1 files changed, 72 insertions, 0 deletions
diff --git a/ui/views/drag_utils_win.cc b/ui/views/drag_utils_win.cc
new file mode 100644
index 0000000..3295f8f
--- /dev/null
+++ b/ui/views/drag_utils_win.cc
@@ -0,0 +1,72 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/views/drag_utils.h"
+
+#include <objidl.h>
+#include <shlobj.h>
+#include <shobjidl.h>
+
+#include "base/win/scoped_comptr.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_win.h"
+#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/gdi_util.h"
+#include "ui/gfx/skbitmap_operations.h"
+
+namespace drag_utils {
+
+static void SetDragImageOnDataObject(HBITMAP hbitmap,
+                                     const gfx::Size& size,
+                                     const gfx::Point& cursor_offset,
+                                     IDataObject* data_object) {
+  base::win::ScopedComPtr<IDragSourceHelper> helper;
+  HRESULT rv = CoCreateInstance(CLSID_DragDropHelper, 0, CLSCTX_INPROC_SERVER,
+                                IID_IDragSourceHelper, helper.ReceiveVoid());
+  if (SUCCEEDED(rv)) {
+    SHDRAGIMAGE sdi;
+    sdi.sizeDragImage = size.ToSIZE();
+    sdi.crColorKey = 0xFFFFFFFF;
+    sdi.hbmpDragImage = hbitmap;
+    sdi.ptOffset = cursor_offset.ToPOINT();
+    helper->InitializeFromBitmap(&sdi, data_object);
+  }
+}
+
+// Blit the contents of the canvas to a new HBITMAP. It is the caller's
+// responsibility to release the |bits| buffer.
+static HBITMAP CreateHBITMAPFromSkBitmap(const SkBitmap& sk_bitmap) {
+  HDC screen_dc = GetDC(NULL);
+  BITMAPINFOHEADER header;
+  gfx::CreateBitmapHeader(sk_bitmap.width(), sk_bitmap.height(), &header);
+  void* bits;
+  HBITMAP bitmap =
+      CreateDIBSection(screen_dc, reinterpret_cast<BITMAPINFO*>(&header),
+                       DIB_RGB_COLORS, &bits, NULL, 0);
+  DCHECK(sk_bitmap.rowBytes() == sk_bitmap.width() * 4);
+  SkAutoLockPixels lock(sk_bitmap);
+  memcpy(
+      bits, sk_bitmap.getPixels(), sk_bitmap.height() * sk_bitmap.rowBytes());
+  ReleaseDC(NULL, screen_dc);
+  return bitmap;
+}
+
+void SetDragImageOnDataObject(const SkBitmap& sk_bitmap,
+                              const gfx::Size& size,
+                              const gfx::Point& cursor_offset,
+                              ui::OSExchangeData* data_object) {
+  DCHECK(data_object && !size.IsEmpty());
+  // InitializeFromBitmap() doesn't expect an alpha channel and is confused
+  // by premultiplied colors, so unpremultiply the bitmap.
+  // SetDragImageOnDataObject(HBITMAP) takes ownership of the bitmap.
+  HBITMAP bitmap = CreateHBITMAPFromSkBitmap(
+      SkBitmapOperations::UnPreMultiply(sk_bitmap));
+
+  // Attach 'bitmap' to the data_object.
+  SetDragImageOnDataObject(bitmap, size, cursor_offset,
+      ui::OSExchangeDataProviderWin::GetIDataObject(*data_object));
+}
+
+}  // namespace drag_utils