[client] windows: implement file clipboard support

client/displayservers/Windows/CMakeLists.txt

@@ -27,6 +27,7 @@ target_link_libraries(displayserver_Windows
   lg_common
   user32
   gdi32
+  ole32
 )
 
 if(ENABLE_EGL)

client/displayservers/Windows/clipboard.c

@@ -29,9 +29,14 @@
 #include "common/debug.h"
 #include "common/windebug.h"
 #include "core/clipboard.h"
+#include "core/clipboard_files.h"
 #include "platform.h"
+#include "platform/windows/clipboard_files.h"
 
-#define WINDOWS_CB_OPEN_ATTEMPTS 8
+#define WINDOWS_CB_OPEN_ATTEMPTS     8
+#define WINDOWS_CB_RETRY_INTERVAL_MS 50
+#define WINDOWS_CB_RETRY_TIMEOUT_MS  5000
+#define WINDOWS_CB_RETRY_TIMER_ID    ((UINT_PTR)0x4C47)
 
 enum WindowsClipboardMessage
 {
@@ -47,6 +52,13 @@ enum WindowsClipboardOperationType
   WINDOWS_CB_OPERATION_DATA,
 };
 
+enum WindowsClipboardCaptureResult
+{
+  WINDOWS_CB_CAPTURE_RETRY,
+  WINDOWS_CB_CAPTURE_TYPES,
+  WINDOWS_CB_CAPTURE_FILES,
+};
+
 struct WindowsClipboardOperation
 {
   struct WindowsClipboardOperation * next;
@@ -79,15 +91,23 @@ struct WindowsClipboardState
   UINT                               pngFormat;
   UINT                               jfifFormat;
   UINT                               jpegFormat;
+  IDataObject                      * remoteFiles;
   LG_ClipboardRequest                canceledRequest;
+  ULONGLONG                          retryDeadline;
+  DWORD                              retrySequence;
   bool                               listener;
   bool                               accepting;
+  bool                               oleInitialized;
+  bool                               applyingRemote;
+  bool                               pendingUpdate;
 };
 
 static SRWLOCK                      windowsCBQueueLock = SRWLOCK_INIT;
 static struct WindowsClipboardState windowsCB;
 static _Atomic(uint64_t)            windowsCBGeneration;
 
+static void updateLocalClipboard(void);
+
 static uint16_t readLE16(const uint8_t * data)
 {
   return (uint16_t)data[0] |
@@ -557,6 +577,8 @@ static bool localTypeAvailable(LG_ClipboardData type)
           IsClipboardFormatAvailable(windowsCB.jpegFormat));
 
     case LG_CLIPBOARD_DATA_FILES:
+      return IsClipboardFormatAvailable(CF_HDROP);
+
     case LG_CLIPBOARD_DATA_NONE:
       return false;
   }
@@ -649,36 +671,294 @@ static bool readLocalClipboard(LG_ClipboardData type,
   return true;
 }
 
