// Copyright (c) 2011 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_UI_VIEWS_FRAME_CONTENTS_CONTAINER_H_
#define CHROME_BROWSER_UI_VIEWS_FRAME_CONTENTS_CONTAINER_H_
#pragma once

#include "base/memory/scoped_ptr.h"
#include "ui/base/animation/animation_delegate.h"
#include "views/view.h"

class TabContents;

namespace ui {
class SlideAnimation;
}

namespace views {
class Widget;
}

// ContentsContainer is responsible for managing the TabContents views.
// ContentsContainer has up to two children: one for the currently active
// TabContents and one for instant's TabContents.
class ContentsContainer : public views::View, public ui::AnimationDelegate {
 public:
  explicit ContentsContainer(views::View* active);
  virtual ~ContentsContainer();

  // Makes the preview view the active view and nulls out the old active view.
  // It's assumed the caller will delete or remove the old active view
  // separately.
  void MakePreviewContentsActiveContents();

  // Sets the preview view. This does not delete the old.
  void SetPreview(views::View* preview, TabContents* preview_tab_contents);

  TabContents* preview_tab_contents() const { return preview_tab_contents_; }

  // Sets the active top margin.
  void SetActiveTopMargin(int margin);

  // Returns the bounds of the preview. If the preview isn't active this
  // retuns the bounds the preview would be shown at.
  gfx::Rect GetPreviewBounds();

  // Fades out the active contents.
  void FadeActiveContents();

  // Shows the fade. This is similiar to |FadeActiveContents|, but is immediate.
  void ShowFade();

  // Removes the fade. This is done implicitly when the preview is made active.
  void RemoveFade();

  // View overrides:
  virtual void Layout();

  // ui::AnimationDelegate overrides:
  virtual void AnimationProgressed(const ui::Animation* animation);

 private:
  class OverlayContentView;

  // Creates the overlay widget. The opacity is set at |initial_opacity|.
  void CreateOverlay(int initial_opacity);

  // Invoked when the contents view of the overlay is destroyed.
  void OverlayViewDestroyed();

  views::View* active_;

  views::View* preview_;

  TabContents* preview_tab_contents_;

  // Translucent Widget positioned right above the active view that is used to
  // make the active view appear faded out.
  views::Widget* active_overlay_;

  // Content view of active_overlay. Used to track when the widget is destroyed.
  OverlayContentView* overlay_view_;

  // Animation used to vary the opacity of active_overlay.
  scoped_ptr<ui::SlideAnimation> overlay_animation_;

  // The margin between the top and the active view. This is used to make the
  // preview overlap the bookmark bar on the new tab page.
  int active_top_margin_;

  DISALLOW_COPY_AND_ASSIGN(ContentsContainer);
};

#endif  // CHROME_BROWSER_UI_VIEWS_FRAME_CONTENTS_CONTAINER_H_