blob: 07905cbf43edebee28ef938cc1aafbfd3b53c4d1 [file] [log] [blame]
// 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 "views/drag_utils.h"
#include <objidl.h>
#include <shlobj.h>
#include <shobjidl.h>
#include "base/win/scoped_comptr.h"
#include "ui/base/dragdrop/os_exchange_data.h"
#include "third_party/skia/include/core/SkBitmap.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"
using ui::OSExchangeData;
using ui::OSExchangeDataProviderWin;
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)) {
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);
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);
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,
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(
// Attach 'bitmap' to the data_object.
SetDragImageOnDataObject(bitmap, size, cursor_offset,
} // namespace drag_utils