// 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 CHROME_BROWSER_UI_VIEWS_PANELS_PANEL_STACK_VIEW_H_
#define CHROME_BROWSER_UI_VIEWS_PANELS_PANEL_STACK_VIEW_H_

#include <list>
#include <map>
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "chrome/browser/ui/panels/native_panel_stack_window.h"
#include "ui/gfx/animation/animation_delegate.h"
#include "ui/views/focus/widget_focus_manager.h"
#include "ui/views/widget/widget_delegate.h"
#include "ui/views/widget/widget_observer.h"

#if defined(OS_WIN)
#include "chrome/browser/ui/views/panels/taskbar_window_thumbnailer_win.h"
#include "ui/base/win/hwnd_subclass.h"
#endif

namespace gfx {
class LinearAnimation;
}
namespace views {
class Widget;
}

// A native window that acts as the owner of all panels in the stack, in order
// to make all panels appear as a single window on the taskbar or launcher.
class PanelStackView : public NativePanelStackWindow,
                       public views::WidgetFocusChangeListener,
#if defined(OS_WIN)
                       public ui::HWNDMessageFilter,
                       public TaskbarWindowThumbnailerDelegateWin,
#endif
                       public gfx::AnimationDelegate {
 public:
  explicit PanelStackView(NativePanelStackWindowDelegate* delegate);
  ~PanelStackView() override;

 protected:
  // Overridden from NativePanelStackWindow:
  void Close() override;
  void AddPanel(Panel* panel) override;
  void RemovePanel(Panel* panel) override;
  void MergeWith(NativePanelStackWindow* another) override;
  bool IsEmpty() const override;
  bool HasPanel(Panel* panel) const override;
  void MovePanelsBy(const gfx::Vector2d& delta) override;
  void BeginBatchUpdatePanelBounds(bool animate) override;
  void AddPanelBoundsForBatchUpdate(Panel* panel,
                                    const gfx::Rect& new_bounds) override;
  void EndBatchUpdatePanelBounds() override;
  bool IsAnimatingPanelBounds() const override;
  void Minimize() override;
  bool IsMinimized() const override;
  void DrawSystemAttention(bool draw_attention) override;
  void OnPanelActivated(Panel* panel) override;

 private:
  typedef std::list<Panel*> Panels;

  // The map value is old bounds of the panel.
  typedef std::map<Panel*, gfx::Rect> BoundsUpdates;

  // Overridden from views::WidgetFocusChangeListener:
  void OnNativeFocusChanged(gfx::NativeView focused_now) override;

  // Overridden from AnimationDelegate:
  void AnimationEnded(const gfx::Animation* animation) override;
  void AnimationProgressed(const gfx::Animation* animation) override;
  void AnimationCanceled(const gfx::Animation* animation) override;

  // Updates the bounds of panels as specified in batch update data.
  void UpdatePanelsBounds();

  // Notifies the delegate that the updates of the panel bounds are completed.
  void NotifyBoundsUpdateCompleted();

  // Computes/updates the minimum bounds that could fit all panels.
  gfx::Rect GetStackWindowBounds() const;
  void UpdateStackWindowBounds();

  views::Widget* CreateWindowWithBounds(const gfx::Rect& bounds);
  void EnsureWindowCreated();

  // Makes the stack window own the panel window such that multiple panels
  // stacked together could appear as a single window on the taskbar or
  // launcher.
  static void MakeStackWindowOwnPanelWindow(Panel* panel,
                                            PanelStackView* stack_window);

#if defined(OS_WIN)
  // Overridden from ui::HWNDMessageFilter:
  bool FilterMessage(HWND hwnd,
                     UINT message,
                     WPARAM w_param,
                     LPARAM l_param,
                     LRESULT* l_result) override;

  // Overridden from TaskbarWindowThumbnailerDelegateWin:
  std::vector<HWND> GetSnapshotWindowHandles() const override;

  // Updates the live preview snapshot when something changes, like
  // adding/removing/moving/resizing a stacked panel.
  void RefreshLivePreviewThumbnail();

  // Updates the bounds of the widget window in a deferred way.
  void DeferUpdateNativeWindowBounds(HDWP defer_window_pos_info,
                                     views::Widget* window,
                                     const gfx::Rect& bounds);
#endif

  NativePanelStackWindowDelegate* delegate_;

  views::Widget* window_;  // Weak pointer, own us.

  // Tracks all panels that are enclosed by this window.
  Panels panels_;

  // Is the taskbar icon of the underlying window being flashed in order to
  // draw the user's attention?
  bool is_drawing_attention_;

#if defined(OS_WIN)
  // The custom live preview snapshot is always provided for the stack window.
  // This is because the system might not show the snapshot correctly for
  // a small window, like collapsed panel.
  scoped_ptr<TaskbarWindowThumbnailerWin> thumbnailer_;
#endif

  // For batch bounds update.
  bool animate_bounds_updates_;
  bool bounds_updates_started_;
  BoundsUpdates bounds_updates_;

  // Used to animate the bounds changes at a synchronized pace.
  scoped_ptr<gfx::LinearAnimation> bounds_animator_;

  DISALLOW_COPY_AND_ASSIGN(PanelStackView);
};

#endif  // CHROME_BROWSER_UI_VIEWS_PANELS_PANEL_STACK_VIEW_H_