Support drag&drop images from camera

PhotoLocator/Helpers/DragDropFileExtractor.cs

@@ -0,0 +1,223 @@
+using OpenCvSharp.Dnn;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Runtime.InteropServices.ComTypes;
+using System.Windows;
+
+namespace PhotoLocator.Helpers
+{
+    static class DragDropFileExtractor
+    {
+        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
+        struct FILEDESCRIPTOR
+        {
+            public uint dwFlags;
+            public Guid clsid;
+            public System.Drawing.Size sizel;
+            public System.Drawing.Point pointl;
+            public uint dwFileAttributes;
+            public FILETIME ftCreationTime;
+            public FILETIME ftLastAccessTime;
+            public FILETIME ftLastWriteTime;
+            public uint nFileSizeHigh;
+            public uint nFileSizeLow;
+            [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
+            public string cFileName;
+        }
+
+        /// <summary>
+        /// Try to extract files from a drag-drop data object. Supports FileDrop and virtual file formats used by cameras (FileGroupDescriptor / FileContents).
+        /// Returns saved file paths when any files were extracted.
+        /// </summary>
+        public static List<string>? TryExtractFiles(System.Windows.IDataObject data, string targetDirectory, Func<string,bool> overwriteCheck)
+        {
+            // Standard file drop
+            if (data.GetDataPresent(DataFormats.FileDrop))
+            {
+                var saved = new List<string>();
+                var droppedObj = data.GetData(DataFormats.FileDrop);
+                if (droppedObj is string[] dropped && dropped.Length > 0)
+                {
+                    foreach (var sourceFileName in dropped)
+                    {
+                        var targetPath = Path.Combine(targetDirectory, Path.GetFileName(sourceFileName));
+                        if (sourceFileName == targetPath || File.Exists(targetPath) && !overwriteCheck(targetPath))
+                            continue;
+                        File.Copy(sourceFileName, targetPath, true);
+                        saved.Add(targetPath);
+                    }
+                    return saved;
+                }
+            }
+
+            // Look for FileGroupDescriptorW or FileGroupDescriptor
+            var formats = data.GetFormats(true);
+            var fgFormat = formats.Contains("FileGroupDescriptorW") ? "FileGroupDescriptorW" : formats.Contains("FileGroupDescriptor") ? "FileGroupDescriptor" : null;
+            if (fgFormat is null)
+                return null;
+
+            // Read FILEGROUPDESCRIPTOR bytes
+            var fgObj = data.GetData(fgFormat);
+            if (fgObj is null) return null;
+            byte[] bytes;
+            if (fgObj is MemoryStream fgStream)
+                bytes = fgStream.ToArray();
+            else if (fgObj is byte[] b)
+                bytes = b;
+            else if (fgObj is UnmanagedMemoryStream ums)
+            {
+                bytes = new byte[ums.Length];
+                ums.Read(bytes, 0, bytes.Length);
+            }
+            else
+                return null;
+
+            var fileNames = new List<string>();
+            var handle = GCHandle.Alloc(bytes, GCHandleType.Pinned);
+            try
+            {
+                var ptr = handle.AddrOfPinnedObject();
+                int count = Marshal.ReadInt32(ptr);
+                var descSize = Marshal.SizeOf<FILEDESCRIPTOR>();
+                for (int i = 0; i < count; i++)
+                {
+                    var itemPtr = IntPtr.Add(ptr, 4 + i * descSize);
+                    var fd = Marshal.PtrToStructure<FILEDESCRIPTOR>(itemPtr);
+                    fileNames.Add(fd.cFileName);
+                }
+            }
+            finally
+            {
+                handle.Free();
+            }
+
+            if (fileNames.Count == 0) return null;
+
+            // Obtain COM IDataObject
+            var unk = Marshal.GetIUnknownForObject(data);
+            try
+            {
+                var iid = typeof(System.Runtime.InteropServices.ComTypes.IDataObject).GUID;
+                Marshal.QueryInterface(unk, in iid, out var pDataObj);
+                if (pDataObj == IntPtr.Zero) return null;
+                try
+                {
+                    var comData = (System.Runtime.InteropServices.ComTypes.IDataObject)Marshal.GetObjectForIUnknown(pDataObj);
+                    // Clipboard format id for FileContents
+                    var fileContentsId = System.Windows.Forms.DataFormats.GetFormat("FileContents").Id;
+
+                    var saved = new List<string>();
+                    for (int index = 0; index < fileNames.Count; index++)
