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      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 #ifndef UI_GFX_IMAGE_IMAGE_UTIL_H_
      6 #define UI_GFX_IMAGE_IMAGE_UTIL_H_
      7 
      8 #include <vector>
      9 
     10 #include "base/basictypes.h"
     11 #include "ui/gfx/gfx_export.h"
     12 
     13 namespace gfx {
     14 class Image;
     15 class ImageSkia;
     16 }
     17 
     18 namespace gfx {
     19 
     20 // Creates an image from the given JPEG-encoded input. If there was an error
     21 // creating the image, returns an IsEmpty() Image.
     22 GFX_EXPORT Image ImageFrom1xJPEGEncodedData(const unsigned char* input,
     23                                             size_t input_size);
     24 
     25 // Fills the |dst| vector with JPEG-encoded bytes of the 1x representation of
     26 // the given image.
     27 // Returns true if the image has a 1x representation and the 1x representation
     28 // was encoded successfully.
     29 // |quality| determines the compression level, 0 == lowest, 100 == highest.
     30 // Returns true if the Image was encoded successfully.
     31 GFX_EXPORT bool JPEG1xEncodedDataFromImage(const Image& image,
     32                                            int quality,
     33                                            std::vector<unsigned char>* dst);
     34 
     35 // Returns the visible (non-transparent) width of the 1x rep of the given
     36 // image. If the image has no transparency, the leading value will be 0 and
     37 // the trailing will be the image width. Return values are in the 1x width
     38 // pixel units. Margins are given in 0-based column format. So if the image
     39 // has only transparent pixels in columns 0, 1, 2, 3, then the leading value
     40 // will be 4. Similarly, if there are all transparent pixels in column
     41 // width-2, width-1, then the trailing margin value will be width-3.
     42 // Returns true if the value is computed from opacity, false if it is a
     43 // default value because of null image, missing Rep, etc.
     44 // This method is only suitable for fairly small images (i.e. 16x16).
     45 // The margins for a completely transparent image will be w/2-1, w/2, but this
     46 // will be an expensive operation: it isn't expected that it will be frequently
     47 // calculated.
     48 GFX_EXPORT bool VisibleMargins(const ImageSkia& image,
     49                                int* leading, int* trailing);
     50 
     51 }  // namespace gfx
     52 
     53 #endif  // UI_GFX_IMAGE_IMAGE_UTIL_H_
     54