details>

---

# Changelog

🆑
- add: Added system
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - -

---------

Co-authored-by: Danger Revolution! <142105406+DangerRevolution@users.noreply.github.com>

Content.Client/Input/ContentContexts.cs

@@ -68,6 +68,7 @@ namespace Content.Client.Input
             human.AddFunction(ContentKeyFunctions.SmartEquipBelt);
             human.AddFunction(ContentKeyFunctions.OpenBackpack);
             human.AddFunction(ContentKeyFunctions.OpenBelt);
+            human.AddFunction(ContentKeyFunctions.OfferItem);
             human.AddFunction(ContentKeyFunctions.MouseMiddle);
             human.AddFunction(ContentKeyFunctions.ArcadeUp);
             human.AddFunction(ContentKeyFunctions.ArcadeDown);

Content.Client/OfferItem/OfferItemIndicatorsOverlay.cs

@@ -0,0 +1,72 @@
+using System.Numerics;
+using Robust.Client.GameObjects;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Client.UserInterface;
+using Robust.Shared.Enums;
+using Robust.Shared.Utility;
+
+namespace Content.Client.OfferItem;
+
+public sealed class OfferItemIndicatorsOverlay : Overlay
+{
+    private readonly IInputManager _inputManager;
+    private readonly IEntityManager _entMan;
+    private readonly IEyeManager _eye;
+    private readonly OfferItemSystem _offer;
+
+    private readonly Texture _sight;
+
+    public override OverlaySpace Space => OverlaySpace.ScreenSpace;
+
+    private readonly Color _mainColor = Color.White.WithAlpha(0.3f);
+    private readonly Color _strokeColor = Color.Black.WithAlpha(0.5f);
+    private readonly float _scale = 0.6f;  // 1 is a little big
+
+    public OfferItemIndicatorsOverlay(IInputManager input, IEntityManager entMan,
+            IEyeManager eye, OfferItemSystem offerSys)
+    {
+        _inputManager = input;
+        _entMan = entMan;
+        _eye = eye;
+        _offer = offerSys;
+
+        var spriteSys = _entMan.EntitySysManager.GetEntitySystem<SpriteSystem>();
+        _sight = spriteSys.Frame0(new SpriteSpecifier.Rsi(new ResPath("/Textures/Interface/Misc/give_item.rsi"),
+            "give_item"));
+    }
+
+    protected override bool BeforeDraw(in OverlayDrawArgs args)
+    {
+        if (!_offer.IsInOfferMode())
+            return false;
+
+        return base.BeforeDraw(in args);
+    }
+
+    protected override void Draw(in OverlayDrawArgs args)
+    {
+        var mouseScreenPosition = _inputManager.MouseScreenPosition;
+        var mousePosMap = _eye.PixelToMap(mouseScreenPosition);
+        if (mousePosMap.MapId != args.MapId)
+            return;
+
+
+        var mousePos = mouseScreenPosition.Position;
+        var uiScale = (args.ViewportControl as Control)?.UIScale ?? 1f;
+        var limitedScale = uiScale > 1.25f ? 1.25f : uiScale;
+
+        DrawSight(_sight, args.ScreenHandle, mousePos, limitedScale * _scale);
+    }
+
+    private void DrawSight(Texture sight, DrawingHandleScreen screen, Vector2 centerPos, float scale)
+    {
+        var sightSize = sight.Size * scale;
+        var expandedSize = sightSize + new Vector2(7f, 7f);
+
+        screen.DrawTextureRect(sight,
+            UIBox2.FromDimensions(centerPos - sightSize * 0.5f, sightSize), _strokeColor);
+        screen.DrawTextureRect(sight,
+            UIBox2.FromDimensions(centerPos - expandedSize * 0.5f, expandedSize), _mainColor);
+    }
+}

