// Copyright (c) 2012 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_AURA_WINDOW_OBSERVER_H_
#define UI_AURA_WINDOW_OBSERVER_H_
#pragma once

#include "ui/aura/aura_export.h"

namespace gfx {
class Rect;
}  // namespace gfx

namespace aura {

class Window;

class AURA_EXPORT WindowObserver {
 public:
  // Invoked when |new_window| has been added as a child of this window.
  virtual void OnWindowAdded(Window* new_window) {}

  // Invoked prior to removing |window| as a child of this window.
  virtual void OnWillRemoveWindow(Window* window) {}

  // Invoked when this window's parent window changes.  |parent| may be NULL.
  virtual void OnWindowParentChanged(Window* window, Window* parent) {}

  // Invoked when SetProperty() or SetIntProperty() is called on |window|.
  // |old| is the old property value.
  virtual void OnWindowPropertyChanged(Window* window,
                                       const char* key,
                                       void* old) {}

  // Invoked when SetVisible() is invoked on a window. |visible| is the
  // value supplied to SetVisible(). If |visible| is true, window->IsVisible()
  // may still return false. See description in Window::IsVisible() for details.
  virtual void OnWindowVisibilityChanged(Window* window, bool visible) {}

  // Invoked when SetBounds() is invoked on |window|. |bounds| contains the
  // window's new bounds.
  virtual void OnWindowBoundsChanged(Window* window, const gfx::Rect& bounds) {}

  // Invoked when |window|'s position among its siblings in the stacking order
  // has changed.
  virtual void OnWindowStackingChanged(Window* window) {}

  // Invoked when a region of |window| is scheduled to be redrawn.
  virtual void OnWindowPaintScheduled(Window* window,
                                      const gfx::Rect& region) {}

  // Invoked when the Window is being destroyed (i.e. from the start of its
  // destructor).
  virtual void OnWindowDestroying(Window* window) {}

  // Invoked when the Window has been destroyed (i.e. at the end of its
  // destructor).
  virtual void OnWindowDestroyed(Window* window) {}

 protected:
  virtual ~WindowObserver() {}
};

}  // namespace aura

#endif  // UI_AURA_WINDOW_OBSERVER_H_