Use ImageSkiaSource to create ImageSkia from ImagePNGReps

ui/gfx/image/image.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/image/image.h"
 
 #include <algorithm>
+#include <set>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/image/image_png_rep.h"
 #include "ui/gfx/image/image_skia.h"
+#include "ui/gfx/image/image_skia_source.h"
 #include "ui/gfx/size.h"
 
 #if !defined(OS_IOS)
 #include "ui/gfx/codec/png_codec.h"
 #endif
 
 #if defined(OS_IOS)
 #include "base/mac/foundation_util.h"
 #include "ui/gfx/image/image_skia_util_ios.h"
 #elif defined(OS_MACOSX)
 #include "base/mac/mac_util.h"
 #include "ui/gfx/image/image_skia_util_mac.h"
 #endif
 
 namespace gfx {
 
 namespace internal {
 
 #if defined(OS_IOS)
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromUIImage(
     UIImage* uiimage);
 // Caller takes ownership of the returned UIImage.
 UIImage* CreateUIImageFromPNG(
-    const std::vector<gfx::ImagePNGRep>& image_png_reps);
+    const std::vector<ImagePNGRep>& image_png_reps);
 gfx::Size UIImageSize(UIImage* image);
 #elif defined(OS_MACOSX)
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromNSImage(
     NSImage* nsimage);
 // Caller takes ownership of the returned NSImage.
-NSImage* NSImageFromPNG(const std::vector<gfx::ImagePNGRep>& image_png_reps,
+NSImage* NSImageFromPNG(const std::vector<ImagePNGRep>& image_png_reps,
                         CGColorSpaceRef color_space);
 gfx::Size NSImageSize(NSImage* image);
 #endif // defined(OS_MACOSX)
 
 #if defined(OS_IOS)
 ImageSkia* ImageSkiaFromPNG(
-    const std::vector<gfx::ImagePNGRep>& image_png_reps);
+    const std::vector<ImagePNGRep>& image_png_reps);
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromImageSkia(
     const ImageSkia* skia);
 #else
 // Returns a 16x16 red image to visually show error in decoding PNG.
 // Caller takes ownership of returned ImageSkia.
 ImageSkia* GetErrorImageSkia() {
   SkBitmap bitmap;
   bitmap.setConfig(SkBitmap::kARGB_8888_Config, 16, 16);
   bitmap.allocPixels();
   bitmap.eraseARGB(0xff, 0xff, 0, 0);
-  return new gfx::ImageSkia(gfx::ImageSkiaRep(bitmap, 1.0f));
+  return new ImageSkia(ImageSkiaRep(bitmap, 1.0f));
 }
 
+class PNGImageSource : public ImageSkiaSource {
+ public:
+  PNGImageSource() {}
+  virtual ~PNGImageSource() {}
+
+  virtual ImageSkiaRep GetImageForScale(float scale) OVERRIDE {
+    if (image_skia_reps_.empty())
+      return ImageSkiaRep();
+
+    const ImageSkiaRep* rep = NULL;

[pkotwicz, 2014/06/19 14:16:13]

Can you please cleanup the comments. Based on the comments it seems as if we are
content with any ImageSkiaRep whose scale is larger than |scale|.

However, what we are trying to do is find the ImageSkiaRep with the smallest
scale which is still bigger or equal to |scale|.

[oshima, 2014/06/19 15:50:40]

will do.

