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

BUG=674
TEST=none

Review URL: http://codereview.chromium.org/9042

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@4625 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 135 insertions, 11 deletions

diff --git a/chrome/browser/bookmarks/bookmark_drop_info.cc b/chrome/browser/bookmarks/bookmark_drop_info.cc
new file mode 100644
index 0000000..646b35b
--- /dev/null
+++ b/chrome/browser/bookmarks/bookmark_drop_info.cc
@@ -0,0 +1,44 @@
+// 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();
+}
diff --git a/chrome/browser/bookmarks/bookmark_drop_info.h b/chrome/browser/bookmarks/bookmark_drop_info.h
new file mode 100644
index 0000000..f4daf89
--- /dev/null
+++ b/chrome/browser/bookmarks/bookmark_drop_info.h
@@ -0,0 +1,85 @@
+// 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.
+
+#ifndef CHROME_BROWSER_BOOKMARKS_BOOKMARK_DROP_INFO_H_
+#define CHROME_BROWSER_BOOKMARKS_BOOKMARK_DROP_INFO_H_
+
+#include <windows.h>
+
+#include "base/timer.h"
+#include "chrome/browser/bookmarks/bookmark_drag_data.h"
+
+namespace views {
+class DropTargetEvent;
+}
+
+// BookmarkDropInfo is a pure virtual class that provides auto-scrolling
+// behavior and a handful of fields used for managing a bookmark drop.
+// BookmarkDropInfo is used by both BookmarkTableView and
+// BookmarksFolderTreeView.
+class BookmarkDropInfo {
+ public:
+  BookmarkDropInfo(HWND hwnd, int top_margin);
+  virtual ~BookmarkDropInfo() {}
+
+  // Invoke this from OnDragUpdated. It resets source_operations,
+  // is_control_down, last_y and updates the autoscroll timer as necessary.
+  void Update(const views::DropTargetEvent& event);
+
+  // Data from the drag.
+  void SetData(const BookmarkDragData& data) { data_ = data; }
+  BookmarkDragData& data() { return data_; }
+
+  // Value of event.GetSourceOperations when Update was last invoked.
+  int source_operations() const { return source_operations_; }
+
+  // Whether the control key was down last time Update was invoked.
+  bool is_control_down() const { return is_control_down_; }
+
+  // Y position of the event last passed to Update.
+  int last_y() { return last_y_; }
+
+  // The drop operation that should occur. This is not updated by
+  // BookmarkDropInfo, but provided for subclasses.
+  void set_drop_operation(int drop_operation) {
+    drop_operation_ = drop_operation;
+  }
+  int drop_operation() const { return drop_operation_; }
+
+ protected:
+  // Invoked if we autoscroll. When invoked subclasses need to determine
+  // whether the drop is valid again as what is under the mouse has likely
+  // scrolled.
+  virtual void Scrolled() = 0;
+
+ private:
+  // Invoked from the timer. Scrolls up/down a line.
+  void Scroll();
+
+  BookmarkDragData data_;
+
+  int source_operations_;
+
+  bool is_control_down_;
+
+  int last_y_;
+
+  int drop_operation_;
+
+  HWND hwnd_;
+
+  // Margin in addition to views::kAutoscrollSize that the mouse is allowed to
+  // be over before we autoscroll.
+  int top_margin_;
+
+  // When autoscrolling this determines if we're scrolling up or down.
+  bool scroll_up_;
+
+  // Used when autoscrolling.
+  base::RepeatingTimer<BookmarkDropInfo> scroll_timer_;
+  
+  DISALLOW_COPY_AND_ASSIGN(BookmarkDropInfo);
+};
+
+#endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_DROP_INFO_H_
diff --git a/chrome/browser/bookmarks/bookmark_utils.cc b/chrome/browser/bookmarks/bookmark_utils.cc
index d9b0be1..bf2576f 100644
--- a/chrome/browser/bookmarks/bookmark_utils.cc
+++ b/chrome/browser/bookmarks/bookmark_utils.cc
@@ -146,9 +146,8 @@ bool ShouldOpenAll(HWND parent, const std::vector<BookmarkNode*>& nodes) {
 
 namespace bookmark_utils {
 
-int PreferredDropOperation(const views::DropTargetEvent& event,
-                           int operation) {
-  int common_ops = (event.GetSourceOperations() & operation);
+int PreferredDropOperation(int source_operations, int operations) {
+  int common_ops = (source_operations & operations);
   if (!common_ops)
     return 0;
   if (DragDropTypes::DRAG_COPY & common_ops)
diff --git a/chrome/browser/bookmarks/bookmark_utils.h b/chrome/browser/bookmarks/bookmark_utils.h
index 0711638..281cf8c 100644
--- a/chrome/browser/bookmarks/bookmark_utils.h
+++ b/chrome/browser/bookmarks/bookmark_utils.h
@@ -14,18 +14,14 @@ class BookmarkNode;
 class PageNavigator;
 class Profile;
 
-namespace views {
-class DropTargetEvent;
-}
-
 // A collection of bookmark utility functions used by various parts of the UI
 // that show bookmarks: bookmark manager, bookmark bar view ...
 namespace bookmark_utils {
 
-// Calculates the drop operation given the event and supported set of
-// operations. This prefers the following ordering: COPY, LINK then MOVE.
-int PreferredDropOperation(const views::DropTargetEvent& event,
-                           int operation);
+// Calculates the drop operation given |source_operations| and the ideal
+// set of drop operations (|operations|). This prefers the following ordering:
+// COPY, LINK then MOVE.
+int PreferredDropOperation(int source_operations, int operations);
 
 // Returns true if the bookmark data can be dropped on |drop_parent| at
 // |index|. A drop from a separate profile is always allowed, where as