+static void releaseRemoteFilesReference(void)
+{
+  if (!windowsCB.remoteFiles)
+    return;
+
+  windowsCB.remoteFiles->lpVtbl->Release(windowsCB.remoteFiles);
+  windowsCB.remoteFiles = NULL;
+}
+
+static bool remoteFilesAreCurrent(void)
+{
+  return windowsCB.oleInitialized && windowsCB.remoteFiles &&
+    OleIsCurrentClipboard(windowsCB.remoteFiles) == S_OK;
+}
+
+static HRESULT setOleClipboard(IDataObject * object)
+{
+  HRESULT status = E_FAIL;
+  DWORD   delay  = 1;
+  // OleSetClipboard can synchronously dispatch a clipboard notification.
+  windowsCB.applyingRemote = true;
+  for (unsigned int attempt = 0;
+      attempt < WINDOWS_CB_OPEN_ATTEMPTS; ++attempt)
+  {
+    status = OleSetClipboard(object);
+    if (SUCCEEDED(status))
+      break;
+    if (attempt + 1U < WINDOWS_CB_OPEN_ATTEMPTS)
+    {
+      Sleep(delay);
+      delay *= 2U;
+    }
+  }
+  windowsCB.applyingRemote = false;
+  if (windowsCB.pendingUpdate && windowsCB.accepting && windowsCB.window)
+  {
+    windowsCB.pendingUpdate = false;
+    if (!PostMessageW(windowsCB.window, WM_CLIPBOARDUPDATE, 0, 0))
+      DEBUG_WINERROR("Failed to replay a Windows clipboard update",
+          GetLastError());
+  }
+  return status;
+}
+
+static bool clearRemoteFilesClipboard(void)
+{
+  if (!windowsCB.remoteFiles)
+    return true;
+
+  if (remoteFilesAreCurrent())
+  {
+    const HRESULT status = setOleClipboard(NULL);
+    if (FAILED(status))
+    {
+      DEBUG_WINERROR("Failed to clear the Windows file clipboard", status);
+      return false;
+    }
+  }
+
+  releaseRemoteFilesReference();
+  return true;
+}
+
+struct WindowsClipboardCapture
+{
+  LG_ClipboardData types[LG_CLIPBOARD_DATA_NONE];
+  size_t           count;
+  uint32_t         mask;
+  uint8_t        * fileData;
+  size_t           fileSize;
+  HWND             owner;
+  DWORD            sequence;
+};
+
+static enum WindowsClipboardCaptureResult captureLocalClipboard(
+    HWND owner, DWORD sequence, struct WindowsClipboardCapture * capture)
+{
+  memset(capture, 0, sizeof(*capture));
+  // Explorer can still own the clipboard when WM_CLIPBOARDUPDATE arrives.
+  // Acquire it before probing formats so that generation is retried instead
+  // of being recorded as an empty clipboard.
+  if (!openClipboard())
+    return WINDOWS_CB_CAPTURE_RETRY;
+
+  if (owner != GetClipboardOwner() ||
+      sequence != GetClipboardSequenceNumber())
+  {
+    CloseClipboard();
+    return WINDOWS_CB_CAPTURE_RETRY;
+  }
+
+  const bool files  = localTypeAvailable(LG_CLIPBOARD_DATA_FILES);
+  bool       copied = false;
+  if (files)
+  {
+    HANDLE handle = GetClipboardData(CF_HDROP);
+    copied = handle && copyGlobalData(handle,
+        &capture->fileData, &capture->fileSize);
+  }
+  else
+  {
+    for (LG_ClipboardData type = LG_CLIPBOARD_DATA_TEXT;
+        type < LG_CLIPBOARD_DATA_FILES; ++type)
+    {
+      if (!localTypeAvailable(type))
+        continue;
+
+      capture->types[capture->count++] = type;
+      capture->mask                   |= UINT32_C(1) << type;
+    }
+  }
+
+  capture->owner              = GetClipboardOwner();
+  capture->sequence           = GetClipboardSequenceNumber();
+  const bool sequenceChanged  = capture->sequence != sequence;
+  const BOOL closed           = CloseClipboard();