Content.Client/OfferItem/OfferItemSystem.cs

@@ -0,0 +1,51 @@
+using Content.Shared.CCVar;
+using Content.Shared.OfferItem;
+using Robust.Client.Graphics;
+using Robust.Client.Input;
+using Robust.Client.Player;
+using Robust.Shared.Configuration;
+
+namespace Content.Client.OfferItem;
+
+public sealed class OfferItemSystem : SharedOfferItemSystem
+{
+    [Dependency] private readonly IOverlayManager _overlayManager = default!;
+    [Dependency] private readonly IPlayerManager _playerManager = default!;
+    [Dependency] private readonly IConfigurationManager _cfg = default!;
+    [Dependency] private readonly IInputManager _inputManager = default!;
+    [Dependency] private readonly IEyeManager _eye = default!;
+
+    public override void Initialize()
+    {
+        Subs.CVar(_cfg, CCVars.OfferModeIndicatorsPointShow, OnShowOfferIndicatorsChanged, true);
+    }
+    public override void Shutdown()
+    {
+        _overlayManager.RemoveOverlay<OfferItemIndicatorsOverlay>();
+
+        base.Shutdown();
+    }
+
+    public bool IsInOfferMode()
+    {
+        var entity = _playerManager.LocalEntity;
+
+        if (entity == null)
+            return false;
+
+        return IsInOfferMode(entity.Value);
+    }
+    private void OnShowOfferIndicatorsChanged(bool isShow)
+    {
+        if (isShow)
+        {
+            _overlayManager.AddOverlay(new OfferItemIndicatorsOverlay(
+                _inputManager,
+                EntityManager,
+                _eye,
+                this));
+        }
+        else
+            _overlayManager.RemoveOverlay<OfferItemIndicatorsOverlay>();
+    }
+}

Content.Client/Options/UI/Tabs/KeyRebindTab.xaml.cs

@@ -183,6 +183,7 @@ namespace Content.Client.Options.UI.Tabs
             AddButton(ContentKeyFunctions.SwapHands);
             AddButton(ContentKeyFunctions.MoveStoredItem);
             AddButton(ContentKeyFunctions.RotateStoredItem);
+            AddButton(ContentKeyFunctions.OfferItem);
 
             AddHeader("ui-options-header-interaction-adv");
             AddButton(ContentKeyFunctions.SmartEquipBackpack);

Content.Client/Options/UI/Tabs/MiscTab.xaml

@@ -49,6 +49,7 @@
                        StyleClasses="LabelKeyText"/>
                 <CheckBox Name="ShowHeldItemCheckBox" Text="{Loc 'ui-options-show-held-item'}" />
                 <CheckBox Name="ShowCombatModeIndicatorsCheckBox" Text="{Loc 'ui-options-show-combat-mode-indicators'}" />
+                <CheckBox Name="ShowOfferModeIndicatorsCheckBox" Text="{Loc 'ui-options-show-offer-mode-indicators'}" />
                 <Label Text="{Loc 'ui-options-general-storage'}"
                        FontColorOverride="{xNamespace:Static s:StyleNano.NanoGold}"
                        StyleClasses="LabelKeyText"/>

