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/overview/window_selector_controller.h"
  19 #include "ash/wm/window_animations.h"
  20 #include "base/message_loop/message_loop.h"
  21 #include "base/strings/utf_string_conversions.h"
  22 #include "ui/aura/window_event_dispatcher.h"
  23 #include "ui/compositor/layer.h"
  24 #include "ui/gfx/canvas.h"
  25 #include "ui/gfx/geometry/safe_integer_conversions.h"
  26 #include "ui/gfx/geometry/size_conversions.h"
  27 #include "ui/gfx/image/image.h"
  28 #include "ui/gfx/transform.h"
  29 #include "ui/views/widget/widget.h"
  30
  31 using wallpaper::WallpaperLayout;
  32 using wallpaper::WALLPAPER_LAYOUT_CENTER;
  33 using wallpaper::WALLPAPER_LAYOUT_CENTER_CROPPED;
  34 using wallpaper::WALLPAPER_LAYOUT_STRETCH;
  35 using wallpaper::WALLPAPER_LAYOUT_TILE;
  36
  37 namespace ash {
  38 namespace {
  39
  40 // A view that controls the child view's layer so that the layer
  41 // always has the same size as the display's original, un-scaled size
  42 // in DIP. The layer then transformed to fit to the virtual screen
  43 // size when laid-out.
  44 // This is to avoid scaling the image at painting time, then scaling
  45 // it back to the screen size in the compositor.
  46 class LayerControlView : public views::View {
  47  public:
  48   explicit LayerControlView(views::View* view) {
  49     AddChildView(view);
  50     view->SetPaintToLayer(true);
  51   }
  52
  53   // Overrides views::View.
  54   void Layout() override {
  55     gfx::Display display = Shell::GetScreen()->GetDisplayNearestWindow(
  56         GetWidget()->GetNativeView());
  57     DisplayManager* display_manager = Shell::GetInstance()->display_manager();
  58     DisplayInfo info = display_manager->GetDisplayInfo(display.id());
  59     float ui_scale = info.GetEffectiveUIScale();
  60     gfx::SizeF pixel_size = display.size();
  61     pixel_size.Scale(1.0f / ui_scale);
  62     gfx::Size rounded_size = gfx::ToFlooredSize(pixel_size);
  63     DCHECK_EQ(1, child_count());
  64     views::View* child = child_at(0);
  65     child->SetBounds(0, 0, rounded_size.width(), rounded_size.height());
  66     gfx::Transform transform;
  67     // Apply RTL transform explicitly becacuse Views layer code
  68     // doesn't handle RTL.  crbug.com/458753.
  69     transform.Translate(-child->GetMirroredX(), 0);
  70     transform.Scale(ui_scale, ui_scale);
  71     child->SetTransform(transform);
  72   }
  73
  74  private:
  75   DISALLOW_COPY_AND_ASSIGN(LayerControlView);
  76 };
  77
  78 }  // namespace
  79
  80 // This event handler receives events in the pre-target phase and takes care of
  81 // the following:
  82 //   - Disabling overview mode on touch release.
  83 //   - Disabling overview mode on mouse release.
