ash/desktop_background/desktop_background_view.cc

   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
  30 namespace ash {
  31 namespace {
  32
  33 // For our scaling ratios we need to round positive numbers.
  34 int 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.
  44 class 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
  78 DesktopBackgroundView::DesktopBackgroundView() {
  79   set_context_menu_controller(this);
  80 }
  81
  82 DesktopBackgroundView::~DesktopBackgroundView() {
  83 }
  84
  85 ////////////////////////////////////////////////////////////////////////////////
  86 // DesktopBackgroundView, views::View overrides:
  87
  88 void 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
 165 bool DesktopBackgroundView::OnMousePressed(const ui::MouseEvent& event) {
 166   return true;
 167 }
 168
 169 void 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
 176 views::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