feature: support to drag and drop patch file into file selector

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/Apply.axaml

@@ -39,7 +39,10 @@
                Watermark="{DynamicResource Text.Apply.File.Placeholder}"
                IsEnabled="{Binding !FromClipboard, Mode=OneWay}"
                IsVisible="{Binding !FromClipboard, Mode=OneWay}"
-               Text="{Binding PatchFile, Mode=TwoWay}">
+               Text="{Binding PatchFile, Mode=TwoWay}"
+               DragDrop.AllowDrop="True"
+               DragDrop.DragOver="DragOverPatchFileBox"
+               DragDrop.Drop="DropOnPatchFileBox">
         <TextBox.Styles>
           <Style Selector="TextBox:disabled Path">
             <Setter Property="Opacity" Value=".6"/>

src/Views/Apply.axaml.cs

@@ -1,5 +1,6 @@
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Platform.Storage;
 
@@ -38,5 +39,52 @@ private async void SelectPatchFile(object _, RoutedEventArgs e)
 
             e.Handled = true;
         }
+
+        private void DragOverPatchFileBox(object sender, DragEventArgs e)
+        {
+            if (!e.DataTransfer.Contains(DataFormat.File))
+            {
+                e.DragEffects = DragDropEffects.None;
+                e.Handled = true;
+                return;
+            }
+
+            var files = e.DataTransfer.TryGetFiles();
+            if (files is not { Length: 1 })
+            {
+                e.DragEffects = DragDropEffects.None;
+                e.Handled = true;
+                return;
+            }
+
+            var file = files[0].Path.LocalPath;
+            if (!file.EndsWith(".patch") && !file.EndsWith(".diff"))
+            {
+                e.DragEffects = DragDropEffects.None;
+                e.Handled = true;
+                return;
+            }
+
+            e.DragEffects = DragDropEffects.Move;
+            e.Handled = true;
+            return;
+        }
+
+        private void DropOnPatchFileBox(object sender, DragEventArgs e)
+        {
+            if (!e.DataTransfer.Contains(DataFormat.File))
+                return;
+
+            var files = e.DataTransfer.TryGetFiles();
+            if (files is not { Length: 1 })
+                return;
+
+            var file = files[0].Path.LocalPath;
+            if (!file.EndsWith(".patch") && !file.EndsWith(".diff"))
+                return;
+
+            TxtPatchFile.Text = file;
+            e.Handled = true;
+        }
     }
 }