[oshima, 2014/06/19 17:15:05]

Done. (your description wasn't exactly correct. please see the updated comment
and let me know if you still don't like it)

+    for (ImageSkiaRepSet::const_iterator iter = image_skia_reps_.begin();
+         iter != image_skia_reps_.end(); ++iter) {
+      if ((*iter).scale() == scale)
+        return (*iter);
+      // gfx::ImageSkia decides which the resource scale factor to use,
+      // so just pick the larger scale.
+      if (!rep || rep->scale() < (*iter).scale())
+        rep = &(*iter);
+      // but if it's larger than the reuqsted scale, that's large enough.
+      if (rep->scale() >= scale)
+        break;
+    }
+    return rep ? *rep : ImageSkiaRep();
+  }
+
+  const gfx::Size size() const {
+    return size_;
+  }
+
+  bool AddPngData(const ImagePNGRep& png_rep) {
+    const gfx::ImageSkiaRep rep = ToImageSkiaRep(png_rep);
+    if (rep.is_null())
+      return false;
+    if (size_.IsEmpty())
+      size_ = gfx::Size(rep.GetWidth(), rep.GetHeight());
+    image_skia_reps_.insert(rep);
+    return true;
+  }
+
+  static ImageSkiaRep ToImageSkiaRep(const ImagePNGRep& png_rep) {
+    scoped_refptr<base::RefCountedMemory> raw_data = png_rep.raw_data;
+    CHECK(raw_data.get());
+    SkBitmap bitmap;
+    if (!PNGCodec::Decode(raw_data->front(), raw_data->size(),
+                               &bitmap)) {
+      LOG(ERROR) << "Unable to decode PNG for " << png_rep.scale << ".";
+      return ImageSkiaRep();
+    }
+    return ImageSkiaRep(bitmap, png_rep.scale);
+  }
+
+ private:
+  struct Compare {
+    bool operator()(const ImageSkiaRep& rep1, const ImageSkiaRep& rep2) {
+      return rep1.scale() < rep2.scale();
+    }
+  };
+
+  typedef std::set<ImageSkiaRep, Compare> ImageSkiaRepSet;
+  ImageSkiaRepSet image_skia_reps_;
+  gfx::Size size_;
+
+  DISALLOW_COPY_AND_ASSIGN(PNGImageSource);
+};
+
 ImageSkia* ImageSkiaFromPNG(
-    const std::vector<gfx::ImagePNGRep>& image_png_reps) {
+    const std::vector<ImagePNGRep>& image_png_reps) {
   if (image_png_reps.empty())
     return GetErrorImageSkia();
+  scoped_ptr<PNGImageSource> image_source(new PNGImageSource);
 
-  scoped_ptr<gfx::ImageSkia> image_skia(new ImageSkia());
   for (size_t i = 0; i < image_png_reps.size(); ++i) {
-    scoped_refptr<base::RefCountedMemory> raw_data =
-        image_png_reps[i].raw_data;
-    CHECK(raw_data.get());
-    SkBitmap bitmap;
-    if (!gfx::PNGCodec::Decode(raw_data->front(), raw_data->size(),
-                               &bitmap)) {
-      LOG(ERROR) << "Unable to decode PNG for "
-                 << image_png_reps[i].scale
-                 << ".";
+    if (!image_source->AddPngData(image_png_reps[i]))
       return GetErrorImageSkia();
-    }
-    image_skia->AddRepresentation(gfx::ImageSkiaRep(
-        bitmap, image_png_reps[i].scale));
   }
-  return image_skia.release();
+  const gfx::Size& size = image_source->size();
+  DCHECK(!size.IsEmpty());
+  if (size.IsEmpty())
+    return GetErrorImageSkia();
+  return new ImageSkia(image_source.release(), size);
 }
 
 scoped_refptr<base::RefCountedMemory> Get1xPNGBytesFromImageSkia(
     const ImageSkia* image_skia) {

[pkotwicz, 2014/06/19 14:16:13]

We should also do scaling here.

[oshima, 2014/06/19 15:50:40]

can you explain why this is necessary?

[pkotwicz, 2014/06/19 21:09:09]

Doing resizing going PNG->ImageSkia and ImageSkia->PNG is nicely symmetric

My other interest is that implementing both makes it possible to simplify
SelectFaviconFramesFromPNGs() (pending approval by the designers about always
using Lanczos3 for resampling)

[oshima, 2014/06/19 21:29:57]

Sorry I still don't understand. This is supposed to get 1x. Why you need scaling
here?

