hands ECS (#7081)

Content.Shared/Hands/Components/HandHelpers.cs

@@ -0,0 +1,34 @@
+using System.Linq;
+
+namespace Content.Shared.Hands.Components;
+
+/// <summary>
+///     These helpers exist to make getting basic information out of the hands component more convenient, without
+///     needing to resolve hands system or something like that.
+/// </summary>
+public static class HandHelpers
+{
+    /// <summary>
+    ///     Returns true if any hand is free. This is a LinQ method, not a property, so
+    ///     cache it instead of accessing this multiple times.
+    /// </summary>
+    public static bool IsAnyHandFree(this SharedHandsComponent component) => component.Hands.Values.Any(hand => hand.IsEmpty);
+
+    /// <summary>
+    ///     Get the number of hands that are not currently holding anything. This is a LinQ method, not a property, so
+    ///     cache it instead of accessing this multiple times.
+    /// </summary>
+    public static int CountFreeHands(this SharedHandsComponent component) => component.Hands.Values.Count(hand => hand.IsEmpty);
+
+    /// <summary>
+    ///     Get a list of hands that are currently holding nothing. This is a LinQ method, not a property, so cache
+    ///     it instead of accessing this multiple times.
+    /// </summary>
+    public static IEnumerable<Hand> GetFreeHands(this SharedHandsComponent component) => component.Hands.Values.Where(hand => !hand.IsEmpty);
+
+    /// <summary>
+    ///     Get a list of hands that are currently holding nothing. This is a LinQ method, not a property, so cache
+    ///     it instead of accessing this multiple times.
+    /// </summary>
+    public static IEnumerable<string> GetFreeHandNames(this SharedHandsComponent component) => GetFreeHands(component).Select(hand => hand.Name);
+}