From b378ccb26a2b025065fe917acbbfcdcc35326f9f Mon Sep 17 00:00:00 2001
From: LongerWarrior <LongerWarrior@gmail.com>
Date: Sun, 22 Mar 2026 18:34:49 +0200
Subject: [PATCH] Allow drag&drop mappings file

---
 FModel/MainWindow.xaml    |  3 +++
 FModel/MainWindow.xaml.cs | 47 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/FModel/MainWindow.xaml b/FModel/MainWindow.xaml
index 8dc4c0b0..b8413665 100644
--- a/FModel/MainWindow.xaml
+++ b/FModel/MainWindow.xaml
@@ -10,6 +10,9 @@
         xmlns:adonisUi="clr-namespace:AdonisUI;assembly=AdonisUI"
         xmlns:adonisControls="clr-namespace:AdonisUI.Controls;assembly=AdonisUI"
         xmlns:adonisExtensions="clr-namespace:AdonisUI.Extensions;assembly=AdonisUI"
+        AllowDrop="True"
+        Drop="OnDrop"
+        PreviewDragOver="OnPreviewDragOver"
         WindowStartupLocation="CenterScreen" Closing="OnClosing" Loaded="OnLoaded" PreviewKeyDown="OnWindowKeyDown"
         Height="{Binding Source={x:Static SystemParameters.MaximizedPrimaryScreenHeight}, Converter={converters:RatioConverter}, ConverterParameter='0.95'}"
         Width="{Binding Source={x:Static SystemParameters.MaximizedPrimaryScreenWidth}, Converter={converters:RatioConverter}, ConverterParameter='0.90'}">
diff --git a/FModel/MainWindow.xaml.cs b/FModel/MainWindow.xaml.cs
index 2c532723..07df9024 100644
--- a/FModel/MainWindow.xaml.cs
+++ b/FModel/MainWindow.xaml.cs
@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
@@ -374,4 +375,50 @@ public partial class MainWindow
         childFolder.IsExpanded = true;
         childFolder.IsSelected = true;
     }
+
+    private void OnPreviewDragOver(object sender, DragEventArgs e)
+    {
+        if (e.Data.GetDataPresent(DataFormats.FileDrop))
+        {
+            var files = (string[]) e.Data.GetData(DataFormats.FileDrop);
+            if (_applicationView.Status.IsReady && files.Any(file => Path.GetExtension(file).Equals(".usmap", StringComparison.OrdinalIgnoreCase)))
+            {
+                e.Effects = DragDropEffects.Copy;
+                e.Handled = true;
+                return;
+            }
+        }
+
+        e.Effects = DragDropEffects.None;
+        e.Handled = true;
+    }
+
+    private async void OnDrop(object sender, DragEventArgs e)
+    {
+        if (!e.Data.GetDataPresent(DataFormats.FileDrop))
+            return;
+
+        var files = (string[]) e.Data.GetData(DataFormats.FileDrop);
+        var usmapFile = files.FirstOrDefault(file => Path.GetExtension(file).Equals(".usmap", StringComparison.OrdinalIgnoreCase));
+
+        if (usmapFile is null)
+            return;
+
+        UserSettings.IsEndpointValid(EEndpointType.Mapping, out var oldMappingsEndpoint);
+        try
+        {
+            var newMappingsEndpoint = new EndpointSettings() { Overwrite = true, FilePath = usmapFile };
+            UserSettings.Default.CurrentDir.Endpoints[(int) EEndpointType.Mapping] = newMappingsEndpoint;
+            await _applicationView.CUE4Parse.InitMappings();
+            _applicationView.SettingsView.MappingEndpoint = newMappingsEndpoint;
+        }
+        catch (Exception ex)
+        {
+            UserSettings.Default.CurrentDir.Endpoints[(int) EEndpointType.Mapping] = oldMappingsEndpoint;
+            FLogger.Append(ELog.Error, () =>
+            {
+                FLogger.Text($"Failed to load mapping file: {ex.Message}", Constants.WHITE, true);
+            });
+        }
+    }
 }