It is true that GetRepresentation(1.0f) may not return 1.0x but it has nothing
to do with
this CL and it's been like that.

If you want to change to make sure it's always return 1.0f, then that should be
an separate issue.
I have a plan to simplify it (with current schemes). I'll also ask if we can
simply uses lancosz. I agree that using different algorithm may not make much
sense as we now support arbitrary scale factors.

   ImageSkiaRep image_skia_rep = image_skia->GetRepresentation(1.0f);
 
   scoped_refptr<base::RefCountedBytes> png_bytes(new base::RefCountedBytes());
   if (image_skia_rep.scale() != 1.0f ||
-      !gfx::PNGCodec::EncodeBGRASkBitmap(image_skia_rep.sk_bitmap(), false,
+      !PNGCodec::EncodeBGRASkBitmap(image_skia_rep.sk_bitmap(), false,
           &png_bytes->data())) {
     return NULL;
   }
   return png_bytes;
 }
 #endif
 
 class ImageRepPNG;
 class ImageRepSkia;
 class ImageRepCocoa;
@@ skipping 189 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ImageRepCocoa);
 };
 #endif  // defined(OS_MACOSX)
 
 // The Storage class acts similarly to the pixels in a SkBitmap: the Image
 // class holds a refptr instance of Storage, which in turn holds all the
 // ImageReps. This way, the Image can be cheaply copied.
 class ImageStorage : public base::RefCounted<ImageStorage> {
  public:
-  ImageStorage(gfx::Image::RepresentationType default_type)
+  ImageStorage(Image::RepresentationType default_type)
       : default_representation_type_(default_type),
 #if defined(OS_MACOSX) && !defined(OS_IOS)
         default_representation_color_space_(
             base::mac::GetGenericRGBColorSpace()),
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
         representations_deleter_(&representations_) {
   }
 
-  gfx::Image::RepresentationType default_representation_type() {
+  Image::RepresentationType default_representation_type() {
     return default_representation_type_;
   }
-  gfx::Image::RepresentationMap& representations() { return representations_; }
+  Image::RepresentationMap& representations() { return representations_; }
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   void set_default_representation_color_space(CGColorSpaceRef color_space) {
     default_representation_color_space_ = color_space;
   }
   CGColorSpaceRef default_representation_color_space() {
     return default_representation_color_space_;
   }
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
  private:
   friend class base::RefCounted<ImageStorage>;
 
   ~ImageStorage() {}
 
   // The type of image that was passed to the constructor. This key will always
   // exist in the |representations_| map.
-  gfx::Image::RepresentationType default_representation_type_;
+  Image::RepresentationType default_representation_type_;
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   // The default representation's colorspace. This is used for converting to
   // NSImage. This field exists to compensate for PNGCodec not writing or
   // reading colorspace ancillary chunks. (sRGB, iCCP).
   // Not owned.
   CGColorSpaceRef default_representation_color_space_;
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
   // All the representations of an Image. Size will always be at least one, with
   // more for any converted representations.
-  gfx::Image::RepresentationMap representations_;
+  Image::RepresentationMap representations_;
 
   STLValueDeleter<Image::RepresentationMap> representations_deleter_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageStorage);
 };
 
 }  // namespace internal
 
 Image::Image() {
   // |storage_| is NULL for empty Images.
@@ skipping 48 matching lines @@
 Image& Image::operator=(const Image& other) {
   storage_ = other.storage_;
   return *this;
 }
 
 Image::~Image() {
 }
 
 // static
 Image Image::CreateFrom1xBitmap(const SkBitmap& bitmap) {
-  return gfx::Image(ImageSkia::CreateFrom1xBitmap(bitmap));
+  return Image(ImageSkia::CreateFrom1xBitmap(bitmap));
 }
 