+  const DWORD closeError      = closed ? ERROR_SUCCESS : GetLastError();
+  const HWND currentOwner     = GetClipboardOwner();
+  const DWORD currentSequence = GetClipboardSequenceNumber();
+  const bool stable           = closed && capture->owner == currentOwner &&
+    capture->sequence == currentSequence && capture->owner == owner &&
+    (!sequenceChanged || (files && owner));
+  if (!stable || (files && !copied))
+  {
+    if (!closed)
+      DEBUG_WINERROR("Failed to close the Windows clipboard", closeError);
+    free(capture->fileData);
+    capture->fileData = NULL;
+    return WINDOWS_CB_CAPTURE_RETRY;
+  }
+
+  return files ? WINDOWS_CB_CAPTURE_FILES : WINDOWS_CB_CAPTURE_TYPES;
+}
+
+static void clearLocalRetry(void)
+{
+  if (windowsCB.window && windowsCB.retryDeadline)
+    KillTimer(windowsCB.window, WINDOWS_CB_RETRY_TIMER_ID);
+  windowsCB.retryDeadline = 0;
+  windowsCB.retrySequence = 0;
+}
+
+static void expireLocalRetry(DWORD sequence)
+{
+  clearLocalRetry();
+  if (!windowsCB.accepting || remoteFilesAreCurrent())
+    return;
+  if (sequence != GetClipboardSequenceNumber())
+  {
+    PostMessageW(windowsCB.window, WM_CLIPBOARDUPDATE, 0, 0);
+    return;
+  }
+
+  windowsCB.localOwner    = GetClipboardOwner();
+  windowsCB.localSequence = sequence;
+  windowsCB.localTypes    = 0;
+  clipboardFiles_clearLocal();
+  clipboard_release();
+}
+
+static void deferLocalClipboard(DWORD sequence)
+{
+  const ULONGLONG now = GetTickCount64();
+  if (!windowsCB.retryDeadline || windowsCB.retrySequence != sequence)
+  {
+    clearLocalRetry();
+    windowsCB.retrySequence = sequence;
+    windowsCB.retryDeadline = now + WINDOWS_CB_RETRY_TIMEOUT_MS;
+  }
+
+  if (now < windowsCB.retryDeadline &&
+      SetTimer(windowsCB.window, WINDOWS_CB_RETRY_TIMER_ID,
+        WINDOWS_CB_RETRY_INTERVAL_MS, NULL))
+    return;
+
+  if (now >= windowsCB.retryDeadline)
+    DEBUG_WARN("Timed out waiting for the Windows clipboard");
+  else
+    DEBUG_WINERROR("Failed to schedule a Windows clipboard retry",
+        GetLastError());
+  expireLocalRetry(sequence);
+}
+
+static void retryLocalClipboard(void)
+{
+  if (windowsCB.window)
+    KillTimer(windowsCB.window, WINDOWS_CB_RETRY_TIMER_ID);
+  if (!windowsCB.retryDeadline)
+    return;
+  if (!windowsCB.accepting || remoteFilesAreCurrent())
+  {
+    clearLocalRetry();
+    return;
+  }
+
+  const DWORD sequence = GetClipboardSequenceNumber();
+  if (sequence != windowsCB.retrySequence)
+  {
+    clearLocalRetry();
+    PostMessageW(windowsCB.window, WM_CLIPBOARDUPDATE, 0, 0);
+    return;
+  }
+  if (GetTickCount64() >= windowsCB.retryDeadline)
+  {
+    DEBUG_WARN("Timed out waiting for the Windows clipboard");
+    expireLocalRetry(sequence);
+    return;
+  }
+
+  updateLocalClipboard();
+}
+
 static void updateLocalClipboard(void)
 {
+  if (windowsCB.applyingRemote)
+  {
+    windowsCB.pendingUpdate = true;
+    return;
+  }
+
   const HWND  owner    = GetClipboardOwner();
   const DWORD sequence = GetClipboardSequenceNumber();
+  if (remoteFilesAreCurrent())
+  {
+    clearLocalRetry();
+    return;
+  }
+  releaseRemoteFilesReference();
   if (owner == windowsCB.window)
     return;
   if (owner == windowsCB.localOwner &&
       sequence == windowsCB.localSequence)
     return;
 
