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/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   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 // This event handler receives events in the pre-target phase and takes care of
  76 // the following:
  77 //   - Disabling overview mode on touch release.
  78 //   - Disabling overview mode on mouse release.
  79 class PreEventDispatchHandler : public ui::EventHandler {
  80  public:
  81   PreEventDispatchHandler() {}
  82   ~PreEventDispatchHandler() override {}
  83
  84  private:
  85   // ui::EventHandler:
  86   void OnMouseEvent(ui::MouseEvent* event) override {
  87     CHECK_EQ(ui::EP_PRETARGET, event->phase());
  88     WindowSelectorController* controller =
  89         Shell::GetInstance()->window_selector_controller();
  90     if (event->type() == ui::ET_MOUSE_RELEASED && controller->IsSelecting()) {
  91       controller->ToggleOverview();
  92       event->StopPropagation();
  93     }
  94   }
  95
  96   void OnGestureEvent(ui::GestureEvent* event) override {
  97     CHECK_EQ(ui::EP_PRETARGET, event->phase());
  98     WindowSelectorController* controller =
  99         Shell::GetInstance()->window_selector_controller();
 100     if (event->type() == ui::ET_GESTURE_TAP && controller->IsSelecting()) {
 101       controller->ToggleOverview();
 102       event->StopPropagation();
 103     }
 104   }
 105
 106   DISALLOW_COPY_AND_ASSIGN(PreEventDispatchHandler);
 107 };
 108
 109 ////////////////////////////////////////////////////////////////////////////////
 110 // DesktopBackgroundView, public:
 111
 112 DesktopBackgroundView::DesktopBackgroundView()
 113     : pre_dispatch_handler_(new PreEventDispatchHandler()) {
 114   set_context_menu_controller(this);
 115   AddPreTargetHandler(pre_dispatch_handler_.get());
 116 }
 117
 118 DesktopBackgroundView::~DesktopBackgroundView() {
 119   RemovePreTargetHandler(pre_dispatch_handler_.get());
 120 }
 121
 122 ////////////////////////////////////////////////////////////////////////////////
 123 // DesktopBackgroundView, views::View overrides:
 124
 125 void DesktopBackgroundView::OnPaint(gfx::Canvas* canvas) {
 126   // Scale the image while maintaining the aspect ratio, cropping as
 127   // necessary to fill the background. Ideally the image should be larger
 128   // than the largest display supported, if not we will scale and center it if
 129   // the layout is WALLPAPER_LAYOUT_CENTER_CROPPED.
 130   DesktopBackgroundController* controller =
 131       Shell::GetInstance()->desktop_background_controller();
 132   gfx::ImageSkia wallpaper = controller->GetWallpaper();
 133   WallpaperLayout wallpaper_layout = controller->GetWallpaperLayout();
 134
 135   if (wallpaper.isNull()) {
 136     canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
 137     return;
 138   }
 139
 140   gfx::NativeView native_view = GetWidget()->GetNativeView();
 141   gfx::Display display = gfx::Screen::GetScreenFor(native_view)->
 142       GetDisplayNearestWindow(native_view);
 143
 144   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
 145   DisplayInfo display_info = display_manager->GetDisplayInfo(display.id());
 146   float scaling = display_info.GetEffectiveUIScale();
 147   if (scaling <= 1.0f)
 148     scaling = 1.0f;
 149   // Allow scaling up to the UI scaling.
 150   // TODO(oshima): Create separate layer that fits to the image and then
 151   // scale to avoid artifacts and be more efficient when clipped.
 152   gfx::Rect wallpaper_rect(
 153       0, 0, wallpaper.width() * scaling, wallpaper.height() * scaling);
 154
 155   if (wallpaper_layout == WALLPAPER_LAYOUT_CENTER_CROPPED) {
 156     // The dimension with the smallest ratio must be cropped, the other one
 157     // is preserved. Both are set in gfx::Size cropped_size.
