ash/wm/frame_painter.h

// 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 ASH_WM_FRAME_PAINTER_H_
#define ASH_WM_FRAME_PAINTER_H_

#include "ash/ash_export.h"
#include "ash/wm/window_state_observer.h"
#include "base/basictypes.h"
#include "base/compiler_specific.h"  // OVERRIDE
#include "base/gtest_prod_util.h"
#include "base/memory/scoped_ptr.h"
#include "ui/aura/window_observer.h"
#include "ui/gfx/animation/animation_delegate.h"
#include "ui/gfx/rect.h"

namespace aura {
class RootWindow;
class Window;
}
namespace gfx {
class Canvas;
class Font;
class ImageSkia;
class Point;
class Size;
class SlideAnimation;
}
namespace views {
class NonClientFrameView;
class View;
class Widget;
}

namespace ash {
class FrameCaptionButtonContainerView;

// Helper class for painting window frames.  Exists to share code between
// various implementations of views::NonClientFrameView.  Canonical source of
// layout constants for Ash window frames.
class ASH_EXPORT FramePainter : public aura::WindowObserver,
                                public gfx::AnimationDelegate,
                                public wm::WindowStateObserver {
 public:
  // Opacity values for the window header in various states, from 0 to 255.
  static int kActiveWindowOpacity;
  static int kInactiveWindowOpacity;
  static int kSoloWindowOpacity;

  enum HeaderMode {
    ACTIVE,
    INACTIVE
  };

  enum Themed {
    THEMED_YES,
    THEMED_NO
  };

  // What happens when the |size_button_| is pressed.
  enum SizeButtonBehavior {
    SIZE_BUTTON_MINIMIZES,
    SIZE_BUTTON_MAXIMIZES
  };

  FramePainter();
  virtual ~FramePainter();

  // |frame| and buttons are used for layout and are not owned.
  void Init(views::Widget* frame,
            views::View* window_icon,
            FrameCaptionButtonContainerView* caption_button_container);

  // Enable/Disable the solo-window transparent header appearance feature.
  static void SetSoloWindowHeadersEnabled(bool enabled);

  // Updates the solo-window transparent header appearance for all windows
  // using frame painters in |root_window|.
  static void UpdateSoloWindowHeader(aura::RootWindow* root_window);

  // Helpers for views::NonClientFrameView implementations.
  gfx::Rect GetBoundsForClientView(int top_height,
                                   const gfx::Rect& window_bounds) const;
  gfx::Rect GetWindowBoundsForClientBounds(
      int top_height,
      const gfx::Rect& client_bounds) const;
  int NonClientHitTest(views::NonClientFrameView* view,
                       const gfx::Point& point);
  gfx::Size GetMinimumSize(views::NonClientFrameView* view);
  gfx::Size GetMaximumSize(views::NonClientFrameView* view);

  // Returns the inset from the right edge.
  int GetRightInset() const;

  // Returns the amount that the theme background should be inset.
  int GetThemeBackgroundXInset() const;

  // Returns true if the header should be painted using a minimalistic style.
  bool ShouldUseMinimalHeaderStyle(Themed header_themed) const;

  // Paints the frame header.
  // |theme_frame_overlay_id| is 0 if no overlay image should be used.
  void PaintHeader(views::NonClientFrameView* view,
                   gfx::Canvas* canvas,
                   HeaderMode header_mode,
                   int theme_frame_id,
                   int theme_frame_overlay_id);

  // Paints the header/content separator line.  Exists as a separate function
  // because some windows with complex headers (e.g. browsers with tab strips)
  // need to draw their own line.
  void PaintHeaderContentSeparator(views::NonClientFrameView* view,
                                   gfx::Canvas* canvas);

  // Returns size of the header/content separator line in pixels.
  int HeaderContentSeparatorSize() const;

  // Paint the title bar, primarily the title string.
  void PaintTitleBar(views::NonClientFrameView* view,
                     gfx::Canvas* canvas,
                     const gfx::Font& title_font);

  // Performs layout for the header based on whether we want the shorter
  // appearance. |shorter_layout| is typically used for maximized windows, but
  // not always.
  void LayoutHeader(views::NonClientFrameView* view, bool shorter_layout);

  // Schedule a re-paint of the entire title.
  void SchedulePaintForTitle(const gfx::Font& title_font);

