// Copyright 2014 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.

#include "ash/frame/default_header_painter.h"

#include "ash/frame/caption_buttons/frame_caption_button_container_view.h"
#include "ash/frame/header_painter_util.h"
#include "base/debug/leak_annotations.h"
#include "base/logging.h"  // DCHECK
#include "grit/ash_resources.h"
#include "third_party/skia/include/core/SkPaint.h"
#include "third_party/skia/include/core/SkPath.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/gfx/animation/slide_animation.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/color_utils.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/image/image.h"
#include "ui/gfx/skia_util.h"
#include "ui/views/view.h"
#include "ui/views/widget/native_widget_aura.h"
#include "ui/views/widget/widget.h"
#include "ui/views/widget/widget_delegate.h"

using views::Widget;

namespace {

// Color for the window title text.
const SkColor kTitleTextColor = SkColorSetRGB(40, 40, 40);
// Color of the active window header/content separator line.
const SkColor kHeaderContentSeparatorColor = SkColorSetRGB(150, 150, 152);
// Color of the inactive window header/content separator line.
const SkColor kHeaderContentSeparatorInactiveColor =
    SkColorSetRGB(180, 180, 182);
// The default color of the frame.
const SkColor kDefaultFrameColor = SkColorSetRGB(242, 242, 242);
// Duration of crossfade animation for activating and deactivating frame.
const int kActivationCrossfadeDurationMs = 200;
// Luminance below which to use white caption buttons.
const int kMaxLuminanceForLightButtons = 125;

// Tiles an image into an area, rounding the top corners.
void TileRoundRect(gfx::Canvas* canvas,
                   const SkPaint& paint,
                   const gfx::Rect& bounds,
                   int corner_radius) {
  SkRect rect = gfx::RectToSkRect(bounds);
  const SkScalar corner_radius_scalar = SkIntToScalar(corner_radius);
  SkScalar radii[8] = {
      corner_radius_scalar, corner_radius_scalar,  // top-left
      corner_radius_scalar, corner_radius_scalar,  // top-right
      0, 0,   // bottom-right
      0, 0};  // bottom-left
  SkPath path;
  path.addRoundRect(rect, radii, SkPath::kCW_Direction);
  canvas->DrawPath(path, paint);
}

// Returns the FontList to use for the title.
const gfx::FontList& GetTitleFontList() {
  static const gfx::FontList* title_font_list =
      new gfx::FontList(views::NativeWidgetAura::GetWindowTitleFontList());
  ANNOTATE_LEAKING_OBJECT_PTR(title_font_list);
  return *title_font_list;
}

}  // namespace

namespace ash {

///////////////////////////////////////////////////////////////////////////////
// DefaultHeaderPainter, public:

DefaultHeaderPainter::DefaultHeaderPainter()
    : frame_(NULL),
      view_(NULL),
      left_header_view_(NULL),
      left_view_x_inset_(HeaderPainterUtil::GetDefaultLeftViewXInset()),
      active_frame_color_(kDefaultFrameColor),
      inactive_frame_color_(kDefaultFrameColor),
      caption_button_container_(NULL),
      height_(0),
      mode_(MODE_INACTIVE),
      initial_paint_(true),
      activation_animation_(new gfx::SlideAnimation(this)) {
}

DefaultHeaderPainter::~DefaultHeaderPainter() {
}

void DefaultHeaderPainter::Init(
    views::Widget* frame,
    views::View* header_view,
    FrameCaptionButtonContainerView* caption_button_container) {
  DCHECK(frame);
  DCHECK(header_view);
  DCHECK(caption_button_container);
  frame_ = frame;
  view_ = header_view;
  caption_button_container_ = caption_button_container;
  UpdateAllButtonImages();
}

int DefaultHeaderPainter::GetMinimumHeaderWidth() const {
  // Ensure we have enough space for the window icon and buttons. We allow
  // the title string to collapse to zero width.
  return GetTitleBounds().x() +
      caption_button_container_->GetMinimumSize().width();
}

void DefaultHeaderPainter::PaintHeader(gfx::Canvas* canvas, Mode mode) {
  Mode old_mode = mode_;
  mode_ = mode;

  if (mode_ != old_mode) {
    UpdateAllButtonImages();
    if (!initial_paint_ && HeaderPainterUtil::CanAnimateActivation(frame_)) {
      activation_animation_->SetSlideDuration(kActivationCrossfadeDurationMs);
      if (mode_ == MODE_ACTIVE)
        activation_animation_->Show();
      else
        activation_animation_->Hide();
    } else {
      if (mode_ == MODE_ACTIVE)
        activation_animation_->Reset(1);
      else
        activation_animation_->Reset(0);
    }
    initial_paint_ = false;
  }

  int corner_radius = (frame_->IsMaximized() || frame_->IsFullscreen()) ?
      0 : HeaderPainterUtil::GetTopCornerRadiusWhenRestored();

