1 // Copyright (c) 2013 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/wallpaper_resizer.h"
6
7 #include "ash/desktop_background/wallpaper_resizer_observer.h"
8 #include "base/bind.h"
9 #include "base/logging.h"
10 #include "base/threading/sequenced_worker_pool.h"
11 #include "base/threading/worker_pool.h"
12 #include "content/public/browser/browser_thread.h"
13 #include "third_party/skia/include/core/SkImage.h"
14 #include "ui/base/resource/resource_bundle.h"
15 #include "ui/gfx/image/image_skia_rep.h"
16 #include "ui/gfx/skia_util.h"
17
18 using content::BrowserThread;
19
20 namespace ash {
21 namespace {
22
23 // For our scaling ratios we need to round positive numbers.
RoundPositive(double x)24 int RoundPositive(double x) {
25 return static_cast<int>(floor(x + 0.5));
26 }
27
28 // Resizes |orig_bitmap| to |target_size| using |layout| and stores the
29 // resulting bitmap at |resized_bitmap_out|.
Resize(SkBitmap orig_bitmap,const gfx::Size & target_size,WallpaperLayout layout,SkBitmap * resized_bitmap_out)30 void Resize(SkBitmap orig_bitmap,
31 const gfx::Size& target_size,
32 WallpaperLayout layout,
33 SkBitmap* resized_bitmap_out) {
34 DCHECK(BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
35 SkBitmap new_bitmap = orig_bitmap;
36
37 const int orig_width = orig_bitmap.width();
38 const int orig_height = orig_bitmap.height();
39 const int new_width = target_size.width();
40 const int new_height = target_size.height();
41
42 if (orig_width > new_width || orig_height > new_height) {
43 gfx::Rect wallpaper_rect(0, 0, orig_width, orig_height);
44 gfx::Size cropped_size = gfx::Size(std::min(new_width, orig_width),
45 std::min(new_height, orig_height));
46 switch (layout) {
47 case WALLPAPER_LAYOUT_CENTER:
48 wallpaper_rect.ClampToCenteredSize(cropped_size);
49 orig_bitmap.extractSubset(&new_bitmap,
50 gfx::RectToSkIRect(wallpaper_rect));
51 break;
52 case WALLPAPER_LAYOUT_TILE:
53 wallpaper_rect.set_size(cropped_size);
54 orig_bitmap.extractSubset(&new_bitmap,
55 gfx::RectToSkIRect(wallpaper_rect));
56 break;
57 case WALLPAPER_LAYOUT_STRETCH:
58 new_bitmap = skia::ImageOperations::Resize(
59 orig_bitmap, skia::ImageOperations::RESIZE_LANCZOS3,
60 new_width, new_height);
61 break;
62 case WALLPAPER_LAYOUT_CENTER_CROPPED:
63 if (orig_width > new_width && orig_height > new_height) {
64 // The dimension with the smallest ratio must be cropped, the other
65 // one is preserved. Both are set in gfx::Size cropped_size.
66 double horizontal_ratio = static_cast<double>(new_width) /
67 static_cast<double>(orig_width);
68 double vertical_ratio = static_cast<double>(new_height) /
69 static_cast<double>(orig_height);
70
71 if (vertical_ratio > horizontal_ratio) {
72 cropped_size = gfx::Size(
73 RoundPositive(static_cast<double>(new_width) / vertical_ratio),
74 orig_height);
75 } else {
76 cropped_size = gfx::Size(orig_width, RoundPositive(
77 static_cast<double>(new_height) / horizontal_ratio));
78 }
79 wallpaper_rect.ClampToCenteredSize(cropped_size);
80 SkBitmap sub_image;
81 orig_bitmap.extractSubset(&sub_image,
82 gfx::RectToSkIRect(wallpaper_rect));
83 new_bitmap = skia::ImageOperations::Resize(
84 sub_image, skia::ImageOperations::RESIZE_LANCZOS3,
85 new_width, new_height);
86 }
87 }
88 }
89
90 *resized_bitmap_out = new_bitmap;
91 resized_bitmap_out->setImmutable();
92 }
93
94 } // namespace
95
96 // static
GetImageId(const gfx::ImageSkia & image)97 uint32_t WallpaperResizer::GetImageId(const gfx::ImageSkia& image) {
98 const gfx::ImageSkiaRep& image_rep = image.GetRepresentation(1.0f);
99 return image_rep.is_null() ? 0 : image_rep.sk_bitmap().getGenerationID();
100 }
101
WallpaperResizer(const gfx::ImageSkia & image,const gfx::Size & target_size,WallpaperLayout layout)102 WallpaperResizer::WallpaperResizer(const gfx::ImageSkia& image,
103 const gfx::Size& target_size,
104 WallpaperLayout layout)
105 : image_(image),
106 original_image_id_(GetImageId(image_)),
107 target_size_(target_size),
108 layout_(layout),
109 weak_ptr_factory_(this) {
110 image_.MakeThreadSafe();
111 }
112
~WallpaperResizer()113 WallpaperResizer::~WallpaperResizer() {
114 }
115
StartResize()116 void WallpaperResizer::StartResize() {
117 DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
118 SkBitmap* resized_bitmap = new SkBitmap;
119 if (!content::BrowserThread::PostBlockingPoolTaskAndReply(
120 FROM_HERE,
121 base::Bind(&Resize, *image_.bitmap(), target_size_,
122 layout_, resized_bitmap),
123 base::Bind(&WallpaperResizer::OnResizeFinished,
124 weak_ptr_factory_.GetWeakPtr(),
125 base::Owned(resized_bitmap)))) {
126 LOG(WARNING) << "PostSequencedWorkerTask failed. "
127 << "Wallpaper may not be resized.";
128 }
129 }
130
AddObserver(WallpaperResizerObserver * observer)131 void WallpaperResizer::AddObserver(WallpaperResizerObserver* observer) {
132 observers_.AddObserver(observer);
133 }
134
RemoveObserver(WallpaperResizerObserver * observer)135 void WallpaperResizer::RemoveObserver(WallpaperResizerObserver* observer) {
136 observers_.RemoveObserver(observer);
137 }
138
OnResizeFinished(SkBitmap * resized_bitmap)139 void WallpaperResizer::OnResizeFinished(SkBitmap* resized_bitmap) {
140 DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
141 image_ = gfx::ImageSkia::CreateFrom1xBitmap(*resized_bitmap);
142 FOR_EACH_OBSERVER(WallpaperResizerObserver, observers_,
143 OnWallpaperResized());
144 }
145
146 } // namespace ash
147