-  LG_ClipboardData types[LG_CLIPBOARD_DATA_NONE];
+  if (!windowsCB.retryDeadline || windowsCB.retrySequence != sequence)
-  size_t           count = 0;
+    atomic_fetch_add_explicit(
-  uint32_t         mask  = 0;
+        &windowsCBGeneration, 1, memory_order_acq_rel);
-  for (LG_ClipboardData type = LG_CLIPBOARD_DATA_TEXT;
-      type < LG_CLIPBOARD_DATA_FILES; ++type)
-  {
-    if (!localTypeAvailable(type))
-      continue;
 
-    types[count++] = type;
+  struct WindowsClipboardCapture capture;
-    mask          |= UINT32_C(1) << type;
+  const enum WindowsClipboardCaptureResult result =
+    captureLocalClipboard(owner, sequence, &capture);
+  if (result == WINDOWS_CB_CAPTURE_RETRY)
+  {
+    if (owner != GetClipboardOwner() ||
+        sequence != GetClipboardSequenceNumber())
+    {
+      clearLocalRetry();
+      PostMessageW(windowsCB.window, WM_CLIPBOARDUPDATE, 0, 0);
+    }
+    else
+      deferLocalClipboard(sequence);
+    return;
   }
 
-  windowsCB.localOwner    = owner;
+  if (result == WINDOWS_CB_CAPTURE_FILES)
-  windowsCB.localSequence = sequence;
+  {
-  windowsCB.localTypes    = mask;
+    HGLOBAL duplicate = makeGlobalData(capture.fileData, capture.fileSize);
-  atomic_fetch_add_explicit(
+    free(capture.fileData);
-      &windowsCBGeneration, 1, memory_order_acq_rel);
+    if (!duplicate)
-  if (count)
+    {
-    clipboard_notifyTypes(types, count);
+      deferLocalClipboard(capture.sequence);
+      return;
+    }
+
+    const bool published = windowsClipboardFiles_setLocalDrop(
+        (HDROP)duplicate);
+    GlobalFree(duplicate);
+    if (!published)
+    {
+      DEBUG_WARN("Failed to capture the Windows file clipboard");
+      deferLocalClipboard(capture.sequence);
+      return;
+    }
+
+    clearLocalRetry();
+    windowsCB.localOwner    = capture.owner;
+    windowsCB.localSequence = capture.sequence;
+    windowsCB.localTypes    = UINT32_C(1) << LG_CLIPBOARD_DATA_FILES;
+    return;
+  }
+
+  clearLocalRetry();
+  windowsCB.localOwner    = capture.owner;
+  windowsCB.localSequence = capture.sequence;
+  windowsCB.localTypes    = capture.mask;
+  clipboardFiles_clearLocal();
+  if (capture.count)
+    clipboard_notifyTypes(capture.types, capture.count);
   else
     clipboard_release();
 }
@@ -827,7 +1107,8 @@ static void handleRemoteData(
   }
 
   if (operation->generation != atomic_load_explicit(
-        &windowsCBGeneration, memory_order_acquire) || !openClipboard())
+        &windowsCBGeneration, memory_order_acquire) ||
+      !clearRemoteFilesClipboard() || !openClipboard())
     goto fail;
   if (operation->generation != atomic_load_explicit(
         &windowsCBGeneration, memory_order_acquire) || !EmptyClipboard())
@@ -835,7 +1116,6 @@ static void handleRemoteData(
     CloseClipboard();
     goto fail;
   }
-
   bool published = false;
   for (size_t i = 0; i < count; ++i)
   {
@@ -853,6 +1133,7 @@ static void handleRemoteData(
           GetLastError());
   }
   CloseClipboard();
+  clipboardFiles_clearLocal();
   windowsCB.localOwner    = GetClipboardOwner();
   windowsCB.localSequence = GetClipboardSequenceNumber();
   windowsCB.localTypes    = 0;
@@ -865,12 +1146,96 @@ fail:
       GlobalFree(handles[i]);
 }
 