  SkPaint paint;
  int active_alpha = activation_animation_->CurrentValueBetween(0, 255);
  paint.setColor(color_utils::AlphaBlend(active_frame_color_,
                                         inactive_frame_color_, active_alpha));

  TileRoundRect(canvas, paint, GetLocalBounds(), corner_radius);

  if (!frame_->IsMaximized() && !frame_->IsFullscreen() &&
      mode_ == MODE_INACTIVE && !UsesCustomFrameColors()) {
    PaintHighlightForInactiveRestoredWindow(canvas);
  }
  if (frame_->widget_delegate() &&
      frame_->widget_delegate()->ShouldShowWindowTitle()) {
    PaintTitleBar(canvas);
  }
  if (!UsesCustomFrameColors())
    PaintHeaderContentSeparator(canvas);
}

void DefaultHeaderPainter::LayoutHeader() {
  UpdateSizeButtonImages(ShouldUseLightImages());
  caption_button_container_->Layout();

  gfx::Size caption_button_container_size =
      caption_button_container_->GetPreferredSize();
  caption_button_container_->SetBounds(
      view_->width() - caption_button_container_size.width(),
      0,
      caption_button_container_size.width(),
      caption_button_container_size.height());

  LayoutLeftHeaderView();

  // The header/content separator line overlays the caption buttons.
  SetHeaderHeightForPainting(caption_button_container_->height());
}

int DefaultHeaderPainter::GetHeaderHeightForPainting() const {
  return height_;
}

void DefaultHeaderPainter::SetHeaderHeightForPainting(int height) {
  height_ = height;
}

void DefaultHeaderPainter::SchedulePaintForTitle() {
  view_->SchedulePaintInRect(GetTitleBounds());
}

void DefaultHeaderPainter::UpdateLeftViewXInset(int left_view_x_inset) {
  if (left_view_x_inset_ != left_view_x_inset) {
    left_view_x_inset_ = left_view_x_inset;
    LayoutLeftHeaderView();
  }
}

void DefaultHeaderPainter::SetFrameColors(SkColor active_frame_color,
                                          SkColor inactive_frame_color) {
  active_frame_color_ = active_frame_color;
  inactive_frame_color_ = inactive_frame_color;
  UpdateAllButtonImages();
}

void DefaultHeaderPainter::UpdateLeftHeaderView(views::View* left_header_view) {
  left_header_view_ = left_header_view;
}

///////////////////////////////////////////////////////////////////////////////
// gfx::AnimationDelegate overrides:

void DefaultHeaderPainter::AnimationProgressed(
    const gfx::Animation* animation) {
  view_->SchedulePaintInRect(GetLocalBounds());
}

///////////////////////////////////////////////////////////////////////////////
// DefaultHeaderPainter, private:

void DefaultHeaderPainter::PaintHighlightForInactiveRestoredWindow(
    gfx::Canvas* canvas) {
  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
  gfx::ImageSkia top_edge = *rb.GetImageSkiaNamed(
      IDR_AURA_WINDOW_HEADER_SHADE_INACTIVE_TOP);
  gfx::ImageSkia left_edge = *rb.GetImageSkiaNamed(
      IDR_AURA_WINDOW_HEADER_SHADE_INACTIVE_LEFT);
  gfx::ImageSkia right_edge = *rb.GetImageSkiaNamed(
      IDR_AURA_WINDOW_HEADER_SHADE_INACTIVE_RIGHT);
  gfx::ImageSkia bottom_edge = *rb.GetImageSkiaNamed(
      IDR_AURA_WINDOW_HEADER_SHADE_INACTIVE_BOTTOM);

  int left_edge_width = left_edge.width();
  int right_edge_width = right_edge.width();
  canvas->DrawImageInt(left_edge, 0, 0);
  canvas->DrawImageInt(right_edge, view_->width() - right_edge_width, 0);
  canvas->TileImageInt(
      top_edge,
      left_edge_width,
      0,
      view_->width() - left_edge_width - right_edge_width,
      top_edge.height());