  84 class PreEventDispatchHandler : public ui::EventHandler {
  85  public:
  86   PreEventDispatchHandler() {}
  87   ~PreEventDispatchHandler() override {}
  88
  89  private:
  90   // ui::EventHandler:
  91   void OnMouseEvent(ui::MouseEvent* event) override {
  92     CHECK_EQ(ui::EP_PRETARGET, event->phase());
  93     WindowSelectorController* controller =
  94         Shell::GetInstance()->window_selector_controller();
  95     if (event->type() == ui::ET_MOUSE_RELEASED && controller->IsSelecting()) {
  96       controller->ToggleOverview();
  97       event->StopPropagation();
  98     }
  99   }
 100
 101   void OnGestureEvent(ui::GestureEvent* event) override {
 102     CHECK_EQ(ui::EP_PRETARGET, event->phase());
 103     WindowSelectorController* controller =
 104         Shell::GetInstance()->window_selector_controller();
 105     if (event->type() == ui::ET_GESTURE_TAP && controller->IsSelecting()) {
 106       controller->ToggleOverview();
 107       event->StopPropagation();
 108     }
 109   }
 110
 111   DISALLOW_COPY_AND_ASSIGN(PreEventDispatchHandler);
 112 };
 113
 114 ////////////////////////////////////////////////////////////////////////////////
 115 // DesktopBackgroundView, public:
 116
 117 DesktopBackgroundView::DesktopBackgroundView()
 118     : pre_dispatch_handler_(new PreEventDispatchHandler()) {
 119   set_context_menu_controller(this);
 120   AddPreTargetHandler(pre_dispatch_handler_.get());
 121 }
 122
 123 DesktopBackgroundView::~DesktopBackgroundView() {
 124   RemovePreTargetHandler(pre_dispatch_handler_.get());
 125 }
 126
 127 ////////////////////////////////////////////////////////////////////////////////
 128 // DesktopBackgroundView, views::View overrides:
 129
 130 void DesktopBackgroundView::OnPaint(gfx::Canvas* canvas) {
 131   // Scale the image while maintaining the aspect ratio, cropping as
 132   // necessary to fill the background. Ideally the image should be larger
 133   // than the largest display supported, if not we will scale and center it if
 134   // the layout is WALLPAPER_LAYOUT_CENTER_CROPPED.
 135   DesktopBackgroundController* controller =
 136       Shell::GetInstance()->desktop_background_controller();
 137   gfx::ImageSkia wallpaper = controller->GetWallpaper();
 138   WallpaperLayout wallpaper_layout = controller->GetWallpaperLayout();
 139
 140   if (wallpaper.isNull()) {
 141     canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
 142     return;
 143   }
 144
 145   gfx::NativeView native_view = GetWidget()->GetNativeView();
 146   gfx::Display display = gfx::Screen::GetScreenFor(native_view)->
 147       GetDisplayNearestWindow(native_view);
 148
 149   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
 150   DisplayInfo display_info = display_manager->GetDisplayInfo(display.id());
 151   float scaling = display_info.GetEffectiveUIScale();
 152   if (scaling <= 1.0f)
 153     scaling = 1.0f;
 154   // Allow scaling up to the UI scaling.
 155   // TODO(oshima): Create separate layer that fits to the image and then
 156   // scale to avoid artifacts and be more efficient when clipped.
 157   gfx::Rect wallpaper_rect(
 158       0, 0, wallpaper.width() * scaling, wallpaper.height() * scaling);
 159
 160   if (wallpaper_layout == WALLPAPER_LAYOUT_CENTER_CROPPED) {
 161     // The dimension with the smallest ratio must be cropped, the other one
 162     // is preserved. Both are set in gfx::Size cropped_size.
 163     double horizontal_ratio = static_cast<double>(width()) /
 164         static_cast<double>(wallpaper.width());
 165     double vertical_ratio = static_cast<double>(height()) /
 166         static_cast<double>(wallpaper.height());
 167
 168     gfx::Size cropped_size;
 169     if (vertical_ratio > horizontal_ratio) {
 170       cropped_size = gfx::Size(
 171           gfx::ToFlooredInt(static_cast<double>(width()) / vertical_ratio),
 172           wallpaper.height());
 173     } else {
 174       cropped_size = gfx::Size(
 175           wallpaper.width(),
 176           gfx::ToFlooredInt(static_cast<double>(height()) / horizontal_ratio));
 177     }
 178
 179     gfx::Rect wallpaper_cropped_rect(
 180         0, 0, wallpaper.width(), wallpaper.height());
 181     wallpaper_cropped_rect.ClampToCenteredSize(cropped_size);
 182     canvas->DrawImageInt(wallpaper,
 183         wallpaper_cropped_rect.x(), wallpaper_cropped_rect.y(),
 184         wallpaper_cropped_rect.width(), wallpaper_cropped_rect.height(),
 185         0, 0, width(), height(),
 186         true);
 187   } else if (wallpaper_layout == WALLPAPER_LAYOUT_TILE) {
 188     canvas->TileImageInt(wallpaper, 0, 0, width(), height());
 189   } else if (wallpaper_layout == WALLPAPER_LAYOUT_STRETCH) {
 190     // This is generally not recommended as it may show artifacts.
