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
13namespace gfx {
14class Image;
15class ImageSkia;
16}
17
18namespace 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.
22GFX_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.
31GFX_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.
48GFX_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