Content.Client/Options/UI/Tabs/MiscTab.xaml.cs

@@ -60,6 +60,7 @@ namespace Content.Client.Options.UI.Tabs
             ShowLoocAboveHeadCheckBox.OnToggled += OnCheckBoxToggled;
             ShowHeldItemCheckBox.OnToggled += OnCheckBoxToggled;
             ShowCombatModeIndicatorsCheckBox.OnToggled += OnCheckBoxToggled;
+            ShowOfferModeIndicatorsCheckBox.OnToggled += OnCheckBoxToggled;
             OpaqueStorageWindowCheckBox.OnToggled += OnCheckBoxToggled;
             FancySpeechBubblesCheckBox.OnToggled += OnCheckBoxToggled;
             FancyNameBackgroundsCheckBox.OnToggled += OnCheckBoxToggled;
@@ -75,6 +76,7 @@ namespace Content.Client.Options.UI.Tabs
             ShowLoocAboveHeadCheckBox.Pressed = _cfg.GetCVar(CCVars.LoocAboveHeadShow);
             ShowHeldItemCheckBox.Pressed = _cfg.GetCVar(CCVars.HudHeldItemShow);
             ShowCombatModeIndicatorsCheckBox.Pressed = _cfg.GetCVar(CCVars.CombatModeIndicatorsPointShow);
+            ShowOfferModeIndicatorsCheckBox.Pressed = _cfg.GetCVar(CCVars.OfferModeIndicatorsPointShow);
             OpaqueStorageWindowCheckBox.Pressed = _cfg.GetCVar(CCVars.OpaqueStorageWindow);
             FancySpeechBubblesCheckBox.Pressed = _cfg.GetCVar(CCVars.ChatEnableFancyBubbles);
             FancyNameBackgroundsCheckBox.Pressed = _cfg.GetCVar(CCVars.ChatFancyNameBackground);
@@ -120,6 +122,7 @@ namespace Content.Client.Options.UI.Tabs
             _cfg.SetCVar(CVars.DiscordEnabled, DiscordRich.Pressed);
             _cfg.SetCVar(CCVars.HudHeldItemShow, ShowHeldItemCheckBox.Pressed);
             _cfg.SetCVar(CCVars.CombatModeIndicatorsPointShow, ShowCombatModeIndicatorsCheckBox.Pressed);
+            _cfg.SetCVar(CCVars.OfferModeIndicatorsPointShow, ShowOfferModeIndicatorsCheckBox.Pressed);
             _cfg.SetCVar(CCVars.OpaqueStorageWindow, OpaqueStorageWindowCheckBox.Pressed);
             _cfg.SetCVar(CCVars.LoocAboveHeadShow, ShowLoocAboveHeadCheckBox.Pressed);
             _cfg.SetCVar(CCVars.ChatEnableFancyBubbles, FancySpeechBubblesCheckBox.Pressed);
@@ -147,6 +150,7 @@ namespace Content.Client.Options.UI.Tabs
             var isDiscordSame = DiscordRich.Pressed == _cfg.GetCVar(CVars.DiscordEnabled);
             var isShowHeldItemSame = ShowHeldItemCheckBox.Pressed == _cfg.GetCVar(CCVars.HudHeldItemShow);
             var isCombatModeIndicatorsSame = ShowCombatModeIndicatorsCheckBox.Pressed == _cfg.GetCVar(CCVars.CombatModeIndicatorsPointShow);
+            var isOfferModeIndicatorsSame = ShowOfferModeIndicatorsCheckBox.Pressed == _cfg.GetCVar(CCVars.OfferModeIndicatorsPointShow);
             var isOpaqueStorageWindow = OpaqueStorageWindowCheckBox.Pressed == _cfg.GetCVar(CCVars.OpaqueStorageWindow);
             var isLoocShowSame = ShowLoocAboveHeadCheckBox.Pressed == _cfg.GetCVar(CCVars.LoocAboveHeadShow);
             var isFancyChatSame = FancySpeechBubblesCheckBox.Pressed == _cfg.GetCVar(CCVars.ChatEnableFancyBubbles);
@@ -163,6 +167,7 @@ namespace Content.Client.Options.UI.Tabs
                                    isDiscordSame &&
                                    isShowHeldItemSame &&
                                    isCombatModeIndicatorsSame &&
+                                   isOfferModeIndicatorsSame &&
                                    isOpaqueStorageWindow &&
                                    isLoocShowSame &&
                                    isFancyChatSame &&