+static void handleRemoteFiles(
+    const struct WindowsClipboardOperation * operation)
+{
+  if (!windowsCB.oleInitialized)
+  {
+    DEBUG_WARN("OLE is unavailable; cannot publish guest clipboard files");
+    return;
+  }
+
+  const uint64_t presentation =
+    clipboardFiles_remotePresentationAcquire();
+  if (!presentation)
+  {
+    DEBUG_WARN("Failed to acquire the guest clipboard file offer");
+    return;
+  }
+
+  IDataObject * object = NULL;
+  if (!windowsClipboardFiles_createRemoteDataObject(
+        presentation, &object) || !object)
+  {
+    clipboardFiles_remotePresentationRelease(presentation);
+    DEBUG_WARN("Failed to create the guest clipboard file object");
+    return;
+  }
+
+  if (operation->generation != atomic_load_explicit(
+        &windowsCBGeneration, memory_order_acquire))
+  {
+    object->lpVtbl->Release(object);
+    return;
+  }
+
+  const HRESULT status = setOleClipboard(object);
+  if (FAILED(status))
+  {
+    DEBUG_WINERROR("Failed to publish guest clipboard files", status);
+    object->lpVtbl->Release(object);
+    return;
+  }
+
+  if (operation->generation != atomic_load_explicit(
+        &windowsCBGeneration, memory_order_acquire))
+  {
+    const HRESULT clearStatus = OleIsCurrentClipboard(object) == S_OK ?
+      setOleClipboard(NULL) : S_OK;
+    releaseRemoteFilesReference();
+    if (FAILED(clearStatus) && OleIsCurrentClipboard(object) == S_OK)
+    {
+      DEBUG_WINERROR("Failed to withdraw stale guest clipboard files",
+          clearStatus);
+      windowsCB.remoteFiles = object;
+    }
+    else
+      object->lpVtbl->Release(object);
+    return;
+  }
+
+  releaseRemoteFilesReference();
+  windowsCB.remoteFiles   = object;
+  windowsCB.localOwner    = GetClipboardOwner();
+  windowsCB.localSequence = GetClipboardSequenceNumber();
+  windowsCB.localTypes    = 0;
+  clipboardFiles_clearLocal();
+  clipboardFiles_remotePresentationDelivered(presentation);
+}
+
 static void handleRemoteRelease(
     const struct WindowsClipboardOperation * operation)
 {
   if (operation->generation != atomic_load_explicit(
-        &windowsCBGeneration, memory_order_acquire) ||
+        &windowsCBGeneration, memory_order_acquire))
-      GetClipboardOwner() != windowsCB.window || !openClipboard())
+    return;
+
+  if (windowsCB.remoteFiles)
+  {
+    const bool current = remoteFilesAreCurrent();
+    if (!clearRemoteFilesClipboard())
+      return;
+    if (current)
+    {
+      windowsCB.localOwner    = GetClipboardOwner();
+      windowsCB.localSequence = GetClipboardSequenceNumber();
+      windowsCB.localTypes    = 0;
+      clipboardFiles_clearLocal();
+    }
+    return;
+  }
+
+  if (GetClipboardOwner() != windowsCB.window || !openClipboard())
     return;
 
   bool released = false;
@@ -884,6 +1249,7 @@ static void handleRemoteRelease(
     windowsCB.localOwner    = GetClipboardOwner();
     windowsCB.localSequence = GetClipboardSequenceNumber();
     windowsCB.localTypes    = 0;
+    clipboardFiles_clearLocal();
   }
 }
 
@@ -997,7 +1363,7 @@ static void handleRemoteNotice(
     return;
   if (operation->dataType == LG_CLIPBOARD_DATA_FILES)
   {
-    handleRemoteRelease(operation);
+    handleRemoteFiles(operation);
     return;
   }
   if (operation->dataType >= LG_CLIPBOARD_DATA_NONE)
@@ -1052,6 +1418,13 @@ static bool eventInit(HWND window)
   if (!window)
     return false;
 
