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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_state_delegate.h"
     16 #include "ash/shell.h"
     17 #include "ash/shell_window_ids.h"
     18 #include "ash/wm/property_util.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/root_window.h"
     23 #include "ui/base/resource/resource_bundle.h"
     24 #include "ui/compositor/layer.h"
     25 #include "ui/gfx/canvas.h"
     26 #include "ui/gfx/image/image.h"
     27 #include "ui/views/widget/widget.h"
     28 
     29 namespace ash {
     30 namespace internal {
     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 }  // namespace
     39 
     40 ////////////////////////////////////////////////////////////////////////////////
     41 // DesktopBackgroundView, public:
     42 
     43 DesktopBackgroundView::DesktopBackgroundView() {
     44   set_context_menu_controller(this);
     45 }
     46 
     47 DesktopBackgroundView::~DesktopBackgroundView() {
     48 }
     49 
     50 ////////////////////////////////////////////////////////////////////////////////
     51 // DesktopBackgroundView, views::View overrides:
     52 
     53 void DesktopBackgroundView::OnPaint(gfx::Canvas* canvas) {
     54   // Scale the image while maintaining the aspect ratio, cropping as
     55   // necessary to fill the background. Ideally the image should be larger
     56   // than the largest display supported, if not we will center it rather than
     57   // streching to avoid upsampling artifacts (Note that we could tile too, but
     58   // decided not to do this at the moment).
     59   DesktopBackgroundController* controller =
     60       Shell::GetInstance()->desktop_background_controller();
     61   gfx::ImageSkia wallpaper = controller->GetWallpaper();
     62   WallpaperLayout wallpaper_layout = controller->GetWallpaperLayout();
     63 
     64   gfx::NativeView native_view = GetWidget()->GetNativeView();
     65   gfx::Display display = gfx::Screen::GetScreenFor(native_view)->
     66       GetDisplayNearestWindow(native_view);
     67 
     68   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
     69   DisplayInfo display_info = display_manager->GetDisplayInfo(display.id());
     70   float scaling = display_info.ui_scale();
     71   if (scaling <= 1.0f)
     72     scaling = 1.0f;
     73   // Allow scaling up to the UI scaling.
     74   // TODO(oshima): Create separate layer that fits to the image and then
     75   // scale to avoid artifacts and be more efficient when clipped.
     76   gfx::Rect wallpaper_rect(
     77       0, 0, wallpaper.width() * scaling, wallpaper.height() * scaling);
     78 
     79   if (wallpaper_layout == WALLPAPER_LAYOUT_CENTER_CROPPED &&
     80       wallpaper_rect.width() >= width() &&
     81       wallpaper_rect.height() >= height()) {
     82     // The dimension with the smallest ratio must be cropped, the other one
     83     // is preserved. Both are set in gfx::Size cropped_size.
     84     double horizontal_ratio = static_cast<double>(width()) /
     85         static_cast<double>(wallpaper.width());
     86     double vertical_ratio = static_cast<double>(height()) /
     87         static_cast<double>(wallpaper.height());
     88 
     89     gfx::Size cropped_size;
     90     if (vertical_ratio > horizontal_ratio) {
     91       cropped_size = gfx::Size(
     92           RoundPositive(static_cast<double>(width()) / vertical_ratio),
     93           wallpaper.height());
     94     } else {
     95       cropped_size = gfx::Size(wallpaper.width(),
     96           RoundPositive(static_cast<double>(height()) / horizontal_ratio));
     97     }
     98 
     99     gfx::Rect wallpaper_cropped_rect(
    100         0, 0, wallpaper.width(), wallpaper.height());
    101     wallpaper_cropped_rect.ClampToCenteredSize(cropped_size);
    102     canvas->DrawImageInt(wallpaper,
    103         wallpaper_cropped_rect.x(), wallpaper_cropped_rect.y(),
    104         wallpaper_cropped_rect.width(), wallpaper_cropped_rect.height(),
    105         0, 0, width(), height(),
    106         true);
    107   } else if (wallpaper_layout == WALLPAPER_LAYOUT_TILE) {
    108     canvas->TileImageInt(wallpaper, 0, 0, width(), height());
    109   } else if (wallpaper_layout == WALLPAPER_LAYOUT_STRETCH) {
    110     // This is generally not recommended as it may show artifacts.