 158     double horizontal_ratio = static_cast<double>(width()) /
 159         static_cast<double>(wallpaper.width());
 160     double vertical_ratio = static_cast<double>(height()) /
 161         static_cast<double>(wallpaper.height());
 162
 163     gfx::Size cropped_size;
 164     if (vertical_ratio > horizontal_ratio) {
 165       cropped_size = gfx::Size(
 166           RoundPositive(static_cast<double>(width()) / vertical_ratio),
 167           wallpaper.height());
 168     } else {
 169       cropped_size = gfx::Size(wallpaper.width(),
 170           RoundPositive(static_cast<double>(height()) / horizontal_ratio));
 171     }
 172
 173     gfx::Rect wallpaper_cropped_rect(
 174         0, 0, wallpaper.width(), wallpaper.height());
 175     wallpaper_cropped_rect.ClampToCenteredSize(cropped_size);
 176     canvas->DrawImageInt(wallpaper,
 177         wallpaper_cropped_rect.x(), wallpaper_cropped_rect.y(),
 178         wallpaper_cropped_rect.width(), wallpaper_cropped_rect.height(),
 179         0, 0, width(), height(),
 180         true);
 181   } else if (wallpaper_layout == WALLPAPER_LAYOUT_TILE) {
 182     canvas->TileImageInt(wallpaper, 0, 0, width(), height());
 183   } else if (wallpaper_layout == WALLPAPER_LAYOUT_STRETCH) {
 184     // This is generally not recommended as it may show artifacts.
 185     canvas->DrawImageInt(wallpaper, 0, 0, wallpaper.width(),
 186         wallpaper.height(), 0, 0, width(), height(), true);
 187   } else {
 188     // Fill with black to make sure that the entire area is opaque.
 189     canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
 190     // All other are simply centered, and not scaled (but may be clipped).
 191     canvas->DrawImageInt(
 192         wallpaper,
 193         0, 0, wallpaper.width(), wallpaper.height(),
 194         (width() - wallpaper_rect.width()) / 2,
 195         (height() - wallpaper_rect.height()) / 2,
 196         wallpaper_rect.width(),
 197         wallpaper_rect.height(),
 198         true);
 199   }
 200 }
 201
 202 bool DesktopBackgroundView::OnMousePressed(const ui::MouseEvent& event) {
 203   return true;
 204 }
 205
 206 void DesktopBackgroundView::ShowContextMenuForView(
 207     views::View* source,
 208     const gfx::Point& point,
 209     ui::MenuSourceType source_type) {
 210   Shell::GetInstance()->ShowContextMenu(point, source_type);
 211 }
 212
 213 views::Widget* CreateDesktopBackground(aura::Window* root_window,
 214                                        int container_id) {
 215   DesktopBackgroundController* controller =
 216       Shell::GetInstance()->desktop_background_controller();
 217   UserWallpaperDelegate* wallpaper_delegate =
 218       Shell::GetInstance()->user_wallpaper_delegate();
 219
 220   views::Widget* desktop_widget = new views::Widget;
 221   views::Widget::InitParams params(
 222       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
 223   if (controller->GetWallpaper().isNull())
 224     params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
 225   params.parent = root_window->GetChildById(container_id);
 226   desktop_widget->Init(params);
 227   desktop_widget->GetNativeWindow()->layer()->SetMasksToBounds(true);
 228   desktop_widget->SetContentsView(
 229       new LayerControlView(new DesktopBackgroundView()));
 230   int animation_type = wallpaper_delegate->GetAnimationType();
 231   wm::SetWindowVisibilityAnimationType(
 232       desktop_widget->GetNativeView(), animation_type);
 233
 234   RootWindowController* root_window_controller =
 235       GetRootWindowController(root_window);
 236
 237   // Enable wallpaper transition for the following cases:
 238   // 1. Initial(OOBE) wallpaper animation.
 239   // 2. Wallpaper fades in from a non empty background.
 240   // 3. From an empty background, chrome transit to a logged in user session.
 241   // 4. From an empty background, guest user logged in.
 242   if (wallpaper_delegate->ShouldShowInitialAnimation() ||
 243       root_window_controller->animating_wallpaper_controller() ||
 244       Shell::GetInstance()->session_state_delegate()->NumberOfLoggedInUsers()) {
 245     wm::SetWindowVisibilityAnimationTransition(
 246         desktop_widget->GetNativeView(), wm::ANIMATE_SHOW);
 247     int duration_override = wallpaper_delegate->GetAnimationDurationOverride();
 248     if (duration_override) {
 249       wm::SetWindowVisibilityAnimationDuration(
 250           desktop_widget->GetNativeView(),
 251           base::TimeDelta::FromMilliseconds(duration_override));
 252     }
 253   } else {
 254     // Disable animation if transition to login screen from an empty background.
 255     wm::SetWindowVisibilityAnimationTransition(
 256         desktop_widget->GetNativeView(), wm::ANIMATE_NONE);
 257   }
 258
 259   desktop_widget->SetBounds(params.parent->bounds());
 260   return desktop_widget;
 261 }
 262
 263 }  // namespace ash