Implement drag and drop of downloads for the Mac downloads page

chrome/browser/cocoa/download_util_mac.mm

+// Copyright (c) 2009 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.
+//
+// Download utility implementation for Mac OS X.
+
+#include "chrome/browser/cocoa/download_util_mac.h"
+
+#include "base/gfx/native_widget_types.h"
+#include "base/sys_string_conversions.h"
+#include "chrome/browser/download/download_manager.h"
+#include "skia/ext/skia_utils_mac.h"
+
+namespace download_util {
+
+void AddFileToPasteboard(NSPasteboard* pasteboard, const FilePath& path) {
+  // Write information about the file being dragged to the pasteboard.
+  NSString* file = base::SysWideToNSString(path.ToWStringHack());
+  NSArray* fileList = [NSArray arrayWithObject:file];
+  [pasteboard declareTypes:[NSArray arrayWithObject:NSFilenamesPboardType]
+                     owner:nil];
+  [pasteboard setPropertyList:fileList forType:NSFilenamesPboardType];
+}
+
+void DragDownload(const DownloadItem* download,
+                  SkBitmap* icon,
+                  gfx::NativeView view) {
+  NSPasteboard* pasteboard = [NSPasteboard pasteboardWithName:NSDragPboard];
+  AddFileToPasteboard(pasteboard, download->full_path());
+
+  // Convert to an NSImage.
+  NSImage* dragImage = gfx::SkBitmapToNSImage(*icon);
+
+  // Synthesize a drag event, since we don't have access to the actual event
+  // that initiated a drag (possibly consumed by the DOM UI, for example).
+  NSPoint position = [[view window] mouseLocationOutsideOfEventStream];
+  NSTimeInterval eventTime = [[NSApp currentEvent] timestamp];
+  NSEvent* dragEvent = [NSEvent mouseEventWithType:NSLeftMouseDragged
+                                          location:position
+                                     modifierFlags:NSLeftMouseDraggedMask
+                                         timestamp:eventTime
+                                      windowNumber:[[view window] windowNumber]
+                                           context:nil
+                                       eventNumber:0
+                                        clickCount:1
+                                          pressure:1.0];
+
+  // Run the drag operation.
+  [[view window] dragImage:dragImage
+                        at:position
+                    offset:NSZeroSize
+                     event:dragEvent
+                pasteboard:pasteboard
+                    source:view
+                 slideBack:YES];
+}
+
+}  // namespace download_util