drag_image_view.cc revision 7dbb3d5cf0c15f500944d211057644d6a2f37371 
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
15namespace ash {
16namespace internal {
17
18namespace {
19using views::Widget;
20
21Widget* 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
39DragImageView::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
48DragImageView::~DragImageView() {
49  widget_->Hide();
50}
51
52void DragImageView::SetBoundsInScreen(const gfx::Rect& bounds) {
53  widget_->SetBounds(bounds);
54  widget_size_ = bounds.size();
55}
56
57void DragImageView::SetScreenPosition(const gfx::Point& position) {
58  widget_->SetBounds(gfx::Rect(position, widget_size_));
59}
60
61void DragImageView::SetWidgetVisible(bool visible) {
62  if (visible != widget_->IsVisible()) {
63    if (visible)
64      widget_->Show();
65    else
66      widget_->Hide();
67  }
68}
69
70void 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