Add "Remember last folder in file pickers" setting, enabled by default

src/Shared.Core/KoikatuAPIBase.cs

@@ -56,6 +56,7 @@ public static bool EnableDebugLogging
         }
 
         private static ConfigEntry<bool> EnableDebugLoggingSetting { get; set; }
+        internal static ConfigEntry<bool> RememberFilePickerFolder { get; set; }
 
         internal static KoikatuAPI Instance { get; private set; }
         internal static new ManualLogSource Logger { get; private set; }
@@ -84,6 +85,7 @@ private void BaseAwake()
             Logger = base.Logger;
 
             EnableDebugLoggingSetting = Config.Bind("Debug", "Show debug messages", false, "Enables display of additional log messages when certain events are triggered within KKAPI. Useful for plugin devs to understand when controller messages are fired. Changes take effect after game restart.");
+            RememberFilePickerFolder = Config.Bind("General", "Remember last folder in file pickers", true, "If true, file picker dialogs will remember the last opened folder and open already inside of it. If false, the dialogs will always open in the default folder.\n\nWarning: This setting only applies to plugins that use the file picker through this API.");
 
             Logger.LogDebug($"Game version {GetGameVersion()} running under {System.Threading.Thread.CurrentThread.CurrentCulture.Name} culture");
 

src/Shared.Core/Utilities/OpenFileDialog.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Runtime.InteropServices;
 using System.Threading;
 
@@ -24,6 +25,12 @@ public class OpenFileDialog
         /// </summary>
         public const OpenSaveFileDialgueFlags MultiFileFlags = SingleFileFlags | OpenSaveFileDialgueFlags.OFN_ALLOWMULTISELECT;
 
+        /// <summary>
+        /// Dictionary storing last opened path per initialDir.
+        /// Key is the initialDir, value is the last opened path.
+        /// </summary>
+        private static readonly Dictionary<string, string> LastOpenedPaths = new Dictionary<string, string>();
+
         /// <inheritdoc cref="ShowDialog(string,string,string,string,OpenSaveFileDialgueFlags,string,IntPtr)"/>
         public static string[] ShowDialog(string title, string initialDir, string filter, string defaultExt, OpenSaveFileDialgueFlags flags, IntPtr owner = default)
         {
@@ -66,7 +73,10 @@ public static string[] ShowDialog(string title, string initialDir, string filter
             ofn.filter = filter.Replace("|", "\0") + "\0";
             ofn.fileTitle = new String(new char[MAX_FILE_LENGTH]);
             ofn.maxFileTitle = ofn.fileTitle.Length;
-            ofn.initialDir = initialDir;
+            if (LastOpenedPaths.TryGetValue(initialDir, out string lastOpenedPath) && KoikatuAPI.RememberFilePickerFolder.Value)
+                ofn.initialDir = lastOpenedPath;
+            else
+                ofn.initialDir = initialDir;
             ofn.title = title;
             ofn.flags = (int)flags;
             if (defaultExt != null) ofn.defExt = defaultExt;
@@ -89,6 +99,7 @@ public static string[] ShowDialog(string title, string initialDir, string filter
             // Save and restore working directory since GetOpenFileName changes it for no good reason
             var currentWorkingDirectory = Environment.CurrentDirectory;
             var run = true;
+
             BepInEx.ThreadingHelper.Instance.StartAsyncInvoke(() =>
             {
                 // Brute force seems to be the only viable way to prevent the current directory from getting changed
@@ -103,6 +114,7 @@ public static string[] ShowDialog(string title, string initialDir, string filter
 
             run = false;
             Environment.CurrentDirectory = currentWorkingDirectory;
+
             UnityEngine.Application.runInBackground = currentRunInBackground;
 
             if (success)
@@ -122,6 +134,7 @@ public static string[] ShowDialog(string title, string initialDir, string filter
                     file = Marshal.PtrToStringAuto(ofn.file);
                 }
 
+                LastOpenedPaths[initialDir] = Path.GetDirectoryName(selectedFilesList[0]);
                 if (selectedFilesList.Count == 1)
                 {
                     // Only one file selected with full path