Inventory Input (#503)

* Create ItemSlotButton

* Refactor inventory buttons

Refactor so that KeyBind handling of inventory and hands are the same.

* Refactor InventoryInterfaceController to call ItemSlotManager with entities

This change allows HandsGUI and InventoryInterfaceController to just call ItemSlotManager.OnButtonPressed with an entity instead of a slot.

* Add CooldownCircle to ItemSlotButton

This allows Hands and Inventory to have cooldown circles on their ItemSlots.

* Refactor HandsGUI to use ItemSlots

This allows functionality and GUI to be the same between Inventory and Hands.

Added clicking empty hand to switch ActiveHand to clicked hand.

* Implement CooldownCircle in ItemSlotManager

Reorganize files

Content.Client/UserInterface/ItemSlotButton.cs

@@ -0,0 +1,79 @@
+using System;
+using Robust.Client.Graphics;
+using Robust.Client.UserInterface.Controls;
+using Robust.Shared.Input;
+using Robust.Shared.Maths;
+
+namespace Content.Client.GameObjects
+{
+    public sealed class ItemSlotButton : MarginContainer
+    {
+        public BaseButton Button { get; }
+        public SpriteView SpriteView { get; }
+        public BaseButton StorageButton { get; }
+        public TextureRect CooldownCircle { get; }
+
+        public Action<BaseButton.ButtonEventArgs> OnPressed { get; set; }
+        public Action<BaseButton.ButtonEventArgs> OnStoragePressed { get; set; }
+
+        public ItemSlotButton(Texture texture, Texture storageTexture)
+        {
+            CustomMinimumSize = (64, 64);
+
+            AddChild(Button = new TextureButton
+            {
+                TextureNormal = texture,
+                Scale = (2, 2),
+                EnableAllKeybinds = true
+            });
+
+            Button.OnPressed += OnButtonPressed;
+
+            AddChild(SpriteView = new SpriteView
+            {
+                MouseFilter = MouseFilterMode.Ignore,
+                Scale = (2, 2),
+                OverrideDirection = Direction.South
+            });
+
+            AddChild(StorageButton = new TextureButton
+            {
+                TextureNormal = storageTexture,
+                Scale = (0.75f, 0.75f),
+                SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
+                SizeFlagsVertical = SizeFlags.ShrinkEnd,
+                Visible = false,
+                EnableAllKeybinds = true
+            });
+
+            StorageButton.OnPressed += OnStorageButtonPressed;
+
+            AddChild(CooldownCircle = new TextureRect
+            {
+                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
+                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                MouseFilter = MouseFilterMode.Ignore,
+                Stretch = TextureRect.StretchMode.KeepCentered,
+                TextureScale = (2, 2),
+                Visible = false,
+            });
+        }
+
+        private void OnButtonPressed(BaseButton.ButtonEventArgs args)
+        {
+            OnPressed?.Invoke(args);
+        }
+
+        private void OnStorageButtonPressed(BaseButton.ButtonEventArgs args)
+        {
+            if (args.Event.Function == EngineKeyFunctions.Use)
+            {
+                OnStoragePressed?.Invoke(args);
+            }
+            else
+            {
+                OnPressed?.Invoke(args);
+            }
+        }
+    }
+}