1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ash/desktop_background/desktop_background_view.h"
6
7#include <limits>
8
9#include "ash/ash_export.h"
10#include "ash/desktop_background/desktop_background_controller.h"
11#include "ash/desktop_background/desktop_background_widget_controller.h"
12#include "ash/desktop_background/user_wallpaper_delegate.h"
13#include "ash/display/display_manager.h"
14#include "ash/root_window_controller.h"
15#include "ash/session/session_state_delegate.h"
16#include "ash/shell.h"
17#include "ash/shell_window_ids.h"
18#include "ash/wm/window_animations.h"
19#include "base/message_loop/message_loop.h"
20#include "base/strings/utf_string_conversions.h"
21#include "ui/aura/window_event_dispatcher.h"
22#include "ui/base/resource/resource_bundle.h"
23#include "ui/compositor/layer.h"
24#include "ui/gfx/canvas.h"
25#include "ui/gfx/image/image.h"
26#include "ui/gfx/size_conversions.h"
27#include "ui/gfx/transform.h"
28#include "ui/views/widget/widget.h"
29
30namespace ash {
31namespace {
32
33// For our scaling ratios we need to round positive numbers.
34int RoundPositive(double x) {
35  return static_cast<int>(floor(x + 0.5));
36}
37
38// A view that controls the child view's layer so that the layer
39// always has the same size as the display's original, un-scaled size
40// in DIP. The layer then transformed to fit to the virtual screen
41// size when laid-out.
42// This is to avoid scaling the image at painting time, then scaling
43// it back to the screen size in the compositor.
44class LayerControlView : public views::View {
45 public:
46  explicit LayerControlView(views::View* view) {
47    AddChildView(view);
48    view->SetPaintToLayer(true);
49  }
50
51  // Overrides views::View.
52  virtual void Layout() OVERRIDE {
53    gfx::Display display = Shell::GetScreen()->GetDisplayNearestWindow(
54        GetWidget()->GetNativeView());
55    DisplayManager* display_manager = Shell::GetInstance()->display_manager();
56    DisplayInfo info = display_manager->GetDisplayInfo(display.id());
57    float ui_scale = info.GetEffectiveUIScale();
58    gfx::SizeF pixel_size = display.size();
59    pixel_size.Scale(1.0f / ui_scale);
60    gfx::Size rounded_size = gfx::ToCeiledSize(pixel_size);
61    DCHECK_EQ(1, child_count());
62    views::View* child = child_at(0);
63    child->SetBounds(0, 0, rounded_size.width(), rounded_size.height());
64    gfx::Transform transform;
65    transform.Scale(ui_scale, ui_scale);
66    child->SetTransform(transform);
67  }
68
69 private:
70  DISALLOW_COPY_AND_ASSIGN(LayerControlView);
71};
72
73}  // namespace
74
75////////////////////////////////////////////////////////////////////////////////
76// DesktopBackgroundView, public:
77
78DesktopBackgroundView::DesktopBackgroundView() {
79  set_context_menu_controller(this);
80}
81
82DesktopBackgroundView::~DesktopBackgroundView() {
83}
84
85////////////////////////////////////////////////////////////////////////////////
86// DesktopBackgroundView, views::View overrides:
87
88void DesktopBackgroundView::OnPaint(gfx::Canvas* canvas) {
89  // Scale the image while maintaining the aspect ratio, cropping as
90  // necessary to fill the background. Ideally the image should be larger
91  // than the largest display supported, if not we will scale and center it if
92  // the layout is WALLPAPER_LAYOUT_CENTER_CROPPED.
93  DesktopBackgroundController* controller =
94      Shell::GetInstance()->desktop_background_controller();
95  gfx::ImageSkia wallpaper = controller->GetWallpaper();
96  WallpaperLayout wallpaper_layout = controller->GetWallpaperLayout();
97
98  if (wallpaper.isNull()) {
99    canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
100    return;
101  }
102
103  gfx::NativeView native_view = GetWidget()->GetNativeView();
104  gfx::Display display = gfx::Screen::GetScreenFor(native_view)->
105      GetDisplayNearestWindow(native_view);
106
107  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
108  DisplayInfo display_info = display_manager->GetDisplayInfo(display.id());
109  float scaling = display_info.GetEffectiveUIScale();
110  if (scaling <= 1.0f)
111    scaling = 1.0f;
112  // Allow scaling up to the UI scaling.
113  // TODO(oshima): Create separate layer that fits to the image and then
114  // scale to avoid artifacts and be more efficient when clipped.
115  gfx::Rect wallpaper_rect(
116      0, 0, wallpaper.width() * scaling, wallpaper.height() * scaling);
117
118  if (wallpaper_layout == WALLPAPER_LAYOUT_CENTER_CROPPED) {
119    // The dimension with the smallest ratio must be cropped, the other one
120    // is preserved. Both are set in gfx::Size cropped_size.