Content.Server/Alert/Click/AcceptingOffer.cs

@@ -0,0 +1,24 @@
+using Content.Shared.OfferItem;
+using Content.Server.OfferItem;
+using Content.Shared.Alert;
+using JetBrains.Annotations;
+
+namespace Content.Server.Alert.Click;
+
+/// <summary>
+/// Accepting the offer and receive item
+/// </summary>
+[UsedImplicitly]
+[DataDefinition]
+public sealed partial class AcceptOffer : IAlertClick
+{
+    public void AlertClicked(EntityUid player)
+    {
+        var entManager = IoCManager.Resolve<IEntityManager>();
+
+        if (entManager.TryGetComponent(player, out OfferItemComponent? offerItem))
+        {
+            entManager.System<OfferItemSystem>().Receive(player, offerItem);
+        }
+    }
+}

Content.Server/OfferItem/OfferItemSystem.cs

@@ -0,0 +1,83 @@
+using Content.Server.Popups;
+using Content.Shared.Hands.Components;
+using Content.Shared.Alert;
+using Content.Shared.Hands.EntitySystems;
+using Content.Shared.OfferItem;
+using Content.Shared.IdentityManagement;
+using Robust.Shared.Player;
+
+namespace Content.Server.OfferItem;
+
+public sealed class OfferItemSystem : SharedOfferItemSystem
+{
+    [Dependency] private readonly AlertsSystem _alertsSystem = default!;
+    [Dependency] private readonly SharedHandsSystem _hands = default!;
+    [Dependency] private readonly PopupSystem _popup = default!;
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        var query = EntityQueryEnumerator<OfferItemComponent>();
+        while (query.MoveNext(out var uid, out var offerItem))
+        {
+            if (!TryComp<HandsComponent>(uid, out var hands) || hands.ActiveHand == null)
+                continue;
+
+            if (offerItem.Hand != null &&
+                hands.Hands[offerItem.Hand].HeldEntity == null)
+            {
+                if (offerItem.Target != null)
+                {
+                    UnReceive(offerItem.Target.Value, offerItem: offerItem);
+                    offerItem.IsInOfferMode = false;
+                    Dirty(uid, offerItem);
+                }
+                else
+                    UnOffer(uid, offerItem);
+            }
+
+            if (!offerItem.IsInReceiveMode)
+            {
+                _alertsSystem.ClearAlert(uid, AlertType.Offer);
+                continue;
+            }
+
+            _alertsSystem.ShowAlert(uid, AlertType.Offer);
+        }
+    }
+
+    /// <summary>
+    /// Accepting the offer and receive item
+    /// </summary>
+    public void Receive(EntityUid uid, OfferItemComponent? component = null)
+    {
+        if (!Resolve(uid, ref component) ||
+            !TryComp<OfferItemComponent>(component.Target, out var offerItem) ||
+            offerItem.Hand == null ||
+            component.Target == null ||
+            !TryComp<HandsComponent>(uid, out var hands))
+            return;
+
+        if (offerItem.Item != null)
+        {
+            if (!_hands.TryPickup(uid, offerItem.Item.Value, handsComp: hands))
+            {
+                _popup.PopupEntity(Loc.GetString("offer-item-full-hand"), uid, uid);
+                return;
+            }
+
+            _popup.PopupEntity(Loc.GetString("offer-item-give",
+                ("item", Identity.Entity(offerItem.Item.Value, EntityManager)),
+                ("target", Identity.Entity(uid, EntityManager))), component.Target.Value, component.Target.Value);
+            _popup.PopupEntity(Loc.GetString("offer-item-give-other",
+                    ("user", Identity.Entity(component.Target.Value, EntityManager)),
+                    ("item", Identity.Entity(offerItem.Item.Value, EntityManager)),
+                    ("target", Identity.Entity(uid, EntityManager)))
+                , component.Target.Value, Filter.PvsExcept(component.Target.Value, entityManager: EntityManager), true);
+        }
+
+        offerItem.Item = null;
+        UnReceive(uid, component, offerItem);
+    }
+}

