ui/gfx/image/image.h

   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 // An Image wraps an image any flavor, be it platform-native GdkBitmap/NSImage,
   6 // or a SkBitmap. This also provides easy conversion to other image types
   7 // through operator overloading. It will cache the converted representations
   8 // internally to prevent double-conversion.
   9 //
  10 // The lifetime of both the initial representation and any converted ones are
  11 // tied to the lifetime of the Image's internal storage. To allow Images to be
  12 // cheaply passed around by value, the actual image data is stored in a ref-
  13 // counted member. When all Images referencing this storage are deleted, the
  14 // actual representations are deleted, too.
  15 //
  16 // Images can be empty, in which case they have no backing representation.
  17 // Attempting to use an empty Image will result in a crash.
  18
  19 #ifndef UI_GFX_IMAGE_IMAGE_H_
  20 #define UI_GFX_IMAGE_IMAGE_H_
  21
  22 #include <map>
  23 #include <vector>
  24
  25 #include "base/basictypes.h"
  26 #include "base/gtest_prod_util.h"
  27 #include "base/memory/ref_counted_memory.h"
  28 #include "base/memory/scoped_ptr.h"
  29 #include "ui/gfx/gfx_export.h"
  30 #include "ui/gfx/native_widget_types.h"
  31
  32 #if defined(OS_MACOSX) && !defined(OS_IOS)
  33 typedef struct CGColorSpace* CGColorSpaceRef;
  34 #endif
  35
  36 class SkBitmap;
  37
  38 namespace {
  39 class ImageTest;
  40 class ImageMacTest;
  41 }
  42
  43 namespace gfx {
  44 struct ImagePNGRep;
  45 class ImageSkia;
  46 class Size;
  47
  48 namespace internal {
  49 class ImageRep;
  50 class ImageStorage;
  51 }
  52
  53 class GFX_EXPORT Image {
  54  public:
  55   enum RepresentationType {
  56     kImageRepCocoa,
  57     kImageRepCocoaTouch,
  58     kImageRepSkia,
  59     kImageRepPNG,
  60   };
  61
  62   typedef std::map<RepresentationType, internal::ImageRep*> RepresentationMap;
  63
  64   // Creates an empty image with no representations.
  65   Image();
  66
  67   // Creates a new image by copying the raw PNG-encoded input for use as the
  68   // default representation.
  69   explicit Image(const std::vector<ImagePNGRep>& image_reps);
  70
  71   // Creates a new image by copying the ImageSkia for use as the default
  72   // representation.
  73   explicit Image(const ImageSkia& image);
  74
  75 #if defined(OS_IOS)
  76   // Does not retain |image|; expects to take ownership.
  77   explicit Image(UIImage* image);
  78 #elif defined(OS_MACOSX)
  79   // Does not retain |image|; expects to take ownership.
  80   // A single NSImage object can contain multiple bitmaps so there's no reason
  81   // to pass a vector of these.
  82   explicit Image(NSImage* image);
  83 #endif
  84
  85   // Initializes a new Image by AddRef()ing |other|'s internal storage.
  86   Image(const Image& other);
  87
  88   // Copies a reference to |other|'s storage.
  89   Image& operator=(const Image& other);
  90
  91   // Deletes the image and, if the only owner of the storage, all of its cached
  92   // representations.
  93   ~Image();
  94
  95   // Creates an image from the passed in 1x bitmap.
  96   // WARNING: The resulting image will be pixelated when painted on a high
  97   // density display.
  98   static Image CreateFrom1xBitmap(const SkBitmap& bitmap);
  99
 100   // Creates an image from the PNG encoded input.
 101   // For example (from an std::vector):
 102   // std::vector<unsigned char> png = ...;
 103   // gfx::Image image =
 104   //     Image::CreateFrom1xPNGBytes(&png.front(), png.size());
 105   static Image CreateFrom1xPNGBytes(const unsigned char* input,
 106                                     size_t input_size);
 107
 108   // Creates an image from the PNG encoded input.