 // static
 Image Image::CreateFrom1xPNGBytes(const unsigned char* input,
                                   size_t input_size) {
   if (input_size == 0u)
-    return gfx::Image();
+    return Image();
 
   scoped_refptr<base::RefCountedBytes> raw_data(new base::RefCountedBytes());
   raw_data->data().assign(input, input + input_size);
 
   return CreateFrom1xPNGBytes(raw_data);
 }
 
 Image Image::CreateFrom1xPNGBytes(
     const scoped_refptr<base::RefCountedMemory>& input) {
   if (!input.get() || input->size() == 0u)
-    return gfx::Image();
+    return Image();
 
-  std::vector<gfx::ImagePNGRep> image_reps;
+  std::vector<ImagePNGRep> image_reps;
   image_reps.push_back(ImagePNGRep(input, 1.0f));
-  return gfx::Image(image_reps);
+  return Image(image_reps);
 }
 
 const SkBitmap* Image::ToSkBitmap() const {
   // Possibly create and cache an intermediate ImageRepSkia.
   return ToImageSkia()->bitmap();
 }
 
 const ImageSkia* Image::ToImageSkia() const {
   internal::ImageRep* rep = GetRepresentation(kImageRepSkia, false);
   if (!rep) {
@@ skipping 94 matching lines @@
 }
 #endif
 
 scoped_refptr<base::RefCountedMemory> Image::As1xPNGBytes() const {
   if (IsEmpty())
     return new base::RefCountedBytes();
 
   internal::ImageRep* rep = GetRepresentation(kImageRepPNG, false);
 
   if (rep) {
-    const std::vector<gfx::ImagePNGRep>& image_png_reps =
+    const std::vector<ImagePNGRep>& image_png_reps =
         rep->AsImageRepPNG()->image_reps();
     for (size_t i = 0; i < image_png_reps.size(); ++i) {
       if (image_png_reps[i].scale == 1.0f)
         return image_png_reps[i].raw_data;
     }
     return new base::RefCountedBytes();
   }
 
   scoped_refptr<base::RefCountedMemory> png_bytes(NULL);
   switch (DefaultRepresentationType()) {
@@ skipping 30 matching lines @@
     return new base::RefCountedBytes();
   }
 
   // Do not insert representations for scale factors other than 1x even if
   // they are available because:
   // - Only the 1x PNG bytes can be accessed.
   // - ImageRepPNG is not used as an intermediate type in converting to a
   //   final type eg (converting from ImageRepSkia to ImageRepPNG to get an
   //   ImageRepCocoa).
   std::vector<ImagePNGRep> image_png_reps;
-  image_png_reps.push_back(gfx::ImagePNGRep(png_bytes, 1.0f));
+  image_png_reps.push_back(ImagePNGRep(png_bytes, 1.0f));
   rep = new internal::ImageRepPNG(image_png_reps);
   AddRepresentation(rep);
   return png_bytes;
 }
 
 SkBitmap Image::AsBitmap() const {
   return IsEmpty() ? SkBitmap() : *ToSkBitmap();
 }
 
 ImageSkia Image::AsImageSkia() const {
@@ skipping 61 matching lines @@
     return 0;
   return GetRepresentation(DefaultRepresentationType(), true)->Height();
 }
 
 gfx::Size Image::Size() const {
   if (IsEmpty())
     return gfx::Size();
   return GetRepresentation(DefaultRepresentationType(), true)->Size();
 }
 
-void Image::SwapRepresentations(gfx::Image* other) {
+void Image::SwapRepresentations(Image* other) {
   storage_.swap(other->storage_);
 }
 
 #if defined(OS_MACOSX)  && !defined(OS_IOS)
 void Image::SetSourceColorSpace(CGColorSpaceRef color_space) {
   if (storage_.get())
     storage_->set_default_representation_color_space(color_space);
 }
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
@@ skipping 12 matching lines @@
   }
   return it->second;
 }
 
 void Image::AddRepresentation(internal::ImageRep* rep) const {
   CHECK(storage_.get());
   storage_->representations().insert(std::make_pair(rep->type(), rep));
 }
 
 }  // namespace gfx