Content.Shared/Alert/AlertType.cs

@@ -52,7 +52,8 @@ namespace Content.Shared.Alert
         SuitPower,
         BorgHealth,
         BorgCrit,
-        BorgDead
+        BorgDead,
+        Offer,
     }
 
 }

Content.Shared/CCVar/CCVars.cs

@@ -810,6 +810,9 @@ namespace Content.Shared.CCVar
         public static readonly CVarDef<bool> CombatModeIndicatorsPointShow =
             CVarDef.Create("hud.combat_mode_indicators_point_show", true, CVar.ARCHIVE | CVar.CLIENTONLY);
 
+        public static readonly CVarDef<bool> OfferModeIndicatorsPointShow =
+            CVarDef.Create("hud.offer_mode_indicators_point_show", true, CVar.ARCHIVE | CVar.CLIENTONLY);
+
         public static readonly CVarDef<bool> LoocAboveHeadShow =
             CVarDef.Create("hud.show_looc_above_head", true, CVar.ARCHIVE | CVar.CLIENTONLY);
 

Content.Shared/Input/ContentKeyFunctions.cs

@@ -54,6 +54,7 @@ namespace Content.Shared.Input
         public static readonly BoundKeyFunction ZoomOut = "ZoomOut";
         public static readonly BoundKeyFunction ZoomIn = "ZoomIn";
         public static readonly BoundKeyFunction ResetZoom = "ResetZoom";
+        public static readonly BoundKeyFunction OfferItem = "OfferItem";
 
         public static readonly BoundKeyFunction ArcadeUp = "ArcadeUp";
         public static readonly BoundKeyFunction ArcadeDown = "ArcadeDown";

Content.Shared/OfferItem/OfferItemComponent.cs

@@ -0,0 +1,26 @@
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.OfferItem;
+
+[RegisterComponent, NetworkedComponent, AutoGenerateComponentState(true)]
+[Access(typeof(SharedOfferItemSystem))]
+public sealed partial class OfferItemComponent : Component
+{
+    [ViewVariables(VVAccess.ReadWrite), DataField, AutoNetworkedField]
+    public bool IsInOfferMode;
+
+    [DataField, AutoNetworkedField]
+    public bool IsInReceiveMode;
+
+    [DataField, AutoNetworkedField]
+    public string? Hand;
+
+    [DataField, AutoNetworkedField]
+    public EntityUid? Item;
+
+    [DataField, AutoNetworkedField]
+    public EntityUid? Target;
+
+    [DataField]
+    public float MaxOfferDistance = 2f;
+}

Content.Shared/OfferItem/SharedOfferItemSystem.Interactions.cs

@@ -0,0 +1,74 @@
+using Content.Shared.Popups;
+using Content.Shared.ActionBlocker;
+using Content.Shared.Input;
+using Content.Shared.Hands.Components;
+using Robust.Shared.Input.Binding;
+using Robust.Shared.Player;
+
+namespace Content.Shared.OfferItem;
+
+public abstract partial class SharedOfferItemSystem
+{
+    [Dependency] private readonly ActionBlockerSystem _actionBlocker = default!;
+    [Dependency] private readonly SharedPopupSystem _popup = default!;
+
+    private void InitializeInteractions()
+    {
+        CommandBinds.Builder
+            .Bind(ContentKeyFunctions.OfferItem, InputCmdHandler.FromDelegate(SetInOfferMode, handle: false, outsidePrediction: false))
+            .Register<SharedOfferItemSystem>();
+    }
+
+    public override void Shutdown()
+    {
+        base.Shutdown();
+
+        CommandBinds.Unregister<SharedOfferItemSystem>();
+    }
+
+    private void SetInOfferMode(ICommonSession? session)
+    {
+        if (session is not { } playerSession)
+            return;
+
+        if ((playerSession.AttachedEntity is not { Valid: true } uid || !Exists(uid)) ||
+            !_actionBlocker.CanInteract(uid, null))
+            return;
+
+        if (!TryComp<OfferItemComponent>(uid, out var offerItem))
+            return;
+
+        if (!TryComp<HandsComponent>(uid, out var hands) || hands.ActiveHand == null)
+            return;
+
+        offerItem.Item = hands.ActiveHand.HeldEntity;
+
+        if (offerItem.IsInOfferMode == false)
+        {
+            if (offerItem.Item == null)
+            {
+                _popup.PopupEntity(Loc.GetString("offer-item-empty-hand"), uid, uid);
+                return;
+            }
+
+            if (offerItem.Hand == null || offerItem.Target == null)
+            {
+                offerItem.IsInOfferMode = true;
+                offerItem.Hand = hands.ActiveHand.Name;
+
+                Dirty(uid, offerItem);
+                return;
+            }
+        }
+
+        if (offerItem.Target != null)
+        {
+            UnReceive(offerItem.Target.Value, offerItem: offerItem);
+            offerItem.IsInOfferMode = false;
+            Dirty(uid, offerItem);
+            return;
+        }
+
+        UnOffer(uid, offerItem);
+    }
+}