+  const HRESULT oleStatus = OleInitialize(NULL);
+  if (SUCCEEDED(oleStatus))
+    windowsCB.oleInitialized = true;
+  else
+    DEBUG_WINERROR("Failed to initialize OLE for clipboard files",
+        oleStatus);
+
   windowsCB.pngFormat  = RegisterClipboardFormatW(L"PNG");
   windowsCB.jfifFormat = RegisterClipboardFormatW(L"JFIF");
   windowsCB.jpegFormat = RegisterClipboardFormatW(L"JPEG");
@@ -1060,6 +1433,11 @@ static bool eventInit(HWND window)
   {
     DEBUG_WINERROR("Failed to register Windows clipboard formats",
         GetLastError());
+    if (windowsCB.oleInitialized)
+    {
+      OleUninitialize();
+      windowsCB.oleInitialized = false;
+    }
     return false;
   }
 
@@ -1067,6 +1445,11 @@ static bool eventInit(HWND window)
   {
     DEBUG_WINERROR("Failed to register the Windows clipboard listener",
         GetLastError());
+    if (windowsCB.oleInitialized)
+    {
+      OleUninitialize();
+      windowsCB.oleInitialized = false;
+    }
     return false;
   }
 
@@ -1083,7 +1466,6 @@ static bool eventInit(HWND window)
 bool windowsCBHandleMessage(HWND window, UINT message,
     WPARAM wParam, LPARAM lParam, LRESULT * result)
 {
-  (void)wParam;
   (void)lParam;
 
   switch (message)
@@ -1102,6 +1484,13 @@ bool windowsCBHandleMessage(HWND window, UINT message,
         updateLocalClipboard();
       *result = 0;
       return true;
+
+    case WM_TIMER:
+      if ((UINT_PTR)wParam != WINDOWS_CB_RETRY_TIMER_ID)
+        return false;
+      retryLocalClipboard();
+      *result = 0;
+      return true;
   }
 
   return false;
@@ -1113,6 +1502,7 @@ void windowsCBEventShutdown(void)
   bool                               listener;
   struct WindowsClipboardOperation * operations;
 
+  clearLocalRetry();
   AcquireSRWLockExclusive(&windowsCBQueueLock);
   window              = windowsCB.window;
   listener            = windowsCB.listener;
@@ -1129,6 +1519,13 @@ void windowsCBEventShutdown(void)
   if (listener && window && !RemoveClipboardFormatListener(window))
     DEBUG_WINERROR("Failed to remove the Windows clipboard listener",
         GetLastError());
+  if (!clearRemoteFilesClipboard())
+    releaseRemoteFilesReference();
+  if (windowsCB.oleInitialized)
+  {
+    OleUninitialize();
+    windowsCB.oleInitialized = false;
+  }
   freeOperations(operations);
 }
 

client/include/core/clipboard.h

@@ -61,7 +61,7 @@ bool clipboard_requestCancel(LG_ClipboardRequest request,
 bool clipboard_request(LG_ClipboardData type,
     LG_ClipboardReplyFn replyFn, void * opaque);
 
-/* File-dataset transport entry points used by clipboard_files.c. */
+/* File-dataset transport entry points used by platform clipboard backends. */
 bool clipboard_fileAcquire(uint64_t dataset, uint64_t acquisition);
 bool clipboard_fileAcquired(uint64_t dataset, uint64_t acquisition,
     LG_ClipboardFileError error);

client/include/core/clipboard_files.h

@@ -23,6 +23,10 @@
 
 #include "interface/clipboard.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 bool clipboardFiles_init(void);
 void clipboardFiles_free(void);
 
