Adds support for autoscrolling on drag to bookmark tree/table....

chrome/browser/bookmarks/bookmark_drop_info.cc

+// Copyright (c) 2006-2008 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 "chrome/browser/bookmarks/bookmark_drop_info.h"
+
+#include "chrome/views/event.h"
+#include "chrome/views/view_constants.h"
+
+BookmarkDropInfo::BookmarkDropInfo(HWND hwnd, int top_margin)
+    : source_operations_(0),
+      is_control_down_(false),
+      last_y_(0),
+      drop_operation_(0),
+      hwnd_(hwnd),
+      top_margin_(top_margin),
+      scroll_up_(false) {
+}
+
+void BookmarkDropInfo::Update(const views::DropTargetEvent& event) {
+  source_operations_ = event.GetSourceOperations();
+  is_control_down_ = event.IsControlDown();
+  last_y_ = event.y();
+
+  RECT client_rect;
+  GetClientRect(hwnd_, &client_rect);
+  scroll_up_ = (last_y_ <= top_margin_ + views::kAutoscrollSize);
+  bool scroll_down = (last_y_ >= client_rect.bottom - views::kAutoscrollSize);
+  if (scroll_up_ || scroll_down) {
+    if (!scroll_timer_.IsRunning()) {
+      scroll_timer_.Start(
+          base::TimeDelta::FromMilliseconds(views::kAutoscrollRowTimerMS),
+          this,
+          &BookmarkDropInfo::Scroll);
+    }
+  } else {
+    scroll_timer_.Stop();
+  }
+}
+
+void BookmarkDropInfo::Scroll() {
+  SendMessage(hwnd_, WM_VSCROLL, scroll_up_ ? SB_LINEUP : SB_LINEDOWN, NULL);
+  Scrolled();
+}