// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_WINDOW_DEFAULT_FRAME_VIEW_H_
#define UI_VIEWS_WINDOW_DEFAULT_FRAME_VIEW_H_

#include <memory>

#include "base/memory/raw_ptr.h"
#include "ui/gfx/image/image_skia.h"
#include "ui/views/controls/button/button.h"
#include "ui/views/widget/widget.h"
#include "ui/views/window/frame_buttons.h"
#include "ui/views/window/frame_view.h"

namespace views {

class FrameBackground;
class ImageButton;
class Widget;

///////////////////////////////////////////////////////////////////////////////
//
// DefaultFrameView
//
//  Provides a fallback frame view that manually renders its frame, caption, and
//  controls. Used on all platforms when no other frame view is specified.
//
////////////////////////////////////////////////////////////////////////////////
class VIEWS_EXPORT DefaultFrameView : public FrameView {
 public:
  explicit DefaultFrameView(Widget* widget);

  DefaultFrameView(const DefaultFrameView&) = delete;
  DefaultFrameView& operator=(const DefaultFrameView&) = delete;

  ~DefaultFrameView() override;

  // Overridden from FrameView:
  gfx::Rect GetBoundsForClientView() const override;
  gfx::Rect GetWindowBoundsForClientBounds(
      const gfx::Rect& client_bounds) const override;
  int NonClientHitTest(const gfx::Point& point) override;
  void GetWindowMask(const gfx::Size& size, SkPath* window_mask) override;
  void ResetWindowControls() override;
  void UpdateWindowIcon() override;
  void UpdateWindowTitle() override;
  void SizeConstraintsChanged() override;

  // Overridden from View:
  void OnPaint(gfx::Canvas* canvas) override;
  void Layout(PassKey) override;
  gfx::Size CalculatePreferredSize(
      const SizeBounds& available_size) const override;
  gfx::Size GetMinimumSize() const override;
  gfx::Size GetMaximumSize() const override;

 private:
  friend class DefaultFrameViewTest;

  // Returns the thickness of the border that makes up the window frame edges.
  // This does not include any client edge.
  int FrameBorderThickness() const;

  // Returns the thickness of the entire nonclient left, right, and bottom
  // borders, including both the window frame and any client edge.
  int NonClientBorderThickness() const;

  // Returns the height of the entire nonclient top border, including the window
  // frame, any title area, and any connected client edge.
  int NonClientTopBorderHeight() const;

  // Returns the y-coordinate of the caption buttons.
  int CaptionButtonY() const;

  // Returns the thickness of the nonclient portion of the 3D edge along the
  // bottom of the titlebar.
  int TitlebarBottomThickness() const;

  // Returns the size of the titlebar icon.  This is used even when the icon is
  // not shown, e.g. to set the titlebar height.
  int IconSize() const;

  // Returns the bounds of the titlebar icon (or where the icon would be if
  // there was one).
  gfx::Rect IconBounds() const;

  // Returns true if the title bar, caption buttons, and frame border should be
  // drawn. If false, the client view occupies the full area of this view.
  bool ShouldShowTitleBarAndBorder() const;

  // Returns true if the client edge should be drawn. This is true if
  // the window is not maximized.
  bool ShouldShowClientEdge() const;

  // Paint various sub-components of this view.
  void PaintRestoredFrameBorder(gfx::Canvas* canvas);
  void PaintMaximizedFrameBorder(gfx::Canvas* canvas);
  void PaintTitleBar(gfx::Canvas* canvas);
  void PaintRestoredClientEdge(gfx::Canvas* canvas);

  // Compute aspects of the frame needed to paint the frame background.
  SkColor GetFrameColor() const;
  gfx::ImageSkia GetFrameImage() const;

  // Performs the layout for the window control buttons based on the
  // configuration specified in WindowButtonOrderProvider. The sizing and
  // positions of the buttons affects LayoutTitleBar, call this beforehand.
  void LayoutWindowControls();

  // Calculations depend on the positions of the window controls. Always call
  // LayoutWindowControls beforehand.
  void LayoutTitleBar();
  void LayoutClientView();

  // Creates, adds and returns a new window caption button (e.g, minimize,
  // maximize, restore).
  ImageButton* InitWindowCaptionButton(Button::PressedCallback callback,
                                       int accessibility_string_id,
                                       int normal_image_id,
                                       int hot_image_id,
                                       int pushed_image_id);

  // Returns the window caption button for the given FrameButton type, if it
  // should be visible. Otherwise NULL.
  ImageButton* GetImageButton(views::FrameButton button);

  // The bounds of the client view, in this view's coordinates.
  gfx::Rect client_view_bounds_;

  // The layout rect of the title, if visible.
  gfx::Rect title_bounds_;

  // Not owned.
  const raw_ptr<Widget> widget_;

  // The icon of this window. May be NULL.
  raw_ptr<ImageButton> window_icon_ = nullptr;

  // Window caption buttons.
  raw_ptr<ImageButton> minimize_button_;
  raw_ptr<ImageButton> maximize_button_;
  raw_ptr<ImageButton> restore_button_;
  raw_ptr<ImageButton> close_button_;

  // Background painter for the window frame.
  std::unique_ptr<FrameBackground> frame_background_;

  // The horizontal boundaries for the title bar to layout within. Restricted
  // by the space used by the leading and trailing buttons.
  int minimum_title_bar_x_ = 0;
  int maximum_title_bar_x_ = -1;

  base::CallbackListSubscription paint_as_active_subscription_ =
      widget_->RegisterPaintAsActiveChangedCallback(
          base::BindRepeating(&DefaultFrameView::SchedulePaint,
                              base::Unretained(this)));
};

}  // namespace views

#endif  // UI_VIEWS_WINDOW_DEFAULT_FRAME_VIEW_H_