@@ -83,4 +87,8 @@ bool clipboardFiles_testLocalRequest(
     const LG_ClipboardFileRequest * request);
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif

client/include/platform/windows/clipboard_files.h

@@ -0,0 +1,43 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _H_LG_PLATFORM_WINDOWS_CLIPBOARD_FILES_
+#define _H_LG_PLATFORM_WINDOWS_CLIPBOARD_FILES_
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <windows.h>
+#include <ole2.h>
+#include <shellapi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+bool windowsClipboardFiles_setLocalDrop(HDROP drop);
+bool windowsClipboardFiles_createRemoteDataObject(uint64_t presentation,
+    IDataObject ** dataObject);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

client/include/platform/windows/clipboard_files_win32.h

@@ -0,0 +1,88 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _H_LG_PLATFORM_WINDOWS_CLIPBOARD_FILES_WIN32_
+#define _H_LG_PLATFORM_WINDOWS_CLIPBOARD_FILES_WIN32_
+
+#include "interface/clipboard.h"
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <windows.h>
+#include <ole2.h>
+#include <shellapi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct WindowsClipboardLocalFiles     WindowsClipboardLocalFiles;
+typedef struct WindowsClipboardRemoteManifest WindowsClipboardRemoteManifest;
+
+typedef struct WindowsClipboardRemoteProviderOps
+{
+  HRESULT (*read   )(void * opaque, uint64_t dataset, uint64_t acquisition,
+      uint64_t node, uint64_t offset, void * data, ULONG length,
+      ULONG * read);
+  void    (*release)(void * opaque, uint64_t dataset, uint64_t acquisition);
+}
+WindowsClipboardRemoteProviderOps;
+
+/* Capture copies the selection metadata. List and read return malloc-owned
+ * buffers which the caller releases with free(). */
+WindowsClipboardLocalFiles * windowsClipboardLocalFilesCapture(HDROP drop,
+    LG_ClipboardFileError * error);
+void windowsClipboardLocalFilesRetain(WindowsClipboardLocalFiles * files);
+void windowsClipboardLocalFilesRelease(WindowsClipboardLocalFiles * files);
+bool windowsClipboardLocalFilesList(WindowsClipboardLocalFiles * files,
+    uint64_t node, void ** data, size_t * size,
+    LG_ClipboardFileError * error);
+bool windowsClipboardLocalFilesRead(WindowsClipboardLocalFiles * files,
+    uint64_t node, uint64_t offset, uint32_t length, void ** data,
+    size_t * size, LG_ClipboardFileError * error);
+
+WindowsClipboardRemoteManifest * windowsClipboardRemoteManifestCreate(void);
+void windowsClipboardRemoteManifestFree(
+    WindowsClipboardRemoteManifest * manifest);
+/* Call NextDirectory before each LIST request, then append the complete
+ * response for the returned node. The first returned node is the wire root. */
+bool windowsClipboardRemoteManifestAppendList(
+    WindowsClipboardRemoteManifest * manifest, uint64_t parent,
+    const void * data, size_t size, LG_ClipboardFileError * error);
+bool windowsClipboardRemoteManifestNextDirectory(
+    WindowsClipboardRemoteManifest * manifest, uint64_t * node);
+bool windowsClipboardRemoteManifestHasEntries(
+    const WindowsClipboardRemoteManifest * manifest);
+
+/* The data object owns one provider lease after a successful return. The
+ * release callback runs once after both the object and all of its streams are
+ * released. A failed call does not invoke it. */
+HRESULT windowsClipboardRemoteCreateDataObject(
+    WindowsClipboardRemoteManifest * manifest, uint64_t dataset,
+    uint64_t acquisition, const WindowsClipboardRemoteProviderOps * ops,
+    void * opaque, IDataObject ** object);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

client/platform/Windows/CMakeLists.txt

@@ -3,6 +3,7 @@ project(client_platform_Windows LANGUAGES C CXX)
 
 add_library(client_platform_Windows STATIC
   clipboard_files.c
+  clipboard_files_win32.c
   config.c
   font.cpp
   input.c
@@ -16,6 +17,7 @@ target_link_libraries(client_platform_Windows
     ole32
     shell32
     shlwapi
+    user32
     uuid
 )
 

client/tests/CMakeLists.txt

@@ -40,17 +40,6 @@ set_tests_properties(event-source-tests PROPERTIES
   TIMEOUT 10
 )
 
