root/chrome/browser/ui/webui/extensions/extension_icon_source.cc

DEFINITIONS

1. BitmapToMemory
2. DesaturateImage
3. ToBitmap
4. GetIconURL
5. LoadImageByResourceId
6. GetSource
7. GetMimeType
8. StartDataRequest
9. GetDefaultAppImage
10. GetDefaultExtensionImage
11. FinalizeImage
12. LoadDefaultImage
13. LoadExtensionImage
14. LoadFaviconImage
15. OnFaviconDataAvailable
16. OnImageLoaded
17. LoadIconFailed
18. ParseData
19. SetData
20. GetData
21. ClearData

// 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 "chrome/browser/ui/webui/extensions/extension_icon_source.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/memory/ref_counted_memory.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/threading/thread.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/image_loader.h"
#include "chrome/browser/favicon/favicon_service_factory.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/extensions/extension_constants.h"
#include "chrome/common/extensions/manifest_handlers/app_launch_info.h"
#include "chrome/common/extensions/manifest_handlers/icons_handler.h"
#include "chrome/common/url_constants.h"
#include "extensions/browser/extension_prefs.h"
#include "extensions/browser/extension_system.h"
#include "extensions/common/extension.h"
#include "extensions/common/extension_resource.h"
#include "grit/component_extension_resources_map.h"
#include "grit/theme_resources.h"
#include "skia/ext/image_operations.h"
#include "ui/base/layout.h"
#include "ui/base/resource/resource_bundle.h"
#include "ui/gfx/codec/png_codec.h"
#include "ui/gfx/color_utils.h"
#include "ui/gfx/favicon_size.h"
#include "ui/gfx/size.h"
#include "ui/gfx/skbitmap_operations.h"
#include "url/gurl.h"

namespace extensions {

namespace {

scoped_refptr<base::RefCountedMemory> BitmapToMemory(const SkBitmap* image) {
  base::RefCountedBytes* image_bytes = new base::RefCountedBytes;
  gfx::PNGCodec::EncodeBGRASkBitmap(*image, false, &image_bytes->data());
  return image_bytes;
}

SkBitmap DesaturateImage(const SkBitmap* image) {
  color_utils::HSL shift = {-1, 0, 0.6};
  return SkBitmapOperations::CreateHSLShiftedBitmap(*image, shift);
}

SkBitmap* ToBitmap(const unsigned char* data, size_t size) {
  SkBitmap* decoded = new SkBitmap();
  bool success = gfx::PNGCodec::Decode(data, size, decoded);
  DCHECK(success);
  return decoded;
}

}  // namespace

ExtensionIconSource::ExtensionIconSource(Profile* profile) : profile_(profile) {
}

struct ExtensionIconSource::ExtensionIconRequest {
  content::URLDataSource::GotDataCallback callback;
  scoped_refptr<const Extension> extension;
  bool grayscale;
  int size;
  ExtensionIconSet::MatchType match;
};

// static
GURL ExtensionIconSource::GetIconURL(const Extension* extension,
                                     int icon_size,
                                     ExtensionIconSet::MatchType match,
                                     bool grayscale,
                                     bool* exists) {
  if (exists) {
    *exists =
        IconsInfo::GetIconURL(extension, icon_size, match) != GURL::EmptyGURL();
  }

  GURL icon_url(base::StringPrintf("%s%s/%d/%d%s",
                                   chrome::kChromeUIExtensionIconURL,
                                   extension->id().c_str(),
                                   icon_size,
                                   match,
                                   grayscale ? "?grayscale=true" : ""));
  CHECK(icon_url.is_valid());
  return icon_url;
}

// static
SkBitmap* ExtensionIconSource::LoadImageByResourceId(int resource_id) {
  std::string contents = ResourceBundle::GetSharedInstance()
      .GetRawDataResourceForScale(resource_id,
                                  ui::SCALE_FACTOR_100P).as_string();

