ui/gfx/image/image_util.cc

   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 "ui/gfx/image/image_util.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "third_party/skia/include/core/SkBitmap.h"
   9 #include "ui/gfx/codec/jpeg_codec.h"
  10 #include "ui/gfx/image/image.h"
  11 #include "ui/gfx/image/image_skia.h"
  12
  13 namespace gfx {
  14
  15 const uint32_t kMinimumVisibleOpacity = 12;
  16
  17 // The iOS implementations of the JPEG functions are in image_util_ios.mm.
  18 #if !defined(OS_IOS)
  19 Image ImageFrom1xJPEGEncodedData(const unsigned char* input,
  20                                  size_t input_size) {
  21   scoped_ptr<SkBitmap> bitmap(gfx::JPEGCodec::Decode(input, input_size));
  22   if (bitmap.get())
  23     return Image::CreateFrom1xBitmap(*bitmap);
  24
  25   return Image();
  26 }
  27
  28 bool JPEG1xEncodedDataFromImage(const Image& image, int quality,
  29                                 std::vector<unsigned char>* dst) {
  30   const gfx::ImageSkiaRep& image_skia_rep =
  31       image.AsImageSkia().GetRepresentation(1.0f);
  32   if (image_skia_rep.scale() != 1.0f)
  33     return false;
  34
  35   const SkBitmap& bitmap = image_skia_rep.sk_bitmap();
  36   SkAutoLockPixels bitmap_lock(bitmap);
  37
  38   if (!bitmap.readyToDraw())
  39     return false;
  40
  41   return gfx::JPEGCodec::Encode(
  42           reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
  43           gfx::JPEGCodec::FORMAT_SkBitmap, bitmap.width(),
  44           bitmap.height(),
  45           static_cast<int>(bitmap.rowBytes()), quality,
  46           dst);
  47 }
  48 #endif  // !defined(OS_IOS)
  49
  50 bool VisibleMargins(const ImageSkia& image, int* leading, int* trailing) {
  51   *leading = 0;
  52   *trailing = std::max(1, image.width()) - 1;
  53   if (!image.HasRepresentation(1.0))
  54     return false;
  55
  56   const ImageSkiaRep& rep = image.GetRepresentation(1.0);
  57   if (rep.is_null())
  58     return false;
  59
  60   const SkBitmap& bitmap = rep.sk_bitmap();
  61   if (bitmap.isNull() || bitmap.width() == 0)
  62     return false;
  63
  64   if (bitmap.isOpaque())
  65     return true;
  66
  67   SkAutoLockPixels l(bitmap);
  68   int inner_min = bitmap.width();
  69   for (int x = 0; x < bitmap.width(); ++x) {
  70     for (int y = 0; y < bitmap.height(); ++y) {
  71       if (SkColorGetA(bitmap.getColor(x, y)) > kMinimumVisibleOpacity) {
  72         inner_min = x;
  73         break;
  74       }
  75     }
  76     if (inner_min < bitmap.width())
  77       break;
  78   }
  79
  80   int inner_max = -1;
  81   for (int x = bitmap.width() - 1; x > inner_min; --x) {
  82     for (int y = 0; y < bitmap.height(); ++y) {
  83       if (SkColorGetA(bitmap.getColor(x, y)) > kMinimumVisibleOpacity) {
  84         inner_max = x;
  85         break;
  86       }
  87     }
  88     if (inner_max > -1)
  89       break;
  90   }
  91
  92   if (inner_min == bitmap.width()) {
  93     *leading = bitmap.width()/2;
  94     *trailing = bitmap.width()/2 + 1;
  95     return true;
  96   }
  97
  98   *leading = inner_min;
  99   *trailing = inner_max;
 100   return true;
 101 }
 102
 103 }  // namespace gfx