Content.Shared/OfferItem/SharedOfferItemSystem.cs

@@ -0,0 +1,155 @@
+using Content.Shared.Interaction;
+using Content.Shared.IdentityManagement;
+using Content.Shared.Hands.Components;
+
+namespace Content.Shared.OfferItem;
+
+public abstract partial class SharedOfferItemSystem : EntitySystem
+{
+    [Dependency] private readonly SharedTransformSystem _transform = default!;
+
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<OfferItemComponent, AfterInteractUsingEvent>(SetInReceiveMode);
+        SubscribeLocalEvent<OfferItemComponent, MoveEvent>(OnMove);
+
+        InitializeInteractions();
+    }
+
+    private void SetInReceiveMode(EntityUid uid, OfferItemComponent component, AfterInteractUsingEvent args)
+    {
+        if (!TryComp<OfferItemComponent>(args.User, out var offerItem))
+            return;
+
+        if (args.User == uid || component.IsInReceiveMode ||
+            (offerItem.IsInReceiveMode && offerItem.Target != uid))
+            return;
+
+        component.IsInReceiveMode = true;
+        component.Target = args.User;
+
+        Dirty(uid, component);
+
+        offerItem.Target = uid;
+        offerItem.IsInOfferMode = false;
+
+        Dirty(args.User, offerItem);
+
+        if (offerItem.Item == null)
+            return;
+
+        _popup.PopupEntity(Loc.GetString("offer-item-try-give",
+            ("item", Identity.Entity(offerItem.Item.Value, EntityManager)),
+            ("target", Identity.Entity(uid, EntityManager))), component.Target.Value, component.Target.Value);
+        _popup.PopupEntity(Loc.GetString("offer-item-try-give-target",
+            ("user", Identity.Entity(component.Target.Value, EntityManager)),
+            ("item", Identity.Entity(offerItem.Item.Value, EntityManager))), component.Target.Value, uid);
+    }
+
+    private void OnMove(EntityUid uid, OfferItemComponent component, MoveEvent args)
+    {
+        if (component.Target == null ||
+            args.NewPosition.InRange(EntityManager, _transform,
+                Transform(component.Target.Value).Coordinates, component.MaxOfferDistance))
+            return;
+
+        UnOffer(uid, component);
+    }
+
+    /// <summary>
+    /// Resets the <see cref="OfferItemComponent"/> of the user and the target
+    /// </summary>
+    protected void UnOffer(EntityUid uid, OfferItemComponent component)
+    {
+        if (!TryComp<HandsComponent>(uid, out var hands) || hands.ActiveHand == null)
+            return;
+
+
+        if (TryComp<OfferItemComponent>(component.Target, out var offerItem) && component.Target != null)
+        {
+
+            if (component.Item != null)
+            {
+                _popup.PopupEntity(Loc.GetString("offer-item-no-give",
+                    ("item", Identity.Entity(component.Item.Value, EntityManager)),
+                    ("target", Identity.Entity(component.Target.Value, EntityManager))), uid, uid);
+                _popup.PopupEntity(Loc.GetString("offer-item-no-give-target",
+                    ("user", Identity.Entity(uid, EntityManager)),
+                    ("item", Identity.Entity(component.Item.Value, EntityManager))), uid, component.Target.Value);
+            }
+
+            else if (offerItem.Item != null)
