Hud refactor (#7202)

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>
Co-authored-by: Jezithyr <jmaster9999@gmail.com>
Co-authored-by: Jezithyr <Jezithyr@gmail.com>
Co-authored-by: Visne <39844191+Visne@users.noreply.github.com>
Co-authored-by: wrexbe <wrexbe@protonmail.com>
Co-authored-by: wrexbe <81056464+wrexbe@users.noreply.github.com>

Content.Client/UserInterface/Systems/Hands/Controls/HandsContainer.cs

@@ -0,0 +1,83 @@
+using System.Linq;
+using Content.Client.UserInterface.Systems.Inventory.Controls;
+using Robust.Client.UserInterface.Controls;
+
+namespace Content.Client.UserInterface.Systems.Hands.Controls;
+
+public sealed class HandsContainer : ItemSlotUIContainer<HandButton>
+{
+    private readonly GridContainer _grid;
+    public int ColumnLimit { get => _grid.Columns; set => _grid.Columns = value; }
+    public int MaxButtonCount { get; set; } = 0;
+
+    public HandsContainer()
+    {
+        AddChild(_grid = new GridContainer());
+        _grid.ExpandBackwards = true;
+    }
+
+    public override HandButton? AddButton(HandButton newButton)
+    {
+        if (MaxButtonCount > 0)
+        {
+            if (ButtonCount >= MaxButtonCount)
+                return null;
+
+            _grid.AddChild(newButton);
+        }
+        else
+        {
+            _grid.AddChild(newButton);
+        }
+
+        return base.AddButton(newButton);
+    }
+
+    public override void RemoveButton(string handName)
+    {
+        var button = GetButton(handName);
+        if (button == null)
+            return;
+        base.RemoveButton(button);
+        _grid.RemoveChild(button);
+    }
+
+    public bool TryGetLastButton(out HandButton? control)
+    {
+        if (Buttons.Count == 0)
+        {
+            control = null;
+            return false;
+        }
+
+        control = Buttons.Values.Last();
+        return true;
+    }
+
+    public bool TryRemoveLastHand(out HandButton? control)
+    {
+        var success = TryGetLastButton(out control);
+        if (control != null)
+            RemoveButton(control);
+        return success;
+    }
+
+    public void Clear()
+    {
+        ClearButtons();
+        _grid.DisposeAllChildren();
+    }
+
+    public IEnumerable<HandButton> GetButtons()
+    {
+        foreach (var child in _grid.Children)
+        {
+            if (child is HandButton hand)
+                yield return hand;
+        }
+    }
+
+    public bool IsFull => (MaxButtonCount != 0 && ButtonCount >= MaxButtonCount);
+
+    public int ButtonCount => _grid.ChildCount;
+}