    111     canvas->DrawImageInt(wallpaper, 0, 0, wallpaper.width(),
    112         wallpaper.height(), 0, 0, width(), height(), true);
    113   } else {
    114     // Fill with black to make sure that the entire area is opaque.
    115     canvas->FillRect(GetLocalBounds(), SK_ColorBLACK);
    116     // All other are simply centered, and not scaled (but may be clipped).
    117     if (wallpaper.width() && wallpaper.height()) {
    118       canvas->DrawImageInt(
    119           wallpaper,
    120           0, 0, wallpaper.width(), wallpaper.height(),
    121           (width() - wallpaper_rect.width()) / 2,
    122           (height() - wallpaper_rect.height()) / 2,
    123           wallpaper_rect.width(),
    124           wallpaper_rect.height(),
    125           true);
    126     }
    127   }
    128 }
    129 
    130 bool DesktopBackgroundView::OnMousePressed(const ui::MouseEvent& event) {
    131   return true;
    132 }
    133 
    134 void DesktopBackgroundView::ShowContextMenuForView(
    135     views::View* source,
    136     const gfx::Point& point,
    137     ui::MenuSourceType source_type) {
    138   Shell::GetInstance()->ShowContextMenu(point, source_type);
    139 }
    140 
    141 views::Widget* CreateDesktopBackground(aura::RootWindow* root_window,
    142                                        int container_id) {
    143   DesktopBackgroundController* controller =
    144       Shell::GetInstance()->desktop_background_controller();
    145   UserWallpaperDelegate* wallpaper_delegate =
    146       Shell::GetInstance()->user_wallpaper_delegate();
    147 
    148   views::Widget* desktop_widget = new views::Widget;
    149   views::Widget::InitParams params(
    150       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
    151   if (controller->GetWallpaper().isNull())
    152     params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
    153   params.parent = root_window->GetChildById(container_id);
    154   desktop_widget->Init(params);
    155   desktop_widget->SetContentsView(new DesktopBackgroundView());
    156   int animation_type = wallpaper_delegate->GetAnimationType();
    157   views::corewm::SetWindowVisibilityAnimationType(
    158       desktop_widget->GetNativeView(), animation_type);
    159 
    160   RootWindowController* root_window_controller =
    161       GetRootWindowController(root_window);
    162 
    163   // Enable wallpaper transition for the following cases:
    164   // 1. Initial(OOBE) wallpaper animation.
    165   // 2. Wallpaper fades in from a non empty background.
    166   // 3. From an empty background, chrome transit to a logged in user session.
    167   // 4. From an empty background, guest user logged in.
    168   if (wallpaper_delegate->ShouldShowInitialAnimation() ||
    169       root_window_controller->animating_wallpaper_controller() ||
    170       Shell::GetInstance()->session_state_delegate()->NumberOfLoggedInUsers()) {
    171     views::corewm::SetWindowVisibilityAnimationTransition(
    172         desktop_widget->GetNativeView(), views::corewm::ANIMATE_SHOW);
    173   } else {
    174     // Disable animation if transition to login screen from an empty background.
    175     views::corewm::SetWindowVisibilityAnimationTransition(
    176         desktop_widget->GetNativeView(), views::corewm::ANIMATE_NONE);
    177   }
    178 
    179   desktop_widget->SetBounds(params.parent->bounds());
    180   return desktop_widget;
    181 }
    182 
    183 }  // namespace internal
    184 }  // namespace ash
    185