 191     canvas->DrawImageInt(wallpaper, 0, 0, wallpaper.width(),
 192         wallpaper.height(), 0, 0, width(), height(), true);
 193   } else {
 194     // Fill with black to make sure that the entire area is opaque.
 195     canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
 196     // All other are simply centered, and not scaled (but may be clipped).
 197     canvas->DrawImageInt(
 198         wallpaper,
 199         0, 0, wallpaper.width(), wallpaper.height(),
 200         (width() - wallpaper_rect.width()) / 2,
 201         (height() - wallpaper_rect.height()) / 2,
 202         wallpaper_rect.width(),
 203         wallpaper_rect.height(),
 204         true);
 205   }
 206 }
 207
 208 bool DesktopBackgroundView::OnMousePressed(const ui::MouseEvent& event) {
 209   return true;
 210 }
 211
 212 void DesktopBackgroundView::ShowContextMenuForView(
 213     views::View* source,
 214     const gfx::Point& point,
 215     ui::MenuSourceType source_type) {
 216   Shell::GetInstance()->ShowContextMenu(point, source_type);
 217 }
 218
 219 views::Widget* CreateDesktopBackground(aura::Window* root_window,
 220                                        int container_id) {
 221   DesktopBackgroundController* controller =
 222       Shell::GetInstance()->desktop_background_controller();
 223   UserWallpaperDelegate* wallpaper_delegate =
 224       Shell::GetInstance()->user_wallpaper_delegate();
 225
 226   views::Widget* desktop_widget = new views::Widget;
 227   views::Widget::InitParams params(
 228       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
 229   if (controller->GetWallpaper().isNull())
 230     params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
 231   params.parent = root_window->GetChildById(container_id);
 232   desktop_widget->Init(params);
 233   desktop_widget->GetNativeWindow()->layer()->SetMasksToBounds(true);
 234   desktop_widget->SetContentsView(
 235       new LayerControlView(new DesktopBackgroundView()));
 236   int animation_type = wallpaper_delegate->GetAnimationType();
 237   wm::SetWindowVisibilityAnimationType(
 238       desktop_widget->GetNativeView(), animation_type);
 239
 240   RootWindowController* root_window_controller =
 241       GetRootWindowController(root_window);
 242
 243   // Enable wallpaper transition for the following cases:
 244   // 1. Initial(OOBE) wallpaper animation.
 245   // 2. Wallpaper fades in from a non empty background.
 246   // 3. From an empty background, chrome transit to a logged in user session.
 247   // 4. From an empty background, guest user logged in.
 248   if (wallpaper_delegate->ShouldShowInitialAnimation() ||
 249       root_window_controller->animating_wallpaper_controller() ||
 250       Shell::GetInstance()->session_state_delegate()->NumberOfLoggedInUsers()) {
 251     wm::SetWindowVisibilityAnimationTransition(
 252         desktop_widget->GetNativeView(), wm::ANIMATE_SHOW);
 253     int duration_override = wallpaper_delegate->GetAnimationDurationOverride();
 254     if (duration_override) {
 255       wm::SetWindowVisibilityAnimationDuration(
 256           desktop_widget->GetNativeView(),
 257           base::TimeDelta::FromMilliseconds(duration_override));
 258     }
 259   } else {
 260     // Disable animation if transition to login screen from an empty background.
 261     wm::SetWindowVisibilityAnimationTransition(
 262         desktop_widget->GetNativeView(), wm::ANIMATE_NONE);
 263   }
 264
 265   desktop_widget->SetBounds(params.parent->bounds());
 266   return desktop_widget;
 267 }
 268
 269 }  // namespace ash