  // Called when the browser theme changes.
  void OnThemeChanged();

  // aura::WindowObserver overrides:
  virtual void OnWindowVisibilityChanged(aura::Window* window,
                                         bool visible) OVERRIDE;
  virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
  virtual void OnWindowBoundsChanged(aura::Window* window,
                                     const gfx::Rect& old_bounds,
                                     const gfx::Rect& new_bounds) OVERRIDE;
  virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE;
  virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE;

  // ash::WindowStateObserver overrides:
  virtual void OnTrackedByWorkspaceChanged(wm::WindowState* window_state,
                                           bool old) OVERRIDE;
  virtual void OnWindowShowTypeChanged(wm::WindowState* window_state,
                                       wm::WindowShowType old_type) OVERRIDE;

  // Overridden from gfx::AnimationDelegate
  virtual void AnimationProgressed(const gfx::Animation* animation) OVERRIDE;

 private:
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, CreateAndDeleteSingleWindow);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeader);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderWithApp);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderWithPanel);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderModal);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderConstrained);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderNotDrawn);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, UseSoloWindowHeaderMultiDisplay);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, GetHeaderOpacity);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, TitleIconAlignment);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest, ChildWindowVisibility);
  FRIEND_TEST_ALL_PREFIXES(FramePainterTest,
                           NoCrashShutdownWithAlwaysOnTopWindow);

  // Returns the offset between window left edge and title string.
  int GetTitleOffsetX() const;

  // Returns the vertical center of the caption button container in window
  // coordinates.
  int GetCaptionButtonContainerCenterY() const;

  // Returns the opacity value used to paint the header.
  // |theme_frame_overlay_id| is 0 if no overlay image is used.
  int GetHeaderOpacity(HeaderMode header_mode,
                       int theme_frame_id,
                       int theme_frame_overlay_id) const;

  // Returns the radius of the header's top corners.
  int GetHeaderCornerRadius() const;

  // Returns true if |window_->GetRootWindow()| should be drawing transparent
  // window headers.
  bool UseSoloWindowHeader() const;

  // Returns true if |root_window| has exactly one visible, normal-type window.
  // It ignores |ignore_window| while calculating the number of windows.
  // Pass NULL for |ignore_window| to consider all windows.
  static bool UseSoloWindowHeaderInRoot(aura::RootWindow* root_window,
                                        aura::Window* ignore_window);

  // Updates the solo-window transparent header appearance for all windows in
  // |root_window|. If |ignore_window| is not NULL it is ignored for when
  // counting visible windows. This is useful for updates when a window is about
  // to be closed or is moving to another root. If the solo window status
  // changes it schedules paints as necessary.
  static void UpdateSoloWindowInRoot(aura::RootWindow* root_window,
                                     aura::Window* ignore_window);

  // Updates the size of the region inside of |window_| in which the resize
  // handles are shown based on |window_|'s show type.
  void UpdateHitTestBoundsOverrideInner();

  // Schedules a paint for the header. Used when transitioning from no header to
  // a header (or other way around).
  void SchedulePaintForHeader();

  // Get the bounds for the title. The provided |title_font| is used to
  // determine the correct dimensions.
  gfx::Rect GetTitleBounds(const gfx::Font& title_font);

  // Not owned
  views::Widget* frame_;
  views::View* window_icon_;  // May be NULL.
  FrameCaptionButtonContainerView* caption_button_container_;
  aura::Window* window_;

  // Window frame header/caption parts.
  const gfx::ImageSkia* top_left_corner_;
  const gfx::ImageSkia* top_edge_;
  const gfx::ImageSkia* top_right_corner_;
  const gfx::ImageSkia* header_left_edge_;
  const gfx::ImageSkia* header_right_edge_;

  // Image ids and opacity last used for painting header.
  int previous_theme_frame_id_;
  int previous_theme_frame_overlay_id_;
  int previous_opacity_;

  // Image ids and opacity we are crossfading from.
  int crossfade_theme_frame_id_;
  int crossfade_theme_frame_overlay_id_;
  int crossfade_opacity_;

  gfx::Rect header_frame_bounds_;
  scoped_ptr<gfx::SlideAnimation> crossfade_animation_;

  DISALLOW_COPY_AND_ASSIGN(FramePainter);
};

}  // namespace ash

#endif  // ASH_WM_FRAME_PAINTER_H_