  // Convert and return it.
  const unsigned char* data =
      reinterpret_cast<const unsigned char*>(contents.data());
  return ToBitmap(data, contents.length());
}

std::string ExtensionIconSource::GetSource() const {
  return chrome::kChromeUIExtensionIconHost;
}

std::string ExtensionIconSource::GetMimeType(const std::string&) const {
  // We need to explicitly return a mime type, otherwise if the user tries to
  // drag the image they get no extension.
  return "image/png";
}

void ExtensionIconSource::StartDataRequest(
    const std::string& path,
    int render_process_id,
    int render_frame_id,
    const content::URLDataSource::GotDataCallback& callback) {
  // This is where everything gets started. First, parse the request and make
  // the request data available for later.
  static int next_id = 0;
  if (!ParseData(path, ++next_id, callback)) {
    // If the request data cannot be parsed, request parameters will not be
    // added to |request_map_|.
    // Send back the default application icon (not resized or desaturated) as
    // the default response.
    callback.Run(BitmapToMemory(GetDefaultAppImage()).get());
    return;
  }

  ExtensionIconRequest* request = GetData(next_id);
  ExtensionResource icon = IconsInfo::GetIconResource(
      request->extension, request->size, request->match);

  if (icon.relative_path().empty()) {
    LoadIconFailed(next_id);
  } else {
    LoadExtensionImage(icon, next_id);
  }
}

ExtensionIconSource::~ExtensionIconSource() {
  // Clean up all the temporary data we're holding for requests.
  STLDeleteValues(&request_map_);
}

const SkBitmap* ExtensionIconSource::GetDefaultAppImage() {
  if (!default_app_data_.get())
    default_app_data_.reset(LoadImageByResourceId(IDR_APP_DEFAULT_ICON));

  return default_app_data_.get();
}

const SkBitmap* ExtensionIconSource::GetDefaultExtensionImage() {
  if (!default_extension_data_.get()) {
    default_extension_data_.reset(
        LoadImageByResourceId(IDR_EXTENSION_DEFAULT_ICON));
  }

  return default_extension_data_.get();
}

void ExtensionIconSource::FinalizeImage(const SkBitmap* image,
                                        int request_id) {
  SkBitmap bitmap;
  ExtensionIconRequest* request = GetData(request_id);
  if (request->grayscale)
    bitmap = DesaturateImage(image);
  else
    bitmap = *image;

  request->callback.Run(BitmapToMemory(&bitmap).get());
  ClearData(request_id);
}

void ExtensionIconSource::LoadDefaultImage(int request_id) {
  ExtensionIconRequest* request = GetData(request_id);
  const SkBitmap* default_image = NULL;

  if (request->extension->is_app())
    default_image = GetDefaultAppImage();
  else
    default_image = GetDefaultExtensionImage();

  SkBitmap resized_image(skia::ImageOperations::Resize(
      *default_image, skia::ImageOperations::RESIZE_LANCZOS3,
      request->size, request->size));

  // There are cases where Resize returns an empty bitmap, for example if you
  // ask for an image too large. In this case it is better to return the default
  // image than returning nothing at all.
  if (resized_image.empty())
    resized_image = *default_image;

  FinalizeImage(&resized_image, request_id);
}

void ExtensionIconSource::LoadExtensionImage(const ExtensionResource& icon,
                                             int request_id) {
  ExtensionIconRequest* request = GetData(request_id);
  ImageLoader::Get(profile_)->LoadImageAsync(
      request->extension, icon,
      gfx::Size(request->size, request->size),
      base::Bind(&ExtensionIconSource::OnImageLoaded, AsWeakPtr(), request_id));
}

void ExtensionIconSource::LoadFaviconImage(int request_id) {
  FaviconService* favicon_service =
      FaviconServiceFactory::GetForProfile(profile_, Profile::EXPLICIT_ACCESS);
  // Fall back to the default icons if the service isn't available.
  if (favicon_service == NULL) {
    LoadDefaultImage(request_id);
    return;
  }

