Fixed an issue where files dragged in from Files were read only

src/QuickPad.Data/QuickPad.Data/StorageFileDataProvider.cs

@@ -2,6 +2,7 @@
 using QuickPad.Standard.Data;
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Text;
 using System.Threading.Tasks;
 using Windows.Storage;
@@ -22,6 +23,24 @@ public async Task<byte[]> LoadDataAsync(StorageFile file)
  return bytes;
  }
 
+ public static bool IsFileReadOnly(StorageFile file)
+ {
+ return (file.Attributes & Windows.Storage.FileAttributes.ReadOnly) != 0;
+ }
+
+ public static async Task<bool> IsFileWritable(StorageFile file)
+ {
+ try
+ {
+ using (var stream = await file.OpenStreamForWriteAsync()) { }
+ return true;
+ }
+ catch (Exception)
+ {
+ return false;
+ }
+ }
+
  public async Task<string> SaveDataAsync(StorageFileWrapper<StorageFile> file, IWriter writer, Encoding encoding)
  {
  List<byte> allBytes = new List<byte>();
@@ -38,8 +57,19 @@ public async Task<string> SaveDataAsync(StorageFileWrapper<StorageFile> file, IW
 
  var bytes = allBytes.ToArray();
 
- // Create sample file; replace if exists.
- await PathIO.WriteBytesAsync(file.Path, bytes);
+
+ if (IsFileReadOnly(file.File) || !await IsFileWritable(file.File))
+ {
+ // For file(s) dragged into Quick Pad, they are read-only
+ // StorageFile API won't work but can be overwritten by Win32 PathIO API
+ // In case the file is actually read-only, WriteBytesAsync will throw UnauthorizedAccessException exception
+ await PathIO.WriteBytesAsync(file.Path, bytes);
+ }
+ else // Use FileIO API to save
+ {
+ // Create file; replace if exists.
+ await FileIO.WriteBytesAsync(file.File, bytes);
+ }
 
  return $"{file.Name} was saved.";
  }