+                    {
+                        var fmt = new FORMATETC
+                        {
+                            cfFormat = (short)fileContentsId,
+                            ptd = IntPtr.Zero,
+                            dwAspect = DVASPECT.DVASPECT_CONTENT,
+                            lindex = index,
+                            tymed = TYMED.TYMED_ISTREAM | TYMED.TYMED_HGLOBAL
+                        };
+
+                        var medium = new STGMEDIUM();
+                        try
+                        {
+                            comData.GetData(ref fmt, out medium);
+                        }
+                        catch
+                        {
+                            continue;
+                        }
+
+                        try
+                        {
+                            var fileName = fileNames[index];
+                            var targetPath = Path.Combine(targetDirectory, fileName);
+                            if (File.Exists(targetPath) && !overwriteCheck(targetPath))
+                                continue;
+
+                            // IStream
+                            if (((int)medium.tymed & (int)TYMED.TYMED_ISTREAM) != 0 && medium.unionmember != IntPtr.Zero)
+                            {
+                                var comStream = (IStream)Marshal.GetObjectForIUnknown(medium.unionmember);
+                                using var outFs = File.Create(targetPath);
+                                CopyIStreamToStream(comStream, outFs);
+                                saved.Add(targetPath);
+                            }
+                            else if (((int)medium.tymed & (int)TYMED.TYMED_HGLOBAL) != 0 && medium.unionmember != IntPtr.Zero)
+                            {
+                                // HGLOBAL: lock and copy
+                                var hglobal = medium.unionmember;
+                                var ptrData = GlobalLock(hglobal);
+                                try
+                                {
+                                    // We don't have size here; attempt to write until null or best-effort using FILEDESCRIPTOR values
+                                    // As a fallback, create file from bytes until GlobalSize
+                                    var globalSize = GlobalSize(hglobal);
+                                    var buffer = new byte[globalSize];
+                                    Marshal.Copy(ptrData, buffer, 0, buffer.Length);
+                                    File.WriteAllBytes(targetPath, buffer);
+                                    saved.Add(targetPath);
+                                }
+                                finally
+                                {
+                                    GlobalUnlock(hglobal);
+                                }
+                            }
+                        }
+                        finally
+                        {
+                            ReleaseStgMedium(ref medium);
+                        }
+                    }
+
+                    return saved.Count > 0 ? saved : null;
+                }
+                finally
+                {
+                    Marshal.Release(pDataObj);
+                }
+            }
+            finally
+            {
+                Marshal.Release(unk);
+            }
+        }
+
+        static void CopyIStreamToStream(IStream comStream, Stream outStream)
+        {
+            const int chunk = 64 * 1024;
+            var buffer = new byte[chunk];
+            var pcbRead = Marshal.AllocCoTaskMem(sizeof(int));
+            try
+            {
+                while (true)
+                {
+                    comStream.Read(buffer, buffer.Length, pcbRead);
+                    int read = Marshal.ReadInt32(pcbRead);
+                    if (read == 0) break;
+                    outStream.Write(buffer, 0, read);
+                }
+            }
+            finally
+            {
+                Marshal.FreeCoTaskMem(pcbRead);
+            }
+        }
+
+        [DllImport("kernel32.dll", SetLastError = true), DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
+        static extern IntPtr GlobalLock(IntPtr hMem);
+
+        [DllImport("kernel32.dll", SetLastError = true), DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        static extern bool GlobalUnlock(IntPtr hMem);
+
+        [DllImport("kernel32.dll", SetLastError = true), DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
+        static extern int GlobalSize(IntPtr hMem);
+
+        [DllImport("ole32.dll"), DefaultDllImportSearchPaths(DllImportSearchPath.System32)]
+        static extern void ReleaseStgMedium(ref STGMEDIUM pmedium);
+    }
+}