  DCHECK_EQ(left_edge.height(), right_edge.height());
  int bottom = left_edge.height();
  int bottom_height = bottom_edge.height();
  canvas->TileImageInt(
      bottom_edge,
      left_edge_width,
      bottom - bottom_height,
      view_->width() - left_edge_width - right_edge_width,
      bottom_height);
}

void DefaultHeaderPainter::PaintTitleBar(gfx::Canvas* canvas) {
  // The window icon is painted by its own views::View.
  gfx::Rect title_bounds = GetTitleBounds();
  title_bounds.set_x(view_->GetMirroredXForRect(title_bounds));
  canvas->DrawStringRectWithFlags(frame_->widget_delegate()->GetWindowTitle(),
                                  GetTitleFontList(),
                                  kTitleTextColor,
                                  title_bounds,
                                  gfx::Canvas::NO_SUBPIXEL_RENDERING);
}

void DefaultHeaderPainter::PaintHeaderContentSeparator(gfx::Canvas* canvas) {
  SkColor color = (mode_ == MODE_ACTIVE) ?
      kHeaderContentSeparatorColor :
      kHeaderContentSeparatorInactiveColor;

  SkPaint paint;
  paint.setColor(color);
  // Draw the line as 1px thick regardless of scale factor.
  paint.setStrokeWidth(0);

  float thickness = 1 / canvas->image_scale();
  SkScalar y = SkIntToScalar(height_) - SkFloatToScalar(thickness);
  canvas->sk_canvas()->drawLine(0, y, SkIntToScalar(view_->width()), y, paint);
}

void DefaultHeaderPainter::LayoutLeftHeaderView() {
  if (left_header_view_) {
    // Vertically center the left header view with respect to the caption button
    // container.
    // Floor when computing the center of |caption_button_container_|.
    gfx::Size size = left_header_view_->GetPreferredSize();
    int icon_offset_y = caption_button_container_->height() / 2 -
                        size.height() / 2;
    left_header_view_->SetBounds(
        left_view_x_inset_, icon_offset_y, size.width(), size.height());
  }
}

bool DefaultHeaderPainter::ShouldUseLightImages() {
  int luminance = color_utils::GetLuminanceForColor(
      mode_ == MODE_INACTIVE ? inactive_frame_color_ : active_frame_color_);
  return luminance < kMaxLuminanceForLightButtons;
}

void DefaultHeaderPainter::UpdateAllButtonImages() {
  bool use_light_images = ShouldUseLightImages();
  caption_button_container_->SetButtonImages(
      CAPTION_BUTTON_ICON_MINIMIZE,
      use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_MINIMIZE_WHITE
                       : IDR_AURA_WINDOW_CONTROL_ICON_MINIMIZE,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_H,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_P);

  UpdateSizeButtonImages(use_light_images);

  caption_button_container_->SetButtonImages(
      CAPTION_BUTTON_ICON_CLOSE,
      use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_CLOSE_WHITE
                       : IDR_AURA_WINDOW_CONTROL_ICON_CLOSE,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_H,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_P);

  caption_button_container_->SetButtonImages(
      CAPTION_BUTTON_ICON_LEFT_SNAPPED,
      use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_LEFT_SNAPPED_WHITE
                       : IDR_AURA_WINDOW_CONTROL_ICON_LEFT_SNAPPED,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_H,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_P);

  caption_button_container_->SetButtonImages(
      CAPTION_BUTTON_ICON_RIGHT_SNAPPED,
      use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_RIGHT_SNAPPED_WHITE
                       : IDR_AURA_WINDOW_CONTROL_ICON_RIGHT_SNAPPED,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_H,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_P);
}

void DefaultHeaderPainter::UpdateSizeButtonImages(bool use_light_images) {
  int icon_id = 0;
  if (frame_->IsMaximized() || frame_->IsFullscreen()) {
    icon_id = use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_RESTORE_WHITE
                               : IDR_AURA_WINDOW_CONTROL_ICON_RESTORE;
  } else {
    icon_id = use_light_images ? IDR_AURA_WINDOW_CONTROL_ICON_MAXIMIZE_WHITE
                               : IDR_AURA_WINDOW_CONTROL_ICON_MAXIMIZE;
  }
  caption_button_container_->SetButtonImages(
      CAPTION_BUTTON_ICON_MAXIMIZE_RESTORE,
      icon_id,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_H,
      IDR_AURA_WINDOW_CONTROL_BACKGROUND_P);
}

gfx::Rect DefaultHeaderPainter::GetLocalBounds() const {
  return gfx::Rect(view_->width(), height_);
}

gfx::Rect DefaultHeaderPainter::GetTitleBounds() const {
  return HeaderPainterUtil::GetTitleBounds(
      left_header_view_, caption_button_container_, GetTitleFontList());
}

bool DefaultHeaderPainter::UsesCustomFrameColors() const {
  return active_frame_color_ != kDefaultFrameColor ||
         inactive_frame_color_ != kDefaultFrameColor;
}

}  // namespace ash