  GURL favicon_url =
      AppLaunchInfo::GetFullLaunchURL(GetData(request_id)->extension);
  favicon_service->GetRawFaviconForURL(
      FaviconService::FaviconForURLParams(favicon_url, chrome::FAVICON,
                                          gfx::kFaviconSize),
      ui::SCALE_FACTOR_100P,
      base::Bind(&ExtensionIconSource::OnFaviconDataAvailable,
                 base::Unretained(this), request_id),
      &cancelable_task_tracker_);
}

void ExtensionIconSource::OnFaviconDataAvailable(
    int request_id,
    const chrome::FaviconBitmapResult& bitmap_result) {
  ExtensionIconRequest* request = GetData(request_id);

  // Fallback to the default icon if there wasn't a favicon.
  if (!bitmap_result.is_valid()) {
    LoadDefaultImage(request_id);
    return;
  }

  if (!request->grayscale) {
    // If we don't need a grayscale image, then we can bypass FinalizeImage
    // to avoid unnecessary conversions.
    request->callback.Run(bitmap_result.bitmap_data.get());
    ClearData(request_id);
  } else {
    FinalizeImage(ToBitmap(bitmap_result.bitmap_data->front(),
                           bitmap_result.bitmap_data->size()), request_id);
  }
}

void ExtensionIconSource::OnImageLoaded(int request_id,
                                        const gfx::Image& image) {
  if (image.IsEmpty())
    LoadIconFailed(request_id);
  else
    FinalizeImage(image.ToSkBitmap(), request_id);
}

void ExtensionIconSource::LoadIconFailed(int request_id) {
  ExtensionIconRequest* request = GetData(request_id);
  ExtensionResource icon = IconsInfo::GetIconResource(
      request->extension, request->size, request->match);

  if (request->size == extension_misc::EXTENSION_ICON_BITTY)
    LoadFaviconImage(request_id);
  else
    LoadDefaultImage(request_id);
}

bool ExtensionIconSource::ParseData(
    const std::string& path,
    int request_id,
    const content::URLDataSource::GotDataCallback& callback) {
  // Extract the parameters from the path by lower casing and splitting.
  std::string path_lower = StringToLowerASCII(path);
  std::vector<std::string> path_parts;

  base::SplitString(path_lower, '/', &path_parts);
  if (path_lower.empty() || path_parts.size() < 3)
    return false;

  std::string size_param = path_parts.at(1);
  std::string match_param = path_parts.at(2);
  match_param = match_param.substr(0, match_param.find('?'));

  int size;
  if (!base::StringToInt(size_param, &size))
    return false;
  if (size <= 0 || size > extension_misc::EXTENSION_ICON_GIGANTOR)
    return false;

  ExtensionIconSet::MatchType match_type;
  int match_num;
  if (!base::StringToInt(match_param, &match_num))
    return false;
  match_type = static_cast<ExtensionIconSet::MatchType>(match_num);
  if (!(match_type == ExtensionIconSet::MATCH_EXACTLY ||
        match_type == ExtensionIconSet::MATCH_SMALLER ||
        match_type == ExtensionIconSet::MATCH_BIGGER))
    match_type = ExtensionIconSet::MATCH_EXACTLY;

  std::string extension_id = path_parts.at(0);
  const Extension* extension = ExtensionSystem::Get(profile_)->
      extension_service()->GetInstalledExtension(extension_id);
  if (!extension)
    return false;

  bool grayscale = path_lower.find("grayscale=true") != std::string::npos;

  SetData(request_id, callback, extension, grayscale, size, match_type);

  return true;
}

void ExtensionIconSource::SetData(
    int request_id,
    const content::URLDataSource::GotDataCallback& callback,
    const Extension* extension,
    bool grayscale,
    int size,
    ExtensionIconSet::MatchType match) {
  ExtensionIconRequest* request = new ExtensionIconRequest();
  request->callback = callback;
  request->extension = extension;
  request->grayscale = grayscale;
  request->size = size;
  request->match = match;
  request_map_[request_id] = request;
}

ExtensionIconSource::ExtensionIconRequest* ExtensionIconSource::GetData(
    int request_id) {
  return request_map_[request_id];
}

void ExtensionIconSource::ClearData(int request_id) {
  std::map<int, ExtensionIconRequest*>::iterator i =
      request_map_.find(request_id);
  if (i == request_map_.end())
    return;

  delete i->second;
  request_map_.erase(i);
}

}  // namespace extensions