feat: add join party event for party finder

XivCommon/Functions/PartyFinder.cs

@@ -1,7 +1,11 @@
 using System;
+using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using Dalamud.Game;
+using Dalamud.Game.Internal.Gui;
+using Dalamud.Game.Internal.Gui.Structs;
 using Dalamud.Hooking;
+using Dalamud.Plugin;
 
 namespace XivCommon.Functions {
     /// <summary>
@@ -10,13 +14,36 @@ namespace XivCommon.Functions {
     public class PartyFinder : IDisposable {
         private delegate byte RequestPartyFinderListingsDelegate(IntPtr agent, byte categoryIdx);
 
+        private delegate IntPtr JoinPfDelegate(IntPtr manager, IntPtr a2, int a3, IntPtr packetData, uint a5);
+
         private RequestPartyFinderListingsDelegate RequestPartyFinderListings { get; }
         private Hook<RequestPartyFinderListingsDelegate>? RequestPfListingsHook { get; }
+        private Hook<JoinPfDelegate>? JoinPfHook { get; }
 
+        /// <summary>
+        /// The delegate for party join events.
+        /// </summary>
+        public delegate void JoinPfEventDelegate(PartyFinderListing listing);
+
+        /// <summary>
+        /// <para>
+        /// The event that is fired when the player joins a party via Party Finder.
+        /// </para>
+        /// <para>
+        /// Requires the <see cref="Hooks.PartyFinder"/> hook to be enabled.
+        /// </para>
+        /// </summary>
+        public event JoinPfEventDelegate? JoinParty;
+
+        private PartyFinderGui PartyFinderGui { get; }
         private bool Enabled { get; }
         private IntPtr PartyFinderAgent { get; set; } = IntPtr.Zero;
+        private Dictionary<uint, PartyFinderListing> Listings { get; } = new();
+        private int LastBatch { get; set; } = -1;
+
+        internal PartyFinder(SigScanner scanner, PartyFinderGui partyFinderGui, bool hook) {
+            this.PartyFinderGui = partyFinderGui;
 
-        internal PartyFinder(SigScanner scanner, bool hook) {
             var requestPfPtr = scanner.ScanText("48 89 5C 24 ?? 48 89 74 24 ?? 57 48 83 EC 40 0F 10 81 ?? ?? ?? ??");
 
             this.RequestPartyFinderListings = Marshal.GetDelegateForFunctionPointer<RequestPartyFinderListingsDelegate>(requestPfPtr);
@@ -29,11 +56,29 @@ namespace XivCommon.Functions {
 
             this.RequestPfListingsHook = new Hook<RequestPartyFinderListingsDelegate>(requestPfPtr, new RequestPartyFinderListingsDelegate(this.OnRequestPartyFinderListings));
             this.RequestPfListingsHook.Enable();
+
+            this.PartyFinderGui.ReceiveListing += this.ReceiveListing;
+
+            var joinPtr = scanner.ScanText("E8 ?? ?? ?? ?? 0F B7 47 28");
+            this.JoinPfHook = new Hook<JoinPfDelegate>(joinPtr, new JoinPfDelegate(this.JoinPfDetour));
+            this.JoinPfHook.Enable();
         }
 
         /// <inheritdoc />
         public void Dispose() {
+            this.PartyFinderGui.ReceiveListing -= this.ReceiveListing;
             this.RequestPfListingsHook?.Dispose();
+            this.JoinPfHook?.Dispose();
+        }
+
+        private void ReceiveListing(PartyFinderListing listing, PartyFinderListingEventArgs args) {
+            if (args.BatchNumber != this.LastBatch) {
+                this.Listings.Clear();
+            }
+
+            this.LastBatch = args.BatchNumber;
+
+            this.Listings[listing.Id] = listing;
         }
 
         private byte OnRequestPartyFinderListings(IntPtr agent, byte categoryIdx) {
@@ -41,6 +86,24 @@ namespace XivCommon.Functions {
             return this.RequestPfListingsHook!.Original(agent, categoryIdx);
         }
 
+        private IntPtr JoinPfDetour(IntPtr manager, IntPtr a2, int a3, IntPtr packetData, uint a5) {
+            // Updated: 5.5
+            const int idOffset = -0x20;
+
+            var ret = this.JoinPfHook!.Original(manager, a2, a3, packetData, a5);
+
+            try {
+                var id = (uint) Marshal.ReadInt32(packetData + idOffset);
+                if (this.Listings.TryGetValue(id, out var listing)) {
+                    this.JoinParty?.Invoke(listing);
+                }
+            } catch (Exception ex) {
+                PluginLog.LogError(ex, "Exception in PF join detour");
+            }
+
+            return ret;
+        }
+
         /// <summary>
         /// <para>
         /// Refresh the Party Finder listings. This does not open the Party Finder.

XivCommon/GameFunctions.cs

@@ -16,7 +16,7 @@ namespace XivCommon {
         public Chat Chat { get; }
 
         /// <summary>
-        /// Party Finder functions
+        /// Party Finder functions and events
         /// </summary>
         public PartyFinder PartyFinder { get; }
 
@@ -24,6 +24,7 @@ namespace XivCommon {
         /// BattleTalk functions and events
         /// </summary>
         public BattleTalk BattleTalk { get; }
+
         /// <summary>
         /// Examine functions
         /// </summary>
@@ -49,7 +50,7 @@ namespace XivCommon {
             var dalamud = (Dalamud.Dalamud) dalamudField!.GetValue(@interface);
 
             this.Chat = new Chat(this, scanner);
-            this.PartyFinder = new PartyFinder(scanner, hooks.HasFlag(Hooks.PartyFinder));
+            this.PartyFinder = new PartyFinder(scanner, @interface.Framework.Gui.PartyFinder, hooks.HasFlag(Hooks.PartyFinder));
             this.BattleTalk = new BattleTalk(this, scanner, seStringManager, hooks.HasFlag(Hooks.BattleTalk));
             this.Examine = new Examine(this, scanner);
             this.Talk = new Talk(scanner, seStringManager, hooks.HasFlag(Hooks.Talk));