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      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
    227