Return an approximately correct drop effect from WebDragTarget::OnDrop.

chrome/browser/tab_contents/web_drop_target_win.cc

 // 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.
 
 #include <windows.h>
 #include <shlobj.h>
 
 #include "chrome/browser/tab_contents/web_drop_target_win.h"
 
 #include "app/clipboard/clipboard_util_win.h"
 #include "app/os_exchange_data.h"
 #include "app/os_exchange_data_provider_win.h"
 #include "chrome/browser/bookmarks/bookmark_drag_data.h"
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tab_contents/web_drag_utils_win.h"
 #include "gfx/point.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/net_util.h"
 #include "webkit/glue/webdropdata.h"
 #include "webkit/glue/window_open_disposition.h"
 
-using WebKit::WebDragOperationsMask;
 using WebKit::WebDragOperationNone;
 using WebKit::WebDragOperationCopy;
 using WebKit::WebDragOperationLink;
 using WebKit::WebDragOperationMove;
+using WebKit::WebDragOperationGeneric;
 
 namespace {
 
 // A helper method for getting the preferred drop effect.
 DWORD GetPreferredDropEffect(DWORD effect) {
   if (effect & DROPEFFECT_COPY)
     return DROPEFFECT_COPY;
   if (effect & DROPEFFECT_LINK)
     return DROPEFFECT_LINK;
   if (effect & DROPEFFECT_MOVE)
     return DROPEFFECT_MOVE;
   return DROPEFFECT_NONE;
 }
 
-DWORD GetPreferredDragCursor(WebDragOperationsMask op) {
-  if (op & WebDragOperationCopy)
-    return DROPEFFECT_COPY;
-  if (op & WebDragOperationLink)
-    return DROPEFFECT_LINK;
-  if (op & WebDragOperationMove)
-    return DROPEFFECT_MOVE;
-  return DROPEFFECT_NONE;
-}
-
 }  // anonymous namespace
 
 // InterstitialDropTarget is like a BaseDropTarget implementation that
 // WebDropTarget passes through to if an interstitial is showing.  Rather than
 // passing messages on to the renderer, we just check to see if there's a link
 // in the drop data and handle links as navigations.
 class InterstitialDropTarget {
  public:
   explicit InterstitialDropTarget(TabContents* tab_contents)
       : tab_contents_(tab_contents) {}
@@ skipping 76 matching lines @@
   // support for (at the moment experimental) drag and drop extensions.
   if (tab_contents_->GetBookmarkDragDelegate()) {
     OSExchangeData os_exchange_data(new OSExchangeDataProviderWin(data_object));
     BookmarkDragData bookmark_drag_data;
     if (bookmark_drag_data.Read(os_exchange_data))
       tab_contents_->GetBookmarkDragDelegate()->OnDragEnter(bookmark_drag_data);
   }
 
   // We lie here and always return a DROPEFFECT because we don't want to
   // wait for the IPC call to return.
-  return GetPreferredDragCursor(drag_cursor_);
+  DCHECK(drag_cursor_ == WebDragOperationNone ||
+         drag_cursor_ == WebDragOperationCopy ||
+         drag_cursor_ == WebDragOperationLink ||
+         drag_cursor_ == (WebDragOperationMove | WebDragOperationGeneric));
+  return web_drag_utils_win::WebDragOpToWinDragOp(drag_cursor_);
 }
 
 DWORD WebDropTarget::OnDragOver(IDataObject* data_object,
                                 DWORD key_state,
                                 POINT cursor_position,
                                 DWORD effect) {
   DCHECK(current_rvh_);
   if (current_rvh_ != tab_contents_->render_view_host())
     OnDragEnter(data_object, key_state, cursor_position, effect);
 
   if (tab_contents_->showing_interstitial_page())
     return interstitial_drop_target_->OnDragOver(data_object, effect);
 
   POINT client_pt = cursor_position;
   ScreenToClient(GetHWND(), &client_pt);
   tab_contents_->render_view_host()->DragTargetDragOver(
       gfx::Point(client_pt.x, client_pt.y),
       gfx::Point(cursor_position.x, cursor_position.y),
       web_drag_utils_win::WinDragOpToWebDragOp(effect));
 
   if (tab_contents_->GetBookmarkDragDelegate()) {
     OSExchangeData os_exchange_data(new OSExchangeDataProviderWin(data_object));
     BookmarkDragData bookmark_drag_data;
     if (bookmark_drag_data.Read(os_exchange_data))
       tab_contents_->GetBookmarkDragDelegate()->OnDragOver(bookmark_drag_data);
   }
 
-  return GetPreferredDragCursor(drag_cursor_);
+  DCHECK(drag_cursor_ == WebDragOperationNone ||
+         drag_cursor_ == WebDragOperationCopy ||
+         drag_cursor_ == WebDragOperationLink ||
+         drag_cursor_ == (WebDragOperationMove | WebDragOperationGeneric));
+  return web_drag_utils_win::WebDragOpToWinDragOp(drag_cursor_);
 }
 
 void WebDropTarget::OnDragLeave(IDataObject* data_object) {
   DCHECK(current_rvh_);
   if (current_rvh_ != tab_contents_->render_view_host())
     return;
 
   if (tab_contents_->showing_interstitial_page()) {
     interstitial_drop_target_->OnDragLeave(data_object);
   } else {
@@ skipping 30 matching lines @@
 
   if (tab_contents_->GetBookmarkDragDelegate()) {
     OSExchangeData os_exchange_data(new OSExchangeDataProviderWin(data_object));
     BookmarkDragData bookmark_drag_data;
     if (bookmark_drag_data.Read(os_exchange_data))
       tab_contents_->GetBookmarkDragDelegate()->OnDrop(bookmark_drag_data);
   }
 
   current_rvh_ = NULL;
 
-  // We lie and always claim that the drop operation didn't happen because we
-  // don't want to wait for the renderer to respond.
-  return DROPEFFECT_NONE;
+  // This isn't always correct, but at least it's a close approximation.
+  // For now, we always map a move to a copy to prevent potential data loss.
+  DWORD drop_effect = web_drag_utils_win::WebDragOpToWinDragOp(drag_cursor_);
+  return drop_effect != DROPEFFECT_MOVE ? drop_effect : DROPEFFECT_COPY;
 }