PhotoLocator/Helpers/ShellContextMenu.cs

@@ -1,7 +1,6 @@
 #nullable disable
 #pragma warning disable CA1032
 #pragma warning disable CA1069
-#pragma warning disable CA1401
 #pragma warning disable CA1707
 #pragma warning disable CA1711
 #pragma warning disable CA1805
@@ -76,7 +75,7 @@ private bool GetContextMenuInterfaces(IShellFolder oParentFolder, IntPtr[] arrPI
                 IntPtr.Zero,
                 (uint)arrPIDLs.Length,
                 arrPIDLs,
-                ref IID_IContextMenu,
+                in IID_IContextMenu,
                 IntPtr.Zero,
                 ref ctxMenuPtr);
 
@@ -106,22 +105,6 @@ private bool GetContextMenuInterfaces(IShellFolder oParentFolder, IntPtr[] arrPI
         /// <returns>true if the message has been handled, false otherwise</returns>
         protected override void WndProc(ref Message m)
         {
-            #region IContextMenu
-
-            if (_oContextMenu != null &&
-                m.Msg == (int)WM.MENUSELECT &&
-                ((int)ShellHelper.HiWord(m.WParam) & (int)MFT.SEPARATOR) == 0 &&
-                ((int)ShellHelper.HiWord(m.WParam) & (int)MFT.POPUP) == 0)
-            {
-                string info;
-                if (ShellHelper.LoWord(m.WParam) == (int)CMD_CUSTOM.ExpandCollapse)
-                    info = "Expands or collapses the current selected item";
-                else
-                    info = string.Empty;
-            }
-
-            #endregion
-
             #region IContextMenu2
 
             if (_oContextMenu2 != null &&
@@ -263,22 +246,19 @@ private IShellFolder GetParentFolder(string folderName)
 
                 IntPtr pStrRet = Marshal.AllocCoTaskMem(MAX_PATH * 2 + 4);
                 Marshal.WriteInt32(pStrRet, 0, 0);
-                nResult = _oDesktopFolder.GetDisplayNameOf(pPIDL, SHGNO.FORPARSING, pStrRet);
+                _oDesktopFolder.GetDisplayNameOf(pPIDL, SHGNO.FORPARSING, pStrRet);
                 var strFolder = new StringBuilder(MAX_PATH);
                 StrRetToBuf(pStrRet, pPIDL, strFolder, MAX_PATH);
                 Marshal.FreeCoTaskMem(pStrRet);
-                pStrRet = IntPtr.Zero;
                 _strParentFolder = strFolder.ToString();
 
                 // Get the IShellFolder for folder
                 IntPtr pUnknownParentFolder = IntPtr.Zero;
-                nResult = oDesktopFolder.BindToObject(pPIDL, IntPtr.Zero, ref IID_IShellFolder, ref pUnknownParentFolder);
+                nResult = oDesktopFolder.BindToObject(pPIDL, IntPtr.Zero, in IID_IShellFolder, ref pUnknownParentFolder);
                 // Free the PIDL first
                 Marshal.FreeCoTaskMem(pPIDL);
                 if (S_OK != nResult)
-                {
                     return null;
-                }
                 _oParentFolder = (IShellFolder)Marshal.GetTypedObjectForIUnknown(pUnknownParentFolder, typeof(IShellFolder));
             }
 
@@ -307,7 +287,7 @@ protected IntPtr[] GetPIDLs(FileInfo[] arrFI)
 
             IntPtr[] arrPIDLs = new IntPtr[arrFI.Length];
             int n = 0;
-            foreach (FileInfo fi in arrFI)
+            foreach (var fi in arrFI)
             {
                 // Get the file relative to folder
                 uint pchEaten = 0;
@@ -346,7 +326,7 @@ protected IntPtr[] GetPIDLs(DirectoryInfo[] arrFI)
 
