widget/gtk/nsImageToPixbuf.cpp@ac0c01689b40
widget/gtk/nsImageToPixbuf.cpp
Thu, 15 Jan 2015 15:59:08 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 15 Jan 2015 15:59:08 +0100
- branch
- TOR_BUG_9701
- changeset 10
- ac0c01689b40
- permissions
- -rw-r--r--
Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* vim:set sw=4 sts=4 et cin: */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #include <gdk-pixbuf/gdk-pixbuf.h>
8 #include "nsImageToPixbuf.h"
10 #include "imgIContainer.h"
11 #include "mozilla/gfx/2D.h"
12 #include "mozilla/RefPtr.h"
13 #include "nsAutoPtr.h"
15 using mozilla::gfx::DataSourceSurface;
16 using mozilla::gfx::SurfaceFormat;
17 using mozilla::RefPtr;
19 NS_IMPL_ISUPPORTS(nsImageToPixbuf, nsIImageToPixbuf)
21 inline unsigned char
22 unpremultiply (unsigned char color,
23 unsigned char alpha)
24 {
25 if (alpha == 0)
26 return 0;
27 // plus alpha/2 to round instead of truncate
28 return (color * 255 + alpha / 2) / alpha;
29 }
31 NS_IMETHODIMP_(GdkPixbuf*)
32 nsImageToPixbuf::ConvertImageToPixbuf(imgIContainer* aImage)
33 {
34 return ImageToPixbuf(aImage);
35 }
37 GdkPixbuf*
38 nsImageToPixbuf::ImageToPixbuf(imgIContainer* aImage)
39 {
40 RefPtr<SourceSurface> surface =
41 aImage->GetFrame(imgIContainer::FRAME_CURRENT,
42 imgIContainer::FLAG_SYNC_DECODE);
44 // If the last call failed, it was probably because our call stack originates
45 // in an imgINotificationObserver event, meaning that we're not allowed request
46 // a sync decode. Presumably the originating event is something sensible like
47 // OnStopFrame(), so we can just retry the call without a sync decode.
48 if (!surface)
49 surface = aImage->GetFrame(imgIContainer::FRAME_CURRENT,
50 imgIContainer::FLAG_NONE);
52 NS_ENSURE_TRUE(surface, nullptr);
54 return SourceSurfaceToPixbuf(surface,
55 surface->GetSize().width,
56 surface->GetSize().height);
57 }
59 GdkPixbuf*
60 nsImageToPixbuf::SourceSurfaceToPixbuf(SourceSurface* aSurface,
61 int32_t aWidth,
62 int32_t aHeight)
63 {
64 MOZ_ASSERT(aWidth <= aSurface->GetSize().width &&
65 aHeight <= aSurface->GetSize().height,
66 "Requested rect is bigger than the supplied surface");
68 GdkPixbuf* pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8,
69 aWidth, aHeight);
70 if (!pixbuf)
71 return nullptr;
73 uint32_t destStride = gdk_pixbuf_get_rowstride (pixbuf);
74 guchar* destPixels = gdk_pixbuf_get_pixels (pixbuf);
76 RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
77 DataSourceSurface::MappedSurface map;
78 dataSurface->Map(DataSourceSurface::MapType::READ, &map);
79 uint8_t* srcData = map.mData;
80 int32_t srcStride = map.mStride;
82 SurfaceFormat format = dataSurface->GetFormat();
84 for (int32_t row = 0; row < aHeight; ++row) {
85 for (int32_t col = 0; col < aWidth; ++col) {
86 guchar* destPixel = destPixels + row * destStride + 4 * col;
88 uint32_t* srcPixel =
89 reinterpret_cast<uint32_t*>((srcData + row * srcStride + 4 * col));
91 if (format == SurfaceFormat::B8G8R8A8) {
92 const uint8_t a = (*srcPixel >> 24) & 0xFF;
93 const uint8_t r = unpremultiply((*srcPixel >> 16) & 0xFF, a);
94 const uint8_t g = unpremultiply((*srcPixel >> 8) & 0xFF, a);
95 const uint8_t b = unpremultiply((*srcPixel >> 0) & 0xFF, a);
97 *destPixel++ = r;
98 *destPixel++ = g;
99 *destPixel++ = b;
100 *destPixel++ = a;
101 } else {
102 MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8);
104 const uint8_t r = (*srcPixel >> 16) & 0xFF;
105 const uint8_t g = (*srcPixel >> 8) & 0xFF;
106 const uint8_t b = (*srcPixel >> 0) & 0xFF;
108 *destPixel++ = r;
109 *destPixel++ = g;
110 *destPixel++ = b;
111 *destPixel++ = 0xFF; // A
112 }
113 }
114 }
116 dataSurface->Unmap();
118 return pixbuf;
119 }
