feat: add friend list

XivCommon/Functions/FriendList/FriendList.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Collections.Generic;
+
+namespace XivCommon.Functions.FriendList {
+    /// <summary>
+    /// The class containing friend list functionality
+    /// </summary>
+    public class FriendList {
+        // Updated: 5.58-HF1
+        private const uint FriendListAgentId = 54;
+        private const int InfoOffset = 0x28;
+        private const int LengthOffset = 0x10;
+        private const int ListOffset = 0x98;
+
+        private GameFunctions Functions { get; }
+
+        /// <summary>
+        /// <para>
+        /// A live list of the currently-logged-in player's friends.
+        /// </para>
+        /// <para>
+        /// The list is empty if not logged in.
+        /// </para>
+        /// </summary>
+        public IList<FriendListEntry> List {
+            get {
+                var friendListAgent = this.Functions.GetAgentByInternalId(FriendListAgentId);
+                if (friendListAgent == IntPtr.Zero) {
+                    return Array.Empty<FriendListEntry>();
+                }
+
+                unsafe {
+                    var info = *(IntPtr*) (friendListAgent + InfoOffset);
+                    if (info == IntPtr.Zero) {
+                        return Array.Empty<FriendListEntry>();
+                    }
+
+                    var length = *(ushort*) (info + LengthOffset);
+                    if (length == 0) {
+                        return Array.Empty<FriendListEntry>();
+                    }
+
+                    var list = *(IntPtr*) (info + ListOffset);
+                    if (list == IntPtr.Zero) {
+                        return Array.Empty<FriendListEntry>();
+                    }
+
+                    var entries = new List<FriendListEntry>(length);
+                    for (var i = 0; i < length; i++) {
+                        var entry = *(FriendListEntry*) (list + i * FriendListEntry.Size);
+                        entries.Add(entry);
+                    }
+
+                    return entries;
+                }
+            }
+        }
+
+        internal FriendList(GameFunctions functions) {
+            this.Functions = functions;
+        }
+    }
+}

XivCommon/Functions/FriendList/FriendListEntry.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Runtime.InteropServices;
+using Dalamud.Game.Text.SeStringHandling;
+using Dalamud.Memory;
+
+namespace XivCommon.Functions.FriendList {
+    /// <summary>
+    /// An entry in a player's friend list.
+    /// </summary>
+    [StructLayout(LayoutKind.Explicit, Size = Size)]
+    public unsafe struct FriendListEntry {
+        internal const int Size = 96;
+
+        /// <summary>
+        /// The content ID of the friend.
+        /// </summary>
+        [FieldOffset(0x00)]
+        public readonly ulong ContentId;
+
+        /// <summary>
+        /// The home world of the friend.
+        /// </summary>
+        [FieldOffset(0x16)]
+        public readonly ushort HomeWorld;
+
+        /// <summary>
+        /// The current world of the friend.
+        /// </summary>
+        [FieldOffset(0x18)]
+        public readonly ushort CurrentWorld;
+
+        /// <summary>
+        /// The job the friend is currently on.
+        /// </summary>
+        [FieldOffset(0x21)]
+        public readonly byte Job;
+
+        /// <summary>
+        /// The friend's raw SeString name. See <see cref="Name"/>.
+        /// </summary>
+        [FieldOffset(0x22)]
+        public fixed byte RawName[32];
+
+        /// <summary>
+        /// The friend's raw SeString free company tag. See <see cref="FreeCompany"/>.
+        /// </summary>
+        [FieldOffset(0x42)]
+        public fixed byte RawFreeCompany[5];
+
+        /// <summary>
+        /// The friend's name.
+        /// </summary>
+        public SeString Name {
+            get {
+                fixed (byte* ptr = this.RawName) {
+                    return MemoryHelper.ReadSeStringNullTerminated((IntPtr) ptr);
+                }
+            }
+        }
+
+        /// <summary>
+        /// The friend's free company tag.
+        /// </summary>
+        public SeString FreeCompany {
+            get {
+                fixed (byte* ptr = this.RawFreeCompany) {
+                    return MemoryHelper.ReadSeStringNullTerminated((IntPtr) ptr);
+                }
+            }
+        }
+    }
+}

XivCommon/GameFunctions.cs

@@ -8,6 +8,7 @@ using Dalamud.Game.Gui;
 using Dalamud.Game.Gui.PartyFinder;
 using XivCommon.Functions;
 using XivCommon.Functions.ContextMenu;
+using XivCommon.Functions.FriendList;
 using XivCommon.Functions.NamePlates;
 using XivCommon.Functions.Tooltips;
 
@@ -87,6 +88,11 @@ namespace XivCommon {
         /// </summary>
         public DutyFinder DutyFinder { get; }
 
+        /// <summary>
+        /// Friend list functions
+        /// </summary>
+        public FriendList FriendList { get; }
+
         /// <summary>
         /// Journal functions
         /// </summary>
@@ -112,6 +118,7 @@ namespace XivCommon {
             this.NamePlates = new NamePlates(this, scanner, hooks.HasFlag(Hooks.NamePlates));
             this.DutyFinder = new DutyFinder(this, scanner);
             this.Journal = new Journal(this, scanner);
+            this.FriendList = new FriendList(this);
 
             if (scanner.TryScanText(Signatures.GetAgentByInternalId, out var byInternalIdPtr, "GetAgentByInternalId")) {
                 this.GetAgentByInternalIdInternal = Marshal.GetDelegateForFunctionPointer<GetAgentByInternalIdDelegate>(byInternalIdPtr);