             IntPtr[] arrPIDLs = new IntPtr[arrFI.Length];
             int n = 0;
-            foreach (DirectoryInfo fi in arrFI)
+            foreach (var fi in arrFI)
             {
                 // Get the file relative to folder
                 uint pchEaten = 0;
@@ -612,10 +592,10 @@ private void ShowContextMenu(Point pointScreen)
 
         #region Shell GUIDs
 
-        private static Guid IID_IShellFolder = new("{000214E6-0000-0000-C000-000000000046}");
-        private static Guid IID_IContextMenu = new("{000214e4-0000-0000-c000-000000000046}");
-        private static Guid IID_IContextMenu2 = new("{000214f4-0000-0000-c000-000000000046}");
-        private static Guid IID_IContextMenu3 = new("{bcfce0a0-ec17-11d0-8d10-00a0c90f2719}");
+        private static readonly Guid IID_IShellFolder = new("{000214E6-0000-0000-C000-000000000046}");
+        private static readonly Guid IID_IContextMenu = new("{000214e4-0000-0000-c000-000000000046}");
+        private static readonly Guid IID_IContextMenu2 = new("{000214f4-0000-0000-c000-000000000046}");
+        private static readonly Guid IID_IContextMenu3 = new("{bcfce0a0-ec17-11d0-8d10-00a0c90f2719}");
 
         #endregion
 
@@ -1198,7 +1178,7 @@ Int32 EnumObjects(
             Int32 BindToObject(
                 IntPtr pidl,
                 IntPtr pbc,
-                ref Guid riid,
+                in Guid riid,
                 ref IntPtr ppv);
 
             // Requests a pointer to an object's storage interface. 
@@ -1253,7 +1233,7 @@ Int32 GetUIObjectOf(
                 uint cidl,
                 [MarshalAs(UnmanagedType.LPArray)]
             IntPtr[] apidl,
-                ref Guid riid,
+                in Guid riid,
                 IntPtr rgfReserved,
                 ref IntPtr ppv);
 

PhotoLocator/MainWindow.xaml.cs

@@ -319,10 +319,33 @@ private void HandlePathEditPreviewKeyUp(object sender, KeyEventArgs e)
 
         private void HandleDrop(object sender, DragEventArgs e)
         {
-            if (e.Data.GetDataPresent(DataFormats.FileDrop) && e.Data.GetData(DataFormats.FileDrop) is string[] droppedEntries && droppedEntries.Length > 0
-                && !droppedEntries.Equals(_draggedFiles))
+            if (e.Data.GetDataPresent(DataFormats.FileDrop) && e.Data.GetData(DataFormats.FileDrop) is string[] droppedEntries && droppedEntries.Length > 0)
             {
-                Dispatcher.BeginInvoke(() => _viewModel.HandleDroppedFiles(droppedEntries));
+                if (!droppedEntries.Equals(_draggedFiles))
+                    Dispatcher.BeginInvoke(() => _viewModel.HandleDroppedFiles(droppedEntries));
+                return;
+            }
+            if (string.IsNullOrEmpty(_viewModel.PhotoFolderPath))
+                return;
+            try
+            {
+                using var cursor = new MouseCursorOverride();
+                var extracted = DragDropFileExtractor.TryExtractFiles(e.Data, _viewModel.PhotoFolderPath, 
+                    existingFile =>
+                    {
+                        return MessageBox.Show(this, $"The file '{existingFile}' already exists. Do you wish to overwrite it?", "Copy files", MessageBoxButton.YesNoCancel, MessageBoxImage.Question) switch
+                        {
+                            MessageBoxResult.Yes => true,
+                            MessageBoxResult.No => false,
+                            _ => throw new OperationCanceledException(),
+                        };
+                    });
+                if (extracted is not null && extracted.Count > 0)
+                    Dispatcher.BeginInvoke(() => _viewModel.SelectFileAsync(extracted[0]));
+            }
+            catch (Exception ex) 
+            {
+                ExceptionHandler.LogException(ex);
             }
         }