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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/drag_drop/drag_image_view.h"
      6 
      7 #include "skia/ext/image_operations.h"
      8 #include "ui/aura/window.h"
      9 #include "ui/compositor/dip_util.h"
     10 #include "ui/gfx/canvas.h"
     11 #include "ui/gfx/size_conversions.h"
     12 #include "ui/views/corewm/shadow_types.h"
     13 #include "ui/views/widget/widget.h"
     14 
     15 namespace ash {
     16 namespace internal {
     17 
     18 namespace {
     19 using views::Widget;
     20 
     21 Widget* CreateDragWidget(gfx::NativeView context) {
     22   Widget* drag_widget = new Widget;
     23   Widget::InitParams params;
     24   params.type = Widget::InitParams::TYPE_TOOLTIP;
     25   params.keep_on_top = true;
     26   params.context = context;
     27   params.accept_events = false;
     28   params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
     29   params.opacity = Widget::InitParams::TRANSLUCENT_WINDOW;
     30   drag_widget->Init(params);
     31   drag_widget->SetOpacity(0xFF);
     32   drag_widget->GetNativeWindow()->set_owned_by_parent(false);
     33   drag_widget->GetNativeWindow()->SetName("DragWidget");
     34   SetShadowType(drag_widget->GetNativeView(), views::corewm::SHADOW_TYPE_NONE);
     35   return drag_widget;
     36 }
     37 }
     38 
     39 DragImageView::DragImageView(gfx::NativeView context) : views::ImageView() {
     40   widget_.reset(CreateDragWidget(context));
     41   widget_->SetContentsView(this);
     42   widget_->SetAlwaysOnTop(true);
     43 
     44   // We are owned by the DragDropController.
     45   set_owned_by_client();
     46 }
     47 
     48 DragImageView::~DragImageView() {
     49   widget_->Hide();
     50 }
     51 
     52 void DragImageView::SetBoundsInScreen(const gfx::Rect& bounds) {
     53   widget_->SetBounds(bounds);
     54   widget_size_ = bounds.size();
     55 }
     56 
     57 void DragImageView::SetScreenPosition(const gfx::Point& position) {
     58   widget_->SetBounds(gfx::Rect(position, widget_size_));
     59 }
     60 
     61 void DragImageView::SetWidgetVisible(bool visible) {
     62   if (visible != widget_->IsVisible()) {
     63     if (visible)
     64       widget_->Show();
     65     else
     66       widget_->Hide();
     67   }
     68 }
     69 
     70 void DragImageView::OnPaint(gfx::Canvas* canvas) {
     71   if (GetImage().isNull())
     72     return;
     73 
     74   // |widget_size_| is in DIP. ImageSkia::size() also returns the size in DIP.
     75   if (GetImage().size() == widget_size_) {
     76     canvas->DrawImageInt(GetImage(), 0, 0);
     77   } else {
     78     float device_scale = 1;
     79     if (widget_->GetNativeView() && widget_->GetNativeView()->layer()) {
     80       device_scale = ui::GetDeviceScaleFactor(
     81           widget_->GetNativeView()->layer());
     82     }
     83     ui::ScaleFactor device_scale_factor =
     84         ui::GetScaleFactorFromScale(device_scale);
     85 
     86     // The drag image already has device scale factor applied. But
     87     // |widget_size_| is in DIP units.
     88     gfx::Size scaled_widget_size = gfx::ToRoundedSize(
     89         gfx::ScaleSize(widget_size_, device_scale));
     90     gfx::ImageSkiaRep image_rep = GetImage().GetRepresentation(
     91         device_scale_factor);
     92     if (image_rep.is_null())
     93       return;
     94     SkBitmap scaled = skia::ImageOperations::Resize(
     95         image_rep.sk_bitmap(), skia::ImageOperations::RESIZE_LANCZOS3,
     96         scaled_widget_size.width(), scaled_widget_size.height());
     97     gfx::ImageSkia image_skia(gfx::ImageSkiaRep(scaled, device_scale_factor));
     98     canvas->DrawImageInt(image_skia, 0, 0);
     99   }
    100 }
    101 
    102 }  // namespace internal
    103 }  // namespace ash
    104