+            {
+                _popup.PopupEntity(Loc.GetString("offer-item-no-give",
+                    ("item", Identity.Entity(offerItem.Item.Value, EntityManager)),
+                    ("target", Identity.Entity(uid, EntityManager))), component.Target.Value, component.Target.Value);
+                _popup.PopupEntity(Loc.GetString("offer-item-no-give-target",
+                    ("user", Identity.Entity(component.Target.Value, EntityManager)),
+                    ("item", Identity.Entity(offerItem.Item.Value, EntityManager))), component.Target.Value, uid);
+            }
+
+            offerItem.IsInOfferMode = false;
+            offerItem.IsInReceiveMode = false;
+            offerItem.Hand = null;
+            offerItem.Target = null;
+            offerItem.Item = null;
+
+            Dirty(component.Target.Value, offerItem);
+        }
+
+        component.IsInOfferMode = false;
+        component.IsInReceiveMode = false;
+        component.Hand = null;
+        component.Target = null;
+        component.Item = null;
+
+        Dirty(uid, component);
+    }
+
+
+    /// <summary>
+    /// Cancels the transfer of the item
+    /// </summary>
+    protected void UnReceive(EntityUid uid, OfferItemComponent? component = null, OfferItemComponent? offerItem = null)
+    {
+        if (component == null && !TryComp(uid, out component))
+            return;
+
+        if (offerItem == null && !TryComp(component.Target, out offerItem))
+            return;
+
+        if (!TryComp<HandsComponent>(uid, out var hands) || hands.ActiveHand == null ||
+            component.Target == null)
+            return;
+
+        if (offerItem.Item != null)
+        {
+            _popup.PopupEntity(Loc.GetString("offer-item-no-give",
+                ("item", Identity.Entity(offerItem.Item.Value, EntityManager)),
+                ("target", Identity.Entity(uid, EntityManager))), component.Target.Value, component.Target.Value);
+            _popup.PopupEntity(Loc.GetString("offer-item-no-give-target",
+                ("user", Identity.Entity(component.Target.Value, EntityManager)),
+                ("item", Identity.Entity(offerItem.Item.Value, EntityManager))), component.Target.Value, uid);
+        }
+
+        if (!offerItem.IsInReceiveMode)
+        {
+            offerItem.Target = null;
+            component.Target = null;
+        }
+
+        offerItem.Item = null;
+        offerItem.Hand = null;
+        component.IsInReceiveMode = false;
+
+        Dirty(uid, component);
+    }
+
+    /// <summary>
+    /// Returns true if <see cref="OfferItemComponent.IsInOfferMode"/> = true
+    /// </summary>
+    protected bool IsInOfferMode(EntityUid? entity, OfferItemComponent? component = null)
+    {
+        return entity != null && Resolve(entity.Value, ref component, false) && component.IsInOfferMode;
+    }
+}

Resources/Locale/en-US/alerts/alerts.ftl

@@ -110,3 +110,6 @@ alerts-revenant-essence-desc = The power of souls. It sustains you and is used f
 
 alerts-revenant-corporeal-name = Corporeal
 alerts-revenant-corporeal-desc = You have manifested physically. People around you can see and hurt you.
+
+alerts-offer-name = Offer
+alerts-offer-desc = Someone offers you an item.

