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