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