-add_executable(windows-clipboard-files-tests
-  clipboard_files_windows_test.c
-  ../platform/Windows/clipboard_files.c
-)
-add_test(NAME windows-clipboard-files-tests
-  COMMAND windows-clipboard-files-tests
-)
-set_tests_properties(windows-clipboard-files-tests PROPERTIES
-  TIMEOUT 10
-)
-
 if(LG_CLIENT_PLATFORM_LINUX)
   add_executable(config-platform-tests
     config_platform_test.c

client/tests/clipboard_files_windows_test.c

@@ -1,103 +0,0 @@
-/**
- * Looking Glass
- * Copyright © 2017-2026 The Looking Glass Authors
- * https://looking-glass.io
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc., 59
- * Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#include "core/clipboard_files.h"
-#include "test.h"
-
-static struct
-{
-  uint64_t              dataset;
-  uint64_t              transfer;
-  LG_ClipboardFileError error;
-  unsigned int          acquired;
-  unsigned int          cancelled;
-}
-trace;
-
-bool clipboard_fileAcquired(uint64_t dataset, uint64_t acquisition,
-    LG_ClipboardFileError error)
-{
-  trace.dataset  = dataset;
-  trace.transfer = acquisition;
-  trace.error    = error;
-  ++trace.acquired;
-  return true;
-}
-
-bool clipboard_fileCancel(uint64_t dataset, uint64_t request,
-    LG_ClipboardFileError reason)
-{
-  trace.dataset  = dataset;
-  trace.transfer = request;
-  trace.error    = reason;
-  ++trace.cancelled;
-  return true;
-}
-
-int main(void)
-{
-  const LG_ClipboardFileRequest request =
-  {
-    .dataset   = UINT64_C(0x1234),
-    .request   = UINT64_C(0x5678),
-    .node      = 1,
-    .operation = LG_CLIPBOARD_FILE_READ,
-  };
-
-  CHECK(clipboardFiles_init());
-  CHECK(!clipboardFiles_remoteOffer(request.dataset));
-  CHECK(!clipboardFiles_remoteReady(request.dataset));
-
-  char  * data = (char *)(uintptr_t)1;
-  size_t  size = 1;
-  CHECK(!clipboardFiles_getRemote("text/uri-list", &data, &size));
-  CHECK(!data);
-  CHECK(size == 0);
-
-  data = (char *)(uintptr_t)1;
-  size = 1;
-  CHECK(!clipboardFiles_getRemotePresentation(
-      1, "text/uri-list", &data, &size));
-  CHECK(!data);
-  CHECK(size == 0);
-
-  clipboardFiles_localAcquire(request.dataset, request.request);
-  CHECK(trace.acquired == 1);
-  CHECK(trace.dataset == request.dataset);
-  CHECK(trace.transfer == request.request);
-  CHECK(trace.error == LG_CLIPBOARD_FILE_ERROR_NOT_SUPPORTED);
-
-  clipboardFiles_localRequest(&request);
-  CHECK(trace.cancelled == 1);
-  CHECK(trace.dataset == request.dataset);
-  CHECK(trace.transfer == request.request);
-  CHECK(trace.error == LG_CLIPBOARD_FILE_ERROR_NOT_SUPPORTED);
-
-  clipboardFiles_localRequest(NULL);
-  CHECK(trace.cancelled == 1);
-  CHECK(clipboardFiles_remoteDataBegin(&request, 0) ==
-      LG_CLIPBOARD_RESULT_FAILED);
-  CHECK(clipboardFiles_remoteDataChunk(&request, 0, NULL, 0) ==
-      LG_CLIPBOARD_RESULT_FAILED);
-  CHECK(clipboardFiles_remoteDataEnd(&request, 0) ==
-      LG_CLIPBOARD_RESULT_FAILED);
-  clipboardFiles_free();
-  return 0;
-}