121    double horizontal_ratio = static_cast<double>(width()) /
122        static_cast<double>(wallpaper.width());
123    double vertical_ratio = static_cast<double>(height()) /
124        static_cast<double>(wallpaper.height());
125
126    gfx::Size cropped_size;
127    if (vertical_ratio > horizontal_ratio) {
128      cropped_size = gfx::Size(
129          RoundPositive(static_cast<double>(width()) / vertical_ratio),
130          wallpaper.height());
131    } else {
132      cropped_size = gfx::Size(wallpaper.width(),
133          RoundPositive(static_cast<double>(height()) / horizontal_ratio));
134    }
135
136    gfx::Rect wallpaper_cropped_rect(
137        0, 0, wallpaper.width(), wallpaper.height());
138    wallpaper_cropped_rect.ClampToCenteredSize(cropped_size);
139    canvas->DrawImageInt(wallpaper,
140        wallpaper_cropped_rect.x(), wallpaper_cropped_rect.y(),
141        wallpaper_cropped_rect.width(), wallpaper_cropped_rect.height(),
142        0, 0, width(), height(),
143        true);
144  } else if (wallpaper_layout == WALLPAPER_LAYOUT_TILE) {
145    canvas->TileImageInt(wallpaper, 0, 0, width(), height());
146  } else if (wallpaper_layout == WALLPAPER_LAYOUT_STRETCH) {
147    // This is generally not recommended as it may show artifacts.
148    canvas->DrawImageInt(wallpaper, 0, 0, wallpaper.width(),
149        wallpaper.height(), 0, 0, width(), height(), true);
150  } else {
151    // Fill with black to make sure that the entire area is opaque.
152    canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
153    // All other are simply centered, and not scaled (but may be clipped).
154    canvas->DrawImageInt(
155        wallpaper,
156        0, 0, wallpaper.width(), wallpaper.height(),
157        (width() - wallpaper_rect.width()) / 2,
158        (height() - wallpaper_rect.height()) / 2,
159        wallpaper_rect.width(),
160        wallpaper_rect.height(),
161        true);
162  }
163}
164
165bool DesktopBackgroundView::OnMousePressed(const ui::MouseEvent& event) {
166  return true;
167}
168
169void DesktopBackgroundView::ShowContextMenuForView(
170    views::View* source,
171    const gfx::Point& point,
172    ui::MenuSourceType source_type) {
173  Shell::GetInstance()->ShowContextMenu(point, source_type);
174}
175
176views::Widget* CreateDesktopBackground(aura::Window* root_window,
177                                       int container_id) {
178  DesktopBackgroundController* controller =
179      Shell::GetInstance()->desktop_background_controller();
180  UserWallpaperDelegate* wallpaper_delegate =
181      Shell::GetInstance()->user_wallpaper_delegate();
182
183  views::Widget* desktop_widget = new views::Widget;
184  views::Widget::InitParams params(
185      views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
186  if (controller->GetWallpaper().isNull())
187    params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
188  params.parent = root_window->GetChildById(container_id);
189  desktop_widget->Init(params);
190  desktop_widget->GetNativeWindow()->layer()->SetMasksToBounds(true);
191  desktop_widget->SetContentsView(
192      new LayerControlView(new DesktopBackgroundView()));
193  int animation_type = wallpaper_delegate->GetAnimationType();
194  wm::SetWindowVisibilityAnimationType(
195      desktop_widget->GetNativeView(), animation_type);
196
197  RootWindowController* root_window_controller =
198      GetRootWindowController(root_window);
199
200  // Enable wallpaper transition for the following cases:
201  // 1. Initial(OOBE) wallpaper animation.
202  // 2. Wallpaper fades in from a non empty background.
203  // 3. From an empty background, chrome transit to a logged in user session.
204  // 4. From an empty background, guest user logged in.
205  if (wallpaper_delegate->ShouldShowInitialAnimation() ||
206      root_window_controller->animating_wallpaper_controller() ||
207      Shell::GetInstance()->session_state_delegate()->NumberOfLoggedInUsers()) {
208    wm::SetWindowVisibilityAnimationTransition(
209        desktop_widget->GetNativeView(), wm::ANIMATE_SHOW);
210    int duration_override = wallpaper_delegate->GetAnimationDurationOverride();
211    if (duration_override) {
212      wm::SetWindowVisibilityAnimationDuration(
213          desktop_widget->GetNativeView(),
214          base::TimeDelta::FromMilliseconds(duration_override));
215    }
216  } else {
217    // Disable animation if transition to login screen from an empty background.
218    wm::SetWindowVisibilityAnimationTransition(
219        desktop_widget->GetNativeView(), wm::ANIMATE_NONE);
220  }
221
222  desktop_widget->SetBounds(params.parent->bounds());
223  return desktop_widget;
224}
225
226}  // namespace ash
227