 109   static Image CreateFrom1xPNGBytes(
 110       const scoped_refptr<base::RefCountedMemory>& input);
 111
 112   // Converts the Image to the desired representation and stores it internally.
 113   // The returned result is a weak pointer owned by and scoped to the life of
 114   // the Image. Must only be called if IsEmpty() is false.
 115   const SkBitmap* ToSkBitmap() const;
 116   const ImageSkia* ToImageSkia() const;
 117 #if defined(OS_IOS)
 118   UIImage* ToUIImage() const;
 119 #elif defined(OS_MACOSX)
 120   NSImage* ToNSImage() const;
 121 #endif
 122
 123   // Returns the raw PNG-encoded data for the bitmap at 1x. If the data is
 124   // unavailable, either because the image has no data for 1x or because it is
 125   // empty, an empty RefCountedBytes object is returned. NULL is never
 126   // returned.
 127   scoped_refptr<base::RefCountedMemory> As1xPNGBytes() const;
 128
 129   // Same as ToSkBitmap(), but returns a null SkBitmap if this image is empty.
 130   SkBitmap AsBitmap() const;
 131
 132   // Same as ToImageSkia(), but returns an empty ImageSkia if this
 133   // image is empty.
 134   ImageSkia AsImageSkia() const;
 135
 136 #if defined(OS_MACOSX) && !defined(OS_IOS)
 137   // Same as ToSkBitmap(), but returns nil if this image is empty.
 138   NSImage* AsNSImage() const;
 139 #endif
 140
 141   // Performs a conversion, like above, but returns a copy of the result rather
 142   // than a weak pointer. The caller is responsible for deleting the result.
 143   // Note that the result is only a copy in terms of memory management; the
 144   // backing pixels are shared amongst all copies (a fact of each of the
 145   // converted representations, rather than a limitation imposed by Image) and
 146   // so the result should be considered immutable.
 147   scoped_refptr<base::RefCountedMemory> Copy1xPNGBytes() const;
 148   ImageSkia* CopyImageSkia() const;
 149   SkBitmap* CopySkBitmap() const;
 150 #if defined(OS_IOS)
 151   UIImage* CopyUIImage() const;
 152 #elif defined(OS_MACOSX)
 153   NSImage* CopyNSImage() const;
 154 #endif
 155
 156   // Inspects the representations map to see if the given type exists.
 157   bool HasRepresentation(RepresentationType type) const;
 158
 159   // Returns the number of representations.
 160   size_t RepresentationCount() const;
 161
 162   // Returns true if this Image has no representations.
 163   bool IsEmpty() const;
 164
 165   // Width and height of image in DIP coordinate system.
 166   int Width() const;
 167   int Height() const;
 168   gfx::Size Size() const;
 169
 170   // Swaps this image's internal representations with |other|.
 171   void SwapRepresentations(gfx::Image* other);
 172
 173 #if defined(OS_MACOSX) && !defined(OS_IOS)
 174   // Set the default representation's color space. This is used for converting
 175   // to NSImage. This is used to compensate for PNGCodec not writing or reading
 176   // colorspace ancillary chunks. (sRGB, iCCP).
 177   void SetSourceColorSpace(CGColorSpaceRef color_space);
 178 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 179
 180  private:
 181   // Returns the type of the default representation.
 182   RepresentationType DefaultRepresentationType() const;
 183
 184   // Returns the ImageRep of the appropriate type or NULL if there is no
 185   // representation of that type (and must_exist is false).
 186   internal::ImageRep* GetRepresentation(
 187       RepresentationType rep_type, bool must_exist) const;
 188
 189   // Stores a representation into the map.
 190   void AddRepresentation(scoped_ptr<internal::ImageRep> rep) const;
 191
 192   // Internal class that holds all the representations. This allows the Image to
 193   // be cheaply copied.
 194   scoped_refptr<internal::ImageStorage> storage_;
 195
 196   friend class ::ImageTest;
 197   friend class ::ImageMacTest;
 198 };
 199
 200 }  // namespace gfx
 201
 202 #endif  // UI_GFX_IMAGE_IMAGE_H_