Resources/Locale/en-US/escape-menu/ui/options-menu.ftl

@@ -41,6 +41,7 @@ ui-options-volume-percent = { TOSTRING($volume, "P0") }
 
 ui-options-show-held-item = Show held item next to cursor
 ui-options-show-combat-mode-indicators = Show combat mode indicators with cursor
+ui-options-show-offer-mode-indicators = Show offer mode indicators with cursor
 ui-options-opaque-storage-window = Opaque storage window
 ui-options-show-looc-on-head = Show LOOC chat above characters head
 ui-options-fancy-speech = Show names in speech bubbles
@@ -135,6 +136,7 @@ ui-options-function-examine-entity = Examine
 ui-options-function-swap-hands = Swap hands
 ui-options-function-move-stored-item = Move stored item
 ui-options-function-rotate-stored-item = Rotate stored item
+ui-options-function-offer-item = Offer something
 ui-options-static-storage-ui = Lock storage window to hotbar
 
 ui-options-function-smart-equip-backpack = Smart-equip to backpack

Resources/Locale/en-US/interaction/offer-item-system.ftl

@@ -0,0 +1,13 @@
+offer-item-empty-hand = You don't have anything in your hand to give!
+
+offer-item-full-hand = Your hand isn't free to receive the item.
+
+offer-item-try-give = You offer the {THE($item)} to {$target}
+offer-item-try-give-target = {$user} offers you a {THE($item)}
+
+offer-item-give = You handed {THE($item)} to {$target}
+offer-item-give-other = {$user} handed {THE($item)} to {$target}
+offer-item-give-target = {$user} handed you a {THE($item)}
+
+offer-item-no-give = You stop offering {THE($item)} to {$target}
+offer-item-no-give-target = {$user} is no longer offer a {THE($item)} to you

Resources/Prototypes/Alerts/alerts.yml

@@ -24,6 +24,7 @@
     - category: Thirst
     - alertType: Magboots
     - alertType: Pacified
+    - alertType: Offer
 
 - type: alert
   id: LowOxygen
@@ -150,6 +151,15 @@
   name: alerts-buckled-name
   description: alerts-buckled-desc
 
+- type: alert
+  id: Offer
+  onClick: !type:AcceptOffer  { }
+  icons:
+  - sprite: /Textures/Interface/Alerts/offer_item.rsi
+    state: offer_item
+  name: alerts-offer-name
+  description: alerts-offer-desc
+
 - type: alert
   id: HumanCrit
   category: Health

Resources/Prototypes/Entities/Mobs/Species/base.yml

@@ -309,6 +309,7 @@
         Asphyxiation: -1.0
   - type: FireVisuals
     alternateState: Standing
+  - type: OfferItem
 
 - type: entity
   save: false

Resources/Textures/Interface/Alerts/offer_item.rsi/meta.json

@@ -0,0 +1,14 @@
+{
+  "version": 1,
+  "license": "CC-BY-SA-3.0",
+  "copyright": "https://github.com/ss220-space/Paradise/blob/master220/icons/mob/screen_alert.dmi",
+  "size": {
+    "x": 32,
+    "y": 32
+  },
+  "states": [
+    {
+      "name": "offer_item"
+    }
+  ]
+}

Resources/Textures/Interface/Misc/give_item.rsi/meta.json

@@ -0,0 +1,14 @@
+{
+  "version": 1,
+  "license": "CC-BY-SA-3.0",
+  "copyright": "https://github.com/ss220-space/Paradise/blob/master220/icons/misc/mouse_icons/give_item.dmi",
+  "size": {
+    "x": 64,
+    "y": 64
+  },
+  "states": [
+    {
+      "name": "give_item"
+    }
+  ]
+}

Resources/keybinds.yml

@@ -255,6 +255,9 @@ binds:
   type: State
   key: V
   mod1: Shift
+- function: OfferItem
+  type: State
+  key: F
 - function: ShowDebugConsole
   type: State
   key: Tilde