V2: Implement reparenting, bounds and visibility change notifications, and write more tests.

ui/v2/src/view_private.h

+// Copyright (c) 2013 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 UI_V2_SRC_VIEW_PRIVATE_H_
+#define UI_V2_SRC_VIEW_PRIVATE_H_
+
+#include "base/observer_list.h"
+#include "ui/v2/public/view.h"
+
+namespace gfx {
+class Rect;
+}
+
+namespace v2 {
+
+class ViewObserver;
+
+// Friend of View. Provides a way to access view state for the implementation
+// of class View.
+class ViewPrivate {

[sky, 2013/10/03 21:28:19]

One disadvantage of this approach vs what we have in aura::LayoutManager is that
in theory anyone can create a ViewPrivate. The aura::LayoutManager constrains
the private interface to only those who need it.

+ public:
+  explicit ViewPrivate(View* view);
+  ~ViewPrivate();
+
+  ObserverList<ViewObserver>* observers() { return &view_->observers_; }
+
+  void ClearParent() { view_->parent_ = NULL; }
+
+  void set_bounds(const gfx::Rect& bounds) { view_->bounds_ = bounds; }
+
+ private:
+  View* view_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViewPrivate);
+};
+
+}  // namespace v2
+
+#endif  // UI_V2_SRC_VIEW_PRIVATE_H_